用于动态硫化热塑性弹性体的Janus粒子增容剂的设计制备及机理研究

Thermoplastic elastomers prepared by dynamic vulcanization (TPV) of non-polar rubber and polar plastics, such as isobutylene-isoprene rubber / nylon (IIR/PA), silicon rubber / nylon (SiR/PA), silicon rubber / thermoplastic polyurethane (SiR/TPU), are suitable for the applications of innerliner of tire treads, automotive and oil pipeline, and wearable device due to their excellent gas barrier properties, oil and heat resistance, comfortable body touch and good wear resistance. However, as the poor compatibility between non-polar rubber and polar plastic, the development of new compatibilization method is necessary to prepare TPV with small phase size and high performance. In this project, we modified the snowman-like Janus particles with PA, PU, SiR, and IIR polymer chains of different lengths and polarities via thiol-alkene and azido-alkyne click reactions, then used the obtained Janus particles as compatibilizers to study their compatibilizing effects on incompatible composite of IIR/PA, SiR/PA, and SiR/TPU. The relationship between the compatibilizing effect of Janus particle compatibilizers and the structural parameters such as the length, polarity, and grafting density of the polymer brushes on the surface of the Janus particles was also investigated, and then the compatibilizing mechanism of Janus particles on polymer incompatible composites was clarified. Moreover, the effect of the compatibilizing effect on the phase structure of IIR/PA, SiR/PA, and SiR/TPU TPV materials was also studied to prepare TPV materials with small phase size and high performance.

丁基橡胶/尼龙（IIR/PA）、硅橡胶/尼龙（SiR/PA）和硅橡胶/热塑性聚氨酯（SiR/TPU）等动态硫化热塑性弹性体（TPV），由于具有优异的耐油性、耐热性、耐磨性等特性，吸引了人们的广泛关注。由于非极性橡胶和极性塑料之间相容性较差，发展新型增容技术解决二者的相容性是制备具有精细相态结构高性能TPV的前提。本项目基于已经量产的雪人状Janus粒子，分别利用巯基-烯烃和叠氮-炔烃的点击反应，将具有不同长度和极性的聚合物链段引入到Janus粒子的两面，并以其为增容剂，研究其对IIR/PA，SiR/PA，SiR/TPU等不相容共混体系的增容效果，揭示了Janus粒子增容剂的增容效果与其结构参数之间的关系，阐明增容机理，并研究上述增容效果对动态硫化IIR/PA、SiR/PA和SiR/TPU热塑性弹性体的相态结构的影响，调控以获得精细相态结构的TPV材料。

极性聚合物与非极性聚合物构成的不相容体系的共混是使聚合物复合材料兼具各组分的特性，产生优异综合性能的重要途径。如何提高两相的相容性，获得精细的相态结构，提高界面作用力是一些共混材料，如特种热塑性动态硫化胶（TPV）的制备过程中所需解决的重要问题。本项目基于雪人状Janus粒子，在其两端分别接枝非极性的聚硅氧烷（PDMS）链段，以及极性的聚氨酯（PU）、聚己内酯（PCL）、尼龙（PA）链段，开发了一系列具有两亲性Janus结构的增容剂，用于增容甲基乙烯基硅胶/聚氨酯（MVQ/TPU），甲基乙烯基硅橡胶/聚己内酯（MVQ/PCL），甲基乙烯基硅橡胶/尼龙（MVQ/PA）构成的不相容体系，获得了比传统增容剂更精细的相态结构，同时所得相态稳定，退火处理后不易聚并。通过调控Janus粒子增容剂表面聚合物链段的长度、极性、接枝密度等因素，揭示了Janus粒子增容剂的增容机理，以及其用于聚合物不相容共混体系增容时增容效果的影响因素。最后，基于已获得的Janus粒子增容剂的增容效果影响因素，设计合成合适结构的Janus粒子增容剂，通过动态硫化制备SiR/TPU TPV,所得热塑性弹性体具有精细的相态结构（SiR分散相尺寸约为2.5μm）。同时，通过结构调整，本项目中的Janus粒子增容剂还可用于功能性弹性体的制备，获得具有形状记忆特性和自修复特性的弹性体材料。本项目的研究从理论上指导了基于Janus粒子的增容剂的结构设计与合成，同时也为不相容共混体系的理想增容剂的开发提供了理论指导。