ACRES --- Affordable Composites from Renewable Sources

A multidisciplinary team is investigating the use of soybean triglycerides as raw materials in the synthesis of new polymers suitable for liquid molding processes. Several patent disclosures have been filed on these novel new materials. The ACRES program taps into a variety of research fields ranging from genetic engineering, food science, composites manufacturing science, and materials synthesis to mechanics, advanced materials characterization, and computer simulation.

Under the ACRES project, soyoil is being used to make affordable and renewable fiber-reinforced composites for high-volume applications.


Background

The synthesis of structurally strong polymers from renewable resources is attractive from both the commercial and environmental perspectives and supports global sustainability. In contrast to typical petroleum-based composite matrix resins such as vinyl esters, polyesters, and epoxies, soy-based composites are optionally biodegradable; as plant oils, they contain fatty acid residues that are readily attacked by lipase-secreting bacteria. They can also be made into long-lasting, durable materials.

The precedent for this research was set some 60 years ago, when Henry Ford made his first fiberglass composite auto body using a plastic matrix derived from soybean products in 1938. Formulated with soy proteins, these materials were found to be highly resistant to impact.


Research

Progress to date on the research includes

  • Identification of the processing requirements to produce affordable high-volume fiber-reinforced composite materials from soy products by resin transfer molding and related molding techniques.
  • Establishment of composite property-cost targets based on commercial glass/vinyl-ester rigid composites.
  • Application of characterization methods for determining the chemical composition of soy products to quantitatively determine the available functional groups for polymerization reactions.
  • Exploration of a broad range of chemistries to convert soy products to composite resins. Several have been found to be potential candidates in terms of affordability and processing-property targets, and an optimal set is being explored.
  • Fabrication of the first composites using both raw soyoil and epoxidized soyoil.

Applications

Potential applications of these innovative materials include

  • the automotive industry--the impact here would be significant, as some 10 million cars are disposed of annually
  • farm machinery and vehicles
  • the construction industry, where soy-based composites reinforced with natural materials like straw could replace wood composites
  • defense, where lightweight, inexpensive, disposable materials are needed
  • rubber, foam, and flexible polymer applications

Future Impact

A number of research groups are now designing and growing genetically engineered soybeans that produce oils with hitherto unattainable levels of unsaturation. The ACRES project stands to make a significant contribution to the use of these new oils in high-tech fields such as composites. The current work is also aimed at developing an effective methodology for the analysis of future resin systems based on renewable resources.