Microstructure Study of Poly(isobutyl Acrylate) and Poly(sec-Butyl Acrylate) by Incremental Analysis of 13C NMR Spectra

Microstructure of poly(isobutyl acrylate) (PiBuA) and poly(sec-butyl acrylate) (PsBuA), prepared by free radical and anionic polymerization, was investigated by 13C NMR spectroscopy. The carbonyl signal in the 100 MHz 13C NMR spectra of both homopolymers provided sufficient resolution to perform detailed analysis of distribution of configurational sequences at the pentad/heptad level. Application of Bernoulli and first order Markov statistics to determine probabilities of configurational sequences and incremental calculation to estimate chemical shifts of the individual sequences allowed for positive simulation of carbonyl signals.