The broader impact/commercial potential of this project involves a significant enhancement in the properties of wood polymer composites (WPCs) by the commercialization of a highly effective bio-based coupling agent made from renewable sources such as plant oils instead of petroleum. By significantly enhancing the properties of WPCs, substantial benefit to society will result by providing new application opportunities for these relatively low cost, light weight biocomposites. Globally millions of metric tons of WPCs are produced each year. Currently, WPCs are used for applications that do not require high load bearing characteristics due to limitations in modulus, strength, and creep. The technical concepts proposed for the Phase I effort are expected to enable higher modulus and strength, by facilitating the use of higher wood flour (WF) loadings, as well as lower deformation by introducing crosslinks into the matrix phase. Although this proposal is focused on the utility of these novel bio-based copolymers as high performance coupling agents, these copolymers have also been demonstrated to be excellent binders for coatings. Thus, commercialization of these copolymers is expected to have a broader impact on society beyond use as coupling agents.
This Small Business Technology Transfer Phase I project will determine the feasibility of novel bio-based polymers to serve as highly effective coupling agents for WPCs. The most common WPCs are based on WF as the dispersed-phase and high density polyethylene (HDPE) as the matrix. WF is a very desirable reinforcement for composites because it is inexpensive, abundant, biodegradable, high modulus, high strength, light weight, and non-abrasive toward processing equipment. The major technical challenge for HDPE/WF composites is obtaining adequate compatibility between the WF fibers and the HDPE matrix. Although the modulus and tensile strength of WF fibers is approximately 40 and 20 times higher than that of the HDPE matrix, respectively, the mechanical property enhancements provided by the WF cannot be fully realized without effective compatibilization. It is the team?s belief that the bio-based polymers proposed for the project possess the ideal chemical composition for effectively coupling the HDPE matrix to the WF fibers to maximize mechanical properties. In addition, the polymers are capable of introducing crosslinks into the matrix phase, which are expected to reduce polymer creep. For the Phase I project, the effect of the chemical composition of the bio-based coupling agent will be a primary factor investigated.
