Location: Functional Foods ResearchTitle: Accelerated thermal aging of bio-based composite wood panels
Submitted to: FIBERS
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2020
Publication Date: 5/21/2020
Citation: Tisserat, B., Montesdeoca, N., Boddu, V.M. 2020. Accelerated thermal aging of bio-based composite wood panels. Fibers. 8(5):32. https://doi.org/10.3390/fib8050032.
Interpretive Summary: There is a great interest to replace synthetic adhesives with bio-based adhesives derived from agricultural by-products. Such adhesives may be used in the fabrication of composite wood panels (CWPs), such as particleboard, plywood, oriented strand board and fiberboard. This project is a continuation of the quest to develop acceptable commercial CWPs. In this study we employed CWPs composed of distiller’s dried grains with solubles and soybean flour as the resin/adhesive/matrix and pine wood shavings. To date, little is known as to how the panels would response to long-term outdoor environmental conditions. In this study, we utilized a thermal cyclic aging chamber to test 10 years of aging within 26 weeks. The information gained from these tests is necessary to address the question of the long-term durability and performance of “green” CWPs. It is important to find the environments that “green” CWPs can be optimally employed. Commercial use of DDGS/soybean flours as bio-based adhesives would benefit both the dry milling and industrial wood manufacturing industries.
Technical Abstract: Replacing petroleum-based adhesives and resins with bio-based alternatives to fabricate composite wood panels (CWPs) is seen as a “green approach” in manufacturing building materials. Very little information exists as how these “green” CWPs would perform in the long-term under typical outdoor environmental conditions. In this study, all-bio-based CWPs were subjected to accelerated long-term cyclic thermal aging over a 10-year period resembling outdoor temperatures of that occurring in Peoria, IL, USA. Yearly thermal cyclic aging temperatures were divided into four seasonal periods corresponding to Winter, Spring, Summer and Fall and varied from as low as -25.6 oC to as high as 40 oC in addition relative humidity changes varied from 35.6 % to 76.4%. The bio-based resin consisted of equal portions of Distiller’s Dried Grains with Solubles (DDGS) and commercial soybean flour ProsanteTM (PRO). CWPs employed were fabricated containing 15 or 50% DDGS/PRO and 85 or 50%. CWP samples were removed at 5, 7.5 and 10-year intervals and tested for changes in their dimensional, flexural properties, dimensional stability, surface roughness, thermophysical, and spectral properties. Accelerated thermal aging altered all the CWP properties and was especially notable after the first 5 years of testing. For example, after 5 years of aging, CWPs consisting of 15% DDGS/PRO and 85% exhibited 63 and 75% reduction in the modulus of rupture and modulus of elasticity, respectively, compared to the untreated control CWP. However, after the 5 years of aging, changes in were minimal.