纤维素基环氧树脂及其木材胶粘剂粘接性能研究

Study on bonding properties of cellulose-based epoxy resin and its wood adhesive

以碱活化的纤维素为原料,通过与环氧乙烷(EO)发生接枝液化反应,合成了液体纤维素基环氧树脂(PHECEP)。然后以E-51为基体树脂,胺类T31为固化剂,硅微粉、硅烷偶联剂KH-560和PHECEP为改性剂,制备纤维素基环氧树脂胶粘剂,并对其进行力学性能、热性能和耐化学性等测试。研究结果表明:在PHECEP掺入量为20%时,抗冲击强度从2.9 kJ/m^(2)提升到50.9 kJ/m^(2);当PHECEP掺入量为5%时,室温下固化7 d的纤维素基胶粘剂拉伸剪切强度比纯E-51提高了171.1%。掺入PHECEP后,实际拉伸剪切强度高于测试中的强度,并且在小分子溶剂中耐受性更优良。通过PHECEP/E-51材料的力学性能、干湿粘接强度、热稳定性和耐化学性等性能的综合评判,得到相对最优的木材胶粘剂配方为:5%PHECEP(相对于E-51质量而言),1%的KH-560、60%的硅微粉和18%的T31固化剂(分别相对于PHECEP和E-51总质量而言)。

Liquid cellulose-based epoxy resin(PHECEP)was synthesized by grafting liquefaction reaction with ethylene oxide(EO)using alkali activated cellulose as raw material.Then,using E-51 as the matrix resin,amine T31 as the curing agent,silica powder,silane coupling agent KH-560 and PHECEP as modifiers,cellulosebased epoxy resin adhesive was prepared,and its mechanical properties,thermal properties,and chemical resistance were tested.The research results showed that,when the addition amount of PHECEP was 20%,the impact strength increased from 2.9 kJ/m^(2) to 50.9 kJ/m^(2).When the addition amount of PHECEP was 5%,the tensile shear strength of cellulose-based adhesive cured for 7 d at room temperature was 171.1%higher than that of pure E-51.After adding PHECEP,the actual tensile shear strength was higher than the tested strength,and the tolerance was better in small molecule solvents.Through the comprehensive evaluation of mechanical properties,wet/dry bonding strength,thermal stability,and chemical resistance of PHECEP/E-51 materials,the relatively optimal formula of wood adhesive was obtained as follows:5%PHECEP(relative to the mass of E-51),1%KH-560,60%silica powder,and 18%T31 curing agent(relative to the total mass of PHECEP and E-51,respectively).