Experimental, Theoretical and Simulation Studies on the Thermal Behavior of PLA-Based Nanocomposites Reinforced with Different Carbonaceous Fillers.

Giovanni Spinelli,Rosella Guarini,Vittorio Romano,Rumiana Kotsilkova,Evgeni Ivanov

doi:10.3390/nano11061511

Giovanni Spinelli, Rosella Guarini + Show 3 more

Open Access

https://doi.org/10.3390/nano11061511

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Abstract

Many research efforts have been directed towards enhancing the thermal properties of polymers, since they are classically regarded as thermal insulators. To this end, the present study focuses on the thermal investigation of poly(lactic acid) (PLA) filled with two types of carbon nanotubes (trade names: TNIMH4 and N7000), two type of graphene nanoplatelets (trade names: TNIGNP and TNGNP), or their appropriate combination. A significant increase in the thermal conductivity by 254% with respect to that of unfilled polymer was achieved in the best case by using 9 wt% TNIGNP, resulting from its favorable arrangement and the lower thermal boundary resistance between the two phases, matrix and filler. To theoretically assist the design of such advanced nanocomposites, Design of Experiments (DoE) and Response Surface Method (RSM) were employed, respectively, to obtain information on the conditioning effect of each filler loading on the thermal conductivity and to find an analytical relationship between them. The numerical results were compared with the experimental data in order to confirm the reliability of the prediction. Finally, a simulation study was carried out with Comsol Multiphysics® for a comparative study between two heat sinks based on pure PLA, and to determine the best thermally performing nanocomposite with a view towards potential use in heat transfer applications.

Highlights

Nowadays, the high demand for custom-made products requires the development of new materials
Heat sinks are passive heat exchangers designed to dissipate the heat generated by electronic devices, transferring it, by natural or forced convection, to a surrounding fluid medium, or in any case away from the device, in order to regulate the increase in temperature resulting from the operation frequency in the electronics industry
It can be observed that, during the thermal transient, the temperature on each surface increases rapidly and, at the same time, the temperature difference between the lower and upper surfaces increases; subsequently, at around 600 s, the temperature profiles tend asymptotically toward constant steady-state values, so that the temperature differences between the lower and upper surfaces asymptotically tend toward a constant value; under steady-state conditions, the heat flow rate supplied at the lower surface is the same as that dissipated by natural convection from the upper surface and from the lateral surface

Summary

Introduction

The high demand for custom-made products requires the development of new materials. Polymers have been identified as promising candidates for this aim, to the point where their current impact on our lives is almost unquantifiable. Polymer-based products have been favorably adopted everywhere: synthetic fibers are increasingly being used for clothing production, plastic bags are adopted for multiple, epoxy glues (and them) are widely present in the field of adhesives, fiberglass or carbon-based reinforced composites are being used as structural parts, and so on, with the list being potentially endless [1]. Due to the increasing interest in environmentally friendly materials over the years, poly(lactic acid) (PLA) has aroused a great deal of attention, and it is being intensely investigated, in both industry and academia [4,5].

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