A novel method combining a conventional free-radical solution polymerization with a chemical saponification was used to synthesize a, cu-dicarboxyl terminated oligo (butyl methacrylate) s (di-CTBMA) with molecular weight below 1500. Here, cn-carboxyl terminated oligo (butyl methacrylate) s (CTBMA) were firstly synthesized by the free-radical polymerization in THF, where 4,4'-azobis(4-cyanovaleric acid) was used as initiator, thioglycolic acid as chain transfer agent, then CTBMA were transformed into di-CTBMA via saponifying CTBMA in dioxane/H_2O/KOH solution. The influences of important reaction parameters, such as the type of organic solvent, react time on the structures of the saponified substances were monitored by determination of functionality / via acid-base titration, MALDI-TOF-MS and ISMS analysis. It shows that di-CTBMA with the functionality of about 2 could be obtained under a certain reaction parameter.

Key words: METHYLPROPENOIC ACID ESTER;LOW POLYMER;FREE REDICAL POLYMERIZATION, MS;DIOXANE;WATER;POTASSIUM HYDROXIDE;SAPONIFICATION