四硼酸钠对SDS改性大豆蛋白胶性能的影响研究

Effects of sodium tetraborate on properties of SDS modified soy protein adhesive

为了解决大豆蛋白胶易腐蚀降解、变稀和稳定性差的问题,以大豆分离蛋白(SPI)为主要原料,十二烷基硫酸钠(SDS)为改性剂,并添加四硼酸钠,制得大豆蛋白改性胶粘剂。着重探讨了四硼酸钠用量对大豆蛋白胶流变行为、稳定性、粘接性能和耐水性能的影响。研究结果表明:添加了四硼酸钠的大豆蛋白胶,固化后表面更为平整和均匀;随着四硼酸钠用量增加,大豆蛋白胶的黏度增加,粘接性能和耐水性能提高;四硼酸钠的加入,能让大豆蛋白胶的保质期延长;当w(四硼酸钠)=1.0%(相对于大豆蛋白胶质量而言)时,保质期能达三个月以上,大豆蛋白胶的粘接强度仍然在2.5 MPa以上,耐水强度也仍然在0.8 MPa以上,能满足国家对II类胶合板的使用要求。

In order to solve the problems of easy corrosion degradation,thinning and poor stability of soy protein adhesive,soy protein isolate(SPI)was used as the main raw material,sodium dodecyl sulfate(SDS)was used as modifier,and sodium tetraborate was added to prepare soy protein modified adhesive.The effects of the amount of sodium tetraborate on rheological behavior,stability,bonding properties and water resistance of soy protein adhesive were emphatically investigated.The research results showed that the surface of soy protein adhesive added with sodium tetraborate was smoother and more uniform after curing.With the increase of sodium tetraborate,the viscosity of soy protein adhesive increased,and the bonding properties and water resistance improved.The shelf life of soy protein adhesive could be prolonged by adding sodium tetraborate.When w(sodium tetraborate)=1.0%(relative to the mass of soy protein adhesive),the shelf life could reach more than three months,the bonding strength of soy protein adhesive was still above 2.5 MPa,and the water resistance strength was still above 0.8 MPa,which could meet the national requirements of type Ⅱ plywood.