Tensile rupture of short fibre filled thermoplastic elastomer

Abstract

Tensile rupture in short silk fibre filled thermoplastic elastomer blends from low-density polyethylene and natural rubber (NR) containing pre-cuts of different lengths has been studied.σ _b, the tensile strength of the blends, was found to decrease with increase in the cut length in accordance with the Griffith's theory of fracture. However, unlike in the case of vulcanized NR, no critical cut length (at which the strength drops abruptly) was found in the case of both blends and unvulcanized NR. The energy to fracture per unit volume,W _b, also varied inversely with the length of the pre-cut. Values of inherent flaw size,I _O, of the composites, determined by extrapolation ofW _b to the value obtained when no initial pre-cut was present, were found to increase with fibre loading. Blends with longitudinally oriented fibres showed higherI _O values than those with transversely oriented fibres.