硅烷偶联剂对地质聚合物基胶合板胶合性能的影响

Effect of Silane Coupling Agent Treatment on the Bonding Properties of Geopolymer-based Plywood

为提高木材与地质聚合物的界面胶合强度,使用KH550、KH560和KH570三种硅烷偶联剂对杨木单板进行涂刷处理,以实验室自制的偏高岭土基地质聚合物为木材胶黏剂,热压制备胶合板,研究硅烷偶联剂处理对杨木单板表面微观形貌和润湿性能、胶接界面化学基团和微观结构、胶合板干态和湿态胶合强度的影响。结果表明:KH550、KH560、KH570偶联剂处理后,木材表面形成的硅烷薄膜层,有利于碱激发剂在木材表面的进一步扩散,平衡接触角分别降低了25.8%、31.8%、14.8%;硅烷偶联剂处理有利于促进地质聚合物在木材内部的渗透,其中偶联剂KH550处理组的地质聚合物在木材中渗透更为均匀;经浓度为10%的KH550处理后,胶合板胶合强度达到最大值,其湿态胶合强度与干态胶合强度分别比未处理材提高了41.5%和47.5%。

In order to improve the bonding strength between wood and geopolymer,silane coupling agents named KH550,KH560 and KH570 were used in this study.Lab-made metakaolin-based geopolymer was used as the wood adhesive,and plywood was prepared by hot-pressing.The effects of different silane coupling agents on the microstructure and wettability of the veneer,microstructure and chemical groups of the bonding interface,and the wet and dry bonding strength of geopolymer-based plywood were evaluated.The results showed that KH550,KH560 and KH570 could form silane thin film layer,which was conducive to the further diffusion of alkali activator on the surface of wood.Compared with the untreated wood,the final equilibrium contact angle of wood treated by KH550,KH560 and KH570 was reduced by 25.8%,31.8%and 14.8%,respectively.Silane coupling agent treatment was beneficial to promote the penetration of geopolymer into wood.Compared with KH560 and KH570,geopolymer penetrated more uniform in the wood treated with KH550.Compared with that of the untreated wood,the adhesive strength of the plywood treated with KH550 at 10%reached the maximum,and the wet bonding strength and dry bonding strength increased by 41.5%and 47.5%,respectively.