Bio-based adhesives have low water resistance and they are less durable than synthetic adhesives, which limits their exterior applications. In this study, a bio adhesive was developed from soybean meal and larch tannin that was designed for exterior use. Phenol hydroxymethylated tannin oligomer (PHTO) was synthesized and then mixed with soybean meal flour in order to obtain a soybean meal-based adhesive (SPA). The results showed that the moisture absorption rate, residual rate, and solid content of SPA with 10 wt % PHTO (mass ratio with respect to the entire adhesive) were improved by 22.8%, 11.6%, and 6.8%, respectively, as compared with that of pure SPA. The wet shear strength of plywood with SPA with 10 wt % PHTO (boiling in 100 °C water for 3 h) was 1.04 MPa when compared with 0 MPa of pure SPA. This met the bond strength requirement of exterior-use plywood (GB/T 9846.3-2004). This improved adhesive performance was mainly due to the formation of a crosslinked structure between the PHTO and the protein and also PHTO self-crosslinking. The formaldehyde emission of the resulting plywood was the same as that of solid wood. The PHTO-modified SPA can potentially extend the applications of SPAs from interior to exterior plywood.
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机译:生物基粘合剂具有低耐水性,并且它们比合成粘合剂更耐用,这限制了其外部应用。在这项研究中,生物粘合剂是由设计用于外部使用的大豆膳食和落叶松单宁。合成酚羟甲基甲基化鞣甘油(pHTO),然后与大豆粕粉混合,以获得大豆膳食的粘合剂(SPA)。结果表明,与10%(相对于整个粘合剂相对于整个粘合剂相对于整个粘合剂相对于整个粘合剂)的水分吸收率,残留速率和固体含量分别提高了22.8%,11.6%和6.8%,相比纯净水疗中心。与0MPa的纯水疗中心相比,具有10wt%pHTO的胶合板具有10wt%pHTO的湿剪切强度(在100℃水中沸腾3小时)为1.04MPa。这满足了外部使用胶合板的债券强度要求(GB / T 9846.3-2004)。这种改善的粘合剂性能主要是由于在PHTO和蛋白质之间形成交联结构,并且在PHTO自交联之间形成。所得胶合板的甲醛排放与实木的甲醛发射相同。 PHTO改性的水疗中心可以将水疗中心与内部到外部胶合板的应用扩展。
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