三聚氰胺—尿素—甲醛共聚树脂的胶接性能

Bonding Properties of Melamine-urea-formaldehyde Resin by Copolymerization

从实际应用出发,利用三聚氰胺(M)对脲醛树脂(UF)进行共聚改性,研究树脂的胶接性能,在尿素(U)分两次(U1、U2)加入的前提下探讨了三聚氰胺的质量分数、添加方式、甲醛(F)与尿素(U)物质的量比及缩聚阶段甲醛与尿素(U1)物质的量比的不同对树脂性能的影响。结果表明:随着F与U1物质的量比以及三聚氰胺质量分数的增加,胶接强度增加,甲醛释放量明显降低;F与U物质的量比升高,胶接强度以及甲醛释放量都明显提高;二次投料可以有效降低甲醛释放量。当n(F)∶n(U)=1.3,n(F)∶n(U1)=1.9,三聚氰胺的加入量为16%时,胶合板胶接强度达到GB/T9846.3—2004I类板的要求,甲醛释放量达到GB/T9846.3—2004E1级。

Melamine was used to modify UF resin by copolymerization based on practical application.The bonding performances of the UF resin were systematically studied.The effects of amount of melamine,adding methods,F/U and F/U1 molar ratios in the condensation stage on the bonding performances of UF were all analysed.Results indicated that,with the increase of F/U1 molar ratio and amount of melamine,the bonding strength increased and the formaldehyde emission decreased obviously.The bonding strength and formaldehyde emission were all improved significantly with F/U molar ratio increasing,but secondary batching could decrease the formaldehyde emission efficiently.The bonding strength of the plywood can meet the requirement of GB/T 9846.3—2004 I when F/U and F/U1 molar ratios are 1.3 and 1.9 respectively and the amount of melamine is 16%,and the formaldehyde emission meets the GB/T 9846.3—2004 E1 grade.