Enhanced thermal properties of poly(lactic acid)/MoS2/carbon nanotubes composites

Abstract

In this work, few-layered molybdenum disulfide (MoS 2 ) was functionalized with metal oxide (M x o y ) nanoparticles which served as a catalyst for carbon nanotubes (cnt) growth in the chemical vapour deposition (cVD) process. the resulting MoS 2 /M x o y /cnt functionalized nanomaterials were used for flame retarding application in poly(lactic acid) (PLA). The composites were extruded with a twinscrew extruder with different wt% loading of the nanomaterial. Full morphology characterization was performed, as well as detailed analysis of fire performance of the obtained composites in relation to pristine PLA and PLA containing an addition of the composites. The samples containing the addition of MoS 2 /M x o y /CNT displayed up to over 90% decrease in carbon oxide (CO) emission during pyrolysis in respect to pristine PLA. Microscale combustion calorimetry testing revealed reduction of key parameters in comparison to pristine PLA. Laser flash analysis revealed an increase in thermal conductivity of composite samples reaching up to 65% over pristine PLA. These results prove that few-layered 2D nanomaterials such as MoS 2 functionalized with CNT can be effectively used as flame retardance of PLA.Greater use of conventional petroleum based commodity resins in various applications have led to inevitable rise of its ecological footprint. Various new eco-friendly biodegradable polymers were developed in order to counteract this effect. With its biodegradability, low emission of greenhouse gas and low production energy PLA currently stands as one of popular alternatives for conventional polymer materials 1 . Due to its high degree of transparency, good mechanical properties, low toxicity and ability to process using equipment as well as relatively low cost and large production volume it shows high potential for packaging, household and biomedical applications. Nevertheless, other potential applications such as in electronics or automotive industry require PLA grades with high impact strength, better processing ability and improved flame retardant behaviour 2 . In order to meet that demand novel methods of modification need to be developed and applied.A common way of improving flame retardancy of polymer is through combining its matrix with flame retardant filler. In the past improved flame resistance was achieved by introduction of halogenated flame retardants (HFR). Nowadays, it faces severe restrictions in Europe and North America due to the release of toxic substances and large amounts of smoke during combustion 3 . Instead, halogen-free flame retardant formulations function more commonly now as an environmentally friendly alternatives for HFR. These include intumescent flame retardants 4,5 , phosphorus-and nitrogen-containing micro-and nanoparticles 6-8 , inorganic substances and silica derivatives 9 which can be used either individually or in combination 10 to achieve optimal flame retardant performance.Polymer/layered inorganic materials composites have high potential for improving thermal properties of polymers. Mo...

Fabrication of Material Extrusion‐Based Carbon Nanotubes/Zinc Oxide Core–Shell Polylactic Acid Nanocomposite Filaments for Advanced Biomedical Applications

“…Regarding the initial and final degradation temperatures, all thermograms are linear, indicating a physical mixing of the PLA and CNS composite. [ 23 ]…”

“…Regarding the initial and final degradation temperatures, all thermograms are linear, indicating a physical mixing of the PLA and CNS composite. [23] The rate of degradation of the PLA/CNS composite filaments is characterized by the derivative thermogravimetric (DTG) thermograms derived from the TGA study. The rate of decomposition is maximum between 300 and 400 °C, as indicated in Figure 5b.…”

Recent Advances and Outlook in 2D Nanomaterial-Based Flame-Retardant PLA Materials

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ZnO nanowire‐decorated Al2O3/graphene aerogel for improving the thermal conductivity of epoxy composites

“…Therefore, fillers with excellent thermal conductivity are often added into epoxy resin matrix to improve its thermal conductivity. [10] At present, common fillers include metal materials, [11][12][13][14] ceramic materials [15][16][17][18][19] and carbon materials, [20][21][22][23][24] and so forth. Among them, alumina has the advantages of large filling capacity, good stability of particle size, so it is an ideal economic and suitable type of filler.…”

“…At present, common fillers include metal materials, [ 11–14 ] ceramic materials [ 15–19 ] and carbon materials, [ 20–24 ] and so forth. Among them, alumina has the advantages of large filling capacity, good stability of particle size, so it is an ideal economic and suitable type of filler.…”