Environmentally Benign Polymeric Packaging from Renewable ResourcesEPA Grant Number: R826733
Title: Environmentally Benign Polymeric Packaging from Renewable Resources
Investigators: Dorgan, John R. , Knauss, Daniel M.
Institution: Colorado School of Mines
EPA Project Officer: Richards, April
Project Period: November 1, 1998 through October 31, 2001 (Extended to June 14, 2003)
Project Amount: $275,000
RFA: Technology for a Sustainable Environment (1999) RFA Text | Recipients Lists
Research Category: Nanotechnology , Sustainability , Pollution Prevention/Sustainable Development
Plastic packaging materials are everywhere in our daily lives. From food wrappings and containers to detergent and soft drink bottles to foam packaging used in shipping delicate goods, many products are surrounded by or contained in polymeric materials. Currently, most polymeric packaging materials are based on non-renewable fossil fuel feedstocks. Most notably, polyethylene is currently produced from ethylene gas, a product of cracking ethane, which comes from non-renewable sources. Incineration of these materials makes a net contribution to atmospheric CO2 and plastics currently account for in excess of 20% of the nation's landfills. In addition, many widely used materials, notably polystyrene and poly(vinyl chloride), are made from noxious or toxic monomeric components. Other polymers involve the use of malignant solvents during their manufacture. There is a pressing need to develop "green" packaging materials based on renewable resources that do not involve the use of toxic or noxious components in their manufacture. These polymers should be biodegradable materials derived from naturally available raw materials, such as corn or other agricultural crops, and they should also allow composting to naturally occurring degradation products or recovery and reconstitution into their monomeric form. The objective of this project is on developing biodegradable and environmentally friendly alternatives to present polymeric materials.
The project developments a scientific basis for the production of industrial scale quantities of polymers and copolymers of lactic acid for use as packaging materials. Poly(lactic acid) (PLA) is an economically feasible material with numerous advantages, including: 1) the ability to produce the lactide monomer from a fermentation of renewable agricultural feedstocks, 2) degradation to lactic acid, a non-toxic, naturally occurring metabolite (and ultimately to carbon dioxide and water), 3) the lack of any net carbon dioxide release (the carbon is fixed by photosynthesis into the plants being fermented), 4) the possibility of recovering lactic acid from collected packaging through simple hydrolysis or alcoholysis, 5) the capability of producing packaging systems which are compostable, 6) a reduction of domestic landfill volumes, 7) an improvement of America's farm economy, and 8) the all important ability to tailor material properties through modifications in molecular architecture and through copolymerization with other monomers.
The project involves modification of PLA structures and copolymerization of lactic acid with other monomers; subsequently the properties of these new polymers are measured to determine their appropriateness for use as packaging materials. In the course of these investigations, the first comprehensive studies of the flow and gas permeation properties of poly(lactic acid) and its derivatives will be conducted and published in the open literature. Fundamental knowledge will be created which will allow the successful commercialization of this family of biobased polymeric packaging materials. These materials come from a renewable and sustainable resource, namely plant material created by photosynthesis. The agricultural origin of the monomer feedstocks will improve the American farm economy and leads to a closed loop with respect to the greenhouse effect of CO2. The required feedstocks are neither noxious nor toxic. In addition, the resulting polymeric materials are either compostable, degradable, or recyclable thus freeing up landfill space. In addition, chemists and chemical engineers will be educated at an advanced level in the science and technology of biobased degradable polymeric materials from renewable resources.