The knowledge of chain entanglement is key to our understanding of the relation between the viscoelastic properties of polymeric material and their microscopic structure and dynamics. This work conducted a detailed study on the role of short chains in the entangled polymer network. A series of poly(ethylene oxide) (PEO) mixtures with bimodal molecular weight distribution were selected for this study. ¹H double-quantum (DQ) NMR combined with the rheology measurement was used to investigate the entangled polymer network. We found that short-chain polymers have the potential to significantly alter the entangled polymer network formed by long-chain polymers. Additionally, both the amount of chain ends and the size of the short-chain polymer were found to have clear disentanglement influences on the entangled polymer network. Moreover, adding low molecular weight PEO to the entangle framework formed by the high molecular weight PEO, resulted in the formation of inhomogeneous entangled polymer networks. The effect of low molecular weight polymers on the entangled polymer networks in PEO melts provides a perspective on the molecular level effect of molecular weight distribution (MWD) on entanglement polymer networks.

中文翻译：

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短链在纠缠聚合物网络中的意外作用

链缠结的知识是我们理解聚合物材料的粘弹性与其微观结构和动力学之间关系的关键。这项工作对短链在纠缠聚合物网络中的作用进行了详细研究。本研究选择了一系列具有双峰分子量分布的聚 (环氧乙烷) (PEO) 混合物。¹H 双量子 (DQ) NMR 与流变测量相结合用于研究缠结聚合物网络。我们发现短链聚合物有可能显着改变由长链聚合物形成的缠结聚合物网络。此外，发现链端的数量和短链聚合物的大小对缠结的聚合物网络具有明显的解缠结影响。此外，将低分子量 PEO 添加到由高分子量 PEO 形成的缠结骨架中，导致形成不均匀的缠结聚合物网络。低分子量聚合物对 PEO 熔体中缠结聚合物网络的影响为分子量分布 (MWD) 对缠结聚合物网络的分子水平影响提供了视角。