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Stereoselective Nature of Graft Copolymers Based on Poly(vinyl chloride): Synthesis of PVC‐ g ‐PMMA and PVC‐ g ‐PIB
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(20010801)202:12<2592::aid-macp2592>3.0.co;2-g
Subject(s) - tacticity , polymer chemistry , copolymer , cationic polymerization , vinyl chloride , isobutylene , polymer , chemistry , methyl methacrylate , polyvinyl chloride , polymerization , reactivity (psychology) , materials science , organic chemistry , medicine , alternative medicine , pathology
Graft polymers from poly(vinyl chloride) with side chains of poly(methyl methacrylate) and poly(isobutylene) obtained by free radical and cationic techniques, respectively, were synthesized. The graft products were separated from the resulting mixtures of homo‐ and copolymers by fractional precipitation or extraction. The graft copolymers were characterized by infrared spectra, elemental analysis, NMR, and osmometric determinations. The quantitative microstructural analysis after grafting reaction has been followed by 13 C NMR spectroscopy. From the results it is concluded that the modification of PVC by graft reactions through free radical and cationic polymerization proceeds by a stereoselective mechanism in that a fraction of isotactic triads is involved. Comparing the results obtained herein and those previously obtained in the nucleophilic substitution on PVC it is concluded that the highly reactive GTTG – isotactic triad conformation which is likely only at mmr tetrad has an apparent implication on the reactivity of the graft reaction. This conclusion was confirmed on the basis of the FT‐IR and the thermal stability of the graft copolymers. This work provides some new insight into the prominent role of the microstructure‐dependent local conformation on the polymer properties.