PVAc乳液-改性油菜籽分离蛋白共混胶黏剂的制备

Preparation of PVAc Emulsion-modified Rapeseed Protein Isolate Blend Adhesive

利用油菜籽分离蛋白(RPI)和聚醋酸乙烯酯(PVAc)乳液制备高性能无醛胶黏剂,代替部分醛类胶黏剂.通过正交试验考察RPI与葡萄糖质量比、改性RPI与PVAc乳液质量比、改性RPI与PVAc乳液共混温度、固化剂质量分数对共混胶黏剂剪切强度的影响,优化热压工艺.结果表明:共混胶黏剂的最佳制备工艺为RPI与葡萄糖质量比85∶15、改性RPI与PVAc乳液质量比7∶3、改性RPI与PVAc乳液共混温度30℃、固化剂质量分数3%;制备胶合板的最优热压工艺参数为热压温度140℃、热压时间1.5 min/mm、热压压力0.8 MPa、施胶量300 g/m2,胶合板干剪切强度为1.865 MPa,按照Ⅱ类板胶合板标准测得湿剪切强度为0.885 MPa.

The high performance formaldehyde free adhesives were prepared by using rapeseed protein isolate(RPI)and vinyl acetate(PVAc)emulsion,so it can replace some aldehyde adhesives.The effects of the mass ratio of RPI to glucose,the mass ratio of modified RPI to PVAc emulsion,the blending temperature of modified RPI and PVAc emulsion,and the mass fraction of curing agent on the shear strength of the blend adhesive were investigated by orthogonal experiments.The results showed that the best preparation process of blend adhesive was RPI to glucose mass ratio 85∶15,modified RPI to PVAc emulsion mass ratio 7∶3,modified RPI and PVAc emulsion blending temperature 30℃,curing agent mass fraction 3%.The optimum hot-pressing parameters for the preparation of plywood are hot-pressing temperature 140℃,hot-pressing time 1.5 min/mm,hot-pressing pressure 0.8 MPa and sizing amount 300 g/m 2.The dry shear strength of plywood is 1.865 MPa,the wet shear strength was 0.885 MPa according to the standard of class II plywood.