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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Plant Polymer Research » Research » Publications at this Location » Publication #92138
Title: PREPARATION AND PROPERTIES OF STARCH-POLYESTER LAMINATE SHEETS BY COEXTRUSION

Author
item WANG, LINFU - JESSUP, GA
item Shogren, Randal
item Carriere, Craig

Submitted to: Annual Meeting of the Bio Environmentally Degradable Polymer Society
Publication Type: Abstract Only
Publication Acceptance Date: 8/22/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: An inherent problem with the use of starch based polymers as biodegradable plastics is their sensitivity to water. One approach toward solving this problem is to laminate thermoplastic starch with water-resistant, biodegradable polyesters. We prepared 3-layer polyester/starch/ polyester sheets using a twin-screw extruder for the starch/water center layer, a single screw extruder for the outer polyester layers, and a feedblock and coathanger type sheet die. The effects of processing conditions, molecular weight, and type of polyester and addition of plasticizer to starch on the coating uniformity and peel strength were studied. Uniformity in overall sheet and coating thickness improved as coating polymer poly(epsilson- caprolactone), (PCL) viscosity decreased, starch melt viscosity increased (lower moisture) and extrusion temperature increased. Peel strengths increased with increased PCL molecular weight and lower extrusion temperatures. Peel strengths were correlated with roughness of the interface. Addition of plasticizer such as glycerol or sorbitol to the starch decreased peel strengths. Peel strengths also varied with the type of polyester coating. Some possible applications of laminated starch sheets include food packaging and controlled release of drugs, pesticides, insect diets, etc.