Development and optimization of crystallization-inhibited polymer networks for strain-induced switching from entropy- to energy-elastic behavior

可结晶、非晶猝灭的聚合物网络在冲击载荷作用下以应变诱导方式自发结晶，具有巨大的冲击和能量吸收能力。然而，由于这种能力在短时间内由于热结晶的开始而丧失，因此本项目的目标是开发一种合成聚合物网络的新概念，该聚合物网络在室温以上的某个阈值温度下保持无定形，并在机械变形下自发结晶。这可以通过一种非晶聚合物和一种能够结晶的聚合物共交联来实现，由此所使用的聚合物表现出显著的部分混溶性，例如，与含有羰基和聚偏氟乙烯（PVDF）的聚合物。在第一步中，寻找一种适合化学交联的反应，它实际上连接了两种聚合物，以便随后研究聚合物的稳定或亚稳混溶性以及它们的热或应变诱导结晶能力作为组成和交联程度的函数。基于所获得的知识，期望实现稳定在非晶态，能够自发应变诱导结晶，并具有无限冲击和能量吸收能力的弹性体。

Crystallizable, amorphously quenched polymer networks, which spontaneously crystallize in a strain-induced manner upon shock loading, possess enormous shock and energy absorption capability. However, since this ability is lost after a short time due to the onset of thermal crystallization, the objective of this project is to develop a novel concept for the synthesis of polymer networks that remain amorphous up to a certain threshold temperature above room temperature and spontaneously crystallize exclusively under mechanical deformation. This is to be achieved by co-crosslinking an amorphous polymer and a polymer capable of crystallization, whereby the polymers used exhibit significant partial miscibility, as is the case, for example, with polymers containing carbonyl groups and polyvinylidene fluoride (PVDF). In the first step, a suitable reaction for the chemical crosslinking is searched, which actually connects both polymers, in order to subsequently study the stable, or metastable miscibility of the polymers and their thermal, or strain-induced crystallization ability as a function of composition and degree of crosslinking. Based on the knowledge gain, the realization of an elastomer stable in the amorphous state, capable of spontaneous strain-induced crystallization, and possessing indefinite shock and energy absorption capability is expected.