Determination of triad sequence distribution of copolymers of maleic anhydride and its derivates with donor monomers by 13C n.m.r. spectroscopy

Abstract

Several alternating and semi-alternating copolymers were analysed by quaternary 13C n.m.r. spectroscopy. The aromatic 'next to polymer chain' carbon (C7) of donor monomer (1) units is sensitive to the unit 1-centred triad sequence distribution. The acceptor monomer is referred to as 0. The chemical shifts of the non-alternating (111), semi-alternating (011+110) and alternating (010) triad sub-peaks were assigned in ppm in Copolymer of monomer with monomer 1111 011 (+) 110 010 triad sequenceMaleic anhydride with styrene147.5145146141.5140.5136.5Maleic anhydride with trans-stilbene138132Maleic anhydride with α-methylstyrene152148148 (145.5)142.5139Maleic anhydride with allylbenzeneNot sensitive to triad sequence distribution and appears at 142-139 ppmCitraconic anhydride with styrene147.5145147143.5137.5Bromomaleic anhydride with styrene147.5145141.5140136.5Dichloromaleic anhydride with styrene147.5145141.5138133Maleimide with styrene147.5145140.5136.5.