Patent ID: 7166304

Claim:
A compound represented by the formula: CH 2 ═CZ-CO 2 -POLY-W-POLY′-Q where Z represents H or alkyl; POLY and POLY′ are poly(alkylene oxide) groups that can be the same or different and are represented by the formula —(CH 2 CHRO) n —CH 2 CHR— in which R is H or alkyl, and n ranges from about 10 to about 4000; Q represents a functional group; and W represents a hydrolytically unstable linkage selected from —O(CH 2 ) m —CO 2 R 1 —CO 2 —, and —O—(CH 2 ) m —CO 2 — where m ranges from 1 to 10, and R 1 is —CH 2 —, —CH 2 CH 2 — or —CH(CH 3 )CH 2 —.