Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements

Ce Shi; Jia-Le Zeng; Ze-Fan Wang; Yong-Feng Men

doi:10.1007/s10118-026-3695-5

Your Location：

Home >

Browse articles >

Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements

RESEARCH ARTICLE | Updated：2026-08-31

- Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements
- Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements
- Chinese Journal of Polymer Science 2026年44卷第9期页码：3104-3118
- Affiliations：
  
  a.State Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
  b.School of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
  c.School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
- Author bio：
  
  zfwang@ciac.ac.cn (Z.F.W.)
  men@ciac.ac.cn (Y.F.M.)
- Funds：
  
  This work was financially supported by the National Natural Science Foundation of China (No. 22303052) and the Shenzhen Natural Science Foundation Project (No. JCYJ20250604181237049). We thank Prof. Alejandro J. Müller for the fruitful discussion.;The authors declare no interest conflict.Melt structural property parameters calculated from rheological measurements, DSC heating curves of dilute PCL after crystallization at different temperatures, SAXS profiles during in situ heating and detailed self-nucleation DSC curves are provided in the electronic supplementary information (ESI). ESI is available free of charge in an online version of this article at https://doi.org/10.1007/s10118-026-3695-5.The related data of this paper is data that should not be shared, and can be obtained from the corresponding author for reasonable reasons.
- DOI：10.1007/s10118-026-3695-5
  中图分类号： [M
- 收稿：2026-03-05，
  
  录用：2026-04-04，
  
  网络首发：2026-07-22，
  
  纸质出版：2026-09-05
- Accepted：
Scan QR Code
Shi, C.; Zeng, J. L.; Wang, Z. F.; Men, Y. F. Molecular segregation and melt memory in dilute polycaprolactone with reduced entanglements. Chinese J. Polym. Sci. 2026, 44, 3104–3118

Ce Shi, Jia-Le Zeng, Ze-Fan Wang, et al. Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements[J]. Chinese Journal of Polymer Science, 2026, 44(9): 3104-3118.
Shi, C.; Zeng, J. L.; Wang, Z. F.; Men, Y. F. Molecular segregation and melt memory in dilute polycaprolactone with reduced entanglements. Chinese J. Polym. Sci. 2026, 44, 3104–3118 DOI： 10.1007/s10118-026-3695-5.

Ce Shi, Jia-Le Zeng, Ze-Fan Wang, et al. Molecular Segregation and Melt Memory in Dilute Polycaprolactone with Reduced Entanglements[J]. Chinese Journal of Polymer Science, 2026, 44(9): 3104-3118. DOI： 10.1007/s10118-026-3695-5.

摘要

This study clarifies that in bimodal polymer mixtures with low entanglement concentrations

the crystallization morphology is strongly related to the molecular weight of the long chains. The lamellar stack structure is determined by the fraction of tie chains. The melt-memory effect has been proven to be related to intrachain interactions rather than entanglements.

Abstract

In polymer processing

low-molecular-weight chemically identical oligomers are typically added to a polymer to improve its processability and mechanical properties by manipulating its entanglement concentration. However

the complicated semi-crystalline morphologies and melt memory effect of less entangled bimodal dispersed mixtures cannot be overlooked. In this study

we systematically examined the crystallization and self-nucleation behavior of poly(

-caprolactone) (PCL) mixtures composed of a relatively

high-molecular-weight (83 kg/mol) fraction and a low-molecular-weight PCL with a mid-chain defect (2 kg/mol). The entanglement concentrations were quantified by linear rheological measurements. Both thermal analysis and small-angle X-ray scattering (SAXS) investigations revealed that pronounced crystallization-induced phase separation (

i.e.

molecular segregation) occurs because of the different nucleation energy barriers. In contrast to our previous investigation using a long chain fraction with a higher molecular weight (200 kg/mol) (

Macromolecules

2024

1632−1641)

the low-molecular-weight oligomer tends to crystallize between adjacent crystalline lamellae composed of long PCL chains due to the lack of intra-crystalline links

for example

entanglements and tie-molecules. The correlation between the melt memory effect and the entanglement concentration was evaluated using self-nucleation experiments. The 2 kg/mol PCL oligomer (with a central defect) did not exhibit melt memory. However

the introduction of high-molecular-weight components

even below the critical entanglement concentration

leads to a wider temperature range

preserving the ordered structure. Our results provide solid evidence that the melt memory effect in polar semi-crystalline polymers originates from the intramolecular interactions of adjacent chain folding rather than entanglements or chain overlaps.

关键词

Keywords

references

Wu, W. L.; Jong, L.; Hanyu, A.; Coyne, L. D.; Stein, R. S. Molecular structure of bimodal polymer networks. Macromolecules 1990 , 23 , 351−353..

Liu, H.-T.; Davey, C. R.; Shirodkar, P. P. Bimodal polyethylene products from UNIPOLTM single gas phase reactor using engineered catalysts. Macromol. Symp. 2003 , 195 , 309−316..

Balzano, L.; Rastogi, S.; Peters, G. Self-nucleation of polymers with flow: the c ase of bimodal polyethylene. Macromolecules 2011 , 44 , 2926−2933..

Men, Y. F.; Rieger, J.; Strobl, G. Role of the entangled amorphous network in tensile deformation of semicrystalline polymers. Phys. Rev. Lett. 2003 , 91 , 4..

Li, W.; Guan, C.; Xu, J.; Chen, Z.-r.; Jiang, B.; Wang, J.; Yang, Y. Bimodal/broad polyethylene prepared in a disentangled State. Ind. Eng. Chem. Res. 2014 , 53 , 1088−1096..

Sattari, M.; Inn, Y.; Wood-Adams, P. M. Wall slip of bimodal polyethylene. Macromolecules 2022 , 55 , 4568−4577..

Zou, C.; Wang, Q.; Si, G.; Chen, C. A co-anchoring strategy for the synthesis of polar bimodal polyethylene. Nat. Comm. 2023 , 14 , 1442..

Ma, Y.; Niu, D.; Liu, J.; Liu, B.; Xu, P.; Jiao, X.; Yang, W.; Liu, T.; Ma, P. Branching-density dependent chain relaxation and orientated crystallization behavior of the stretched polylactic acid melt. Macromolecules 2025 , 58 , 5674−5687..

Wang, J.; Niu, D.; Yu, T.; Xu, P.; Yang, W.; Ma, P. Highly oriented polymorphism in polyglycolic acid via coupling of chain Entanglement and extensional strain. Macromolecules 2026 , 59 , 3431−3443..

Glaser, R. H.; Mandelkern, L. On the fractionation of homopolymers during crystallization from the pure melt. J. Polym. Sci. B: Polym. Phys. 1988 , 26 , 221−234..

Cheng, S. Z. D.; Wunderlich, B. Molecular segregation and nucleation of poly(ethylene oxide) crystallized from the melt. 1. calorimetric study. J. Polym. Sci. B: Polym. Phys. 1986 , 24 , 577−594..

Cheng, S. Z. D.; Wunderlich, B. Molecular segregation and nucleation of poly(ethylene oxide) crystallized from the melt. 2. kinetic-study. J. Polym. Sci. B: Polym. Phys. 1986 , 24 , 595−617..

Hu, W.; Frenkel, D.; Mathot, V. B. F. Intramolecular Nucleation model for polymer crystallization. Macromolecules 2003 , 36 , 8178−8183..

Hu, W. B. Molecular segregation in polymer melt crystallization: Simulation evidence and unified-scheme interpretation. Macromolecules 2005 , 38 , 8712−8718..

Saalwächter, K.; Thurn-Albrecht, T.; Paul, W. Recent progress in understanding polymer crystallization. Macromol. Chem. Phys. 2023 , 224 , 2200424..

Wang, Z.; Schaller, M.; Petzold, A.; Saalwächter, K.; Thurn-Albrecht, T. How entanglements determine the morphology of semicrystalline polymers. Proc. Natl. Acad. Sci. 2023 , 120 , e2217363120..

Wang, Z.; Schaller, M.; Petzold, A.; Saalwächter, K.; Thurn-Albrecht, T. Origin of lamellar stack structures in dilute semicrystalline polymers: role of entanglements and tie-molecules. Macromolecules 2024 , 57 , 1632−1641..

Bristow, J. F.; Kalika, D. S. Investigation of semicrystalline morphology in poly(ether ether ketone)/poly(ether imide) blends by dielectric relaxation spectroscopy. Polymer 1997 , 38 , 287−295..

Pan, P.; Zhao, L.; Yang, J.; Inoue, Y. Fra ctional Crystallization and phase segregation in binary miscible poly(butylene succinate)/poly(ethylene oxide) crystalline blends: effect of crystallization temperature. Macromol. Mater. Eng. 2013 , 298 , 201−209..

Wang, J.; Miao, X.; Zeng, J.; Li, X.; Dong, Y.; Li, Y.; Bian, F.; You, J. Structure evolution of PVDF/PBSU interpenetrating crystal frameworks during deformation investigated by in-situ synchrotron radiation SAXS/WAXS. Giant 2025 , 22 , 100354..

Muller, A. J.; Balsamo, V.; Arnal, M. L.; Jakob, T.; Schmalz, H.; Abetz, V. Homogeneous nucleation and fractionated crystallization in block copolymers. Macromolecules 2002 , 35 , 3048−3058..

Lorenzo, A. T.; Arnal, M. L.; Sanchez, J. J.; Muller, A. J. Effect of annealing time on the self-nucleation behavior of semicrystalline polymers. J. Polym. Sci. B: Polym. Phys. 2006 , 44 , 1738−1750..

Trujillo, M.; Arnal, M. L.; Müller, A. J.; Laredo, E.; Bredeau, S.; Bonduel, D.; Dubois, P. Thermal and morphological characterization of nanocomposites prepared by in-situ polymerization of high-density polyethylene on carbon nanotubes. Macromolecules 2007 , 40 , 6268−6276..

Lorenzo, A. T.; Arnal, M. L.; Müller, A. J.; Lin, M.-C.; Chen, H.-L. SAXS/DSC analysis of the lamellar thickness distribution on a SSA thermally fractionated model polyethylene. Macromol. Chem. Phys. 2011 , 212 , 2009−2016..

Sangroniz, L.; Cavallo, D.; Muller, A. J. Self-nucleation effects on polymer crystallization. Macromolecules 2020 , 53 , 4581−4604..

Liu, X.; Yu, W. Role of chain dynamics in the melt memory effect of crystallization. Macromolecules 2020 , 53 , 7887−7898..

Arandia, I.; Mugica, A.; Zubitur, M.; Arbe, A.; Liu, G.; Wang, D.; Mincheva, R.; Dubois, P.; Müller, A. J. How composition determines the properties of isodimorphic poly(butylene succinate-ran-butylene azelate) random biobased copolymers: from single to double crystalline random copolymers. Macromolecules 2015 , 48 , 43−57..

Liu, X. R.; Wang, Y.; Wang, Z. F.; Cavallo, D.; Muller, A. J.; Zhu, P.; Zhao, Y.; Dong, X.; Wang, D. J. The origin of memory effects in the crystallization of polyamides: role of hydrogen bonding. Polymer 2020 , 188 , 122117..

Fernández-Tena, A.; Pérez-Camargo, R. A.; Coulembier, O.; Sangroniz, L.; Aranburu, N.; Guerrica-Echevarria, G.; Liu, G.; Wang, D.; Cavallo, D.; Müller, A. J. Effect of molecular weight on the crystallization and melt memory of poly(ε-caprolactone) (PCL). Macromolecules 2023 , 56 , 4602−4620..

Sangroniz, L.; Müller, A. J.; Cavallo, D. Origin of melt memory effects in poly(ethylene oxide): the crucial role of entanglements. Macromol. Rap. Comm. 2024 , 45 , 2400011..

AliAboudzadeh, M.; Sangroniz, L.; Coulembier, O.; Ferranti, M.; Costanzo, S.; Grizzuti, N.; Cavallo, D.; Müller, A. J. Decoupling the roles of chain length, entanglements and intermolecular interactions on the melt memory of semicrystalline homopolymers. Macromolecules 2026 , 59 , 3371−3383..

[Rubinstein, M.; Colby, R. H. Polymer Physics ; Oxford University Press, 2003 , p. 361−422..

Wang, Z.; Zeng, J.; Liang, Y.; Zhang, R.; Zhu, C.; Xu, J.; Müller, A. J. The effect of entanglement concentration on th e melt memory of polyethylene random copolymer. Polymer 2025 , 332 , 128576..

Gao, H.; Vadlamudi, M.; Alamo, R. G.; Hu, W. Monte carlo simulations of strong memory effect of crystallization in random copolymers. Macromolecules 2013 , 46 , 6498−6506..

Reid, B. O.; Vadlamudi, M.; Mamun, A.; Janani, H.; Gao, H.; Hu, W.; Alamo, R. G. Strong memory effect of crystallization above the equilibrium melting point of random copolymers. Macromolecules 2013 , 46 , 6485−6497..

Chen, X.; Mamun, A.; Alamo, R. G. Effect of level of crystallinity on melt memory bove the equilibrium melting temperature in a random ethylene 1-utene copolymer. Macromol. Chem. Phys. 2015 , 216 , 1220−1226..

Chen, X.; Wignall, G. D.; He, L.; Lopez-Barron, C.; Alamo, R. G. SANS Evidence of liquid–liquid phase separation leading to inversion of crystallization rate of broadly distributed random ethylene copolymers. Macromolecules 2017 , 50 , 4406−4414..

[Michell, R. M.; Mug ica, A.; Zubitur, M.; Muller, A. J. Self-Nucleation of crystalline phases within homopolymers, polymer blends, copolymers, and nanocomposites. In Polymer Crystallization I: From Chain Microstructure to Processing , Auriemma, F., Alfonso, G. C., DeRosa, C. Eds.; Advances in Polymer Science, Vol. 276; Springer, 2017 , p. 215..

Sangroniz, L.; Cavallo, D.; Santamaria, A.; Müller, A. J.; Alamo, R. G. Thermorheologically complex self-seeded melts of propylene–ethylene copolymers. Macromolecules 2017 , 50 , 642−651..

Chen, X.; López-Barrón,C.; Zeng, Y.; Alamo, R. G. Concentration fluctuations in the early stages of LLPS and partial dissolution of melt-memory in broadly distributed ethylene copolymers. Polymer 2018 , 148 , 181−190..

Liu, P.; Xue, Y.; Men, Y. Melt Memory Effect beyond the equilibrium melting point in commercial isotactic polybutene-1. Ind. Eng. Chem. Res. 2019 , 58 , 5472−5478..

Ren, M.; Chen, X.; Sang, Y.; Alamo, R. G. Comparative effects on recrystallization of melt-memory and liquid–liquid phase separation in Ziegler–Natta and metallocene ethylene copolymers with bimodal comonomer composition distribution. Ind. Eng. Chem. Res. 2020 , 59 , 19260−1927 1..

Liao, Y.; Pan, L.; Ma, Z.; Cavallo, D.; Liu, G.; Wang, D.; Müller, A. J. How 4-(7-Octen-1-yl)-N,N-diphenylaniline co-units induce strong melt memory effects in isotactic polypropylene random copolymers. Polymer 2023 , 282 , 126184..

[Ruland, W. The evaluation of the small-angle scattering of lamellar two-phase systems by means of interface distribution functions. Colloid Polym. Sci. 1977 , 255 , 417–427..

[Seidlitz, A.; Thurn-Albrecht, T. Small-angle X-ray scattering for morphological analysis of semicrystalline polymers. In Polymer morphology , John Wiley & Sons, Inc, 2016 , pp. 151–164..

Schulz, M.; Seidlitz, A.; Kurz, R.; Bärenwald, R.; Petzold, A.; Saalwächter, K.; Thurn-Albrecht, T. The Underestimated Effect of Intra-crystalline chain dynamics on the morphology and stability of semicrystalline polymers. Macromolecules 2018 , 51 , 8377−8385..

Schäfer, M.; Wallstein, N.; Schulz, M.; Thurn-Albrecht, T.; Saalwächter, K. Intra-crystalline dynamics in oligomer-diluted poly(ethylene oxide). Macromol. Chem. Phys. 2020 , 221 , 1900393..

Schulz, M.; Schäfer, M.; Saalwächter, K.; Thurn-Albrecht, T. Competition between crystal growth and intracrystalline chain diffusion determines the lamellar thickness in semicrystalline polymers. Nat. Comm. 2022 , 13 , 119..

Yu, Q.; Anuar, A.; Petzold, A.; Balko, J.; Saalwächter, K.; Thurn-Albrecht, T. The semicrystalline morphology of polybutylene succinate supports a general scheme based on intracrystalline dynamics. Macromol. Chem. Phys. 2023 , 224 , 2200459..

[Ferry, J. D. Viscoelastic Properties of Polymers ; Wiley, 1970.

van Ruymbeke, E.; Masubuchi, Y.; Watanabe, H. Effective value of the dynamic dilution exponent in bidisperse linear polymers: from 1 to 4/3. Macromolecules 2012 , 45 , 2085−2098..

[Shahid, T.; Huang, Q.; Oosterlinck, F.; Clasen, C.; van Ruymbeke, E. Dynamic dilution exponent in monodisperse entangl ed polymer solutions. Soft Matter 2017 , 13 , 269–282..

Lauritzen, J.; Hoffman, J. Extension of theory of growth of chain-folding polymer crystals to large undercoolings. J. Appl. Phys. 1973 , 44 , 4340−4352..

[Hoffman, J.D.; G, T. D.; Lauritzen, J. I. The rate of crystallization of linear polymers with chain folding. In Treatise on Solid State Chemistry , Hannay, N. B. Ed.; Springer-Verlag US, 1976 , p. 497..

[Wunderlich, B. in Macromolecular Physics , Academic Press, 1976 , pp. 1−114..

Wunderlich, B. Molecular nucleation and segregation. Faraday Discuss. Chem. Soc. 1979 , 68 , 239−243..

Zhang, R.; Du, M.; Jariyavidyanont, K.; Androsch, R.; Zhuravlev, E.; Schick, C. Fast scanning calorimetry of semicrystalline polymers: from fundamental research to industrial applications. Acc. Chem. Res 2025 , 6 , 627−637..

Huang, Y. L.; Brown, N. The effect of molecular weight on slow crack growth in linear polyethylene homopolymers. J. Mater. Sci. 1988 , 23 , 3648−3655..

Qiao, Y. N.; Men, Y. F. Intercrystalline links determined kinetics of Form II to I polymorphic transition in polybutene-1. Macromolecules 2017 , 50 , 5490−5497..

Huang, Y.; Xu, Z. D.; Huang, Y. P.; Ma, D. Z.; Yang, J. C.; Mays, J. W. Characterization of poly(epsilon-caprolactone) via size exclusion chromatography with online right-angle laser-light scattering and viscometric detectors. Int. J. Polym. Anal. Charact. 2003 , 8 , 383−394..

Schulz, M.; Seidlitz, A.; Petzold, A.; Thurn-Albrecht, T. The effect of intra-crystalline chain dynamics on melting and reorganization during heating in semicrystalline polymers. Polymer 2020 , 196 , 122441..

Blundell, D. J.; Keller, A.; Kovacs, A. J. A new self-nucleation phenomenon and its application to the growing of polymer crystals from solution. J. Polym. Sci. B: Polym. Phys. 1966 , 4 , 481−486..

[Blundell, D. J.; Keller, A. Nature of self-seeding polyethylene crystal nuclei. J. Macromol. Sci. B Phys . 1968 , 2 301–336..

Fillon, B.; Thierry, A.; Wittmann, J. C.; Lotz, B. Self-nucleation and recrystallization of polymers - isotactic polypropylene, beta-phase - beta-alpha-conversion and beta-alpha-growth transitions. J. Polym. Sci. B: Polym. Phys. 1993 , 31 , 1407−1424..

Pérez, R. A.; Córdova, M. E.; López, J. V.; Hoskins, J. N.; Zhang, B.; Grayson, S. M.; Müller, A. J. Nucleation, crystallization, self-nucleation and thermal fractionation of cyclic and linear poly(ε-caprolactone)s. React. Funct. Polym. 2014 , 80 , 71−82..

Sangroniz, L.; Sangroniz, A.; Meabe, L.; Basterretxea, A.; Sardon, H.; Cavallo, D.; Müller, A. J. Chemical structure drives memory effects in the crystallization of homopolymers. Macromolecules 2020 , 53 , 4874−4881..

[Sangroniz, L.; Jang, Y.-J.; Hillmyer, M. A.; Müller, A. J. The role of intermolecular interactions on melt memory and thermal fractionati on of semicrystalline polymers. J. Chem. Phys . 2022 , 156 , 144902..

Sangroniz, L.; Safari, M.; Martínez de Ilarduya, A.; Sardon, H.; Cavallo, D.; Müller, A. J. Disappearance of melt memory effect with comonomer incorporation in isodimorphic random copolyesters. Macromolecules 2023 , 56 , 7879−7888..

Androsch, R.; Di Lorenzo, M. L. Crystal nucleation in glassy poly(l-lactic acid). Macromolecules 2013 , 46 , 6048−6056..

Lemstra, P. J. Chapter 1: High-performance polyethylene fibers. Adv. Ind. Eng. Polym. Res. 2022 , 5 , 49−59..

Wang, Z.; Li, B.; Christakopoulos, F.; Xie, K.; Zhu, C.; Xu, J.; Müller, A. J. Structure formation and unexpected ultrafast re-entanglement dynamics of disentangled ultrahigh molecular weight polyethylene. Macromolecules 2024 , 57 , 10240−10252..

Wang, Z.; Sangroniz, L.; Xu, J.; Zhu, C.; Müller, A. Polymer Physics behind the Gel-Spinning of UHMWPE Fibers. Macromol. Rapid Commun. 2024 , 45 , 2400124..

浏览量

Downloads

CSCD

文章被引用时，请邮件提醒。

Submit

工具集

关联资源

A Facile Strategy to Enhance the Formation of Stereocomplex Crystallites in Poly(L-lactic acid)/Poly(D-lactic acid) Blend with High Molecular Weights

Mixing of Racemic Poly(L-lactide)/Poly(D-lactide) Blend with Miscible Poly(D,L-lactide): Toward All Stereocomplex-type Polylactide with Strikingly Enhanced SC Crystallizability

Two-way Shape Memory Effect of Polycaprolactone-based Polyurethane via Synergistic Role of Hydrogen Bonding and Crystallization Tuned by Malic Acid

From Molecular Defect to Macroscopic Performance: Manipulating Dichroism and Mechanics in Iodine-doped Poly(vinyl alcohol) via Ethylene Incorporation

Upgrading Commercially Available Polyethylene to High-value Materials with Strong Mechanical Performance and Hydrophilicity by Blending with Ethylene/meta-Methoxystyrene Copolymers