Study On The Properties And Technology Of Devulcanized Epdm Rubber By Microwave

Microwave devulcanization method is an efficient, energy-saving and environmentally friendly rubber recycling methods, microwave devulcanization method will have broad prospects for development. Microwave devulcanization method had used to prepare r-EPDM. The performance of microwave devulcanized rubber and traditionally prepared recycled rubber were compared, and devulcanization process, factors that affect devulcanization, devulcanization mechanism, and performance of recycled rubber were studied.By exploring microwave devulcanization process under laboratory conditions, find that temperature has an important influence on the effect of devulcanization. The effective devulcanization temperature of EPDM is160℃, the optimal devulcanization power is700W, and the optimal time is16min, the highest temperature is about280℃, the optimal parts of incorporated recycled rubber were20parts.Effects of plasticizer on devulcanization differ at different stages, In the early stage of devulcanization, due to the polarity of plasticizer, it will accelerate the warming process of devulcanization rubber powder. In the late stage of devulcanization, plasticizer was thermally volatileed, and the reaction rate is reduced.Perform the microscopic characterization of rubber powder before and after devulcanization, and find that radicals generating from the breakage of chemical bond of rubber powder will be combined with oxygen to generate a new oxygen-contain ing groups at high temperature, the higher the temperature, the higher the content of oxygen-containing groups; With the recycled rubber surface contact angle increases, the hydrophilicity become poor; With the Tg of rubber powder increases, the tangent of loss angle increases; The presence of oxygen will reduce the performance of powder. In the next production, oxygen should be avoided to reduce the effect on the devulcanization regeneration.The design of the microwave devulcanization equipment were participated in, and find that temperature measurement and control device, stirring device and sealed device should add to the microwave devulcanization equipment, as compared to ordinary microwave oven. The devulcanization process in microwave devulcanization equipment was studied. The optimal devulcanization process parameters are as folows:the rubber powder filling volume is5kg, the stirring speed is60r/min, the secondary intermittent devulcanization was used, the desulfurization temperature is about240℃each, and the optimal parts of blended recycled rubber filling is15parts.