Table of contents of Chinese Journal of Polymer Science Cheng-guo Liu (a), Hong-feng Xie (a), Zhi-liu Wang (a), Hu Yang( a), Rong-shi Cheng (a, b) /qikan/cpaper/zhaiyao.asp?bsid=7607 Base on the principle of absolute quantification of size exclusion chromatography (SEC), a light scattering (LS) detector coupled with a concentration detector (refractive index detector) is utilized to determine the compositions of complicated binary mixtures. A theoretical analysis predicts that the response factors for both LS and RI detectors are linear functions with the composition of any specified polymer mixtures in the binary polymer mixtures. Two pairs of complicated binary mixtures were used to test the theory mentioned in the present paper, and the experimental results show an excellent accordance with the theory. Fri, 20 May 2010 17:02:44 GMT Rapid Communication Ahmed Aouissi, Salim Salem Al-Deyab, Hassan Al-Shehri /qikan/cpaper/zhaiyao.asp?bsid=7609 Three Keggin-type heteropolyanions, namely H(3)PMo(12)O(40¡¤)13H(2)O, (NH(4))(3)PMo(12)O(40¡¤)4H(2)O and H(3)PW(12)O(40¡¤)13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation (H(+), NH(4)(+)) and the peripheral atoms (Mo, W) on the polymerization were investigated. It has been found that when the protons of H(3)PMo(12)O(40¡¤)13H(2)O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms (Mo) were replaced by their homologous (W), the polymerization rate increased twofold. As for the viscosity average molecular weight (Mv) of polymer products, it was found that the high molecular weight (7930) was obtained by using H(3)PW(12)O(40¡¤)13H(2)O. The molecular weight (Mv) obtained by H(3)PMo(12)O(40¡¤)13H(2)O and (NH(4))(3)PMo(12)O(40¡¤)4H(2)O was 6470 and 6810, respectively. Fri, 20 May 2010 17:02:44 GMT Papers Su-yun Jie, Wen-hua Sun, Tianpengfei Xiao /qikan/cpaper/zhaiyao.asp?bsid=7608 The discovery of highly active 2,6-bis(imino)pyridyl iron and cobalt complexes provided a milestone of late-transition metal catalysts for ethylene oligomerization and polymerization with being currently investigated for the scale-up process. The crucial problems are remaining in the catalytic systems: the catalytic systems targeting ethylene polymerization produce more oligomers at elevated reaction temperatures, however, there is a recognizable amount of high-molecular-weight polyethylene remained in the modified catalytic system for the oligomerization process. Beyond the modification of bis(imino)pyridyl metal complexes, several alternative procatalysts¡¯ models have been developed in our group. This review highlighted the achievements in exploring new iron and cobalt complexes with tridentate NNN ligands as procatalysts for ethylene oligomerization and polymerization. Fri, 20 May 2010 17:02:44 GMT Feature Article Miao-miao Xiao (a), Bin Tong( a), Wei Zhao (a), Jian-bing Shi (a), Yue-xiu Pan (a), Jin-bo Shen (a), Jun-ge Zhi (b), Yu-ping Dong (a ) /qikan/cpaper/zhaiyao.asp?bsid=7611 The stability of full-conjugated self-assembled (SA) multilayer films based on partially doped polyaniline (PANI) as a polycation and poly(o-aminobenzoic acid) (PCAN), poly(aniline-2-sulfonic acid) (PSAN) as polyanions is investigated in alkali aqueous solutions. The self-assembled PANI-PCAN films keep their stability within 24 h in 1 mol/L NaOH solution, the PANI-PSAN films, however, maintain the stability for 20 min in the same condition because the solubility of PSAN in alkali solutions is much higher than that of PCAN. The electrochemical properties of the SA films are determined, and the film-CdS composites formed in situ are also reported. Fri, 20 May 2010 17:02:44 GMT Papers Jin Chen,Zhi-yong Huang /qikan/cpaper/zhaiyao.asp?bsid=7610 Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths N(b), arm lengths N(a )and arm densities m are carried out to study the elastic behavior of comb-like polymer chains. The radius of gyration, the shape factors and bond length in different cases during elastic process are calculated, and it is found that the comb-like polymer molecules with longer backbone or shorter arm are more close to linear chains. But the arm density m affects the chain conformation non-monotonously. Some thermodynamic properties are also studied. Average Helmholtz free energy and elastic force f all increase with elongation ratio  for all chains. Fri, 20 May 2010 17:02:44 GMT Papers Ying-ying Pan( a, b), Xi-fei Yu (a), Tong-fei Shi (a),Li-jia An (a) /qikan/cpaper/zhaiyao.asp?bsid=7614 A series of H-shaped (PS)(2)PEG(PS)(2) block copolymers with different PS chain lengths were prepared. The influence of different confinements active on the crystallization and self-nucleation (SN) behavior of the PEG blocks was investigated by differential scanning calorimetry (DSC). When the content of the crystalline block was high, a classical SN behavior was obtained. The block copolymer with PEG content of 49% (by weight) showed a classical SN behavior with a narrow self-nucleation domain and had bimodal crystallization exotherms. When the PEG dispersed as separated microdomains in the block copolymer, the self-nucleation domain disappeared and only annealing was observed. Fri, 20 May 2010 17:02:44 GMT Papers Shu-jun Liang a, b, c, Jian-ping Deng b, c , Wan-tai Yang b, c /qikan/cpaper/zhaiyao.asp?bsid=7612 Synthesis and characterization of the copolymers (PAG) of¦Á-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR) and thermogravimetery (TG). Based on the copolymer compositions determined by (1)H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ¡À 0.012 and 0.883 ¡À 0.046 respectively by Kelen-T¨¹dös method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions. Fri, 20 May 2010 17:02:44 GMT Papers Mei Zhang a, b, Chun-fang Zhang a, Zhi-kan Yao a, Jun-li Shi a, Bao-ku Zhu a, You-yi Xu a /qikan/cpaper/zhaiyao.asp?bsid=7613 High density polyethylene (HDPE)/polyethylene-block-poly(ethylene glycol) (PE-b-PEG) blend porous membranes were prepared via thermally induced phase separation (TIPS) process using diphenyl ether (DPE) as diluent. The phase diagrams of HDPE/PE-b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry (DSC). By varying the content of PE-b-PEG, the effects of PE-b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The chemical compositions of whole membranes and surface layers were characterized by elementary analysis, Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Water contact angle, static protein adsorption and water flux experiments were used to evaluate the hydrophilicity, antifouling and water permeation properties of the membranes. It was found that the addition of PE-b-PEG increased the pore size of the obtained blend membranes. In the investigated range of PE-b-PEG content, the PEG blocks could not aggregate into obviously separated domains in membrane matrix. More importantly, PE-b-PEG could not only be retained stably in the membrane matrix during membrane formation, but also enrich at the membrane surface layer. Such stability and surface enrichment of PE-b-PEG endowed the blend membranes with improved hydrophilicity, protein absorption resistance and water permeation properties, which would be substantially beneficial to HDPE membranes for water treatment application. Fri, 20 May 2010 17:02:44 GMT Papers Xu-juan Li, Gan-ji Zhong, Zhong-ming Li /qikan/cpaper/zhaiyao.asp?bsid=7615 The non-isothermal crystallization of poly(L-lactide) (PLLA) under quiescent and steady shear flow conditions was in situ investigated by using polarizing optical microscopy (POM) with a hot shear stage and wide-angle X-ray diffraction (WAXD). The shear rate and the cooling rate both play a significant role in the final crystalline morphology and crystallinity. Under quiescent conditions, the morphology assumes different sized spherulites, and its crystallinity dramatically reduces with increasing the cooling rate. On the other hand, the shear flow increases the onset crystallization temperature, and enhances the final crystallinity. When the shear rate is above 5 s(-1), cylindrite-like crystals are observed, furthermore, their content depends on the cooling rate. Fri, 20 May 2010 17:02:44 GMT Papers Xue-ping Wu a, Xian-long Zhang b, Chun-xiang Lu a, Li-cheng Ling c /qikan/cpaper/zhaiyao.asp?bsid=7616 Thermal properties of acrylonitrile (AN)-acrylamide (AM) copolymers for carbon fibers were studied by DSC and in situ FTIR techniques in nitrogen (N(2)) and air flows. The cyclization mechanism and stabilization behavior of polyacrylonitrile (PAN) were discussed. In N(2) flow, it was found that AM had the ability to initiate and accelerate cyclization process, which was confirmed by the fact that the initiation of nitriles shifted to a lower temperature. Compared to AN homopolymer, the initiation temperature of cyclization was ahead 32 K by introducing 3.59 mol% AM into the copolymer. The exothermic reaction was relaxed due to the presence of two separated exothermic peaks. Accompanied by DSC, in situ FTIR and calculation of activation energy, the two peaks were proved to be caused by ionic cyclization and free radical cyclization, respectively, and the corresponding cyclization mechanism was proposed. With increasing in AM content, the ionic cyclization tends to be dominant and the total heat liberated first increases and then decreases. For AN homopolymer, the activation energy of cyclization is 179 kJ/mol. For AN-AM copolymer (containing 3.59 mol% AM), the activation energy of ionic cyclization is 96 kJ/mol and that of free radical cyclization is 338 kJ/mol. In air flow, similar cyclization routes occur and the difference is the contribution of oxidation. The oxygen in environment has no remarkable effect on cyclization of AN homopolymer but retards the cyclization of AN-AM copolymers. For AN-AM copolymer with 3.59 mol% AM, the cyclization temperature is postponed 10¡ãC in air. Fri, 20 May 2010 17:02:44 GMT Papers Xiu-qin Zhang, Bao-quan Xie, Rong-bo Li, Lei Kong, Du-jin Wang /qikan/cpaper/zhaiyao.asp?bsid=7617 Syndiotactic polypropylene (sPP) as-spun fiber (sPP1) and drawn fiber (sPP2) were prepared by melt-spinning and melt-spinning/hot-drawing, respectively. The structure transition of the two fibers induced by annealing at different temperatures and the corresponding mechanical properties were subsequently investigated by the combination of Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD) and tensile testing. The results indicate that the chain conformation and crystal forms of the two sPP fibers are not obviously changed at low annealing temperature (40¡ãC). With increasing the annealing temperature, the trans-planar conformation and mesophase in sPP1 and sPP2 fibers can be completely transformed to helical conformation and crystal form I under tension. Upon removing the tension, a small amount of mesophase and trans-planar conformation will be regained. The mechanical properties of the annealed fibers are manifestly dependent on their initial structure and the annealing temperature. Fri, 20 May 2010 17:02:44 GMT Papers Jiang-wei Zhao, Han Zhu, Yi-xian Wu, Rui Jian, Guan-ying Wu /qikan/cpaper/zhaiyao.asp?bsid=7618 FTIR spectroscopy in combination with a diamond tipped attenuated total reflectance (ATR) immersion probe was utilized to study in situ the copolymerization of butadiene (Bd) and isoprene (Ip) with neodymium-based catalyst in hexane. The relationship between the signal intensity of monomer and its concentration was investigated. The kinetic study of copolymerization of Bd and Ip was further conducted, and the monomer reactivity ratios were determined via in situ ATR FTIR. The signal band at 1010 cm(-1) was assigned to wagging vibration of Bd and its intensity was proportional to Bd concentration ([Bd]) in the range of 0.46-3.88 mol¡¤L(-1). The signal bands at 890 and 989 cm(-1) were assigned to wagging vibration of Ip and the signal intensity was also proportional to Ip concentration ([Ip]) in the range of 0.08-4.73 mol¡¤L(-1) at 890 cm(-1) and 0.08-7.49 mol¡¤L(-1) at 989 cm-1, respectively. Thus the signal band at 1010 cm(-1 )was chosen to monitor Bd concentration and bands at 989 and 890 cm(-1) to monitor Ip concentration during the copolymerization, respectively. It was demonstrated that the conversions of Bd and Ip calculated from FTIR data agreed very well with those obtained gravimetrically. The polymerization rates were first order with respect to both [Bd] and [Ip], respectively at different polymerization temperatures. The apparent propagation activation energy for Bd and Ip could be determined to be 54.4 kJ¡¤mol(-1) and 57.7 kJ¡¤mol(-1), respectively. The monomer reactivity ratios were calculated to be 1.08 for Bd (rBd) and 0.48 for IP (rIp) based on FTIR data. The Bd-Ip copolymer products with random sequence could be obtained with only one glass transition temperature. Fri, 20 May 2010 17:02:44 GMT Papers Xin-jun Zhang, Fei Yuan, Yong-liang Wang, Zi-jian Zhang, Wei Wang /qikan/cpaper/zhaiyao.asp?bsid=7619 Three dendronized polymers from generation one to generation three have been prepared by complexing negatively charged Fr¨¦chet-type dendrons with a polyanion, poly(diallydimethylammonium chloride) (PDADMAC). The grafting degree has been confirmed mainly by elemental analysis. In dilute solutions of tetrahydrofuran, static light scattering studies indicate that the first generation complex has a coil-like conformation, even more flexible than PDADMAC. The second and third generation complexes exhibit polyelectrolyte behavior. Dynamic light scattering experiments indicate that all the three complexes have almost the same hydrodynamic radius, indicating that they might own similar coil conformation. Atomic force microscopy shows the existence of disordered globules formed by one or a couple of complex coils. All these observations can be explained by the flowerlike coil conformation, which is formed by the intra-molecular association. This is totally different from the stretched chain conformation formed by covalently connected dendronized polymers. This result also explains why some ordered supramolecular structures, found in condensed state of the similar complexes, are not as perfect as those of conventional dendronized polymers. Fri, 20 May 2010 17:02:44 GMT Papers Bing-tao Wang (a, b), Yan Zhang( b), Ping-an Song (a, b), Zheng-hong Guo (b), Jie Cheng( b), Zheng-ping Fang( a, b) /qikan/cpaper/zhaiyao.asp?bsid=7621 Biodegradable aliphatic/aromatic copolyesters, poly(butylene terephthalate-co-lactate) (PBTL) were prepared via direct melt polycondensation of terephthalic acid (TPA), 1,4-butanediol (BDO) and poly(L-lactic acid) oligomer (OLLA). The effects of polymerization time and temperature, as well as aliphatic/aromatic moiety ratio on the physical and thermal properties were investigated. The largest molecular weight of the copolyesters was up to 64100 with molecular weight distribution index of 2.09 when the polycondensation was carried out at 230¡ãC for 6 h. DSC, XRD, DMA and TGA analysis clearly indicated that the degree of crystallinity, glass-transition temperature, melting point, decomposition temperature, tensile strength, elongation and Young¡¯s modulus were influenced by the ratio between TPA and OLLA in the final copolyesters. Hydrolytic degradation results demonstrated that the incorporation of biodegradable lactate moieties into the aromatic polyester could efficiently improve hydrolytic degradability of the copolymer even though it still had many aromatic units in the main chains. Fri, 20 May 2010 17:02:44 GMT Papers Hao Wang( a, c), Hong-rui Song( b), Xue-si Chen( c), Ying-jie Deng (a) /qikan/cpaper/zhaiyao.asp?bsid=7620 Poly(¦Á-hydroxy octanoic acid) was first used as an additive for the preparation of electrospun ultra-fine fibers of poly(ethylene glycol)-b-poly(L-lactide) (PEG-PLLA). Ibuprofen was loaded in the electrospun ultra-fine fibers. The results from environmental scanning electron microscopy (ESEM), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) demonstrated that ibuprofen could be perfectly entrapped in the fibers electrospun from PEG-PLLA using ¦Á-hydroxy octanoic acid or PEG-b-poly(¦Á-hydroxy octanoic acid) (PEG-PHOA) as additives. Compared with electrospun PEG-PLLA fibers which entrapped 20 wt% ibuprofen, the PEG-PLLA electrospun fibers containing PEG-PHOA exhibited integral and robust after 1 week incubated in 37¡ãC, pH 7.4 phosphate buffer solution with 10 ¦Ìg/mL proteinase K. Compared with electrospun fibers without PEG-PHOA, the concentration of proteinase K in release media had less effect on the release rate of ibuprofen. An unique release profile was found from PEG-PLLA fiber after the incorporation of PEG-PHOA. Enzyme degradation experiments demonstrated that PEG-PHOA but not ¦Á-hydroxy octanoic acid monomer was the crucial factor for integrity maintenance of the electrospun fibers, which may be due to the enzyme degradation tolerance property of the PEG-PHOA polymer additive. Fri, 20 May 2010 17:02:44 GMT Papers Jin-nan Wang a, b, Yang Zhou a, b, Ai-min Li a, b, Li Xu a, b, Ling Xu a, b /qikan/cpaper/zhaiyao.asp?bsid=7622 Adsorption of humic, tannic and gallic acids by a macro weakly basic ion-exchange resin JN-01 was studied. The adsorption capacity of this resin for gallic and tannic acids is much higher than that for humic acid, which can be explained on the basis of both their molecular size and ionization degree. Furthermore, humic acid is separated into different components with molecular weight in the range from 2000 Da to 100000 Da by ultra-filter, and their adsorption isotherms on resin JN-01 indicate that humic acid¡¯s molecular weight is an important factor which makes significant influence on adsorption. Finally, changes in the amount of Cu(2+) and Pb(2+) adsorbed on resin JN-01 as a function of the concentration of each of these three acids were studied. A large increase in the heavy metal ions uptake is observed in the presence of humic substance, such advantages are due to the interactions between the heavy metal ions and the unbound functional groups of the adsorbed organic acids. Fri, 20 May 2010 17:02:44 GMT Papers Jing-jing Yan, Wen-xi Ji, Er-qiang chen, Zi-chen Li, De-hai Liang /qikan/cpaper/zhaiyao.asp?bsid=7623 The effects of heating rate on the aggregate behavior of poly(ethylene oxide)-b-poly(N-isopropylacrylamide) in aqueous solutions were investigated in detail by laser light scattering and TEM. By employing two separate heating protocols, step-by-step heating at < 5 K/step and one-step jump, to heat the sample from 15(o)C to the selected temperature, we found that the heating rate only showed significant effect on the aggregates above the cloud point. The aggregate formed by step-by-step heating exhibited a much larger size and a broader size distribution than those formed by one-step jump heating. Moreover, neither of the aggregates were ideal micellar structures as indicated by the size and the R(g)/R(h) values. On the contrary, at temperatures below the cloud point where the block copolymer formed core-shelled micelles, the heating rate showed negligible effect on the size and size distribution of the micelles. Since the system underwent a phase separation above the cloud point, the heating rate effect could be reasonably explained by the phase separation mechanisms: the nucleation-and-growth mechanism in the metastable region and the spinodal decomposition mechanism in the unstable region. Fri, 20 May 2010 17:02:44 GMT Papers Qing-yuan Li, Yi-xian Wu, Wen-yan Ma, Ri-wei Xu, Guan-ying Wu, Wan-tai Yang /qikan/cpaper/zhaiyao.asp?bsid=7624 The copolymerization of 4-vinylbenzyl chloride (VBC) and vinyl acetate (VAC) was carried out in toluene at 75¡ãC via radical polymerization using 2,2¡ä-azo-bis-(isobutyronitrile) (AIBN) as an initiator. The random copolymers of poly(4-vinylbenzyl chloride-co-vinyl acetate) (P(VBC-co-VAC)) with number average molecular weight (Mn) from 2000 to 6900, relatively narrow molecular weight distribution (MWD, Mw/Mn ca. 2.0) and with different copolymer composition of 4-vinylbenzyl chloride (VBC) from 17 mol% to 62 mol% could be obtained. The P(VBC-co-VAC) copolymers with an average number of 7 to 13 initiating sites of benzyl chloride per macromolecule could be used for the cationic polymerization of isobutylene (IB). The cationic polymerizations of IB were further conducted by using P(VBC-co-VAC) copolymers as macroinitiators in conjunction with TiCl4 at-40¡ãC in CH(2)Cl(2). The effects of VBC/TiCl(4) (molar ratio) on monomer conversion, M(n) and MWD of the resultant copolymers were investigated under 3 sets of conditions. It is found that P(VBC-co-VAC)-g-PIB copolymers with relatively narrow MWD (M(w)/M(n) ca. 2.0) and with terminal tert-chlorine functional groups in branched PIB chains could be successfully synthesized when VBC/TiCl(4) (molar ratio) was set in the range from 0.10 to 1.12. The unimodal GPC curve of the P(VBC-co-VAC)-g-PIB copolymers by RI detector was almost in harmony with the GPC curve by UV detector. The TEM image of the P(VBC-co-VAC)-g-PIB copolymer stained by RuO indicated that the copolymer formed a two-phase morphology with P(VBC-co-VAC)-rich domains of 20-100 nm in size tethered by PIB branch segments. Fri, 20 May 2010 17:02:44 GMT Papers Wen-zhi Wang, Yong-hua Zhang /qikan/cpaper/zhaiyao.asp?bsid=7633 Long chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids and characterized by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance ((1)H-NMR). The thermal behaviors were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The solubility, dynamic mechanical, physical and mechanical properties of the polyamides have also been investigated. The resultant polyamides have intrinsic viscosity ranging from 1.7 dL/g to 2.1 dL/g. Their melting temperatures range from 305¡ãC to 343¡ãC, and the glass transition temperatures fall in the range of 125¨C130¡ãC. The tensile strength of the polyamides is above 100 MPa. Wed, 20 Jul 2010 17:02:44 GMT Papers Jiang-wei Zhao, Han Zhu, Yi-xian Wu, Wei-wei Zhou, Guan-ying Wu, Ri-wei Xu /qikan/cpaper/zhaiyao.asp?bsid=7634 A series of butadiene-isoprene copolymers (BIR) with various compositions were synthesized with a neodymium-based catalyst system. The microstructure, composition and sequence of copolymers were characterized by FTIR and 13C-NMR spectroscopy. The crystallization behavior of the BIR copolymers was investigated by DSC analysis. The results demonstrate that the content of cis-1,4 configuration in both butadiene (Bd) and isoprene (Ip) units are around 98% when Bd content in feed (f(Bd)) covering the range from 55.7 mol% to 96.0 mol%. The reactivity ratios of Bd and Ip were determined to be 1.40 and 0.48 respectively. The random copolymers of Bd and Ip show only one glass transition temperature (T(g)) from -107.4¡ãC to -80.5¡ãC, which is dependent on the composition and fits nicely with Fox equation. The sequence distribution followed the first-order Markov statistical model. It is found that the copolymer chains with higher Bd content contain longer polybutadiene (PBd) segments, and the sequence length of PBd segments (NBd) exhibits great influence on the crystallization behavior of the copolymer. The copolymers with N(Bd )¡Ý 11.8 could crystallize at low temperatures (-71¡ãC to -43¡ãC). The crystallization temperature and enthalpy values decreased gradually with decreasing N(Bd). The copolymers with N(Bd )¡Ü 7.9 are amorphous even at very low temperatures (0¡ãC to -150¡ãC) due to the short PBd segments. Wed, 20 Jul 2010 17:02:44 GMT Papers Liang Han, Yong Wang, Li Liu, Fang-ming Xiang, Ting Huang, Zuo-wan Zhou /qikan/cpaper/zhaiyao.asp?bsid=7632 The effect of ¦Á phase nucleating agent (NA) 1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS) on crystallization and physical properties of polypropylene/calcium carbonate (PP/CaCO(3)) composites has been comparatively investigated. Compared with binary PP/CaCO(3 )composites, in which CaCO(3 )exhibits weak heterogeneous nucleation, inconspicuous reinforcement and toughening effects for PP, the introduction of a few amounts of DMDBS induces a great increase of the degree of crystallinity. Largely improved tensile properties, fracture toughness at relatively higher temperature and heat deformation temperature (HDT) are observed for DMDBS nucleated PP/CaCO(3 )composites. Wed, 20 Jul 2010 17:02:44 GMT Papers Jun-chao Wei (a, b), Jing-ru Sun( a), Hai-juan Wang( a), Xue-si Chen (a, b), Xia-bin Jing (a, b) /qikan/cpaper/zhaiyao.asp?bsid=7636 Hydroxyapatite/poly(L-lactide) (HA/PLLA) nanocomposites were prepared by the solvent mixing method. The isothermal crystallization behavior was studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results show that the crystallization behavior of HA/PLLA composites was strongly affected by the content of HA and crystallization temperature, and the addition of HA could promote nucleation and enhance the crystallization rate. When isothermal crystallization was carried out at 110¡ãC, the HA/PLLA nanocomposite with 1% HA content crystallized most rapidly among all the composites and the half crystallization time was only 1.0 min. Banded spherulites were observed for the HA/PLLA composites, but no banded spherulites were seen in the crystals of PLLA under the same condition. Wed, 20 Jul 2010 17:02:44 GMT Papers Mohammad Najafi (a), Hossein Roghani-Mamaqani (b), Mehdi Salami-Kalajahi (a, b), Vahid Haddadi-Asl (a, b) /qikan/cpaper/zhaiyao.asp?bsid=7635 An optimized and high-performance Monte Carlo simulation is developed to take thorough account of four different cases of termination in styrene ATRP. According to the simulation results, the bimolecular termination rate constant sharply drops throughout the polymerization when either chain-length dependency of termination rate constant, gel effect, or both together is applied to the simulation. In addition, as expected, the initiator is quickly decomposed at the early stages of the polymerization. The concentration of the catalyst in lower oxidation state decreases at first and then plateaus at higher conversion; furthermore, the steady concentration of M(t)(n)Y/L in the polymerization is the highest when the chain-length-dependent diffusion-controlled termination rate constant is employed in the simulation. The rates of deactivation and chain end degradation reactions are also smaller in this case. Therefore, the fraction of dormant chains is higher throughout the reaction and consequently the portion of dead polymers decreases. Besides, molecular weight increases linearly with conversion; however, when neither gel effect nor chain-length dependency of termination rate constant is considered, the molecular weight deviates from linearity at the end of the reaction. The peak of chain length distribution shifts toward higher molecular weight too during the reaction. Finally, the molecular weight distribution broadens at higher conversion; however, the chain length distribution of polymers produced under conditions of applying chain-length-dependent diffusion-controlled termination rate constant is narrower. Wed, 20 Jul 2010 17:02:44 GMT Papers Khalil Faghihi, Mohsen Hajibeygi /qikan/cpaper/zhaiyao.asp?bsid=7638 Six new optically active and flame-retardant poly(amide-imide)s PAIs 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six chiral N,N'-(pyromellitoyl)-bis-L-amino acid 3a£­3f with bis(3-aminophenyl)phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone (NMP), triphenyl phosphite (TPP), calcium chloride (CaCl(2)) and pyridine. The polymerization reactions produced a series of optically active poly(amide-imide)s with good yield and good inherent viscosity of 0.34£­0.70 dLg(-1). The resulted polymers were fully characterized by means of FTIR and 1H-NMR spectroscopy, gel permeation chromatography (GPC), elemental analyses, inherent viscosity and solubility tests. Thermal properties and flame-retardant behavior of the PAIs 5a-5f were investigated using thermal gravimetric analysis (TGA and DTG) and limiting oxygen index (LOI). Data obtained by thermal analysis (TGA and DTG) revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the resulting polymers were capable of exhibiting good flame retardant properties. N,N'-(pyromellitoyl)-bis-L-amino acids 3a-3f were prepared in quantitative yields by the condensation reaction of pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylicacid-1,2,4,5-dianhydride) 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution. Wed, 20 Jul 2010 17:02:44 GMT Papers Yan Wang, Li-fang Zhang, Pei Wang, Li-juan Shen /qikan/cpaper/zhaiyao.asp?bsid=7637 Rare earth aryloxides substituted by various alkyl groups [Ln(OAr)(3)] such as methyl, isopropyl and tertbutyl, were used as single component catalysts to affect ring-opening polymerization of L-lactide (LLA). The catalytic activity, polymerization characteristics, polymerization kinetics and the mechanism were studied. It was found that the catalytic activity of rare earth aryloxides is influenced by both the structure and the number of alkyl groups on the phenyl ring. The stronger the electron-donation ability of the alkyl group, the higher the catalytic activity will be. An increase in the number of the substitute group will result in a higher catalytic activity. Lanthanum tris(2,4,6-tri-tert-butylphenolate) [La(OTTBP)(3)] exhibits the highest activity among all lanthanum aryloxides. According to the (1)H-NMR data, it was proposed that the LLA polymerization proceeded via a coordination-insertion mechanism involving cleavage of acyl-oxygen bond of the lactide. Wed, 20 Jul 2010 17:02:44 GMT Papers Chang-yu Tang (a), Wei Chen (b, c), Wen-qing Chen (b, c), Qiang Fu (a), Zong-liang Du (c), Yang Ye( c), Makoto Onishi( d), Naoki Abe (d ) /qikan/cpaper/zhaiyao.asp?bsid=7639 Polyvinylidene fluoride (PVDF) hollow fiber membranes prepared from spinning solutions with different polyvinyl pyrrolidone (PVP) contents (1% and 5%) at different extrusion rates were obtained by wet/dry phase process keeping all other spinning parameters constant. In spinning these PVDF hollow fibers, dimethylacetamide (DMAc) and PVP were used as a solvent and an additive, respectively. Water was used as the inner coagulant. Dimethylformamide (DMF) and water (30/70) were used as the external coagulant. The performances of membranes were characterized in terms of water flux, solute rejection for the wet membranes. The structure and morphology of PVDF hollow fiber were examined by BET adsorption, dry/wet weight method and scanning electron microscopy (SEM). It is found that the increase in PVP content and extrusion rate of spinning solution can result in the increase of water flux and decrease of solute rejection. The improvements of interconnected porous structure and pore size are induced by shear-thinning behavior of spinning solution at high extrusion rates, which could result in the increase of water flux of hollow fiber membranes. The increase of extrusion rate also leads to the increase of membrane thickness due to the recovery effect of elastic property of polymer chains. Wed, 20 Jul 2010 17:02:44 GMT Papers Ayman S. Ayesh /qikan/cpaper/zhaiyao.asp?bsid=7640 Poly(methylmetacrylate) (PMMA)/Y(0.0025) Si(0.025) Ba(0.9725) (Ti((0.9))Sn(0.1))O(3 )(YBTS) composites were prepared at different weight ratios of YBTS (0 wt%, 5 wt%, 10 wt% and 20 wt% YBTS) in order to investigate effect of YBTS additions on the electrical and optical properties of PMMA host. The electrical properties (impedance, dielectric constant dielectric loss and AC conductivity) were studied in the frequency range 10 kHz-1 MHz and in temperature range 20-90(o)C. Upon increasing the contents of YBTS ceramic, we observed a reduction in the impedance and an increase in the dielectric constant, dielectric loss and AC conductivity of PMMA host. We also found that the relaxation process at high YBTS contents was due to relaxation in the ionic conductivity. The absorption coefficient (¦Á) has been determined in the wavelength range 230-800 nm at room temperature for all YBTS-PMMA composites. Moreover, the addition of YBTS ceramic highly enhances the UV absorption of PMMA host especially below 300 nm. Addition of 20 wt% YBTS ceramic to PMMA host decreases the optical energy gap from 5 eV to 3.41 eV. Correlations between electrical, optical and SEM results are reported. Wed, 20 Jul 2010 17:02:44 GMT Papers Fu-qian Sun, Xin-song Li, Pei-ting Cao, Jin-ku Xu /qikan/cpaper/zhaiyao.asp?bsid=7641 The hydrophilicity of silicone hydrogels used as soft corneal contact lens plays an important role in wearing comfort. In order to enhance hydrophilicity and protein resistance, silicone hydrogel membranes were modified by atmospheric pressure glow discharge plasma (APGDP) induced surface graft polymerization of N-vinyl pyrrolidone (NVP) and poly(oligoethylene glycol methyl ether methacrylate) (PEGMA) in this paper. XPS analysis demonstrated the success of graft polymerization of NVP and PEGMA onto the surface of silicone hydrogel membranes. The hydrophilicity of silicone hydrogels was characterized by the measurement of water contact angle (WCA). The result showed that NVP grafted silicone hydrogel has the WCA of about 68¡ã and PEGMA grafted silicone hydrogel has the lowest WCA of about 62¡ã, while the pristine silicone hydrogel is hydrophobic with the WCA of about 103¡ã. Protein resistance of silicone hydrogels was investigated by the method of bicinchoninic acid assay using bovine serum albumin (BSA) as a model. It¡¯s found that the grafted silicone hydrogel has a significant improvement of protein resistance, and PEGMA grafting is more efficient for the reduction of protein adsorption than NVP grafting. The silicone hydrogel membranes grafted with NVP and PEGMA are good candidates of soft corneal contact lenses. Wed, 20 Jul 2010 17:02:44 GMT Papers Kai Zhang (a), Man Zhao (a), Lei Cai (b), Zheng-ke Wang( b), Yong-fu Sun (b), Qiao-ling Hu (b ) /qikan/cpaper/zhaiyao.asp?bsid=7642 In an effort to develop biomaterials to meet guided tissue regeneration (GTR) standards for periodontal tissue recovery, a homogeneous and transparent chitosan (CS)/hydroxyapatite (HA) membrane with potential applications as GTR barrier in periodontal therapy has been prepared via in situ compositing. The membrane has been designed to have a smooth-rough asymmetric structure that meets the demand for GTR. Component and morphology of the membrane are characterized by XRD and SEM. It can be indicated that HA was in situ synthesized uniformly in the CS membrane. Mechanical experiments of the membranes with various HA contents show that their tensile strengths are adequate for periodontal therapy. Biological properties of the membrane have been performed by cell toxicity assays, hemolysis tests and animal experiments. Results indicate that the membrane has good biocompatibility and inductive effect for cell growth. Therefore this membrane can be potentially applied as GTR barrier membrane for periodontal tissue regeneration. Wed, 20 Jul 2010 17:02:44 GMT Papers Zhe Cui, Bao-jun Qu /qikan/cpaper/zhaiyao.asp?bsid=7643 Synergistic effects of layered double hydroxide (LDH) with intumescent flame retardanct (IFR) of phosphorus-nitrogen (NP) compound in the polypropylene/ethylene-propylene-diene/IFR/LDH (PP/EPDM/IFR/LDH) nanocomposites and related properties were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), limiting oxygen index (LOI), UL-94 test, cone calorimeter test (CCT) and thermo-gravimetric analysis (TGA). The XRD and TEM results show that the intercalated and/or exfoliated nanocomposites can be obtained by direct melt-intercalation of PP/EPDM into modified LDH and that LDH can promote the IFR additive NP to disperse more homogeneously in the polymer matrix. The SEM results provide positive evidence that more compact charred layers can be obtained from the PP/EPDM/NP/LDH sample than those from the PP/EPDM/LDH and PP/EPDM/NP samples during burning. The LOI and UL-94 rating tests show that the synergetic effects of LDH with NP can effectively increase the flame retardant properties of the PP/EPDM/NP/LDH samples. The data from the CCT and TGA tests indicate that the PP/EPDM/NP/LDH samples apparently decrease the HRR and MLR values and thus enhance the flame retardant properties and have better thermal stability than the PP/EPDM/LDH and PP/EPDM/NP samples. Wed, 20 Jul 2010 17:02:44 GMT Papers Mohammad Sirousazar (a, b), Mortaza Yari (c) /qikan/cpaper/zhaiyao.asp?bsid=7644 The hydrogel wound dressing based on polyvinyl alcohol (PVA) was prepared by the freezing-thawing cyclic method. The dehydration kinetics of prepared hydrogels was determined using the experimental method and mathematical modeling based on diffusion mechanism. The results show that the dehydration rate of PVA hydrogel wound dressing inversely depends on the hydrogel thickness as well as water content of the wound. On the other hand, the initial water content of hydrogel and the atmospheric humidity have little direct effect on the dehydration rate. The good agreement between experimental and mathematical modeling results in early stages of dehydration process shows that the predominate factor determining the dehydration of these wound dressings is diffusion. Wed, 20 Jul 2010 17:02:44 GMT Papers Xia Zhan, Ji-ding Li, Cheng Fan, Xiao-long Han /qikan/cpaper/zhaiyao.asp?bsid=7650 Ultra-fine silicalite-1 particles were modified with four kinds of chlorosilanes (dodecyltrichlorosilane, octyltrichlorosilane, hexadecyltrichlorosilane and octadecyltrichlorosilane) and characterized by FI-IR, TGA, contact angle measurements and BET analysis. It was found that the surface hydrophobicity of silicalite-1 particles was improved significantly as the alkyl group was strongly bonded to the particle surface. Modified silicalite-1 particles were incorporated into PDMS (poly(dimethylsiloxanediol)) membranes, which were applied for the pervaporation separation of ethanol/water mixtures. The effect of surface properties, zeolite loading and operation conditions on pervaporation performance of the membranes was investigated. The separation factor of PDMS membranes filled with modified silicalite-1 increased considerably compared with that filled with unmodified ones, and the total flux decreased with increasing zeolite loading. The solution and diffusion selectivity of hybrid membranes were also measured to explain the pervaporation properties of silicalite-1 filled PDMS membranes. It was found that modification of silicalite-1 with dodecyltrichlorosilane effectively improved the solution and diffusion selectivity of silicalite-1 filled PDMS membranes with high zeolite loading. This may be attributed to the high surface hydrophobicity of modified silicalite-1 and its good integration with PDMS membranes. Both the high separation factor and solution selectivity indicated that modification of silicalite-1 with chlorosilanes was an effective method to improve the selectivity of silicalite-1/PDMS hybrid membranes for ethanol. Wed, 20 Jul 2010 17:02:44 GMT Papers Chen Yao, Xin-song Li, K. G. Neoh, Zhi-long Shi , E. T. Kang /qikan/cpaper/zhaiyao.asp?bsid=7645 Antibacterial poly(D,L-lactide) (PDLLA) fibrous membranes were developed via electrospinning, followed by surface modification which involved plasma pretreatment, UV-induced graft copolymerization of 4-vinylpyridine (4VP) and quaternization of the grafted pyridine groups with hexylbromide. The success of modification with quaternized pyridinium groups on the PDLLA fibrous membranes was ascertained by X-ray photoelectron spectroscopy (XPS). The antibacterial activities of these membranes were assessed against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The PDLLA fibrous membranes modified with quaternized pyridinium groups showed antibacterial efficiency against both bacteria as high as 99.999%. The results demonstrated that the antibacterial activity was based on the interaction of the positive charge of pyridinium group and negatively charged cell membrane of bacteria, resulting in loss of membrane permeability and cell leakage. Wed, 20 Jul 2010 17:02:44 GMT Papers Khalil Faghihi, Meisam Shabanian, Atena Izadkhah /qikan/cpaper/zhaiyao.asp?bsid=7646 Five new optically active polyamides (PAs) 6a-6e were prepared by direct polycondensation reaction of 2-(1,3-isoindolinedione-2-yl)-glutaric acid 4 as a new chiral diacid with various aromatic diamines 5a-5e in a medium consisting of triphenyl phosphite (TPP), calcium chloride, pyridine (Py) and N-methyl-2-pyrrolidone (NMP). The polycondensation reaction produced a series of polyamids 6a-6e in quantitative yields with inherent viscosities of 0.26-0.39 dL/g. The resulting polymers were fully characterized by means of (1)H-NMR, FT-IR spectroscopy, elemental analysis, inherent viscosity and specific rotation. Thermal properties of these polymers were investigated using thermal gravimetric analysis (TGA) and differential thermal gravimetry (DTG). Phthalimide rings as a bulky pendent group in the polymer chains disturb the interchain and intrachain interactions and make these PAs readily soluble in polar, aprotic solvents such as N,N-dimethyl acetamide (DMAc), N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP) and sulfuric acid. Wed, 20 Jul 2010 17:02:44 GMT Papers Majid Peyravi (a, b), Masoomeh Akhfash Ardestani (a, b), Ali Akbar Babaluo (a, c, d), Mir Karim Razavi Aghjeh (c, d), Seyed Roohollah Pishghadam (a, b), Elham Jannatdoust (a, b) /qikan/cpaper/zhaiyao.asp?bsid=7647 Segmented block copolymer based on nylon6 (N6) and polyethylene oxide (PEO) with stochiometric ratio was synthesized via a two-step process. The first step represents end capping of N6 in the presence of adipic acid leading to carboxy terminated N6, and the second one is polycondensation of the latter product with PEO in the presence of catalyst and thermostabilizer to form a high molecular weight multi-block copolymer. Several methods were applied to characterize the synthesized copolymer such as Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential thermal analysis, differential scanning calorimetry, X-ray diffraction and atomic force microscopy. The obtained results confirmed the multi-block structure for copolymer with a very high degree of micro-phase separation. Atomic force microscopy micrographs indicated that the morphology was the dispersion of high stiffness nanostructured polyamide (PA) domains in the amorphous region of PEO matrix, which can be very important in their performance for membrane processes. Wed, 20 Jul 2010 17:02:44 GMT Papers Zhong-bin Xu (a, b), Wei-wei Kong (a), Ming-xing Zhou (a), Mao Peng (a ) /qikan/cpaper/zhaiyao.asp?bsid=7649 This study investigated the influence of various organically modified montmorillonites (organoclays) on the structure and properties of rigid polyurethane foam (RPUF) nanocomposites. The organoclays were modified with cetyltrimethyl ammonium bromide (CTAB), methyl tallow bis(2-hydroxyethyl) quaternary ammonium chloride (MT2ETOH) and tris(hydroxymethyl)aminomethane (THMA) and denoted as CMMT, Cloisite 30B and OMMT, respectively. MT2ETOH and THMA contain hydroxyl groups, while THMA does not have long aliphatic tail in its molecule. X-ray diffraction and transmission electron microscopy show that OMMT and Cloisite 30B can be partially exfoliated in the RPUF nanocomposites because their intercalating agents MT2ETOH and THMA can react with isocyanate. However, CMMT modified with nonreactive CTAB is mainly intercalated in the RPUF matrices. At a relatively low filler content, the RPUF/CMMT composite foam has a higher specific compressive strength (the ratio of compressive strength against the apparent density of the foams), while at relatively high filler contents, RPUF/Cloisite 30B and RPUF/OMMT composites have higher specific compressive strengths, higher modulus and more uniform pore size than the RPUF/CMMT composite. Wed, 20 Jul 2010 17:02:44 GMT Papers Bor-Kuan Chen, Shuen-Hung Lo, Shu-Feng Lee /qikan/cpaper/zhaiyao.asp?bsid=7648 A new methacrylamide monomer, hexylamine methacrylamide (MAHA), was synthesized and used in polymerizations. The homopolymer of MAHA and its copolymers were synthesized by free radical polymerization techniques with N-isopropyl acrylamide (NIPAAm) in two different compositions. The quaternization of the homopolymer and copolymers were carried out using 1-bromopropane. The copolymers with NIPAAm and a low MAHA content showed temperature-responsive behavior in an aqueous environment. The lower critical solution temperatures (LCSTs) of these polymers varied between 32¡ãC and 44¡ãC. The LCSTs of quaternized copolymers were higher than those of neutral copolymers because they were more hydrophilic. The obtained homopolymers and copolymers were tested for antibacterial activities against S. aureus and E. coli. The quaternized water-soluble copolymers showed antibacterial activities against S. aureus. The quaternization resulted in the synthesis of both antibacterial and temperature-responsive copolymers. Wed, 20 Jul 2010 17:02:44 GMT Papers Jian Gao, Xiao-ting Fu, Ming-ming Ding, Qiang Fu /qikan/cpaper/zhaiyao.asp?bsid=7652 Blends of polystyrene (PS) and polypropylene (PP) were prepared through melt compounding. With an increase of PS content up to 30 wt%, the tensile strength of PP/PS blends increased from 37.4 MPa to 42.2 MPa, although the blends were widely regarded as immiscible. The DSC results showed that there¡¯s slight decrease in melting temperature of PP, showing insufficient evidence for partial compatibility between PP and PS. Almost no variation of distinct characterization peaks were observed in FTIR spectra of PS/PP blends compared with those of neat PP and PS, indicating there is no chemical interactions between PP and PS. Since the morphology investigation showed a droplet structure as PS content was up to 30 wt%, the improvement of tensile strength could be simply considered as due to the reinforcing effect of dispersed rigid PS particles on the PP, combining with partial compatibility between them as evaluated by change of C(p) at glass transition for both PS and PP. More interestingly, DSC and DMA results showed that the blending of PS and PP could lead to a substantial decrease of the glass transition temperature (T(g)) of PP, and increase of Tg of PS. The annealing experiment was carried out to understand the change of T(g) in PP/PS blends. It is believed that the compressive stress generated by the contracting PP should be the dominant mechanism for the T(g) elevation of PS. On the other hand, the T(g )decrease of PP is likely owing to the creation of a large amount free interface of PP and the dilatation of the PP phase resulting from the corresponding tension exerted by PS during cooling. Wed, 20 Jul 2010 17:02:44 GMT Papers Long Fang, Yi-hu Song, Xiao-nan Zhu, Shao-hui Chen, Pei-hua Du , Qiang Zheng /qikan/cpaper/zhaiyao.asp?bsid=7651 Influences of lanthanum stearate (LaSt3) and calcium stearate/zinc stearate (Ca/Zn) stabilizers on stabilization efficiency of dibutyltin dilaurate (DBTDL) to polyvinyl chloride (PVC) in air were investigated. The results revealed that the stabilization effect of DBTDL could be achieved by the La/Sn stabilizers with a ratio of 8/2. Addition of DBTDL could enhance thermal property and reduce dynamic storage modulus (G¡¯) at 180(o)C for PVC containing LaSt(3) or Ca/Zn stabilizers. On the other hand, incorporation of LaSt(3) did not influence the stabilization efficiency of DBTDL markedly; while addition of Ca/Zn stabilizers could significantly decrease thermal property for the DBTDL stabilized PVC. Furthermore, the effects of LaSt(3) and Ca/Zn stabilizers on the stabilization efficiency of DBTDL were explained in the framework of ionization potential. Wed, 20 Jul 2010 17:02:44 GMT Papers Feng-yuan Yu( a), Hong-bin Zhang (a), Zhi-gang Wang(( b+)), Wei Yu (a), Chi-xing Zhou (a) /qikan/cpaper/zhaiyao.asp?bsid=7653 The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization (FIC) model based on the conformation tensor incorporating the pre-shear effect was proposed. The model is capable of predicting the overshoot phenomena of the stress and the flow-induced free energy change of the polymeric system at high pre-shear rates. Under the condition of flow, the increase in the activated nuclei number was contributed by the flow-induced free energy change, which showed an overwhelming effect on the nuclei formation during the pre-shear process at high shear rates. The half crystallization time (((t)1/2)) of polypropylene (PP) as functions of pre-shear rate and pre-shear time at different crystallization temperatures was predicted and compared with the experiment data. Both numerical and experimental results showed that t(1/2) of PP decreased dramatically when the flow started but leveled off at long times. It was found that two transformation stages in t(1/2) existed within a wide range of shear rates. For the first stage where the melting polymer experienced a relatively weak shear flow, the acceleration of crystallization kinetics was mainly contributed by the steady value of free energy change while in the second stage for high shear rates, strong overshoot in flow-induced free energy change occurred and the crystallization kinetics was thus significantly enhanced. The overshoots in stress and flow-induced free energy change reflected an important role of flow on the primary nucleation especially when the flow was strong enough. Wed, 20 Jul 2010 17:02:44 GMT Papers