明胶改性脲醛树脂

Preparation of Gelatin Modified Urea-Formaldehyde Resin

脲醛树脂是目前工业生产中最主要且无可替代的人造板胶黏剂,改善其胶合强度和甲醛释放量一直是研究热点。本研究以传统的“碱-酸-碱”工艺合成脲醛树脂,在合成过程的酸性阶段和冷却出料阶段分别加入明胶,对脲醛树脂进行改性。通过红外光谱、核磁共振碳谱、差式扫描量热仪等对树脂的结构和固化性能进行分析,并对胶黏剂改性前后的胶合性能、黏度、固化时间等进行测试。结果表明,不同阶段改性后的UF树脂固化温度降低、固化时间缩短,黏度和胶合强度均增加,甲醛释放量降至1.39 mg·L^(-1),达到GB/T 18580-2001中要求的E1级。

Urea formaldehyde resin is the most important and irreplaceable wood-based panel adhesive in industrial production.Improving its bonding strength and formaldehyde emission has always been a research hotspot.In this paper,urea formaldehyde resin was synthesized by the traditional"alkali-acid-alkali"process.Gelatin was added in the acid stage and cooling discharge stage of the synthesis process to modify the urea formaldehyde resin.The structure and curing properties of the resin were analyzed by FT-IR,13 C NMR,and differential scanning calorimetry.The bonding properties,viscosity and curing time before and after modification were tested.The results showed that the curing temperature and curing time of the modified UF resin decreased,the viscosity and bonding strength increased,and the formaldehyde emission decreased to 1.39 mg/L,reaching the E1 level required in China national standard(GB/T 18580-2001).