Study on Microstructure, Rheological, and Mechanical Properties of Cellulose Short Fiber Reinforced TPVs Based on EPDM/PP

The morphology, rheology, and mechanical properties of the dynamically vulcanized thermoplastic elastomer based on EPDM/PP (60/40, w:w) containing 5, 10, and 20% of cellulose short fiber were studied. From the results it was found that addition of 5% of cellulose fiber has no significant effect on the maximum torque associated with the dynamic vulcanization stage, while higher concentration of fibers decreased the maximum torque. These results were explained in terms of influence of cellulose fibers on the extent of agglomeration formed between the cured rubber particles. The results of tensile test performed on the samples showed that incorporation of 5% of cellulose fibers into the sample has an increasing effect on elongation at break with no appreciable change in tensile behavior. However increasing the cellulose fibers content of the sample to 20% had a remarkable change in tensile properties of the sample resulting in a toughened plastic type behavior. The melt elasticity of the sample containing 5% of cellulose fibers particularly at low shear rate range was found to be lower than that of the sample without fibers indicating the role of fibers in weakening of cured rubber particle agglomeration. This was supported with the results of the relaxation time distribution HQ) and scanning electron microscopy of the samples. POLYM. COMPOS., 30:182-187, 2009. (C) 2008 Society of Plastics Engineers