摘要
以低沸点氯苯为溶剂,在加压条件下进行了六亚甲基-1,6-二氨基甲酸甲酯(HDC)液相催化热解制备六亚甲基-1,6-二异氰酸酯(HDI)的研究;通过TG-DTG技术对HDC热解过程进行了分析,筛选了催化剂,优化了工艺条件,并通过原位FTIR技术推测了HDC的催化热解机理。实验结果表明,HDC热解制备HDI分两步完成;优化的反应条件为:采用Co2O3催化剂、反应温度230℃、HDC含量为溶剂质量的2.5%、催化剂用量为HDC质量的5%、N2流量为600 mL/min、反应时间3 h,在此条件下,HDC的转化率可达100%、HDI收率可达83%左右。机理研究推测:Co2O3催化剂是通过进攻HDC的氨基甲酸甲酯基团上的C=O双键,最终使酯基断裂形成异氰酸根基团。
The catalytic thermal decomposition of 1, 6-hexamethylene dicarbamate（HDC） to 1, 6-hexamethylene diisocyanate（HDI） under pressure with chlorobenzene as the low-boiling solvent was studied. The HDC decomposition process was characterized by means of TG-DTG and in-situ FTIR. The results showed that, the decomposition was carried out by a two-step process. Under the optimal conditions of Co2O3 as the catalyst, reaction temperature 230 ℃, HDC mass fraction 2.5%（based on chlorobenzene）, catalyst mass fraction 5%（based on HDC）, N2 flowrate 600 mL/min and reaction time 3 h, the conversion of HDC and the yield of HDI reached 100% and 83%, respectively. The research for the reaction mechanism indicated that the thermal decomposition was due to Co2O3 catalyst attacking the C=O double bonds of the carbamate groups, which led to the ester groups breaking and the isocyanate forming
出处
《石油化工》
CAS
CSCD
北大核心
2013年第10期1141-1147,共7页
Petrochemical Technology
基金
国家科技支撑重大项目课题(2013BAC11B03)
中国科学院知识创新工程重要方向项目(KGCX2-YW-215)
