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Blends of poly(ethylene terephthalate) with Co[poly(ethylene terephthalate‐ p ‐oxybenzoate)]. IV. Interchange reactions and their effects on the thermal and crystallization behaviors
Author(s) -
Ou ChengFang,
Lin ChenChong
Publication year - 1996
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/(sici)1097-4628(19960829)61:9<1455::aid-app4>3.0.co;2-i
Subject(s) - crystallization , materials science , ethylene , copolyester , polymer chemistry , melting point , chemical engineering , moiety , poly ethylene , polymer , composite material , organic chemistry , polyester , chemistry , catalysis , engineering
Poly(ethylene terephthalate) (PET) was blended with a co[poly(ethylene terephthalate‐ p ‐oxybenzoate)] (POB‐PET) copolyester which is a liquid crystalline polymer consisting of p ‐oxybenzoate and ethylene terephthalate units in a 40/60 mol ratio (P46). The level of P46 liquid crystalline polymer varies from 10 to 50 wt %. All the blends were prepared by melt‐mixing in a Brabender Plasticorder at 275°C for different times. The thermal and crystallization behaviors of blends depend on the blending time and the composition of blends, viz., the content of the p ‐oxybenzoate (POB) moiety incorporated into the blends. The interchange reactions detected by proton NMR analysis occur during the processing at a greater level if the blending time increases. The interchange reactions hinder the crystallization processes of PET and result in a decrease of the melting point, the heat of fusion, crystallization temperature, and the heat of crystallization of the original PET. The effects of the interchange reaction on thermal and crystallization behaviors of the blends may be attributed to the insertion of the rigid POB units into the soft PET chain. © 1996 John Wiley & Sons, Inc.