戊二醛改性核桃饼粕胶接体系的性能评估

Performance evaluation of bonding system of walnut meal modified with glutaraldehyde

旨在以核桃饼粕为原料制备具有优良耐水性能的蛋白基胶黏剂,以不同用量的戊二醛为改性剂制备了一系列改性核桃饼粕胶接体系,测定其基本性能、固化特征、胶合强度以及结构特征,以此评估戊二醛改性核桃饼粕胶接体系的性能。结果表明:戊二醛用量越大,改性核桃饼粕胶接体系的黏度总体越大;改性核桃饼粕胶接体系均可在160℃以下完成交联固化,尤以戊二醛用量为2.5%时的固化峰值温度最低(123℃);经63℃热水处理后胶合板样品的胶合强度最大可达0.87 MPa,胶接体系具备优异的耐水性;傅里叶红外光谱(FT-IR)分析表明戊二醛中醛基(—COH)可与核桃饼粕中羧基(—COOH)和氨基(—NH2)之间形成良好的交联,为胶接体系胶合强度及耐水性提供了重要支撑。综上,戊二醛用量为2.5%时所制备的核桃饼粕胶接体系性能较优。

In order to prepare protein adhesive with excellent water resistance from walnut meal,a series of modified walnut meal bonding systems(MWMBS)were prepared with different amounts of glutaraldehyde as modifier.The basic properties,curing characteristics,bonding strength and structural characteristics were determined to evaluate the performance of the MWMBS.The results showed that the viscosity of MWMBS generally increased with the increase of amount of glutaraldehyde.The MWMBS had the appropriate cross-linking curing temperature,which can be completed within 160℃,especially when the amount of glutaraldehyde was 2.5%,the peak curing temperature was the lowest(123℃).The optimal bonding strength of plywood samples after 63℃hot water treatment could reach 0.87 MPa,and the bonding system had excellent water resistance.Fourier infrared spectroscopy(FT-IR)analysis showed that aldehyde group(—COH)in glutaraldehyde could form good cross-linking with carboxyl group(—COOH)and amino group(—NH2)in walnut meal,which provided important support for the bonding strength and water resistance of the system.In conclusion,the MWMBS prepared with 2.5%glutaraldehyde exhibits superior performance.