CAJ | 학술논문

对无溶剂条件下金属氧化物催化苯氨基甲酸甲酯(MPC)热分解制备苯异氰酸酯(PI)的反应进行了研究，控制适宜的加热温度和绝对真空度，产物PI和甲醇以蒸气状态分离出反应器，使分离与热解反应同时进行，再采用分段冷凝的方式将PI和甲醇分离并收集，发现金属氧化物中氧化锌(ZnO)具有较好的催化活性。考察了制备方法对ZnO催化性能的影响，结果表明以碱式碳酸锌热分解制备的ZnO，在400℃焙烧时性能最好。对ZnO催化剂进行了XRD和TEM表征，发现催化剂颗粒大小是影响催化性能的重要因素，最佳的催化剂粒径为40 nm左右。当ZnO用量为MPC用量的1%(wt)，在加热温度为200℃，绝对真空度为100 mmHg时，MPC转化率为57.2%，PI选择性为91.1%。与溶剂法相比，该方法可得到更高浓度的目标产物，并减少分离提纯的能耗和污染。
대무용제조건하금속양화물최화분안기갑산갑지(MPC)열분해제비분이청산지(PI)적반응진행료연구，공제괄의적가열온도화절대진공도，산물PI화갑순이증기상태분리출반응기，사분리여열해반응동시진행，재채용분단냉응적방식장PI화갑순분리병수집，발현금속양화물중양화자(ZnO)구유교호적최화활성。고찰료제비방법대ZnO최화성능적영향，결과표명이감식탄산자열분해제비적ZnO，재400℃배소시성능최호。대ZnO최화제진행료XRD화TEM표정，발현최화제과립대소시영향최화성능적중요인소，최가적최화제립경위40 nm좌우。당ZnO용량위MPC용량적1%(wt)，재가열온도위200℃，절대진공도위100 mmHg시，MPC전화솔위57.2%，PI선택성위91.1%。여용제법상비，해방법가득도경고농도적목표산물，병감소분리제순적능모화오염。
Solvent-free synthesis of phenyl isocyanate (PI) by thermal decomposition of methyl N-phenyl carbamate (MPC) with metal oxides as the catalyst was studied. The temperature and vacuum conditions were kept optimal to obtain PI and methanol vapors, which were then separated and collected by condensation. The results show that zinc oxide (ZnO) has better activity than other metal oxides used, and ZnO prepared by calcinating basic zinc carbonate at 400℃ shows best performance. XRD and TEM results show that the particle size of the catalysts has remarkable effect on the catalytic performance, and the optimal particle size is approximately 40 nm. Under the optimum reaction conditions (ZnO/MPC:1 wt%, heating temperature:200℃, vacuum value:100 mmHg), the conversion of MPC and the selectivity of PI are 57.2%and 91.1%, respectively. Compared with reactions under solvent condition, higher PI concentration can be obtained in the solvent-free method. Moreover, energy consumption and potential pollution can be reduced during separation and purification.