Preparation And Properties Of SBR Matrix Composite Foams

Polyurethane(PU)and ethylene/vinyl acetate copolymer(EVA)are widely used to foam material matrix due to the high performance of PU foam material and low cost,respectively.However,the process PU foam need to use prepolymers containing isocyanate as the raw material for liquid foam,raw material is toxic and volatile cause air pollution and expensive.The properties of EVA foamed materials are poor and the production cost is high.Therefore,it is important to prepare a foamed materials with the high performance,price cheap and high universality.The rubber foamed materials are widely used to shock absorption,sound insulation,heat preservation and other fields due to the excellent performance.However,the rubber foams were less application in foams mainly because of the big Mooney viscosity and high shrinkage which lead to reduced yield and increase production cost.The low Mooney viscosity,low shrinkage and shrinkage control of SBR/EVA foam rubber composite materials were prepared using industrial styrene butadiene rubber(SBR)and EVA by mechanical melt blending method in this work including the following contents:(1)The formula of SBR foams were studied by the method of orthogonal experiment design and single factor design.The effect of the foaming agent,cross-linking agent and adding additives content on the physical and mechanical properties of the SBR foams was discussed.Scanning Electron Microscopy(SEM),Fourier Infrared Spectrometer(FTIR),Differential Scanning Calorimetry(DSC),Raman Spectroscopy were used to analyze the effect mechanism of the synergy of double cross-linking agents(S and DCP)on the decreasing of Mooney viscosity and shrinkage for the SBR foaming materials.The results showed that the SBR foaming materials Mooney viscosity and shrinkage were23.4 and 2.25%,respectively.At the same time,the tensile strength,elongation at break and tear strength of SBR foams increased to 3.475 MPa,54.63 N/mm and1.78 × 103%,respectively.(2)The SBR/EVA blend matrix was prepared by mechanical melt blendingmethod.The compatibility of SBR/EVA blend matrix and vulcanizing properties were characterized by SEM,FTIR,DSC and Rheometer,respectively.The results showed that the compatibility of SBR and EVA increased as the VA content increasing mainly because of the lively hydrogen atoms on the SBR molecular chains and the carboxyl oxygen on the EVA molecular chains.(3)EVA/SBR foams were prepared by moulding method,the effect of EVA content on the morphology,shrinkage and the stability of shrinkage of EVA/SBR foams were studied.The alternately cross-linking process between SBR and EVA in the conditions of S and DCP cross-linking existent and the support role of EVA in the composite system were analyzed.