A kinetics analysis of the continuous decrosslinking process of silane crosslinked polyethylene under supercritical methanol condition
Baek Bum Ki (1), Na Won Jun (1), La Yun Ho (1), Hong Soon Man (1)*, Han Haksoo (2), Koo Chong Min (1)
(1) Korea Institute of Science and Technology - Seongbuk-gu - Korea, (2) Yonsei University - Seodaemun-gu - Korea
The continuous recycling process of silane crosslinked polyethylene (silane XLPE) in supercritical methanol was investigated. The variation of gel contents with supercritical reaction temperature and reaction time was kinetically investigated. The kinetic parameters in the process were obtained and calculated on the basis of the experimental data. The complete decrosslinking reaction of silane XLPE was accomplished at 380°C within 12 min, and at 390°C within 4 min. The increase in reaction temperature and reaction time could expedite decrease in gel contents of XLPE products. The chemical kinetics of decrossinking reaction was proposed based on the gel concentration. The decrosslinking rate of XLPE was fitted well with the first order reaction model and the correlation value was 0.94397. The calculated kinetic constants at 360°C, 380°C, and 390°C were 0.288 ± 0.0228 min-1, 0.621 ± 0.0478 min-1, and 0.897 ± 0.0320 min-1, respectively. The value of activation energy was 131.68 kJ/mol.