Starch-filled polyolefins

Another approach to improving the properties of starch-filled polyolefin materials involves the use of ethylene-acrylate copolymers in blends with PE.45 Addition of copolymers of ethylene with methyl acrylate, ethyl acrylate or butyl acrylate were shown to improve the properties of PE films, allowing for higher starch contents. Coextrusion of starch-containing films with outer layers incorporating oxidative pro-degradants has also been utilized 46 The inner layer can contain up to 40% starch the... 

Thermoplastic starch alone can be moulded as traditional thermoplastic materials its sensitivity to humidity, however, makes it unsuitable for most applications. Starch-filled degradable polyolefins show good disintegration properties. There is no evidence, however, of a significant biodegradation of the fragments produced by disintegration. 

Starch in granular state has been used as filling agent for polyolefin and as a component in synthetic polymer blends. In such cases, a small amount of starch (6-30%) is blended with synthetic polymers like polyethylene (PE) or polypropylene (PP), increasing the products biodegradability (Evangelista et al, 1991 Bagheri, 1999). 

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