Environmental Effects on the Properties of Biopolymer Service-ware Products

Abstract

The current trend towards sustainability has promoted a new interest in biodegradable plastics. Although there have been many studies on the behavior of biodegradable plastics, the changes in properties that may occur during use have not been fully documented. The mechanical properties of seven commercial service-ware items produced with biodegradable plastics were analyzed in this investigation. The effects of UV exposure, humidity, and accelerated aging on the mechanical properties were studied. In general, samples from polylactic acid and wheat straw had properties comparable to traditional synthetic plastics used in this application. However, the strength of other polymers such as bagasse, fiber pulp and potato starch was less than that of comparable synthetic plastics. The mechanical properties of the biopolymers generally deteriorated significantly upon exposure to UV radiation and humidity, with polylactic acid, wheatstraw, potato starch, and the bamboo bulrush wheatstraw blend being affected the most. Accelerated aging data indicate that after 6 months under ambient conditions, the potato starch, wheatstraw, and bamboo bulrush wheatstraw blend have a significant reduction in strength and modulus. In general, the thermal analysis behavior of most of the plastics was similar indicating a major weight loss of about 69–97% over a temperature range of 250–400⁰C. Additional improvements may be necessary to increase the environmental resistance of these biopolymers so that they can be effective replacements for traditional plastics.