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Influence of chain structure and molecular weight of poly(vinylidene fluoride) on the morphology of its thermoreversible gels in acetophenone, ethyl benzoate, and glyceryl tributyrate
Author(s) -
Mal Sukumar,
Nandi Arun K.
Publication year - 1999
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/(sici)1521-3935(19990501)200:5<1074::aid-macp1074>3.0.co;2-m
Subject(s) - morphology (biology) , nucleation , polymer , polymer chemistry , scanning electron microscope , acetophenone , solvent , materials science , chemical engineering , fluoride , chemistry , organic chemistry , composite material , inorganic chemistry , engineering , genetics , biology , catalysis
The morphology of thermoreversible gels of three commercial poly(vinylidene fluoride) (PVF 2 ) samples in the three solvents acetophenone (ACTP), ethyl benzoate (EB), and glyceryl tributyrate (GTB) are studied by means of scanning electron microscopy (SEM). The PVF 2 /ACTP gels have a spheroidal morphology, the PVF 2 /GTB gels have a fibrillar morphology, and the PVF 2 /EB gels have a mixed morphology containing both the fibrillar and the spheroidal texture. The fibrillar and spheroidal radii increase with increasing gelation temperature and polymer concentration. At identical gelation condition the radii decrease with increasing head to head (H—H) defect structure in the polymer chain and also with increasing molecular weight. These results are explained with the nucleation and growth mechanism of polymer crystals in solution. It is concluded from this study that though a polymer/solvent compound formation is responsible for the fibrillar morphology it does not affect the nucleation and growth process controlling the radii of spheroids and fibrils.