Extrusion-blown films from graft polymers prepared from cereal flour

摘要

Moisture-shrinkable films can be extrusion blown from flour-poly(methyl acrylate) graft copolymers. The films shrink when exposed at room temperature to relative humidities approaching 100%. The films have potential application in shrink-wrapping irregularly shaped articles without application of heat. Easy removal of the films by water washing is another feature suitable for this use. This invention allows the use of unmodified cereal flour in lieu of gelatinized starch as the substrate for graft polymerization. This substitution greatly simplifies the preparation and isolation of the graft copolymers and reduces the expense of the process by lowering raw material costs.