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Interfacial tension of polypropylene/polystyrene: Degradation of polypropylene
Author(s) -
Visscher E. J.,
Willemse R. C.
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11512
Subject(s) - polypropylene , polystyrene , materials science , polymer , surface tension , composite material , tension (geology) , polymer chemistry , thermodynamics , ultimate tensile strength , physics
The coefficient of the decrease of the interfacial tension of polypropylene/polystyrene with temperature is considerably higher than the value of other polymer pairs. This coefficient can be estimated by considering the change of the interaction parameters with temperature, but this approach fails for polypropylene/polystyrene, and other mechanisms are expected to play a role. In this paper it is shown that polypropylene starts to degrade at higher temperatures, leading to smaller polymer chains, which decrease the interfacial tension. Besides the change of the interaction parameters with temperature, these smaller molecules also contribute to the temperature coefficient, leading to an apparently high coefficient. The smaller molecules, however, lead to a permanent lower interfacial tension, e.g. the interfacial tension of polypropylene/polystyrene at 200°C is 4.9, 3.9, and 3.0 mN/m, if the polypropylene is first processed at 200, 250, and 300°C, respectively.