Free Formaldehyde Reduction in Urea-formaldehyde Resin Adhesive: Modifier Addition Effect and Physicochemical Property Characterization

作     者：Liu, Keke Su, Changqing Ma, Weiwu Li, Hailong Zeng, Zheng Li, Liqing 

作者机构：Cent South Univ Sch Energy Sci & Engn Changsha 410083 Hunan Peoples R China 

出 版 物：《BIORESOURCES》 (BioResour.)

年 卷 期：2020年第15卷第2期

页      面：2339-2355页

核心收录：

学科分类：082903[工学-林产化学加工工程] 08[工学] 0829[工学-林业工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 082201[工学-制浆造纸工程] 0822[工学-轻工技术与工程] 

基　　金：Key Research and Development program of Hunan Province [2016SK2005] National Natural Science Foundation of China 

主　　题：Urea-formaldehyde resin Free formaldehyde Modification Melamine Polyvinyl alcohol Adipic acid dihydrazide 

摘      要：Melamine, polyvinyl alcohol, and adipic acid dihydrazide as modifiers were added to urea-formaldehyde (UF) resin for reducing the free formaldehyde. The influence of addition amount and addition stage of modifiers on the physicochemical property and free formaldehyde content of UF resin was tested. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA) were used to determine the structural change and thermal stability of the resins. The results revealed that the UF resin added with 6% melamine had the lowest free formaldehyde content of 0.31%. Among all modified resins added with equal amount of modifier in different stages, the UF resin added with 3% polyvinyl alcohol in the second alkaline stage achieved the lowest free formaldehyde content of 0.33%. More importantly, the comprehensive effect of melamine, polyvinyl alcohol, and adipic acid dihydrazide on the free formaldehyde content of resin was studied. The free formaldehyde content in the UF resin added with the comprehensive modifiers achieved 0.24% content, and formaldehyde emission of this kind of adhesive was just 0.21 mg/g. Coupling the experimental results with the characterization data, comprehensive modifiers can reduce the formation of chemical bonds (methylene and ether bonds) in the resin and improve thermal stability of UF resin effectively.