Investigation of the rubber elasticity and properties of polyurethane elastomers with different silicon carbide contents

Abstract

Silicon carbide (SiC) powder was added to a polyurethane elastomer (PUR) to produce the composites. PUR was synthesized by mixing polyether polyol (PETP, Mw = 6000 g/mol) and 4,4′diphenylmethane diisocyanate. The stress-strain curves were carried out to estimate the effect of SiC on rubber elastic behaviour of PUR composites. As SiC content increases, the rubber elasticity region is noticeably decreased which can clearly be seen in the stress-strain curve, this could be attributed to the distribution of the SiC particles in the PUR matrix which prevents the cross-linking chain mobility of PUR and therefore affects the deformation while stretching. Furthermore, the decrease in the elongation at break is also co-related to the SiC content which hindrance the molecular mobility of the PUR chain. Shore A and D hardness increase by increasing SiC content up to 88 Shore A and 37 Shore D at 30 wt.% SiC. This is mainly due to the addition of SiC particles which act as active fillers in PUR matrix. The tensile strength and Young's modulus are slightly increased when SiC content was increased. These observations support that Sick particles act as reinforcement which is active fillers and affect the stiffness in the elastic deformation of PUR.