Environmental-Stress Crazing and Cracking of Poly(methyl Methacrylate) Poly (Vinylidene Fluoride) Blends

摘要

The tensile properties of miscible blends of poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride) (PVF2) were determined in air. These results were interpreted in terms of the plasticization caused by adding PVF2 to PMMA and the crystallinity of the blends. Strength exhibits a minimum, and elongation at break shows a maximum as a function of blend composition because of the competition between these two effects. The critical strain for the development of crazes or cracks was determined for blends in the presence of seven different liquids by using a Bergen strain jig. For all liquids, this threshold strain or stress increased dramatically as the PVF2 content of the blend increased. Keywords: Chemical resistance.