It is still a great challenge to mimic the structure and function of natural rubber by introducing polar components into synthetic polyisoprene. In order to explore the function of phosphate groups on the mechanical properties of polyisoprene rubber, a terminally functionalized compound (PIP-P) containing phosphate groups was synthesized and further vulcanized to prepare the model compound V-PIP-P. Through analyzing the test results, it was found that these phosphate groups formed polar aggregates in non-polar polyisoprene rubber matrix, serving as an additional dynamic cross-linking sites, which increases the cross-linking density and improves mechanical properties. The influence of the phosphate groups on the strain-induced crystallization (SIC) was further investigated via synchrotron wide-angle X-ray diffraction (WAXD) experiment. These phosphate group aggregates not only reduced the onset strain of SIC, but also slowed down the molecular chain mobility, which hinder the crystal lateral growth. The above results help us to gain a deeper understanding for the function of phosphate groups in the formation of “naturally occurring network” and guide the molecular design of next generation polyisoprene rubber.

通过将极性组分引入合成聚异戊二烯来模仿天然橡胶的结构和功能仍然是一个巨大的挑战。为了探索磷酸酯基团对聚异戊二烯橡胶的机械性能的作用，合成了具有磷酸酯基团的末端官能化化合物（PIP-P），并进一步硫化以制备模型化合物V-PIP-P。通过分析测试结果，发现这些磷酸酯基团在非极性聚异戊二烯橡胶基质中形成极性聚集体，作为附加的动态交联位点，从而增加了交联密度并改善了机械性能。磷酸基团对应变诱导结晶（SIC）的影响进一步通过同步加速器广角X射线衍射（WAXD）实验。这些磷酸基团聚集体不仅降低了SIC的起始应变，而且减慢了分子链的迁移率，从而阻碍了晶体的横向生长。以上结果有助于我们更深入地了解磷酸基团在“天然网络”形成中的功能，并指导下一代聚异戊二烯橡胶的分子设计。