Premium
Thermal aging of plasticized PVC. I. Weight loss kinetics in the PVC—didecylphtalate system
Author(s) -
Audouin L.,
Dalle B.,
Metzger G.,
Verdu J.
Publication year - 1992
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.1992.070451204
Subject(s) - activation energy , arrhenius equation , kinetics , diffusion , thermodynamics , polyvinyl chloride , vinyl chloride , materials science , kinetic energy , evaporation , chemistry , polymer chemistry , analytical chemistry (journal) , polymer , composite material , chromatography , copolymer , physics , quantum mechanics
Weight‐loss kinetics were studied for 10 industrial extruded samples of poly(vinyl chloride) (PVC) plasticized by 20–30% by weight of didecylphtalate at 85, 95, 105, 110, and 120deg;C. For the most unstable samples, which contained a light coplasticizer, the weight‐loss rate obeyed Fick's law. In the other cases, it was constant in the early period of exposure. The apparent Arrhenius parameters (i.e., preexponential factor and activation energy) were intercorrelated and varied strongly from one sample to another. This was explained by the existence of two distinct kinetic regimes corresponding, respectively, to diffusion or evaporation, the whole process being controlled by the slowest step, and a transition between both regimes occurring in the temperature range of exposure. In the proposed model, small changes of the preexponential factor of diffusion from one sample to another are sufficient to take into account the observed behavior.