"Greener" hybrid adhesives composed of urea formaldehyde resin and cottonseed meal for wood based composites

Authors: LIU, MING - Mississippi State University; WU, YIQIANG - Central South University Of Forestry And Technology; WANG, YAN - Mississippi State University; He, Zhongqi; WAN, HUI - Mississippi State University

Submitted to: Journal of Cleaner Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2018
Publication Date: 3/24/2018
Citation: Liu, M., Wang, Y., Wu, Y., He, Z., Wan, H. 2018. "Greener" adhesives composed of urea-formaldehyde resin and cottonseed meal for wood-based composites. Journal of Cleaner Production. 187:361-371.

Interpretive Summary: Urea formaldehyde (UF) resins are one of the most widely used adhesives in wood based composites. The major concerns of the resin utilization are free formaldehyde release. As a renewable raw materials, water washed conttonseed meal can be used in wood bonding. To produce “greener” adhesives with less formaldehyde emission, the raw materials (urea and formaldehyde) of UF resins were partially replaced by washed cottonseed meal with the ratios from 10% to 50%. The chemical properties and operable parameters of the hybrid adhesives were comparable to, or even better than pure UF resins. The hybrid adhesives with 10% to 40% of cottonseed meal showed soaked adhesive strengths higher than either UF resin or cottonseed meal alone. Cottonseed meal, up to 30% in the hybrid adhesives, had good dispersions and acted as a reinforcement for the hybrid adhesive other than a filler or an additive. Data in this work indicated these hybrid adhesives improved the performance of pure UF resins while retained its outstanding features, which could be used immediately to replace UF resins in current manufacturing lines for wood based composites.

Technical Abstract: Urea formaldehyde (UF) resins are one of the most widely used adhesives in wood based composites. The major concerns of the resin utilization are free formaldehyde release and poor water resistance. As a renewable raw materials, water washed conttonseed meal can be used in wood bonding. To produce “greener” adhesives with less formaldehyde emission, the raw materials (urea and formaldehyde) of UF resins were partially replaced by washed cottonseed meal with the ratios from 10% to 50%. The hybrid adhesives were characterized by multiple instrumental analyses and adhesive strength measurements. The hybrid adhesives showed the chemical compositions, thermal stabilities, and rheological properties similar to, or even better than pure UF resins. The hybrid adhesives with 10% to 40% of cottonseed meal showed soaked adhesive strengths two-times higher than either UF resin or cottonseed meal alone. Cottonseed meal had good dispersions in the hybrid adhesives with up to 30% portion. It acted as a reinforcement for the hybrid adhesive other than a filler or an additive. Data in this work indicated these hybrid adhesives improved the performance of pure UF resins while retained its outstanding features, which could be used immediately to replace UF resins in current manufacturing lines for wood based composites.