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Effect of Temperature on Dynamic Physical Behavior of Poly(vinyl chloride) Gel Structure with Ester Plasticizers
Author(s) -
Semsarzadeh M. A.,
Barikani S. M.,
Ansari M.
Publication year - 2006
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200690104
Subject(s) - plasticizer , vinyl chloride , gel point , materials science , viscoelasticity , polymer chemistry , lower critical solution temperature , glass transition , dissipation factor , polymer , phthalate , polyvinyl chloride , chemical engineering , composite material , dielectric , optoelectronics , engineering , copolymer
Dynamic viscoelastic properties of poly(vinyl chloride) (PVC)/bis(2‐ethylhexyl) phthalate (DOP) and PVC/di‐n‐butyl sebacate (DBS) gels with molecular weight distribution (M w /M n ), of 2.16 and various polymer concentrations c, have been studied as a function of temperature. These PVC gels exhibited an elastic solid at room temperature T, and gradually became liquid (sol) with increasing temperature. The sol‐gel transition took place at a critical gel temperature at which the scaling law of G′(ω) ∼ G″(ω) ∝ ω n held, allowing an accurate determination of the critical gel temperature by means of the frequency ω independence of the loss tangent. In this study the scaling exponent n, was 0.75–0.77. This is in good agreement with the previous results observed at different temperatures and suggests the formation of a similar fractal structure of the PVC gels. The gel strength S g , at the gel point increased with increasing PVC concentration. These results suggest a unique character and structure for the gel points of PVC‐plasticizers.