Functionalization of syndiotactic polystyrene with succinic anhydride in the presence of aluminum chloride

Syndiotactic polystyrene has been chemically modified with succinic anhydride by use of Friedel-Crafts acylation reaction in the presence of anhydrous aluminum chloride in carbon disulfide. The modified syndiotactic polystyrene containing -COCH₂CH₂COOH fragments in side phenyl rings, named succinoylated syndiotactic polystyrene (s-sPS), was characterized by FTIR and ¹H NMR spectroscopy. The effects of reaction conditions on the degree of succinoylation of s-sPS were investigated. In addition, the effects of incorporation of carboxyl groups into syndiotactic polystyrene on the thermal behavior were studied by differential scanning calorimetry in comparison with pure syndiotactic polystyrene. It was found that the crystallization temperature, melting temperature, and degree of crystallinity of the modified polymer decreased with increasing the degree of succinoylation, while the glass transition temperature increased.