MSU Researchers Create Improved Nanocomposite Biodegradeable Film for Packaging

“Green” biobased polymer-clay nanocomposite packaging technologies with improved oxygen and moisture barrier properties have been developed by Michigan State University (MSU) (East Lansing, MI) researchers. Amar K. Mohanty, Yashodhan Parulekar, Mariappan Chidambarakumar, Napawan Kositruangchai and Bruce R. Harte created biodegradable polymeric nanocomposite compositions that are particularly useful for food packaging. The compositions are comprised of three materials: a biobased biodegradable polymer of polylactic acid (PLA) or polyhydroxybutyrate (PHB), a petroleum-based biodegradable polymer (poly-(butylene adipate-co-terephthalate) (PBAT), and a fatty acid triglyceride quaternary ammonium salt modified nanoclay which together yield a high-barrier, biodegradable material for packaging. The composition is formed by reactive blending, particularly extrusion, according to U.S. Patent 7,619,025.

Blending a biobased biodegradable polymer and a petroleum-based biodegradable polymer creates a material with high bio-content to satisfy environmental and sustainability issues. High/good barriers are achieved by adding a nanoclay, but improvements are only achieved if optimum dispersion and compatibility are created. Clay is inherently hydrophilic and hence does not mix with the organic polymer matrix. This leads to agglomeration and poor properties and this has to be overcome by specifically modifying the clay surface. Performance limitations and high cost however, have limited these biopolymers and biodegradable polymers to niche markets. Nano-reinforcements of such materials with specific organoclays create new value-added applications and lead to more usage, which will subsequently reduce the cost.

The specific organic modified clays are synergistic to the enhancement of barrier properties. The multilayer plastic films currently used for gas and water vapor barrier purposes can thus be replaced by a monolayer of plastic nanocomposite film.

The total nano-enabled food and beverage packaging market in the year 2008 was $4.13 billion, which is expected to grow in 2009 to $4.21 billion and forecasted to grow to $7.30 billion by 2014, at a compound average growth rate (CAGR) of 11.65%. Active technology represents the largest share of the market, with $2.7 billion in 2008, followed by intelligent packaging with $1.03 billion, and finally, controlled release packaging of $360 million. In 2014, the active segment will remain the largest, with $4.35 billion in sales, and the intelligent segment will grow to $2.47 billion sales, according to Nano-Enabled Packaging For The Food And Beverage Industry – A Global Technology, Industry And Market Analysis published by Innovative Research and Products Inc (iRAP, Inc)