Macromolecules, Vol.28, No.22, 7363-7369, 1995
Stereochemical Structure of Poly(Cyclohexyl Acrylate) Studied by One-Dimensional and 2-Dimensional C-13-H-1 Spectroscopy
The stereochemical structure of poly(cyclohexyl acrylate) (PCHA) prepared under different polymerization conditions was studied by the combination of one- and two-dimensional C-13 NMR methods. The assignments of the triad, tetrad, and pentad signals were carried out according to conformational and configurational approaches. In general, the sensitivity of the observed C-13 NMR signals assigned to sequences of triad and tetrad is well reproduced by the C-13 chemical shifts estimated via the gamma-gauche effect method. For PCHA prepared by radical and anionic polymerization (using different solvents and catalysts), a first-order Markov model is required to fit the observed intensities at the tetrad and pentad level, rather than the classical Bernoullian statistics.
Keywords:NMR CHEMICAL-SHIFTS;METHYL-METHACRYLATE;MODEL COMPOUNDS;POLYACRYLATES;POLYVINYL-CHLORIDE);COPOLYMERS;RELAXATION;POLYMERS;SPECTRA