Submitted to: Materials Research Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/8/1996
Publication Date: N/A
Technical Abstract: A loose-fill foam packaging material has been developed from starch graft poly(methyl acrylate) and its physical and biodegradable properties have been characterized. An innovative graft polymerization process allowed complete conversion of methyl acrylate into low percentage graft copolymers. The optimization of the chemical reaction conditions produced foam material having high molecular weight graft copolymers and low content methyl acrylate homopolymer. Such materials exhibited considerably improved performance following mechanical processing. Both single and twin screw extruders were used for the resin compounding and loose-fill foam processing. A homogeneous phase was observed for starch graft poly(methyl acrylate) resin pellets indicating that graft copolymer has excellent compatibility. Compared to twin screw extruder, single screw extrusion produced foam of much smaller cell size and lower density. The resilience range (63-71%) of this product tested under wide variety of humidity and temperature conditions suggested their suitability as packaging materials. Biodegradation studies were also conducted to characterize the biodegradable performance of these foams. Initial data indicated a rapid degradation of starch portion of the matrix, whereas, poly(methyl acrylate) remains relatively stable.