Download or read book Characterization and Surface Modification of Rubber from Recycled Tires written by Huan Liang and published by . This book was released on 2015 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: End of life tires raise severe environmental problems and must be disposed of or recycled. Due to their cross-linked structure, they do not melt or dissolve, and are usually ground into a powder (ground tire rubber or GTR) and mixed with a matrix (asphalt or a thermoplastic polymer) for reuse. The recycling industry encounters two main problems. First, quality control is difficult due to the lack of solubility of the powder and to the limited technical means of these small industries. Rapid and low-cost methods are needed to improve characterization of GTR. This work focused on the use of these two techniques and of X-ray fluorescence spectrometry (XRF), as there are reports in the literature showing than these may be used, respectively, to determine cross-link density, monomer and elemental composition. The second problem is the poor adhesion between most polymers and GTR, resulting in parts that lack mechanical strength and tend to crumble. Some studies focus on adding monomer and initiator to GTR and doing in-situ polymerization of graft chains onto the surface. However, molecular weight of grafts is unknown and it is not possible to verify if the molecular weight is above the chain entanglement molecular weight. Photochemical reactions were used to graft thiol-terminated polymer chains of known molecular weight by using free carbon double bonds that exist on the GTR surface. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were used to detect the surface changes and graft degree. Mechanical properties measurement was used to monitor the treated samples blends with polystyrene matrix.