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Thermal and rheological properties of acrylic copolymers possessing crystallizable polyester side chains
Author(s) -
Scholsky K. M.,
Orler E. B.,
Bixler K. J.,
Stackman R. W.
Publication year - 1991
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19910420118
Subject(s) - side chain , copolymer , polymer chemistry , materials science , polymer , polyester , crystallinity , prepolymer , crystallization , polycaprolactone , styrene , gel permeation chromatography , grafting , melting point , chemical engineering , chemistry , organic chemistry , polyurethane , composite material , engineering
Ring‐opening of ϵ‐caprolactone onto styrene/acrylic acid copolymers was found to occur readily in the presence of a styrene/acrylic acid copolymer at 220 °C. Gel permeation chromatography and extraction experiments utilizing supercritical CO 2 suggest that the caprolactone has grafted onto the polymer backbone as polyester side chains. DSC analysis of the modified polymers indicates that the grafted side chains lower the main chain T g , and when present at sufficiently high levels, contribute crystallinity to the modified materials. Both the melting point and heat of fusion of the modified materials were found to increase as a function of the amount of caprolactone grafted onto the prepolymer. It is unclear whether the formation of crystallites was the result of reaching a critical side chain length, a concentration effect, or a combination of both. The extent of grafting was also found to have a pronounced effect on the melt rheology and rates of crystallization of these materials presumably due to the increased free volume afforded by the polycaprolactone side chains.