SYNTHESIS OF COMPOSITES FROM POLYVINYL ALCOHOL LOADED WITH RESIDUES OF PRINTED CIRCUIT BOARDS
Composites. 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. Regarding the thermal analysis, it was testified a reduction in the evaporation of the solvent mass and a production of residual mass crescent with the increasement of the charge percentage. This increase is due to the compound of silicon and metals present in the dust of the boards. On the flammability essay, it was possible to observe that the increase of dust board mass causes the increase of the flame propagation resistance on the composites, in consequence of the presence of compounds that act as flame-retardant on the printed circuit boards.