The mechano-chemical reactions in elastomers
Polimery 1997, No 7-8, 450
The chemical reactions induced by mechanical energy imparted toelastomer molecules ("mechanochemical reactions”) were reviewed starting with Hancock's (1820) fundamental work. They accompany each rubber processing step including cold and hot mastication (mechanochemical degradation), formation of rubber bound with (cold and hot processed mixes) carbon black or white fillers, and preparation of grafted and block copolymers by comastication of different rubbers. These reactions can initiate block or graft copolymerization of vinyl monomers with masticated rubber and functionalization of rubber by reactants, e.g., amines, maleic acid esters, etc., carrying suitable chemical groups. The resulting products can serve as compatibilizers of immiscible rubber—rubber or rubber—plastic systems, as macromolecular antioxidants, and asmix additives for reactively processed rubbers. On daily use of rubber goods, the reactions play a special role. Mechanical stress can initiate thermooxidative aging processes or promote oxidation in vulcanized rubber on abrasive wear. Modem mechanochemical recycling methods applied to rubber scrapand to used-up rubber, especially spent car tyres, take resort in devulcanization ("De Link Process”) and in ultrasonic treatment.