COMPOSITIONAL SEQUENCE DETERMINATION OF ACRYLAMIDE ALKYL ACRYLATE COPOLYMERS BY NMR-SPECTROSCOPY

Acrylamide/ethyl acrylate (A/E) and acrylamide/butyl acrylate (A/B) co polymers were prepared by free radical solution polymerization. Copoly mer composition was determined from the nitrogen content of the copoly mers. The copolymer composition data were used to determine the reacti vity ratios for the copolymerization of A/E and A/B copolymer systems by Kelen-Tudos (KT) and nonlinear error in variables (EVM) methods. Th e reactivity ratios obtained are r(A) = 0.59 +/- 0.05 and r(E) = 0.91/-0.09 for A/E copolymer system and r(A) = 0.71+/-0.05 and r(B) = 1.27 +/-0.08 for A/B copolymer system. Microstructures in terms of the tria d distribution from C-13 NMR spectroscopy were found to be in good agr eement with those calculated from the theoretical models and Monte Car lo (MC) simulations. MC simulations were also used to determine the de gree of polymerization of the two copolymer systems.