Studies of Allyl Alcohol Radical Polymerization by PFG-HMQC and HMBC NMR at 750 MHz

Abstract

The structures of poly(allyl alcohol) were characterized by one-and two-dimensional gradient-enhanced heteronuclear multiple quantum coherence (gHMQC) and gradient-enhanced heteronuclear multiple-bond connectivity (gHMBC) NMR spectroscopy. Main-chain structures and chain-end structures were identified from the spectra. The polymerization of allyl alcohol can be described by degradative chain transfer to allyl alcohol monomers, which results in distinctive chain ends as well as low molecular weight polymers. After the allylic hydrogen abstraction by initiator radicals, allyl radicals produce chain ends with vinyl groups and aldehyde groups. The chain-end structures were identified by the correlation peaks in gHMQC and gHMBC spectra.

Structure–Property Relationship of Thin Plasma Deposited Poly(allyl alcohol) Films

“…Firstly, all spectra exhibit the stretching vibrations which are characteristic for poly (allyl alcohol): the mOH stretching vibration at *3,400 cm -1 associated with CH(as) at hydrogen by radicals, chain ends with vinyl groups and aldehyde groups can be obtained [1]. Therefore, the C=O stretching vibration characteristic for carbonyl bonds near 1,700 cm -1 is also found associated with mC=C at *1,660 cm -1 .…”

“…CH 2 CH CH 2 OH -H The radicals formed by H abstraction are resonance-stabilized and frequently result in termination by reaction with other propagating radicals. Therefore, the polymerization of allyl monomers produces low molecular weight products and unique chain-end structures [1,2].…”

“…The lines are guides for the eyes of allylic radicals have enol resonance structures, which can tautomerize to produce aldehyde.The allylic radicals formed in the abstraction reaction are relatively unreactive to other allyl monomers because of its resonance stabilization[1,28].The C1 s spectrum of the derivatized PAAl05 layer was deconvoluted into five peaks, including an additional component at 293.0 eV for the CF 3 bond. The following values are obtained for the concentration: (C-C/C-H): 35.49%, (C-O): 14.17%, (C=O): 17.70%, (COO): 16.60% and (CF 3 ): 16.03%.…”

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

“…Brar et al has studied extensively the microstructure of various (meth) acrylate copolymer systems by various NMR techniques [36][37][38]. In this article, we report the microstructure of poly(2-N-carbazolylethyl acrylate-co-methyl methacrylate) using high-resolution 1D ( 1 H, 13 C{ 1 H}, 90,45) and 2D (HSQC, TOCSY, HMBC) [35][36][37][38][39][40][41][42][43] NMR spectroscopy techniques. A comprehensive analysis of the complex and overlapped regions of 13 C{ 1 H} NMR spectra was done with the aid of various 2D NMR techniques.…”

Comprehensive Sequence Distribution Analysis of Butyl methacrylate-Acrylonitrile Copolymers by Two-dimensional NMR Spectroscopy

“…Hence, these 2D NMR experiments in conjugation with 1D technique furnish an efficient method for studying the microstructure of polymers. [23][24][25][26][27][28][29][30][31][32][33][34] Lot of work has been reported in literature [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] regarding acrylonitrile and alkyl methacrylate copolymers. Recently, Yeo et al 51 characterized acrylonitrile/methyl methacrylate copolymers by FT-IR, DSC, TGA, 1 H NMR and 13 C NMR.…”