Influência da adição de Grafeno, obtido por esfoliação eletroquímica, nas propriedades térmicas e mecânica do Prolipropileno

Abstract

Thermal conductivity, the ability of bodies to transfer heat, is an important property used in the industrial environment to determine the efficiency gain of products such as solar collectors, cooling fins, among others, as well as the tensile strength, which presents the efforts, which the studied materials can be submitted, such as application in collectors. One possibility of increasing thermal conductivity is the addition of materials that promote energy transfer. Graphene, a recently isolated material, has the highest heat transfer currently known under natural conditions. This work aimed to mix graphene in polypropylene, in the formation of a nano composite, in order to observe the variation of thermal conductivity and mechanical tensile strength for possible application in solar collectors. Therefore, graphene was synthesized by electrochemical exfoliation; synthesis, data processing, Raman spectroscopy, infrared with Fourier transform, x ray diffraction were performed. With these data we identified, with greater reliability, that the material obtained would in fact be graphene. From the identification of the material, samples (cylinders) were made with CP741 polypropylene pellets, supplied by the solar collector company HELIOSSOL. The cylinders were obtained through the thermoforming process with constructive dimensions of cylinders of (100X25) mm. Subsequently, the samples were subjected to tests according to the hot wire method according to DIM 5110 046 parts 1, to determine their thermal conductivity and mechanical traction, according to ASTM D638 - 10, to observe the mechanical properties between to samples. The result obtained in the sample with graphene (nano composite) showed thermal conductivity, 20% higher than the sample without the addition of graphene; while the tensile strength obtained results lower than expected; however, in the case of solar collectors, the impact of this loss of traction does not suppress the thermal gain obtained. Thus, it was possible to prove a satisfactory functionalization for application in solar collectors.