NMR studies of ionomers. 3. Synthesis and microstructure of poly(ethyl acrylate‐co‐lithium acrylate)

Copolymers of ethyl acrylate (EA) with lithium acrylate (LiA) with relatively low contents of LiA units (up to 30%) were synthesized by alkaline hydrolysis of poly(EA). 13 C‐NMR spectra of these copolymers registered in a mixture of deuterated benzene with deuterated methanol (85:15 v/v) presented configurational splittings of the ester methylene, methylene main chain, and ester carbonyl group signals. Assignments of these splittings were made and Bernoulli statistics with a meso probability of 0.48 could fit both poly(EA) and poly(EA‐co‐LiA). Only the CO signal of the copolymer was sensitive to sequence distribution and indicated that the LiA units have a tendency to be isolated on the chain. Two‐dimensional HETCOR pulse sequence helped to assign the main chain proton spectrum.