水杨酸乙酯双封端异氰酸酯产物的合成及鉴定

研究了水杨酸乙酯双封端1,6 六亚甲基二异氰酸酯(HDI)的反应。讨论了温度、催化剂用量、加料方式、加料时间及反应时间对该反应的影响。用正交实验设计方法,优选了反应条件:n(水杨酸乙酯)/n(HDI)=2 4,反应温度85℃,反应时间10h,催化剂用量为HDI质量的1 0%。双封端产物产率(相对于合成粗产物而言)达到90 25%。用熔点和薄层色谱分析定性验证了产物质量。用红外光谱和气质联机分析证实了产物的结构。用热重分析(TG/DTA)测定产物热分解温度为116℃。

Synthesis and Identification of the Product of Hexamethylene Diisocyanate Diblocked by Ethyl Salicylate

The diblocking reaction between ethyl salicylate and hexamethylene diisocyanate was studied.Effects of temperature,dosage of catalyst and the rate and sequence of addition of reactants were investigated.The choice of reaction conditions was based on a Latin Square experimental design.The optimum conditions for blocking reaction were n(ethyl salicylate)/n(HDI)=2.4 at 85 ℃ for 10 h,with w(catalyst)/w(HDI)=0.01.Yeild of diblocked product(based on the crude product)was 90.25%.The crude product was purified by treatment with sodium bisufite followed by extraction with propanol.The purity and structure of the purified product were analysed and identified by melting point,TLC,IR and GC-MS.The thermal decomposition temperature of the purified product was 116 ℃ measured by TG/DTA.