Commodity thermoplastics, degradability

High molecular weight polyethylene is virtually nonbio-degradable. Being a commodity thermoplastic widely used in disposable packaging and consequently a very visible component of urban litter, there is interest in rendering the material environmentally biodegradable. 

Shebani et al. [20] noted that removing extractives improved the thermal stability of different wood species. Therefore, using extracted wood for the production of wood-plastic composite (WPCs) would improve the thermal stability of WPCs. Because wood and other bio-fibres easily undergo thermal degradation beyond 200°C, thermoplastic matrix used in the composites is mainly limited to low-melting-temperature commodity thermoplastics like polyethylene (PE) and polypropylene (PP). However, the inherently unfavourable thermomechanical and creep properties of the polyolefin matrix limit some structural applications of the materials. 

This was followed by the results of a number of case studies of exposure on a variety of materials including wood-plastic composites, polymer sport field coverings, and subcomponent systems common to photovoltaic panels. Degradation of commodity thermoplastic and thermoplastic systems was also presented. 

Polylactic acid or polylactide (PLA) is a thermoplastic aliphatic polyester that can be derived from renewable resources, such as corn starch or sugarcanes. Although PLA has been known for more than a century, it has become of great commercial interest in recent years because of its renewability and degradability to natural metabolites. In addition, the properties of PLA can be varied over a wide range which makes it suitable to be used as a substitute to many petroleum based commodity plastics, such as polyolefins,... 

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