摘要
以高浓度甲醛制备摩尔比1.1∶1的脲醛树脂,选用三种不同固化剂(NH_4Cl,HCOOH,NH_4Cl+尿素)对树脂的胶接性能和耐热性能进行分析和评价,并借助13C-NMR和DMA进行表征。研究结果表明:高浓度甲醛制备的脲醛树脂具有较高的黏度和固含量,游离甲醛含量很低,仅为0.075%。较普通脲醛树脂,其羟甲基含量、缩聚度和交联度分别提高了6.33%、5.87%和58.19%。以NH_4Cl、HCOOH作为固化剂时,树脂具有较高的胶合强度,较普通脲醛树脂分别提高了74%和78%。仅以甲酸作为固化剂时,树脂具有较优的耐热性能。
Low mole ratio F/U（1.1：1） urea-formaldehyde（UF） resin was prepared with high concentration formaldehyde.Evaluation and analysis of bonding performance and heat resistance of this resin was studied based on three different curing agent（NH_4Cl, HCOOH, NH_4Cl ＋ urea） by 13C-NMR and DMA.The results show tha t this resin had significantly high v iscosity and solid content, and free formaldehyde content was low to 0.075%.Hydroxymethyl content, degree of polycondensation and crosslinking of this resin increased by 6.33%, 5.87% and 6.33% respectively.Compared with common UF resin, bonding strength of this UF resin was higher by 74% and 78% when NH_4 Cl and HCOOH were as the curing agent.Only with HCOOH as curing agent, this resin had excellent heat resistance.
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2017年第2期101-104,共4页
Journal of Central South University of Forestry & Technology
基金
"十二五"国家科技支撑计划(2012BAD24B03)项目
西南林业大学科研启动项目(111421)
林业公益性行业科研专项(201304505)
关键词
高浓度甲醛
UF
固化剂
耐热性能
concentrated formaldehyde
UF resin
curing agent
heat resistance
