Kinetic study of styrene/maleic anhydride copolymers using succine anhydride as the model compound

The reaction of aniline with succinic anhydride, a low molecular weight poly[styrene-co-(maleic anhydride)], and a high molecular weight poly[styreneco-( maleic anhydride)] were used to determine if these polymer reactions are diffusion- or reaction-controlled. Kinetic study protocols were developed to determine the rate constants for the succinic anhydride/aniline model reaction and for the 50/50 and 86/14 copolymers. These protocols were then used to gather kinetic data. The succinic anhydride/aniline reaction was determined to be exothermic and to have an induction period. The succinic anhydride/aniline reaction was also determined to have an experimental rate constant of 13 L/molmin 25% at 67 +/- 1.5 degrees Celsius. For the copolymer/aniline reactions, the experimental rate constants at 67 +/- 1.5 degrees Celsius were determined to be .051 L/molmin 15% for the 50/50 polymer and .008 L/molmin 18% for the 86/14 polymer. The model reaction was found to be 250 times faster than the 50/50 polymer/aniline reaction and 1600 times faster than the 86/14 polymer/aniline reaction. The 50/50 polymer/aniline reaction was determined to be 6 times faster than the 86/14 polymer/aniline reaction. At 20 1.5 degrees Celsius, the theoretical diffusion-controlled rate constant for the succinic anhydride/aniline reaction was determined to be 7.09 x 10^11 L/molmin and the experimental rate of reaction was determined to be 0.72 L/molmin 25%. Thus, these reactions were determined to be reaction-controlled