ARS | Publication request: Long-term performance of thermoplastic composite material with cotton burr and stem (CBS) as a partial filler

Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 2010
Publication Date: September 18, 2010
Citation: Bajwa, S., Kalidindi, S., Bajwa, D., Holt, G.A. 2010. Long-term performance of thermoplastic composite material with cotton burr and stem (CBS) as a partial filler [abstract]. Association for the Advancement of Industrial Crops Conference, September 18-22, 2010, Fort Collins, Colorado. Available: http://www.aaic.org/10program.htm. Fibers and Cellulosics Division.

Technical Abstract: Rationale: Cotton burr and stem (CBS) fraction of cotton gin byproducts has shown promise as a fiber filler in thermoplastic composites, with physical and mechanical properties comparable to that made with wood fiber fillers. However, the long-term performance of this composite material is not known. It is important to evaluate the long-term performance of this composite as it is developed as a replacement for southern yellow pine in non-structural and outdoor building applications. Objective: The objective of this study was to evaluate the long-term performance of thermoplastic composite with CBS as the filler, in comparison to wood-polymer composite (WPC). Method: An experiment was conducted by manufacturing thermoplastic composite with CBS replacing wood in varying proportions as the fiber filler. All fiber materials were ground to a size of 20-60 mesh. Wood: CBS ratios of 100:0, 75:25, 50:50, and 25:75 by percentage weight were used as the treatment. The composite used 50% of fiber filler, 40% HDPE, and 10% of other additives, all by weight. The samples were manufactured using a commercial scale single screw extruder into 25x 152 mm rectangular profile. The extruded samples were water cooled, conditioned, and then subjected to accelerated aging as per ASTM D1307 standard. All the samples were then tested for flexural strength, nail holding capacity and water absorption. Results: The samples from the first two three cycles of aging showed a gradual decrease in water absorption and thickness swelling. In general, the modulus of elasticity deteriorated with number of cycles of aging, while flexural strength showed a cyclic behavior of deterioration followed by some recovery. This behavior is comparable to those reported for wood polymer composites. Conclusion: Long-term performance of thermoplastic composite with cotton burr as the filler was comparable to that of wood polymer composites.