摘要
用聚乙烯醇(PVA)作为改性剂,在不同的弱酸性条件下合成脲醛树脂(UF),并用正交实验法得出了弱酸性起始条件合成聚乙烯醇改性脲醛树脂的最优工艺为:最终n(甲醛):n(尿素)=1.2:1、起始pH值为6.5、碱性阶段反应温度85℃、PVA加入量占尿素总量1%。用该工艺制备的PVA改性UF的游离甲醛含量、胶合强度均能满足GB/T 14732-2006标准要求,并且相应胶合板的甲醛释放量为4.80mg/L,达到了GB/T 9846.3-2004标准中E_2级指标要求。
With polyvinyl alcohol(PVA) as modifier,the synthesis technology of urea-formaldehyde resin(UF) under different initial weak acidity conditions was studied through an orthogonality experiment.The results indicated that the UF resin modified by PVA satisfied the standard of GB/T 14732—2006 and the formaldehyde emission(4.80mg/L) of corresponding plywood reached the E_2 level index requirement in GB/T9846.3—2004 standard when final molar ratios of n(F):n(U) was 1.2:1.the initial pH was 6.5.the temperature of alkaline stage reaction was 85℃ and mass fractions of PVA was 1%in total urea.
出处
《林产工业》
北大核心
2015年第12期36-39,44,共5页
China Forest Products Industry
基金
江苏省高等学校2014年大学生实践创新训练计划项目
201410333006Z
关键词
弱酸
聚乙烯醇
脲醛树脂
游离甲醛
胶合强度
甲醛释放量
Weak acid
Polyvinyl alcohol(PVA)
Urea-formaldehyde resin(UF)
Free formaldehyde
Bonding strength
Formaldehyde emission