Development of potentially biodegradable polyamide-6 and polyvinyl alcohol blends: Physico-mechanical properties, thermal properties, and soil test

Blends of polyamide-6 with 5,7.5,10,15, and 20 wt % of polyvinyl alcohol (PVA) were prepared by the extruding in a corotating twin-screw extruder. The extrudate strands were cut into pellets and injection-molded to make test specimens. These specimens were tested for physico-mechanical properties such as tensile strength, impact strength, density, water absorption, hardness, and thermal characteristics by differential scanning calorimetry, heat distortion temperature (HDT), vicat softening point (VSP), and melt flow index. The prepared blends show enhanced biodegradation, water absorption, and density, but it is observed that the introduction of PVA into the polyamide-6 matrix shows considerable reduction in tensile strength, impact strength, HDT, VSP, and hardness initially, but subsequent addition does not show significant reduction because of the enhanced interaction between amide groups of polyamide-6 and hydroxyl groups of PVA. (c) 2005 Wiley Periodicals, Inc.