Effect of Silica and Silane Coupling Agent on Mechanical Properties and Failure Modes of Blends of Plasticized Poly (Vinyl Chloride) and Copolyester Thermoplastic Elastomer

摘要

Mechanical properties and failure modes of blends of plasticized poly (vinyl chlroide) and copolyester thermoplastic elastomer have been studied with special reference to the effect of blend ratio, addition of silica filler and coupling agent. Incorporation of silica filler increases the hardness, modulus and tear strength of the blends. Tensile strength, elongation at break, impact strength and tensile set decrease with the addition of silica filler. Addition of small amount of coupling agent (1.5phr) along with the filler reduces the viscosity of the system. This enables economic processability. Moreover, the coupling agent marginally increases the physical properties such as tear resistance, tensile strength, elongation at break and impact strength of the filled systems. The effect of silica on the crystallinity of the samples has been investigated by X-ray diffraction studies. In order to study the mechanism of failure, tensile and tear failure surfaces have been examined by scanning electron microscopy and it was found that the fractographs depend on the type of failure, blend ratio, presence of filler and coupling agent.