Preparation and Its Properties of the Urea Modified Soy Protein Isolate Adhesives

摘要

Soy proteins have shown great potential for use as renewable and environmentally friendly adhesives. The orthogonal experiments are designed for the urea-modified soy protein isolate (SPI) adhesives and the optimum formula is obtained. The mass concentrations of SPI and urea are 14% and 8%(relative to the total mass of SPI and water), the reaction temperature and time are 35°C and 60 min, respectively. Some basic and adhesion properties and its structure of the modified SPI adhesive for the optimum formula are measured. The viscosity is 43Pa.s, and the dry-and wet-state adhesion strengths of the urea-modified SPI optimum formula are 0.96MPa and 0.78MPa(>0.72MPa), respectively according to GB/T10724-2006, which satisfied with the requirement of the II-type plywood. Its surface hydrophobicity is improved and the thermal properties is slightly improved after 200°C.