| 摘要 |
A polymer containing repeating units having the formula I <FORM:1114545/C3/1> in which R1 represents a group -CH2COOH, <FORM:1114545/C3/2> or -CH2CH)COOH)2 may be prepared by reacting any poly(vinyl alcohol), having an inherent viscosity measured in water of 0.2 to 0.9, with an isocyanate of formula R2.CNO in which R2 represents a group <FORM:1114545/C3/3> or -CH2.CH(COOR)2 where R is an alkyl group, and then hydrolysing the product. Homopolymers containing units of Formula I or copolymers containing at least 20 weight per cent of units of Formula I, the remaining unit having Formula II <FORM:1114545/C3/4> where y is a hydroxyl, an ester, an N-alkylamide an N,N-dialkylamide group or a group -OCONH.R2.COOR3, where R2 and R3 are each alkyl groups containing up to five carbon atoms, may be prepared. In the examples the isocyanate employed are carbethoxy methyl isocyanate and diethyl a -isocyanato succinate. |
