Specifics of the Surface of Tire Crumb Regenerate Produced by the Explosive Circulation Method

Abstract

A complex analysis of the crumbed rubber produced by the explosive circulation method has been performed by the methods of AFM, X-ray diffraction, gas chromatography, mass spectrometry, and gel-permeation chromatography (GPC). The results of the small- and wide-angle X-ray diffraction study have revealed an amorphous structure of the samples without supramolecular ordering at a distance scale of ~1–40 nm. Globular formations of a size of 5–20 nm on the crumb surface combined into clusters of various shapes and sizes in the range 100–1000 nm have been found by means of the AFM method. Individual nanoglobules and small and large clusters of these nanoglobules appeared to be randomly covering the surface of the examined samples. It has been established that the nanoglobules partially consist of saturated and unsaturated hydrocarbons of low-molecular weight, which belonging to classes of linear, cyclic, and aromatic compounds. Most of the nanoglobules are represented by oligomeric products having 3–5 units, as well as compounds of higher molecular weight. All of the above compounds provide better adhesion of the regenerate to different matrices than that produced by other methods. The composition of the nanoscaled globules includes secondary products of reactions of low-molecular hydrocarbons formed from rubber tires at their explosive circulation grinding.