Estudio de las propiedades termo-mecánicas y de inflamabilidad de mezclas poliméricas de PP con residuos sólidos pirolíticos de desechos vehiculares

Abstract

The final disposal of vehicles out of use gives rise to an environmental issue, so that, in Europe there are companies dedicated to the disassembly and recovery of those components that can be reused, among these components are plastic waste. In the present research, it is proposed to treat those plastics through a pyrolytic process with the purpose of transforming them into solid residue, in order to be used as part of the additives in a flame retardant system in a polypropylene matrix. Vehicle wastes were segregated by relative density method (ASTM D 792-08), characterized and were subsequently incorporated into a process of thermal pyrolysis. Using the resultant pyrolytic solid residue (PSR), a polymer mixture was prepared which had the polypropylene as matrix. Its thermal, mechanical and flammability properties were evaluated through the Thermogravimetric analysis, Modulus of elasticity, Tensile strength, Percentage of deformation and the Limiting oxygen index. Vehicle waste (DPV) are formed by 82.97% of high density residue, which allowed to obtain 32.08% of High density pyrolytic solid residue (HDSR), while using low density waste, 6.69% of Low density pyrolytic solid waste (LDSR) was obtained. Regarding its thermo-mechanical and flammability properties, it was noted that adding the PSR obtained from low density and high density wastes influenced the properties of the polypropylene matrix. As for their mechanical properties, if we compare the matrix formed by polypropylene and retarding additives with and without PSR; the maximum strength in the polypropylene matrix with LDSR showed a slight decrease, while the matrix with HDSR showed a slight increase. In addition, in the LDSR and HDSR samples, the percentage of deformation of the material decreased by 52.02% and 49.17%, respectively. While the modulus of elasticity was increased by 30.12% for the sample with LDSR and 30.73% with HDSR. Likewise, the addition of PSR did not increase its flame retardant activity since the Limiting oxygen index value remained the same as when flame retardant additives were added, in 30%; while with HDSR it decreased to 29%. This indicates that the composition of the above-mentioned solid residues favors to the polypropylene composites considering that the addition of the PSR brought with it the decrease of the concentration of other additives used and of the polypropylene. This due to the chemical composition of the pyrolytic solid residues that act as a source of carbon and flame retardant minerals reinforcing their fireproof properties.