STEREOCHEMICAL STRUCTURES OF SOME POLYACRYLATES STUDIED BY ONE-DIMENSIONAL AND 2-DIMENSIONAL C-13-H-1 NMR-SPECTROSCOPY

The stereochemical structures of samples of poly(ethyl acrylate) (PEA) , poly(butyl acrylate) (PBuA) and poly(2-ethylhexyl acrylate) (PEHA), prepared by group transfer and anionic polymerization, were studied by C-13 and H-1 n.m.r. spectroscopy. The main-chain CH2 Spectral range w as analysed by the application of the inverse C-13-H-1 HETCOR two-dime nsional n.m.r. technique. A very similar HETCOR pattern was found for all polymers studied. In all cases, main-chain CH2 lines in the H-1 an d C-13 n.m.r. spectra could be assigned to configurational tetrads; fo r PEA and PBuA a partial assignment of carbon resonances to configurat ional hexads was possible. While PEHA prepared both by group transfer and anionic polymerization and PEA prepared by group transfer polymeri zation can be well approximated by Bernoullian statistics, for PEA and PBuA prepared by anionic polymerixation a first-order Markov model is required to fit the observed intensities at the hexad level.