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Butyl rubber reclamation by combined microwave radiation and chemical reagents
Author(s) -
Khavarnia Masumeh,
Movahed Saeed Ostad
Publication year - 2016
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.43363
Subject(s) - natural rubber , reagent , vulcanization , materials science , sulfenamide , swelling , sulfur , raw material , synthetic rubber , composite material , nuclear chemistry , chemical engineering , polymer chemistry , chemistry , organic chemistry , metallurgy , engineering
Rubber recycling is growing worldwide because of increasing raw material costs. In addition, extensive use of rubber articles and their eventual disposal is a major concern for the environment. Butyl rubber (IIR) was devulcanized by microwave radiation with the aid of devulcanizing reagents and oil. The effect of several devulcanizing reagents, hexadecylamine (HAD), diphenyl disulfide (DPDS), N ‐cyclohexyl‐2‐benzothiozyl sulfenamide (CBS), and tetramethylthiuram disulfide (TMTD) on devulcanization process, was studied. The investigation was carried out in various microwave radiation temperatures and different amounts of aromatic and paraffinic oils. The results showed that waste rubber powder with a median particle size of 279 μ m was devulcanized efficiently. It was confirmed when devulcanization % of the devulcanizates were measured by swelling tests. Among of the devulcanizing reagents and based on Horix analysis, HDA with the sol fraction, crosslink density (CLD), and devulcanization percent of 14%, 25 mol / m 3and 64%, respectively, was the most suitable devulcanizing reagent. In addition, compound with 30 and 6 phr paraffinic oil and HDA in formulation, respectively, had maximum devulcanization % (83%). The devulcanizing temperature of this compound was 180 ° C . For the most of all compounds, during microwave radiation, a part of disulfides crosslinks were broken and released sulfurs giving new mono and polysulfides bridges. This resulted in the higher CLDs for some compounds when they compared with CLD of the initial waste rubber. In the morphological study of the devulcanized compounds, vulcanized rubbers clearly showed in the SEM micrographs surrounded by a matrix of devulcanized rubber. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43363.