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Structural heterogeneities of suspension poly(vinyl chloride). II. Formation of compact glassy particles and the cause of their difficult processing
Author(s) -
Lukáš Rudolf,
Michalcová Jaroslava,
Ková Věra Tyráč
Publication year - 1985
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1985.070300232
Subject(s) - vinyl chloride , polymerization , suspension polymerization , materials science , polymer chemistry , suspension (topology) , polymer , vinyl polymer , chemical engineering , polyvinyl chloride , radical polymerization , composite material , copolymer , mathematics , homotopy , pure mathematics , engineering
By modifying the polymerization process of suspension polymerization of vinyl chloride, poly(vinyl chloride) (PVC) samples were prepared containing various amounts of compact glassy particles. It was found that these particles probably arise by a different polymerization mechanism than usual suspension particles, namely, as a result of the nonhomogeneous distribution of initiator in vinyl chloride drops of the polymerization system. It was proved experimentally that the lower heat stability of difficultly processible particles is due to a side reaction between the initiator radical and the PVC polymer chain which causes dehydrochlorination of PVC already under polymerization conditions. This reaction may also explain the yet unknown mechanism of formation of internal double bonds in PVC produced by the radical polymerization of vinyl chloride. In conclusion, the difficult processibility of compact glassy particles is discussed as a consequence of the insufficient drying of these particles in the usual drying process.