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Recycling of roofing membrane rubber by ultrasonic devulcanization
Author(s) -
Yun Jushik,
Isayev A. I.
Publication year - 2003
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.10067
Subject(s) - materials science , vulcanization , natural rubber , composite material , ultimate tensile strength , ultrasonic sensor , membrane , thermal stability , chemical engineering , physics , biology , acoustics , engineering , genetics
The recycling of vulcanizates based on EPDM roofing membrane rubber using a new ultrasonic devulcanization reactor with a grooved barrel was carried out. This reactor provided continuous devulcanization at an output as high as 2.52 g/s. Die pressure and ultrasonic power consumption were measured as a function of processing conditions. The mechanical properties of virgin vulcanized and revulcanized roofing membranes were measured. Tensile strength of the revulcanized rubber was found to be similar to that of the virgin vulcanizate. Gel fraction, crosslink density, and dynamic properties of the virgin vulcanizate, the ultrasonically devulcanized rubber, and the revulcanized rubber were determined. Also, dynamic properties and the cure behavior of the virgin compound and of the devulcanized roofing membrane were investigated. All these properties were found to be dependent on processing conditions during devulcanization. The thermal stability of the virgin compound, virgin vulcanizate, and devulcanized and revulcanized rubbers were studied by means of TGA. It was found that the thermal stability of all the vulcanizates in air and nitrogen environments remained practically intact, while that of devulcanized rubber in air environment was a function of processing conditions.