NMR analysis of the microstructure of poly(methyl acrylate‐co‐N‐vinylcarbazole)

Abstract

SYNOPSISThe microstructure of a series of high conversion copolymers of methyl acrylate (MA) and N-vinylcarbazole (NVC) was characterized by NMR. 'H-and 13C-NMR spectra were assigned by comparison to the homopolymers and by using heteronuclear shift correlation spectroscopy. MA-centered triad distributions were obtained from the carbonyl carbon. Distributions of NVC sequences were determined from aromatic carbons 1 and 8a, and aromatic proton 1.These experimentally determined sequence distributions were compared to those calculated from reactivity ratios approximated from the copolymer compositions. Agreement was very good for low NVC content copolymers. Three signals were particularly useful in providing rapid assessment of the distribution of NVC units within low NVC content copolymers: proton 1 and carbon 1 of NVC and the carbonyl carbon of MA. 0 1992

Comprehensive analysis of stereoregularity and sequence distribution in 2-N-carbazolylethyl acrylate and methyl methacrylate copolymers by 2D NMR spectroscopy and their thermal studies

“…The side chain -OCH 2 and -NCH 2 methylene carbons of C unit along with -OCH 3 carbon of the M unit appear as singlet around 62.07, 42.05 and 51.75 ppm, respectively, reflecting their insensitivity to compositional and configurational sequences. The aromatic carbons of the side-chain carbazole moiety appear as singlet in the region 108.62-140.23 ppm as reported by Dias et al [47,48].…”

Complete Spectral Assignment of Poly(N-Vinylcarbazole-co-Methyl Acrylate)s by NMR Spectroscopy

“…11 Correct assignments of the carbazole ring in poly(N-vinylcarbazole) are reported by Dias et al 12 The methine carbon resonances of both V and M units of the copolymer are sensitive to compositional sequences. The expanded region of methine carbon of the V unit in the DEPT-90 spectra of V/M copolymers with different mole fractions of V and the corresponding homopolymer is shown in Figure 3 MMV, and VMV triads respectively.…”

“…The crosspeaks 10-13 show relative change in intensity with the change in copolymer composition and are therefore assigned to compositional sequences. The crosspeaks centered at δ 1.40/4.10 (10) and at δ 1.80/4.40 (11) ppm are assigned to the coupling of the β-methylene protons in the VV centered tetrads (MVVV and MVVM) respectively with the methine protons in MVV triad and the crosspeaks centered at δ 1.85/4.10 (12) and at δ 2.00/4.40 (13) ppm are assigned to the coupling of the β-methylene protons in the MV centered tetrads (VMVV and MMVV) respectively with the methine protons in MVV. The crosspeak in the region around δ 1.90-1.40/3.80-3.15 (14) ppm is assigned to the coupling of the β-methylene protons in the VV dyad with the methine protons in VVV triad.…”

“…7 It is well known that NMR spectroscopy is probably the most effective method for characterizing the microstructure of polymers. [8][9][10] Crone and Natansohn 11 have reported the NMR analysis of microstructure of poly(methyl acrylate-co-N-vinylcarbazole). They have assigned the aliphatic and aromatic region in the proton spectra and aromatic region in the carbon spectra of the copolymers.…”