Extrusion of Thermoplastic Starch: Effect of “Green” and Common Polyethylene on the Hydrophobicity Characteristics

Muhammad Pervaiz^1,2*, Philip Oakley^1,3, Mohini Sain^1,4,5

¹Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada.
²GreenCore Composites Inc., Sarnia, Canada.
³The Delphi Group, Ottawa, Canada.
⁴Centre of Advanced Chemistry, King Abdulaziz University, Jeddah, KSA.
⁵Mechanical Engineering Department, Luleå University of Technology, Luleå, Sweden.

DOI: 10.4236/msa.2014.512085                

Abstract

Novel plastics that are biodegradable, environmentally benign, and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this research work was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. With a recent emergence of “green” polyethylene (GPE), sourced from renewable feedstock, it has become possible to develop novel biodegradable polymers for various applications. In this work, GPE was melt blended with starch in three different ways; reactive extrusion of GPE and starch facilitated by maleic anhydride (MAH) and dicumyl peroxide (DCP), melt blending of GPE and starch by extrusion, and melt blending of maleated polyethylene and starch by extrusion. Comprehensive testing and analysis has shown that all methods reduced water absorption significantly with some variations across the board.

Keywords

Biopolymers, Thermoplastic Starch, Biodegradable, Green Polyethylene, Hydrophobic, Water Absorption, Melt-Blending of Starch, Renewable Resources

Conflicts of Interest

The authors declare no conflicts of interest.

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