Dynamically vulcanized thermoplastic elastomer blends of natural rubber and polypropylene

摘要

Dynamic vulcanization of a soft grade of thermoplastic natural rubber (TPNR) was carried out using several concentrations of Hexamethylene N,N' bis (tert-butyl peroxy carbamate) (HBTP).The blends were melt mixed in a Brabender plasti-corder.The effectiveness of dynamic vulcanization was investigated using the Brabender plastograms,swelling index measurements,rheological behavior by means of a capillary rheometer,dynamic mechanical properties,and tensile testing.It was found that varying the HBTP concentration had a great influence on the rheological behavior as well as the dynamic and tensile properties of the material.The increase of HBTP dosage resulted in an increase of the extent of crosslinking and caused an increase of the elastic modulus and a reduction of the loss modulus.The ultimate tensile strength and elongation at break also increased with increasing HBTP loading.The rheograms indicated that the blends exhibit a pseudoplastic behavior.