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|標題:||A Non-phosgene Route to Polyurea Using Diphenyl 4,4''-Methylene Diphenylcarbamate (DP-MDC) as The Key Precursor
由Diphenyl 4,4&;apos;&;apos;-Methylene Diphenylcarbamate (DP-MDC) 作為前驅物應用於非光氣法製備聚尿素高分子之研究
In this research, an improved non-phosgene process of making polyurea has been developed based on a method found previously in our laboratory. In the new process, diphenyl 4,4''-methylene diphenylcarbamate (DP-MDC), long-chained polyether diamines (eg., Jeffamines) and several different diamine extenders were carried out in the tetramethylene sulfone (TMS; bp 285 ℃) in replacing dimethyl solfoxide (DMSO) as the solvent in the polymerization. In our most desirable polymerization condition, the initial mixing temperature of 90 ℃ for 1 hours was initiated to start out the amination reaction, and that was followed by a subsequent step of vacuum distillation at about 140 ℃(under about 7×10-3mm of pressure) to drive off Phenol from the reaction mixture, in shifting the reaction equilibrium toward polyurea formation that lasted for 1-2 hours. After the distillation, the resulting polyurea was isolated by precipitation in water. TMS being a high boiling solvent could be separated from Phenol and water to recover > 90% after each runs. Through this rapid and efficient process, high yields and high molecular weights of polyurea were prepared with the recovery of the by-product and the solvent.
此研究為改善本實驗室先前所發展以非光氣法合成聚尿素高分子之綠色製程。在新的製程中，以溶劑Tetramethylene sulfone (TMS ; bp 285℃)取代先前使用的溶劑dimethyl solfoxide (DMSO)，將Diphenyl 4,4’-methylene diphenylcarbamate (DP-MDC)與長鏈聚醚二元胺(如Jeffamine)及數種不同二元胺(Diamines)直接進行聚合反應。本研究目前最合適的聚合條件為，一開始在溫度90℃下先反應1小時，此時amino group會和phenylcarbamate group進行胺化反應(Amination)，之後接續使用減壓蒸餾(約7×10-3mmHg)在140℃下1-2小時移除置換出之酚以驅使反應平衡朝向胺取代進行而生成聚尿素高分子。反應結束後，將此溶液直接倒入水中即可沉澱出聚尿素高分子，溶劑TMS經蒸餾回收後，其總回收率可達90%以上。透過此製程之改進，不僅可直接製備高產率及高分子量的聚尿素高分子，並且副產物酚與溶劑TMS亦可簡便地分離與回收。
|Appears in Collections:||化學工程學系所|
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