News Release Distributed 11/13/06
An LSU AgCenter project to make natural fiber-reinforced plastic composites using recycled plastics and wood or other agricultural fibers recently received a $791,568 grant from the U.S. Department of Agriculture and the U.S. Department of Energy.
The grant is one of 17 given nationally for biomass research, development and demonstration projects, said Dr. Qinglin Wu, project leader in the School of Renewable Natural Resources.
The LSU AgCenter grant is for research designed to enhance creative approaches in developing next generation advanced technologies. The project aims to find technologically feasible and economically acceptable solutions for using wood and other natural fibers together with commingled waste plastics, Wu said.
"Because of a continuing proliferation of plastic resin types, the recycling industry cannot sort out all the contaminants – making more plastic waste," Wu said. "Combining waste plastics with natural fibers to produce high-quality industrial products provides a prospective solution for using biomass resources and leading to new economic development in an environmentally friendly manner."
The resulting fiber-reinforced plastic composites could be used to make weather-resistant products such as roofing shingles, patio furniture, decking and other structural materials. Other uses could be for bumpers, dashboards and similar components for automobiles and other power equipment.
Wu said the grant will allow the research to move to a larger scale by investing in machines that can make extruded or molded fiber-plastic materials in larger sizes and quantities.
"We want to create a process that can be commercialized," Wu said.
Wu cited Louisiana’s large plastics manufacturing base along with the state’s fiber production – both forest products and other agricultural by-products – as important to his research.
"This is a marriage of plastics and fiber," he said. "The ideal place for these industries to merge is in Louisiana."
Wu and his research team have been combining recycled plastics with such fibers as rice straw, wood and bagasse – the fibers remaining after the juice is squeezed out of sugarcane – for several years.
"We have already created in the laboratory products with potential applications," Wu said.
The researchers have created co-polymers reinforced with natural fibers to reduce brittleness and increase strength. A new twin-screw extrusion machine in the Forest Products Development Center combines fibers and plastics under heat and pushes the product out like toothpaste from a tube.
Using a combination of 50 percent plastics and 50 percent fibers, Wu and his team can produce materials with similar handling properties as wood – meaning they can be sawed or drilled.
For homes, they can be used for decking or interior moldings in various colors. They can replace treated wood that could eventually split and decay. And they’re termite resistant.
These materials also can be used to make automobile components, such as bumpers and dashboards, Wu said. And, unlike fiberglass, these natural fiber-plastic compounds can be recycled.
Because molded materials have to flow, Wu said, these materials have to have a higher ratio of plastic to wood.
"For example, a product could be made of 70 percent recycled plastic and 30 percent rice straw, 30 percent rice husk or 30 percent pine wood," Wu said.
Because of the way they’re formed, extruded materials can contain longer fibers and larger proportions of fiber, making them stiffer than plastics but less brittle than wood. They’re not as strong as wood, however, Wu said, because the fibers are shorter.
The researchers also are looking at nano particles – such as nanoclays – to improve the bonds between the plastics and the natural fibers. Nanoclays are extremely small, microscopic bits of clay that can separate during composite mixing to form a layered structure at a nano – or microscopic – scale.
"The polymer molecules can then penetrate into the layered clays to form stronger bonds, leading to enhanced composite properties," Wu said.
"The bond between wood and plastic is not a true chemical bond but a physical bond," Wu said. "We’re looking at nano technology using nanoclays with a new generation of coupling agents to create chemical bridges or bonds between them. The agents attach with chemical bonds to both the plastics and the wood fibers. Then their chemical properties create a stronger composite material."
The next step is to acquire an industrial-sized, twin-screw extrusion machine to evaluate different formulations and create testing samples.
"The current wood composites laboratory has state-of-the art equipment essential to polymer-based composite research," Wu said. "It’s considered to be one of the best composite labs in the South."
Wu credits Louisiana Board of Regents’ grants from the Louisiana Education Quality Support Fund, as well as other grants from the National Science Foundation, USDA, the Governor’s Biotechnology Initiative Program and private funds, for helping to equip the current laboratory. That was instrumental in being able to compete successfully for the latest grant, he said.
Wu’s long-term goal is to form a Louisiana Bio-fiber Polymer Composite Consortium under the LSU AgCenter umbrella.
"We’re ready to commercialize composite technology which will contribute to economic development and industry growth in Louisiana," Wu said.
Wu is the Roy O. Martin Sr. Professor in Composites and Engineered Wood Products in the LSU AgCenter’s School of Renewable Natural Resources. Other members of the research team are Dr. Craig M. Clemons at the USDA Forest Products Laboratory in Madison, Wis., Dr. Kun Lian at the LSU Center for Advanced Microstructures and Devices and Dr. Yong Lei of the AgCenter’s Louisiana Forest Products Development Center.
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Contacts: Qinglin Wu at (225) 578-8369 or qwu@agcenter.lsu.edu
Writer: Rick Bogren at (225) 578-5839 or rbogren@agcenter.lsu.edu