Aging Resistance Properties of Poplar Plywood Bonded by Soy Protein-Based Adhesive

作者：Zeng, Xiangling; Luo, Jing; Hu, Jihang; Li, Jianzhang; Gao, Qiang^*; Li, Li^*

来源：BioResources, 2016, 11(2): 4332-4341.

DOI：10.15376/biores.11.2.4332-4341

• Aging resistance
• Soybean protein-based adhesive
• Poplar plywood
• Wet-dry cycle
• Accelerated aging method

The aging resistance properties of poplar plywood prepared with soy protein-based adhesives were investigated. The shear strength of soybean meal/bisphenol epoxy resin (SM/EP) adhesive increased by 197.5% (surface layer) to 1.19 MPa and 153.5% (core layer) to 1.09 MPa compared to soybean meal (SM) adhesive. Wet-dry cycles of 25 +/- 3 degrees C, 63 +/- 2 degrees C, and 95 +/- 2 degrees C accelerated the aging of poplar plywood with soy protein-based adhesive. After eight 25 +/- 3 degrees C wet-dry cycles, the shear strength of plywood bonded with SM/EP adhesive was reduced to 0.88 MPa (surface layer) and 0.71 MPa (core layer). Furthermore, the shear strength of SM adhesive gradually decreased to 0 (surface and core layer) after six and five 25 +/- 3 degrees C wet-dry cycles. The shear strength of SM/EP adhesives was reduced to 0.96 MPa and 0.79 MPa (surface and core layer) after eight 63 +/- 2 degrees C wet-dry cycles, and 0.53 MPa and 0.27 MPa (surface and core layer) after eight 95 +/- 2 degrees C wet-dry cycles. Vertical density profiles indicated that the decrease of shear strength could be attributed to several factors: The small molecules were dissolved, the molecular chains of the adhesives were hydrolyzed by water, and the interior and thermal stress destroyed the bonding structure.

• 出版日期2016-5
• 单位北京林业大学