| 摘要 |
<p>A method for breaking crosslinks in vulcanised rubber comprises swelling the rubber in a fluid at supercritical temperature and pressure followed by a rapid reduction in pressure (e.g. by using a release valve) so as to vaporise the fluid. Although the crosslinks are broken, the integrity and molecular weight of the rubber molecules is maintained. Preferably, the fluid is formed from a gas having a supercritical temperature of 120{C or less. The gas may be carbon dioxide, nitrogen, or a refrigerant. The supercritical fluid may also extract low molecular weight materials from the rubber, such as monomers, oils, waxes, and soaps. The vulcanised rubber may in the form of granules or other particulate material and may be derived from natural rubber or a synthetic polymer. The devulcanised rubber may be subsequently revulcanised or it may be used as a component in a new rubber composition.</p> |
