A novel wood‐binding domain of a wood–plastic coupling agent: Development and characterization

Abstract

Abstract Poly( N ‐acryloyl dopamine) (PAD) was successfully synthesized through free‐radical homopolymerization of N ‐acryloyl‐ O,O ′‐diphenylmethyldopamine and subsequent deprotection. The adhesive ability of PAD to wood was studied in detail. PAD underwent substantial oxidation and crosslinking reactions at about 80°C. Therefore, maple veneer samples bonded with PAD powder at a press temperature of 120°C had high shear strength and high water resistance. In contrast to conventional wood adhesives such as phenol‐formaldehyde and urea‐formaldehyde resins, PAD resulted in an increase, rather than a decrease, in the shear strengths of two‐ply laminated maple veneer test specimens that had undergone a water soaking and drying treatment. A mixture of PAD and polyethylenimine (PEI) resulted in much higher shear strength than PAD alone. To achieve high shear strength and high water resistance, the maple specimens bonded with PAD–PEI mixtures had to be cured above 150°C because reactions between PAD and PEI occurred at about 150°C. The water resistance of the maple specimens bonded with the PAD–PEI mixtures was dependent on the PAD:PEI weight ratio and the curing temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1078–1084, 2003