To improve the flame-retardant efficiency and water resistance of ammonium polyphosphate (APP), the UV-curable pentaerythritol triacrylate (PETA) was used to microencapsulate APP via the UV curing polymerization method. The prepared PETA-microencapsulated APP (PETA-APP) was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric (TG) analysis. PETA-APP was used as intumescent flame retardant (IFR) alone to flame retard polypropylene (PP). The water resistance of PP/PETA-APP composites was investigated, and the effect of PETA on the combustion behaviors of PP/APP composites was studied through limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter (CC) test, respectively. With 40 wt% of PETA-APP, the PP/PETA-APP system could achieve a LOI value of 30.0% and UL-94 V-0 rating after treatment in hot water for 168 h, while the LOI value of the system containing 40 wt% uncoated APP was only 19.2%, and it failed to pass the UL-94 rating. CC test results showed that the heat release rate (HRR), mass loss rate (MLR) and smoke production rate (SPR) of PP/PETA-APP system decreased significantly compared with PP/APP system, especially the peak of HRR was decreased by 51.4%. The mechanism for the improvement of flame reatardancy for PP/PETA-APP composites was discussed based on FTIR and X-ray photoelectron spectroscopy (XPS) tests. All these results illustrated that simultaneous improvement of flame retardancy and water resistance for PP/APP was achieved through coating UV-curable PETA onto APP.

A novel kind of ligand free aurum nanoparticles (Au NPs)/poly(p-phenylene-vinylene) (PPV) composites was prepared via a simple approach. Although there were no ligands coating on the surface of the Au NPs, the Au NPs/PPV precursor composite exhibited excellent stability that no obvious variance was found as long as 6 months at ~4 ℃ in aqueous and alcohol mixed solutions. This was attributed to the strong interaction between Au NPs and PPV precursor, which was further strengthened after heat transformation. Fourier transform infrared (FTIR) and Raman spectra showed the interaction between benzene ring in PPV and Au NPs led to the part transformation of the sp² hybrid orbital into the sp³ one during the composite formation. As a result, the photoluminescence (PL) life time of PPV in the composite was longer than that of pure PPV. The Au NPs/PPV composite exhibited good photo-electric response, indicating their potential application in the area of the photoelectric conversion devices.

Microporous hypercross-linked conjugated quinonoid chromophores represent a novel class of amorphous polymers, synthesized by the reaction of anthracene with dimethoxy methane in the presence of FeCl₃ catalyst. Their N₂ adsorption isotherms confirm their microporous nature. Diffuse reflectance UV-Visible (DRS UV-Vis) spectroscopy confirms their matrix built with the conjugated quinonoids by their broad light absorption characteristics extending from 1000 nm to 200 nm with the absorbance maximum close to 400 nm. The catalyst cross-linked anthracene with ―CH₂― bridges and subsequently dehydrogenating them to form quinonoids. Their Fourier transform infrared (FTIR) spectra showed their characteristic quinonoid vibrations between 1600 and 1700 cm^-1. The synthesis of polymers was carried out at 30, 40, 50, 60, 70 and 80 ℃, but the quinonoid content of the polymer obtained at 80 ℃ was higher than that of the others. Their scanning electron microscopy (SEM) images showed microspheres of 1 to 5 μm size built with tiny particles. Their surfaces were not smooth. The polymer synthesized at 80 ℃ showed 5.1 wt% CO₂ sorption at 25 ℃ and 0.1 MPa, but when it was re-cross-linked, the CO₂ sorption increased to 8 wt%. Hence, hypercross-linked conjugated quinonoid chromophores of anthracene are good for sorption of CO₂.

In this study, bacteria associated with marine organisms were screened for the production of exopolysaccharides (EPSs) on MY media containing sea salts (2.5%-10%). Three selected isolates were identified as Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26 using 16S rRNA gene sequencing. Optimization of the growth and EPS production kinetics in relation to incubation time were assessed. The purified EPS yield was 590, 650 and 540 mg·L^-1 culture media respectively in Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26. Biochemical and FTIR analyses revealed the presence of biologically important functional groups in the EPS produced by all the three isolates. The EPS produced by Nitratireductor sp. PRIM-24 and Alteromonas sp. PRIM-21 showed 2.0% sulfate content. These bacterial EPS also showed antioxidant and emulsifying activities and the EPS produced by Enterobacter sp.PRIM-26 showed significantly higher antioxidant activities in terms of superoxide (IC₅₀ 0.33 mg·mL^-1) and DPPH (IC₅₀ 0.44 mg·mL^-1) radical scavenging. It also showed higher emulsifying activities against selected hydrophobic substrates with EI₂₄ values above 60%. From the results of the study, it can be concluded that the isolated bacteria produce EPS that can be investigated in detail for biotechnological applications.

We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly(ethylene glycol) functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis (TGA) exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry (DSC) was further employed to investigate the thermal phase transitions, that three different signals (T_g, T_c, and T_m) were shown upon the second heating process. Moreover, CH₂Cl₂ solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials.

In this study, the effect of annealing temperature on the impact toughness of β-nucleated polypropylene random copolymer (PPR) and ethylene-propylene-diene terpolymer (EPDM) blends was investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). Interestingly, the impact strength of β-PPR/20EPDM blend annealed at 120 ℃ is 1.8 times as high as that of unannealed samples. In addition, the crystalline structure, the relaxation of chain segments and fracture morphology of β-PPR/EPDM blends were also investigated to explore the toughening mechanism related to annealing. The results show that annealing at moderate temperatures results in the improvement of integrity of the crystal structure and the relative content of β-phase. The work provides a possible method to toughen the semicrystalline polymer at low temperatures by annealing.

The structure of bidisperse polyethylene (PE) nanocomposite mixtures of 50:50 (by mole) of long and short chains of C₁₆₀H₃₂₂/C₈₀H₁₆₂ and C₁₆₀H₃₂₂/C₄₀H₈₂ filled with spherical nanoparticles were investigated by a coarse-grained, on lattice Monte Carlo method using rotational isomeric state theory for short-range and Lennard-Jones for long-range energetic interactions. Simulations were performed to evaluate the effect of wall-to-wall distance between fillers (D), polymer-filler interaction (w) and polydispersity (number of short chains in the mixture) on the behavior of the long PE chains. The results indicate that long chain conformation statistics remain Gaussian regardless of the effects of confinement, interaction strength and polydispersity. The various long PE subchain structures (bridges, dangling ends, trains, and loops) are influenced strongly by confinement whereas monomer-filler interaction and polydispersity did not have any impact. In addition, the average number of subchain segments per filler in bidisperse PE nanocomposites decreased by about 50% compared to the nanocomposite system with monodisperse PE chains. The presence of short PE chains in the polymer matrix leads to a reduction of the repeat unit density of long PE chains at the interface suggesting that the interface is preferentially populated by short chains.

In order to prepare a novel hemostatic dressing for uncontrolled hemorrhage, a porous chitosan sponge was coated with self-assembled (thrombin/tannic acid)_n films, which were based on hydrogen bonding interactions between thrombin and tannic acid at physiologic pH. According to the whole blood clotting test, the coated chitosan sponges showed a significantly high rate of blood clotting due to the addition of thrombin. On the other hand, the storable half-life of immobilized thrombin is extended to 66.9 days at room temperature, which is 8.5 times longer than unfixed thrombin. It is because of the immobilization effect of, not only the porous structure of chitosan sponge but also the interactions between thrombin and tannic acid. In addition, the tannic acid has similar antibacterial effect to chitosan. Therefore, it is an excellent combination of chitosan, thrombin and tannic acid. Besides, all of materials in this research have been approved by the United States Food and Drug Administration (FDA). So the chitosan-based sponge is a promising candidate dressing for uncontrolled hemorrhage due to its storable, bio-safe and highly effective hemostatic properties.

Core-shell structured polyacrylic (named CSSP) impact modifiers consisting of a rubbery poly(n-butyl acrylate) core and a rigid poly(methyl methacrylate) shell with a size of about 353 nm were prepared by seed emulsion polymerization. The CSSP modifiers with different core-shell weight ratios (90/10, 85/15, 80/20, 75/25, 70/30, 65/35 and 60/40) were used to modify the toughness of poly(butylene terephthalate) (PBT) by melt blending. It was found that the polymerization had a very high instantaneous conversion (> 95.7%) and overall conversion (99.7%). The morphology of the core-shell structure was confirmed by means of transmission electron microscopy. Scanning electron microscopy was used to observe the morphology of the fractured surfaces. Differential scanning calorimeter was used to study the crystallization behaviors of PBT/CSSP blends. The dynamic mechanical analyses of PBT/CSSP blends showed two merged transition peaks of PBT matrix, with the presence of CSSP core-shell structured modifier, that were responsible for the improvement of PBT toughness. The results indicated that the notch impact strength of PBT/CSSP blends with a core-shell weight ratio of 75/25 was almost 8.64 times greater than that of pure PBT, and the mechanical properties agreed well with the SEM observation.

This work reports synthesis and characterization of heterocyclic functionalized polymers, poly(triazole-ether-imidazole) s (PTAEI), from a dialkyne-terminated compound, 3-(4,5-bis(4-(propargyloxy)phenyl)-1H-imidazol-2-yl)-9-ethyl-9H-carbazole, by using click reaction. PTAEIs were characterized and their properties such as solubility, thermal, mechanical, photophysical and metal ions adsorption were investigated. These polymers had weight average molar masses (M_w) in the range of 19100-26700 g/mol, exhibited excellent solubility in polar aprotic solvents and formed low-colored flexible thin films by solution casting method. They exhibited good thermal stability with glass transition temperatures (T_g) between 160 °C and 211 °C and 10% weight loss temperatures (T10%) in the range of 308-426 °C. Nanocomposites of PTAEIs with epoxide-terminated Fe₃O₄ showed that strong interfacial interaction between inorganic particles and the polymer matrix contributed to the enhanced thermal and mechanical properties. The photoluminescence intensity of the PTAEIs increased and the spectra red shifted with increasing Fe₃O₄ content. The PTAEIs and nanocomposites were tested for their extraction capability of metal ions from aqueous solutions either individually or in the mixture.

The effects of aluminum hypophosphite (AHP) as a synergistic agent on the flame retardancy and thermal degradation behavior of intumescent flame retardant polypropylene composites (PP/IFR) containing ammonium polyphosphate (APP) and triazine charring-foaming agent (CFA) were investigated by limiting oxygen index (LOI), UL-94 measurement, thermogravimetric analysis (TGA), cone calorimeter test (CONE), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It was found that the combination of IFR with AHP exhibited an evident synergistic effect and enhanced the flame retardant efficiency for PP matrix. The specimens with the thickness of 0.8 mm can pass UL-94 V-0 rating and the LOI value reaches 33.5% based on the total loading of flame retardant of 24 wt%, and the optimum mass fraction of AHP/IFR is 1:6. The TGA data revealed that AHP could change the degradation behavior of IFR and PP/IFR system, enhance the thermal stability of the IFR and PP/IFR systems at high temperatures and promote the char residue formation. The CONE results revealed that IFR/AHP blends can efficiently reduce the combustion parameters of PP, such as heat release rate (HRR), total heat release (THR), smoke production rate (SPR) and so on. The morphological structures of char residue demonstrated that AHP is of benefit to the formation of a more compact and homogeneous char layer on the materials surface during burning. The analysis of XPS indicates that AHP may promote the formation of sufficient char on the materials surface and improve the flame retardant properties.

A facile, efficient and environment friendly method is established to prepare poly(vinyl alcohol) (PVA) based graphene oxide-montmorillonite (GO-MMT) nanocomposites in aqueous media. GO-MMT nanohybrid is obtained by the combination of GO and MMT in water without any reducing or stabilizing agents. The formation of GO-MMT nanohybrid is due to the hydrogen bonding and crosslinking effects. The sodium ions within MMT sheets act as crosslinkers between GO sheets and MMT platelets. The resultant nanocomposites are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and mechanical testing. Compared to that of pure PVA, PVA nanocomposites show enhanced thermal stabilities and mechanical properties, which results from strong interfacial adhesion of the nanoadditives in PVA matrix. The further increase in the tensile strength and modulus results from strong interaction between PVA chains and layered GO-MMT as well as good mechanical properties of GO-MMT hybrid, compared to PVA/GO and PVA/MMT nanocompsoites.

The influence of poly(methylmethacrylate-co-N-vinyl-2-pyrrolidone), P(MMA-co-VP), on corrosion of carbon steels (J55, N80, P110SS and C110 steels) in 3.5 wt% NaCl solution saturated with CO₂ was evaluated using static high pressure and high temperature (HPHT) autoclave. The surface was further evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and contact angle measurements. Quantum chemical calculations have been used to evaluate the structural, electronic and reactivity parameters of the inhibitor on the steels surface. SEM, XRD and contact angle measurement studies reveal that the surface of metals are quite unaffected after use of inhibitor in 3.5% NaCl solution saturated with CO₂.

The miscibility, isothermal crystallization kinetics and morphology of the poly(vinylidene fluoride) (PVDF)/poly(ethylene adipate) (PEA) blends have been studied by differential scanning calorimetry (DSC), optical microscopy (OM) and scanning electron microscopy (SEM). A depression of the equilibrium melting point of PVDF was observed. From the melting point data of PVDF, a negative but quite small value of the interaction parameter χ_PVDF-PEA is derived using the Flory-Huggins equation, implying that PVDF shows miscibility with PEA to some extent. Nonisothermal and isothermal crystallization kinetics suggest that the crystallization rate of PVDF decreases with increasing the amount of PEA, and a contrary trend was found when PEA crystallizes with the increase of the amount of PVDF. It was further disclosed that the blend ratio and crystallization temperature affect the texture of PVDF spherulites greatly, which determines the subsequent crystallization of PEA. At high temperatures, e.g. 150 ℃, the band spacing of PVDF spherulites increases with the addition of PEA content and the spherulitic structure becomes more open. In this case, spherulitic crystallization of PEA is not observed for all blend compositions. At low temperatures, e.g. 130 ℃, for the PEA-rich blends, the interpenetrated structures are eventually formed by the penetration of the spherulites of PEA growing within the pre-existing PVDF spherulites.

A facile, safe and economical reducing agent, sodium hypophosphite (NaH₂PO₂·H₂O), has been successfully employed for ambient temperature living radical copolymerization of styrene (St) and methyl methacrylate (MMA). Such effective reducing agent significantly improved the reactivity of low reactive St monomers during the copolymerization, where the reactivity ratios of St and MMA were determined to be 0.50 and 0.36 by Finemann-Ross method. Thus the copolymerizations proceeded fast and showed typical living/controlled features, as evidenced by pseudo first-order kinetics of polymerization, linear increase in molecular weight versus monomer conversion, and low polydispersity index values. Effects of the concentration of reducing agent and the monomer feed ratio on the copolymerization were investigated in detail. Furthermore, gel permeation chromatography and ¹H-NMR analyses as well as chain extension experiments confirmed the high chain-end functionality of the resultant copolymer.