Thermo-responsive shape memory behavior of co-crosslinked VMQ/POE blends
Co-crosslinked methyl vinyl silicone rubber/polyolefin elastomer(VMQ/POE)blends with thermos-responsive shape memory properties were obtained by mechanically blending and chemically crosslinking VMQ with POE.The shape memory properties of the VMQ/POE blends were determined by crosslinking,crystallization and melting.Among them,the degree of crosslinking had a significant effect on crystallization and melting.In this paper,the influence of crosslinking agent on the vulcanization characteristics as well as the thermal,tensile,and bending shape memory properties of the blends was analyzed emphatically.The results showed that the vulcanization curve of the blends with crosslinking agent displayed typical vulcanization characteristics,such as scorch,thermal vulcanization and flat vulcanization,and the crosslinking rate and gelation rate of the blends increased with the increase of crosslinking agent content.Under the same tensile stress load,the maximum strain value and fixed rate of the blends gradually decreased,while the recovery rate increased first and then decreased with the increase of crosslinking agent content.The blends exhibited well cyclic tensile shape memory stability.The maximum strain and fixation rate of the blends did not change obviously,while their recovery rate increased significantly.Under the same bending stress,the fixation angle,recovery angle and recovery rate of the blends all increased with the increase of crosslinking agent content.Comparatively,when crosslinking agent content was between 0.5～1.0phr,the blends had better tensile and bending shape memory performance.
万方数据
维普
