Microstructural analysis of methyl methacrylate lauryl methacrylate copolymers using 13C NMR spectroscopy

C-13 NMR spectra (75.5 MHz) of methyl methacrylate (M)-lauryl methacrylate (L) copolymers prepared by group transfer polymerization (GTP) were analyzed far sequence distribution and relative stereochemical configuration of monomer units along the macromolecular chains. The concentrations of M- and L-centered triads, determined experimentally from alpha-CH3 and C = O resonance signals, were in good agreement with those calculated statistically, taking into consideration the terminal copolymerization model and Bernoullian distribution of stereoregularity, with the statistical parameters P-ij determined from the reflectivity ratios r(M) = 1.38 +/- 0.11 and r(L) = 0.68 +/- 0.10 and the coisotacticity parameters sigma(MM) = 0.24, sigma(LL) = 0.27,sigma(ML) = sigma(LM) = sigma* = 0.30.