Long-term performance of poly(vinyl chloride) cables, Part 2: Migration of plasticizer
2008 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 93, no 9, 1704-1710 p.Article in journal (Refereed) Published
Cable samples with plasticized poly(vinyl chloride) insulations were aged in air at temperatures between 80 and 155 degrees C. The concentrations of the plasticizer (di-(2-ethylhexyl) phthalate, DEHP) in the insulations of the aged cables were determined by extraction of samples in tetrahydrofuran followed by analysis of the extract by liquid chromatography. The plasticizer concentration data for different ageing times were analysed by numerical methods, fitting Fick's second law with a concentration-dependent diffusivity. The analysis showed that the transport of the plasticizer to the surrounding air phase was controlled by diffusion at 120 and 155 degrees C with an activation energy of 89 kJ mol(-1). The evaporation of the plasticizer from the outer boundary was rate controlling at lower temperatures (<= 100 degrees C), The rate of evaporation was initially constant and independent of the plasticizer concentration at both 80 and 100 degrees C. The activation energy for the initial DEHP loss rate from PVC at these temperatures was the same as that obtained for evaporation of pure DEHP on a glass plate at 60-100 degrees C measured by thermogravimetry, 98 2 kJ mol-1. Furthermore, the evaporation rate of pure DEHP on a glass plate was also of the same order of magnitude as the rate of plasticizer loss from the cable insulation. Extrapolation of the plasticizer loss rate data (from the cable at 80 degrees C and from pure liquid DEHP at temperatures between 60 and 100 IQ to 25 degrees C predicted a maximum loss of plasticizer of 1% over 25 years. This is in accordance with earlier presented data and with the data presented in this report.
Place, publisher, year, edition, pages
[Ekelund, M.; Azhdar, B.; Hedenqvist, M. S.; Gedde, U. W.] Royal Inst Technol, Sch Chem Sci & Engn, SE-10044 Stockholm, Sweden., 2008. Vol. 93, no 9, 1704-1710 p.
long-term prediction, evaporation, plasticizer migration, poly(vinyl chloride), BRANCHED POLYETHYLENE, PHTHALATE, POLYMERS, PVC, PARAMETERS, TRANSPORT, PRESSURE, KINETICS, HPLC
IdentifiersURN: urn:nbn:se:kth:diva-14089DOI: 10.1016/j.polymdegradstab.2008.05.030ISI: 000259795600013ScopusID: 2-s2.0-50849127815OAI: oai:DiVA.org:kth-14089DiVA: diva2:329635
QC 201007132010-07-132010-07-132010-11-04Bibliographically approved