Ethylene-propylene-diene monomer rubber (EPDM)-based ground wastes (W-EPDM) are reutilized as rubber matrix in plug material compounds for automotive applications. Production scraps of target product are ground to 35, 40 and 60 mesh in ambient conditions. Effect of particle size and the amount of W-EPDM is studied. A new trial product of maleated ethylene-propylene rubber (EPM) and bitumen are used to improve interphase adhesion of the waste and the virgin EPDM. Cure characteristics, physico-mechanical and aging properties of all compounds are determined. Micro structure of the vulcanizates is studied for explaining dispersion and interaction between different phases. Reutilization of W-EPDM causes some reasonable deterioration in cure characteristics and mechanical properties of the product. However, some systematic and alternative recipes for plug materials are suggested considering cost and environmental benefits.

The effects of epoxidized natural rubber (ENR) and maleic anhydride-grafted polybutadiene (PB-g-MA) as compatibilizers to rubber formulations with and without organo-modified layered silicates are investigated. The physical properties and curing characteristics of composites are studied by moving die rheometer, rubber process analyzer, tensile, tear, and hardness testing. The state of organoclay intercalation was determined by X-ray diffraction method. The addition of compatibilizers, especially ENR 50, results in further intercalation or exfoliation of the organoclay that increased the clay dispersion in the rubber matrix. ENR 50 with organo-modified clay improves the physical properties and changes the curing profile. The addition of PB-g-MA without organoclay increases the tensile strength (r max ) by increasing the stock viscosity of the rubber compound. Interestingly, simultaneous increase in hardness and r max is achieved in the presence of both compatibilizers, a characteristic that is difficult to achieve and sometimes required in rubber processing. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: [1530][1531][1532][1533][1534][1535] 2011