| 초록 |
Bisacetoacetamides 4 and 5 were prepared by the reaction of diamine compounds with diketene in N,N-Dimethylformamide (DMF) at 80 ℃ for 2 h. Bisacetoacetamides were reacted with diamines to yield low molecular weight linear polyureas having end amino groups. Oligomers were synthesised by means of phosgen-free method. End group analysis is used to determine the number average molecular weight of oligourea. Analytical methods for end amino group detection were a potentiometric titration and a nuclear magnetic resonance spectroscopy (NMR), and oligourea was also used as a comonomer for polyurea-imide. Polyurea-imide was prepared by the reaction of amine-terminated oligourea with pyromellitic dianhydride in N-methyl-2-pyrrolidinone (NMP). |
