| 摘要 |
1289548 Cellulose carbonates RANKS HOVIS McDOUGALL Ltd 3 Dec 1970 [18 Dec 1969] 61701/69 Heading C3A Cellulose carbonates are prepared by reacting cellulose or 6-substituted cellulose with an alkyl or aryl chloroformate in dimethylsulphoxide, dimethylformamide or mixtures thereof with other miscible organic solvents devoid of -OH, -SH, -NH, and -NH 2 groups. The reaction is preferably carried out using methyl, ethyl, phenyl or benzyl chloroformates, optionally in the presence of a base such as triethylamine. The 6-substituted cellulose may be methyl, hydroxyethyl, carboxymethyl or diethylaminoethyl cellulose and the products may be transfused cyclic carbonates, e.g. 2,3- or may contain o-ethyloxycarbonyl groups or mixtures of both. The carbonates so prepared may be further chemically modified for example by treatment with ammonia or benzylamine. |
