SYNTHESIS OF COMPOSITES FROM POLYVINYL ALCOHOL LOADED WITH RESIDUES OF PRINTED CIRCUIT BOARDS
Polyvinyl alcohol. Flame retardants. Printed Circuit Boards.
The renewal of technology causes the increase of electronical waste on the environment. The search of methods for the treatment of these wastes generate big discussions in national ambit as well as in an international ambit. The printed circuit board originating from obsolete equipment rises great interest in researches, since they have diverse metals in their composition which can be recovered. However, the studies that seek to recover the substrate originating from the withdrawal of metals are still scarce. Composite materials have been largely researched and because they provide improvements on the mechanical, thermal and physiochemical properties of materials to determined applications. On this context, it was developed composites with printed circuit board residue, having as a matrix polyvinyl alcohol. It was used 5%, 10%, e 20%, in mass, of board dust to produce the composites, which were submitted to thermal analysis (TG/DTG/DSC). The mechanical properties (abrasion and friction coefficient) were determined by mechanical essays pin-on-disc. The topography of the surface was analyzed by Scanning Electron Microscope. Next, the samples passed through the test of flammability to evaluate the behavior of them before the flame. Based on the results of the mechanical essay, it was verified that there was not significant variation on the friction coefficient and abrasion of the materials. In relation to the thermal analysis, there was a reduction of the thermal stability of the composites. In the flammability test, it was possible to observe that the increase of the mass of the powder plate causes the increase of the flame propagation resistance in the composites, due to the presence of compounds that act as flame retardants in the printed circuit boards. The analysis of SEM images indicated good adhesion of the fibers on the surface of the matrix and allowed the analysis of the wear path of the composites.