Premium
Synthesis of PVC‐ graft ‐PMMA Through Stereoselective Nucleophilic Substitution on PVC
Author(s) -
Martínez Gerardo,
de Santos Elena,
Millán José Luis
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010701)202:11<2377::aid-macp2377>3.0.co;2-6
Subject(s) - tacticity , chemistry , nucleophilic substitution , cyclohexanone , polymer chemistry , copolymer , sn2 reaction , triad (sociology) , stereoselectivity , vinyl chloride , sulfoxide , substitution reaction , organic chemistry , polymerization , polymer , catalysis , psychology , psychoanalysis
The substitution reaction of poly(vinyl chloride) (PVC) with potassium ethylxanthogenate was performed in cyclohexanone. The evolution of unreacted iso‐, hetero‐ and syndiotactic triad contents with degree of substitution has been followed by 13 C NMR spectroscopy. By comparing quantitatively the microstructure changes with degree of substitution and taking into account that the reaction is of S N 2 type, the substitution is proved to proceed exclusively through the mm triad of mmr tetrad, which enhances the stereoselective nature of the reaction. This conclusion was confirmed on the grounds of the FT‐IR results. From this stereospecific chemical modification of PVC the thiolation reaction through hydrolysis under basic conditions and, the subsequent reaction with methyl methacrylate in the presence of dimethyl sulfoxide offer a method for the preparation of stereoselective graft copolymers. After grafting no variation of the microstructure of the chain has been proved. This novel contribution is an original approach to the prominent role of the microstructure‐dependent local conformation in the mechanisms of reactions of PVC. These results have been used to study the effect of the aforementioned structures on the thermal stability of the graft copolymers and therefore provide new approaches to better comprehension at molecular level of the structure‐property relationships.