Preparation And Structure And Property Of Thermoplastic Elastomer Blends

Thermoplastic elastomer (TPE) is a kind of polymer materials which has the properties of rubber elasticity and thermoplastic plastic. In order to obtain polymer materials with better comprehensive properties to meet the requirements of application, more and more researches on TPE modified were performed in recent years, among which the blending modification of TPE is the most used method. In this thesis, thermoplastic elastomer blends were prepared using acrylates TPE(AC-TPE) and styrene type TPE(TPES) as main raw material via hot melt blending and the structure and property were investigated.This thesis consists of four parts.Part One, the influence of processing parameters on the mechanical properties of AC-TPE/TPES/SEBS-g-MAH ternary blends. A series of AC-TPE/TPES/SEBS-g-MAH ternary blends were prepared in different processing parameters and their mechanical properties were studied to determine the optimal processing parameters. The results showed that when the mixer temperature was175-185℃, mixer time was lOmin, press molding time was10min, molding temperature was155-165℃and molding pressure was8MPa, the blends had the optimal mechanical properties.Part Two, AC-TPE/TPES binary blends were prepared through hot melt blending. The properties of blends were investigated. The results showed that AC-TPE/TPES was immiscible blend system. With the increase of TPES, the tensile strength and elastic modulus of the blends decreased and breaking elongation increased significantly. With low content of TPES, the blends formed a "sea-island structure" and AC-TPE for continuous phase, and TPES for dispersed phase. When the TPES’s content is close to AC-TPE’s content, the blends formed a bicontinuous phase structure; with high content of TPES, the blends formed a "sea-island structure" and TPES for continuous phase, and AC-TPE for dispersed phase. Blend damping suspension performance was enhanced, especially in the ratio of AC-TPE/TPES=1:1, damping suspension performance was greatly improved. Heat-resisting performance of blends was enhanced with the increase of TPES.Part Three, AC-TPE/TPES/SEBS-g-MAH ternary blends were prepared and their properties were investigated. EVA-g-MAH and SEBS-g-MAH were added to AC-TPE/TPES blends as compatilizers. The characteristic peaks of AC-TPE and TPES shifted and the size of phase seperation reduced obviously compared to binary blends; split phase changed with the relative amount of AC-TPE and TPES, and the compatilizers were wrapped around the dispersed phase playing a role of bridge to connect dispersed phase and continuous phase. SEBS-g-MAH is better than EVA-g-MAH for AC-TPE/TPES blend system.Part Four, AC-TPE/TPES/SEBS-g-MAH/CaCO3/silane coupling agent blends were prepared and their properties were investigated. The results indicated that the addition of CaCO3could significantly improve the rigidity of AC-TPE/TPES/SEBS-g-MAH ternary blends. But the reinforcing and toughening effects of CaCO3were not enough to offset the internal defects, so the mechanical properties declined. With the addition of silane coupling agent, mechanical performance of doping CaCO3materials was improved, and silane coupling agent with long chains and amphiphilic structure had better compatibility with the blends. KH-570is better than AC-76.