大豆蛋白改性集成材用三聚氰胺-尿素-甲醛树脂

为降低胶黏剂体系中游离的甲醛含量,增加其耐久性,以改性大豆蛋白为改性剂,合成改性三聚氰胺-尿素-甲醛共缩聚树脂MUF-1,并对其基本性能、胶合性能等进行测试分析。结果表明:在"弱碱-弱酸-弱碱"合成工艺的初始碱性阶段,添加9%改性大豆蛋白改性MUF树脂效果最佳,合成树脂黏度适中,操作性好,利于集成材生产,体系中游离甲醛含量较未改性树脂降低52%;用改性后的MUF-1树脂制备的胶合木具有良好的胶合性能及耐水性能,满足国家结构集成材标准。核磁共振(13C-NMR)分析结果表明,改性大豆蛋白的引入会在一定程度上阻碍缩聚反应的进行,红外光谱分析结果亦与之印证。动态热机械性能分析(DMA)测试分析表明改性后的MUF-1树脂起始固化温度降低,在固化速率基本一致的情况下,较之未改性MUF树脂固化更彻底,体现出较优的力学性能。

Study on the soy been protein modified melamine-urea-formaldehyde resin for glulam

In order to reduce free formaldehyde content of the synthetic resin, and increase its durability, the modified soy been pro-tein was used to compound copolycondensation melamine-urea-formaldehyde ( MUF ) resin and the basic performances, bonding strength were tested. The results showed that, during the synthetic process of first alkali stage, adding 9% of the soy protein to modi-fy the MUF was the best as the following reasons:the modified resin had an appropriate viscosity which is helped to the production of glulam;lower free formaldehyde content decreased 52% compared to the control. After measuring the mechanical properties and water resistant stripping ratio, the glulam which made by the modified resin have showed good performance reaching the national standard on viscosity and water resistance. The results of 13 C-NMR and FT-IR analysis suggested that soy been protein would hinder the polycondensation reaction. The DMA test analysis indicated that compared with the unmodified MUF resin, the modified resin MUF-1 had lower initial curing temperature and cured more thoroughly and better mechanical properties under the same solidification rate.