Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Materials Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , P. R. China.
ACS Appl Mater Interfaces. 2018 Nov 14;10(45):39293-39306. doi: 10.1021/acsami.8b15037. Epub 2018 Oct 30.
Although the concept of molecular composites (MCs) is very promising, there are major obstacles arising from the immiscibility of the rigid-rod with the random-coil polymers. Here, we developed a novel method for fabricating an in situ reinforced MC system with nonequilibrium self-assembled nanofibrous structures based on bisphenol A epoxy resin, 4,4'-diaminodiphenylsulfone, bismaleimide, and a polyphenylene ether (PPO) oligomer. A variety of spectroscopic and morphological techniques were used to probe the structural evolution from the emergence of nanofibrils, to growth and aggregation of nanofibers, and then to the formation of in situ reinforced MC with strong interfacial interactions. The in situ nanofibers within the polymer matrix could be formed by the polymerization force extruding the PPO phase through the interspaces within the simultaneous interpenetrating network polymers during the cure process of the thermosetting resin system. Compared to the control sample, the in situ nanofiber-reinforced MC exhibited better thermal properties and flame retardancy. In particular, the obtained MC showed a significant improvement in glass transition temperature and mechanical properties, which were mainly attributed to the restriction of high thermal stability of PPO on the segmental motion of polymer chains, the toughening and reinforcement behaviors of PPO nanofibers on the matrix, and the chemical interaction at the PPO/matrix interface.
虽然分子复合材料（MCs）的概念很有前途，但刚性棒状聚合物与无规卷曲聚合物的不混溶性带来了重大障碍。在这里，我们开发了一种基于双酚 A 环氧树脂、4,4'-二氨基二苯砜、双马来酰亚胺和聚苯醚（PPO）低聚物的原位增强 MC 系统的新型制造方法，该系统具有非平衡自组装纳米纤维结构。采用多种光谱和形态技术来探测结构演变，从纳米纤维的出现，到纳米纤维的生长和聚集，再到具有强界面相互作用的原位增强 MC 的形成。在热固性树脂体系的固化过程中，聚合物基体中的原位纳米纤维可以通过聚合力将 PPO 相挤出，通过同时互穿网络聚合物中的空隙来形成。与对照样品相比，原位纳米纤维增强 MC 表现出更好的热性能和阻燃性。特别是，所得到的 MC 在玻璃化转变温度和机械性能方面表现出显著的提高，这主要归因于 PPO 的高热稳定性对聚合物链段运动的限制、PPO 纳米纤维对基体的增韧和增强作用以及 PPO/基体界面的化学相互作用。
