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Updated: Jul 28, 2025

Optimization of Crystal Growth for Neutron Macromolecular Crystallography
Published on: March 13, 2021
Tunable Crystallization Kinetics and Crystal Polymorphism in Semicrystalline Polymers: Insight into the Multilevel
Lingling Ni1, Shanshan Xu1, Chenxuan Sun1
1College of Chemical and Biological Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Abstract:
The melting of semicrystalline polymers is a typical multistep process and involves a series of intermediate melt states. However, the structural characteristics of the intermediate polymer melt is unclear. Herein, we choose polymorphic trans-1,4-polyisoprene (tPI) as a model polymer system and elucidate the structures of the intermediate polymer melt and their strong effects on the following crystallization process. We find that the metastable β crystals of the tPI melt first into an intermediate state and then recrystallize in new crystals upon thermal annealing. The intermediate melt shows multilevel structural order at the chain level depending on the melting temperature. The conformationally ordered melt can memorize the initial crystal polymorph and accelerate the crystallization process, while the ordered melt without the conformational order can only enhance the crystallization rate. This work provides deep insight into the multilevel structural order of polymer melts and its strong memory effects on the crystallization process.
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