Milled Glass Fiber Filled-Poly(Ethylene Terephthalate-co-Isophthalate) Composites - Thermal and Mechanical Properties

Abstract

Fracture and thermal behavior of injection-molded poly (ethylene terephthalate-co-isophthalate) filled with milled glass fiber has been studied as a function of fiber content in the range 0-40% by weight. Composite Young's modulus and tensile strength increased with fiber percentage, and good agreement was found with theoretical predictions. Low rate fracture tests were carried out on injection-molded SENB specimens. Fracture toughness ( K ic ) and fracture energy ( G ic ) could be obtained by applying Linear Elastic Fracture Mechanics (LEFM). Results seemed to indicate improved fracture toughness if compared with homopolymer poly (ethylene terephthalate) composites. The reason was attributed to a lower crystallinity developed in the matrix, which promoted higher plastic strain.