2003 Progress Report: Composite Resins and Adhesives from PlantsEPA Grant Number: R829576
Title: Composite Resins and Adhesives from Plants
Investigators: Wool, R. P.
Institution: University of Delaware
EPA Project Officer: Richards, April
Project Period: January 1, 2002 through December 31, 2004
Project Period Covered by this Report: January 1, 2003 through December 31, 2004
Project Amount: $325,000
RFA: Technology for a Sustainable Environment (2001) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
The objective of this research project is to develop the fundamental science and engineering in support of recent technology breakthroughs in the field of high-performance, low-cost, composite resins and adhesives from plant oils for new liquid molding and adhesion applications. The research focuses on: (1) determination of the optimal fatty acid distribution (FAD) function of chemically functionalized plant oils (soy, corn, linseed, olive, sunflower) using simulation, vector percolation theory, and experiments to minimize the recently discovered fragility of crosslinked triglyceride networks in the matrix; (2) development of a natural and glass fiber sizing or coupling agent using difunctionalized high-oleic genetically engineered oils applied in situ in the liquid molding manufacturing step (RTM and VARTM) to tailor the fiber-matrix interface strength; (3) development of a rubber toughening particle (low glass transition temperature [Tg]) using the new water-based PSA micro-latex particle technology, applied during liquid molding to enhance impact strength and promote self-healing of damage using high-energy ion-cluster surfaces developed for SMC; (4) development of an interfacial and matrix toughening (high Tg) agent using chemically modified lignin; (5) development of a natural fiber preform binder using a highly branched structure of the PSA latex particles (linear chains); and (6) VARTM manufacture of the first large structures using natural fiber preforms and the optimized bio-based resins in support of the shaped engineered wood substitute materials proposed for new housing construction and civil infrastructure.
Considerable progress was made in understanding the fundamental relationship between the FAD function, the level of functionalization, and the extent of reaction on the strength and modulus of the bio-based composite resins derived from plant oils. The results have been accepted for publication in the Journal of Polymer Science Part B: Polymer Physics. This led to the development of a new universal theory of fracture of polymers, entitled the “Rigidity Percolation Model of Fracture of Polymers”. In addition, the thermal properties, particularly the Tg, have been analyzed for thin films and the bulk using the gradient percolation theory of finite size lattices. The resulting new theory of the glass transition is in excellent agreement with the experiment and will be presented at the American Chemical Society (ACS) Annual Meeting in Philadelphia, PA, in August 2004. The rigidity percolation (RP) model of fracture also is used to design new high-performance resins that can be used in automotive and agricultural equipment such as John Deere tractors, as presented to Congress in support of the Green Chemistry Bill.
The first bio-based elastomers were synthesized from genetically engineered high-oleic oils and found to have useful properties. These unique materials also were compatible with nanoclays and could be used to make crosslinked elastomers. They have the potential to act as self-healing nanobeams because of our unique control of the extent of exfoliation permitting the reversible opening and closing of intercalated nanobeams. Such materials could have considerable impact resistance, and unlike current rubber-toughened plastics, would also have the ability to heal the impact damage. The initial results will be presented at the ACS Annual Meeting in August 2004.
We found a chemical method to solubilize lignin in the bio-based resins with considerable improvement in properties. The RP model of fracture predicts that for highly crosslinked resins, the existence of free radical traps would increase the fracture energy to a maximum value at a concentration of lignin c* equivalent to the crosslink density. We found that about c* = 2 percent lignin resulted in a 300 percent increase in fracture energy. This mechanism can be optimized in future studies. Two papers have been submitted for publication.
A hurricane resistant roof was built from recycled paper and soybeans using a uniquely designed monolithic roof. This application is potentially the highest volume application of bio-based composite materials derived from low-cost, environmentally friendly, renewable resources. Its foam-core engineered structure also imparts huge thermal energy savings in addition to the safety factor of the storm-resistant design. The results were presented in the October 2003 edition of Newsweek, the November 2003 issue of Architectural Record, and will be featured in the RIBA Journal (the magazine of the Royal Institute of British Architects) in September 2004. The results were presented to Congress in support of the Green Chemistry Bill. C&E News also will feature an article in August 2004.
Intel has expressed interest in the new, low-dielectric constant composites suited for electronic material applications, which were were made from chicken feather fibers and soy resin. The results are featured in the July 2003 edition of Discover Magazine. Pyrolysis of the chicken feathers also resulted in a new, high-modulus reinforcement material, which needs further study. Several papers have been accepted for publication and a patent application is pending. The chicken feather chip was presented to Congress during testimony in support of the Green Chemistry Bill.
Soybean oils were found to be solvents for carbon nanotubes, which opens several new opportunities for environmentally friendly processing of these highly valuable materials. The Phase Diagram for any solvent with carbon nanotubes is near completion and this will be significant in self-assembly of nanostructures, nanotube fiber processing, selective deposition in electronic materials, and successful dispersal to make improved composite materials.
Green Engineering Teaching
The principal investigator developed a new course at the University of Delaware entitled “Green Engineering”, which is in concert with the Principles of Green Engineering developed by the U.S. Environmental Protection Agency (EPA) in collaboration with several investigators. The text for the course was written by Drs. Allen and Shonard. Twenty-five senior chemical engineering students and three industrial engineers have taken the course.
The principal investigator was informed by the National Science Foundation and the EPA that future funding for the Technology for a Sustainable Environment (TSE) program is regrettably not available, and this research is being terminated in the next few months, as the grant expires in the next quarter. We will investigate new funding sources in collaboration with the TSE Program.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 44 publications||26 publications in selected types||All 19 journal articles|
||Lu J, Hong CK, Wool RP. Bio-based nanocomposites from functionalized plant oils and layered silicate. Journal of Polymer Science Part B-Polymer Physics 2004;42(8):1441-1450||