Análise dos parâmetros de soldagem e tensão superficial de polipropileno copolímero como requisitos de projeto de tubos de calor oscilante

Abstract

The use of polymer for flexible oscillating heat pipes (OHPs) has investigated for its potential in electronic component cooling. This study aimed to assess the significance of welding parameters and the material surface tension in the design process. It addresses the characteristics of heat pipes and material selection, with a particular emphasis on polymers. Additionally, the study investigates surface tension and its impact on thermal performance, as polymer welding while critically analyzing the existing literature on polymer OHPs. Random polypropylene copolymer (PPR) is used as the material, characterized using DSC, and pressed to produce tensile test specimens. Welding was analyzed by temperature, pressure, and welding time variation, evaluating their influence on mechanical resistance through tensile testing. In addition, test specimens are subjected to plasma treatment for varying durations, it was analyzed the contact angle of the droplet and post-plasma mechanical properties. The results indicate that welding parameters do not significantly affect the weld strength, whereas plasma treatment reduces the surface tension by more than 50%, without causing severe polymer degradation. Consequently, it is inferred that the use of welding protection methods is preferable to strict control of parameters. Furthermore, it is concluded that nitrogen plasma treatment can be employed to enhance the thermal efficiency of OHPs by promoting surface modification in hydrophobic polymers.