ARS | Publication request: Physical and mechanical properties of extruded poly(lactic acid)-based Paulownia elongata biocomposites

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 14, 2012
Publication Date: December 5, 2012
Citation: Tisserat, B., Joshee, N., Mahapatra, A.K., Selling, G.W., Finkenstadt, V.L. 2013. Physical and mechanical properties of extruded poly(lactic acid)-based Paulownia elongata biocomposites. Industrial Crops and Products. 44:88-96.

Interpretive Summary: This research was conducted to test the feasibility of employing juvenile wood acquired from Paulownia trees as bio-filler in thermoplastics. Rapidly growing woody biomass trees offer a huge unexploited source of biofuels, bio-fillers, foods, and chemicals that can be grown on marginal lands. Wood plastic composites (WPC) produce useful products with less petroleum consumption by substitution with bio-based wood. We demonstrated that Paulownia wood flour can be employed a bio-filler with polylactic acid to create a WPC. Materials made with these WPC can be substituted for plastic items.

Technical Abstract: Paulownia wood flour (PWF), a byproduct of milling lumber, was tested as bio-filler with polylactic acid (PLA). Paulownia wood (PW) shavings were milled and separated into particle fractions and then blended with PLA with a single screw extruder. Mechanical and thermal properties were tested. Differential scanning calorimetry showed that PLA-PW blends with smaller particle sizes had lower glass transition and melting temperatures compared to blends containing larger particle sizes. Biocomposites with smaller particles also exhibited tensile strength values similar to neat PLA but had Young's modulus values that were 25 % higher than neat PLA. However, elongation values decreased in all PLA-PW blends compared to neat PLA. Microscopic examination of the biocomposites revealed distinct differences between morphologies. PLA-PWF blends exhibited distinct color changes based on the size of the wood particle size employed.