近日，韩国首尔大学Jung Hyeun Kim及其课题组研究出热退火对全生物源多元醇合成的热固性聚氨酯弹性体冷结晶能力的影响。相关论文于2025年3月5日发表在《结构化学》杂志上。

据介绍，生物多元醇被认为是合成环保聚氨酯产品的核心材料。然而，一种流行的生物多元醇，聚三亚甲基醚二醇（PO3G），不愿意结晶，因此表现出冷结晶行为。这种异常行为导致低温下机械性能不稳定，限制了其在形状记忆器件中的应用，其中结晶是一种基本机制。

为了分析这一反常现象，研究人员比较了不同醚多元醇的对称特性和碳骨架的奇偶效应。发现PO₃G的结晶速率较慢，因为它的醚键需要特定的链排列才能进行吸引作用。因此，开发了一种热学习机制来恢复由生物多元醇合成的弹性体的正常结晶行为。在高温退火条件下，反复加热和冷却可诱导氨基甲酸乙酯交换反应，重构链取向，实现快速结晶。结果表明，通过引入重复热处理，可以精确控制聚氨酯弹性体的结晶程度，从而提高生物多元醇在聚合物领域的潜在应用。

附：英文原文

Title: Effect of thermal annealing on cold crystallization ability of thermoset polyurethane elastomer synthesized from fully bio-derived polyol

Author: anonymous

Issue&Volume: 2025-03-05

Abstract: Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products. However, one of the popular bio-polyols, polytrimethylene ether glycol (PO3G), is reluctant to crystallize and therefore exhibits a cold crystallization behavior. This abnormal behavior causes unstable mechanical properties at low-temperature and limits its applications in shape memory devices where crystallization is an essential mechanism. To analyze the unusual phenomenon, we compared different ether polyols focusing on symmetry characteristics and the even-odd effect of carbon backbones. It is found that PO₃G has a slow crystallization rate because its ether linkages require specific chain arrangement for attractive interactions. Consequently, a thermal learning mechanism is developed to restore the normal crystallization behavior of elastomers synthesized from the bio-polyol. Repetitive heating and cooling cycles with high-temperature annealing induce urethane exchange reaction and reconstruct the chain orientations for fast crystallization. Results suggest the degree of crystallizations in polyurethane elastomer can be precisely controlled by introducing repetitive thermal treatments to enhance the potential applications of bio-polyols in the polymer industries.

DOI: 10.1016/j.cjsc.2025.100568

Source: http://cjsc.ac.cn/cms/issues/774