氰酸酯/环氧树脂CE-40体系的固化反应

采用差示扫描量热(DSC)方法计算得到氰酸酯/环氧树脂CE-40体系反应动力学常数,分析了温度和浓度对反应速率的影响,同时结合红外光谱对各温度段发生的反应进行了推断。研究表明,CE-40体系有两个反应温度区——低温区(150℃-180℃)和高温区(200℃-250℃)。低温区是环氧与氰酸酯直接反应,产物为三聚氰酸酯和口恶唑啉,反应速率对浓度敏感,随反应物浓度下降而降低;高温区是低温区的生成物与环氧的进一步反应,主要产物为口恶唑烷酮和异氰酸脲,反应温度决定了反应速率。

Cure Reaction of CE-40 Cyanate Ester/Epoxy Resin System

The co-cure reaction of cyanate ester/epoxy resin CE-40 system was investigated by differential scanning calorimeter(DSC).The kinetic parameters were obtained from the exothermic curves.Effects of temperature and concentration on the rate of cure were analyzed.Cure reactions at several temperature stages have been concluded by DSC combined with the FT-IR results.The results show that cure reactions of CE-40 system mainly occur in two curing temperature regions——the lower reaction temperature ranges from 150 ℃ to 180 ℃ and the higher reaction temperature from 200 ℃ to 250 ℃.In lower reaction temperature region,the cyanate ester groups mainly trimerize and react with epoxy group directly to form the triazine ring and oxazoine.The curing rate is sensitive to content of cyanate ester and epoxy group and decreases with decreasing reactant concentration.However,at higher temperature,the above resultant triazine ring and oxazoine react with epoxy group to form oxazolidinone and isocyanurate.The reaction temperature dominates curing rate.