Processing and characterization of LDPE/starch products

Abstract

Low-density polyethylene/plastisized starch blends varying in starch content were processed by conventional extrusion, injection-molding, and film-blowing techniques. Polyethylene-g-maleic anhydride (PE-g-MA) was used as a compatibilizer. X-ray diffraction was used to investigate starch destructurization during extrusion and on subsequent processing. The effect of starch content on the blends was evaluated by mechanical property measurement and scanning electron microscopy. Starch, except for being a biodegradable material, can also act as a reinforcing agent. The reinforcing effect of starch was only realized in injection-molded materials. Processing–structure–property relationships could explain this behavior. The present study also brought out the effect that the degree of molecular orientation existing in a polymeric matrix may have on the coupling performance of an adhesion promoter. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2548–2557, 2001