摘要
合成了一种低醛 /酚摩尔比 (1.3∶1)的Resol型酚醛预聚物。利用TG -MS详细研究了热交联固化后树脂的热分解特征。低于 35 0℃时 ,主要表现为分子内醚键断裂和脱端羟甲基 ,并逸出H2 O、CO2 和CH3 OH等产物及它们的碎片。在 35 0℃～ 75 0℃范围内 ,大分子主链在不同位置发生主链断裂而形成一甲基苯酚、二甲基苯酚和三甲基苯酚等产物及它们的碎片。
Resol type phenol/formaldehyde prepolymer is synthesized at lower molar ratio of formaldehyde / phenol (1.3∶1).Pyrolysis behavior of the phenolic resin thermally cured is investigated by thermogravimetric mass spectra(TG MS). As the pyrolytic temperature is lower than 350℃, mainly the cleavage of intramolecular ether linkage and the removal of end hydroxymethyl occurs,and some molecules such as H 2O, CO 2, and CH 3OH and their fragments are detected. As the pyrolytic temperature is between 350℃ to 750℃, the bond cleavage occurs at different positions of the phenolic resin main chain, and methyl phenol,dimethyl phenol, and trimethyl phenol and their fragments are observed, implying that the improvement of thermal stability of phenolic main chain might be one of the key factors to avoid the defects in Resol type phenolic resin based C/C composites.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2003年第1期18-23,共6页
Aerospace Materials & Technology
