胺化改性木质素合成聚氨酯胶粘剂的研究

采用Mannich法对纯化木质素进行胺化改性,以提高其活泼氢数量和木质素的反应活性;然后以此作为部分聚乙二醇的替代物,将其与异氰酸酯反应合成PU(聚氨酯)胶粘剂。结果表明:胺化木质素中引入的氮含量约为2.64%,说明木质素的活性明显提高;当w(胺化木质素)=25%时,相应PU胶粘剂的湿胶接强度(1.53 MPa)达到GB/T 9846—2004标准中Ⅰ类胶合板的指标要求,并且其热稳定性能得以明显提高;胺化木质素可以取代部分聚乙二醇,其含量对胶粘剂的力学性能和热稳定性能影响显著。

Study on synthesizing aminated lignin-based polyurethane adhesives

In order to improve active hydrogen number and reactivity of lignin,an aminated lignin,which purification lignin was modified by amine,was made by Mannich method.Then a PU(polyurethane) adhesive was synthesized by reaction between aminated lignin as part substitute of polyethylene glycol and isocyanate.The results showed that the lignin activity was obviously increased because nitrogen content introduced into aminated lignin was about 2.64%.The wet bonding strength(1.53 MPa) of the corresponding PU adhesive could meet index requirement of plywood-I class in GB/T 9846—2004 standard,and its thermal stability was obviously improved when mass fraction of aminated lignin was 25%.The aminated lignin could replace part polyethylene glycol,and the influences of aminated lignin contents on mechanical properties and thermal stability for adhesives were prominent.