Monomer unit sequence distribution and linkage configurations at citraconic anhydride units in the copolymers of citraconic anhydride and styrene prepared in carbon tetrachloride

摘要

The triad monomer unit sequence distribution and the cis and hans Linkage configurations at the cyclic citraconic anhydride units are quantitatively determined for the copolymers of citraconic anhydride (alpha-methylmaleic anhydride) (CA) and styrene (ST) prepared with AIBN in CCl4 solutions at 50 degrees C. Semi-alternating copolymers are obtained for most feed compositions with rigidly alternating copolymers being formed when CA in feed is more than 90%. Greater than 50% of the linkages at CA units are found to be in cis configuration in semi-alternating copolymers. This may be explained if the donor-acceptor complex formed between CA and ST participates in the copolymerization.