Wu Qiang, Fang Jiafeng, Zheng Minghuan, Luo Yan, Wang Xu, Xu Lixin, Zhang Chunhui
College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
College of Engineering, Zhejiang A&F University, Hangzhou, 311300, China.
Polymers (Basel). 2019 Jan 19;11(1):175. doi: 10.3390/polym11010175.
The thermoplastic vulcanizates (TPVs) of polypropylene (PP)/silicone rubber (SR) were prepared by dynamic vulcanization (DV) technology. The mixing torque, morphology, viscoelasticity, and creep response of PP/SR TPVs were investigated by torque rheometer, scanning electron microscope (SEM), transmission electron microscope (TEM), rotational rheometer, and dynamic mechanical analysis (DMA). A mixing-torque study showed that torque change and dynamic-vulcanization time increased with SR content increasing in the DV process, but DV rate was independent of SR content. TEM images indicated that the phase inversion of PP/SR-60 TPV from bicontinuous to a sea⁻island structure took place in the DV process, and a hot press would break the rubber aggregates and shrink a large SR phase. Dynamic-strain measurement demonstrated that PP/SR TPVs exhibit a distinct "Payne effect", which can be attributed to the destruction and reconstruction of SR physical networks. Complex viscosity indicated that SR content did not affect the processability of PP/SR TPVs at high shear rates. Furthermore, the creep deformation and recovery of PP/SR TPVs at solid and melt states were studied, respectively.
采用动态硫化（DV）技术制备了聚丙烯（PP）/硅橡胶（SR）热塑性硫化胶（TPV）。通过转矩流变仪、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、旋转流变仪和动态力学分析（DMA）研究了PP/SR TPV的混合转矩、形态、粘弹性和蠕变响应。混合转矩研究表明，在DV过程中，转矩变化和动态硫化时间随SR含量的增加而增加，但DV速率与SR含量无关。TEM图像表明，PP/SR-60 TPV在DV过程中发生了从双连续结构到海岛结构的相转变，热压会破坏橡胶聚集体并使大的SR相收缩。动态应变测量表明，PP/SR TPV表现出明显的“Payne效应”，这可归因于SR物理网络的破坏和重建。复数粘度表明，SR含量在高剪切速率下不影响PP/SR TPV的加工性能。此外，还分别研究了PP/SR TPV在固态和熔融态下的蠕变变形和恢复情况。
