Thermoplastic elastomers from blends of polystyrene and natural rubber: morphology and mechanical properties

Thermoplastic elastomers (TPEs) from blends of natural rubber and polystyrene (NR/PS) have been prepared. Morphology and properties of these blends have been studied with special reference to the effect of blend ratio, processing conditions and vulcanising systems. The mechanical properties and morphology of the blends are dependent on the processing conditions, i.e, whether the samples are prepared by the melt mixing technique or by the solution casting technique. Three different solvents namely chloroform, benzene and carbon tetrachloride were used as the casting solvents. Differences in mechanical and morphological properties were observed in each case which in turn depend upon the interaction of the solvent with the constituent homopolymers. Attempts have been made to correlate the morphology with properties, Experimental values were compared with different theoretical models, The effects of dynamic crosslinking using sulphur, peroxide and mixed systems on morphology and mechanical properties of NR/PS blends have also been studied. (C) 1998 Elsevier Science Ltd. All rights reserved.