Identification of polymers in waste tyre reinforcing fibre by thermal analysis and pyrolysis

• Waste reinforcing fibre was studied as a mixture of fibre (or cord) and microfibre.
• The fibre was composed of Rayon, PET-Dacron and aramid.
• The microfibre contained Nylon 6,6, Nylon 6, Rayon and PET-Dacron.
• TGA, DSC, FTIR and GC–MS are accurate in determining the composition of polymer blends.

The composition of the reinforcing fibre obtained from the recycling of scrap tyres was analyzed with a view to finding the most suitable applications for it. The material (RF) was separated into two different parts i.e. fibre (F) and microfibre (MF) to ensure the maximum homogeneity of the material under study. Thermogravimetric analysis (TG) together with differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR) were used to identify the polymers present in the waste and to determine in what proportions they were present. Determination of the temperatures of maximum volatile matter evolution (Tmax), the yield at the end of the pyrolysis and the melting temperatures yielded very useful results for the identification of the polymers. In order to confirm the results obtained, pyrolysis of the pure polymers was carried out and the decomposition products were analyzed. The results were then compared with the oil composition data derived from the pyrolysis of the waste fibres. Our results showed the presence of two polyamides, rayon, polyester and aramid.