Enhancement of the Mechanical Properties of PEBAX Graphene Nanocomposite Using Supercritical Fluid Assisted Extrusion Polymer Processing Technique

Abstract

Medical tubing used in minimally invasive devices presents a number of design considerations depending on the material used, design requirements (such as sufficient stiffness, flexibility and biocompatibility) and processing conditions. Currently, manufacturing industries adopt co-extrusion systems to meet design specifications, by using multilayer configuration leading to higher cost per device and increased complexity. This paper investigates the mechanical performance of nanocomposites using supercritical carbon dioxide assisted polymer processing technique. The use of innovative medical compounds such as PEBAX graphene nanocomposites have resulted in measurable improvements in mechanical properties. This study also presents the effect of supercritical carbon dioxide on the mechanical and physical properties of the polymer matrix. The mechanical properties have been investigated using dynamic mechanical analysis (DMA) and mechanical tensile test, where sufficient reinforcement was observed depending on the composition of graphene within PEBAX matrix. ATR-FTIR was used to further analyze the effect of supercritical carbon dioxide and interactions within the polymer composite matrix.

Crystallization Behavior of Pebax–Graphene Composite Matrix with and without Supercritical Carbon Dioxide Assisted Polymer Processing Technique

“…This problem of agglomeration and higher probabilities of defective graphene through chemical exfoliation, in turn, restricts the use of graphene for some promising applications [6][7][8][9][10][11] . In recent years supercritical assisted processing of graphene-based composites has attracted many researchers, which overcomes the problem of agglomeration and defective graphene nanoparticles [11][12][13] .…”

“…Several research and review articles are also available with an emphasis on the synthesis and processibility of scCO 2 graphene composites for a myriad range of applications, mostly concentrating on single-step autoclave techniques 5,6,[11][12][13][25][26][27][28] . A number of researchers have also reported the continuous industrial standard processing of graphene-based composite three-dimensional foams 6,[28][29][30] .…”

“…31−35 Initial investigation on enhancements of thermal and mechanical properties of Pebax−graphene composites with (reprocessed) and without scCO 2 processing has already been reported. 12 Therefore, as a continuation of the initial work, in order to scientifically understand the actual reason for the enhancement of such scCO 2 assisted processing on the exfoliation of graphene within the Pebax matrix, this paper uses differential scanning calorimetry (DSC) to understand the crystallization kinetics and X-ray diffraction spectra (XRD) to complement the results obtained Graphene with a thickness of 6−8 nm, specific surface area of 120 m 2 /g, and purity of 99.5% was procured from Ionic Liquid Technologies, USA. No additional graphene modification was carried out during the course of the experimental procedure.…”

“…In addition, maintaining the intrinsic properties (an exfoliated state without agglomeration) of graphene within any matrix is one of the biggest challenges faced by the researchers and manufacturing industries. This problem of agglomeration and higher probabilities of defective graphene through chemical exfoliation, in turn, restricts the use of graphene for some promising applications. − In recent years supercritical assisted processing of graphene-based composites has attracted many researchers, which overcomes the problem of agglomeration and defective graphene nanoparticles. − …”

“…The properties of supercritical carbon dioxide (scCO 2 ) are most commonly documented in the literature, and it is a commonly used substance, due to attractive properties such as nontoxicity, nonflammability, and easily achievable critical parameters. − Extensive research has been carried out in scCO 2 -assisted polymer processing for tailoring electrical, , thermal, , mechanical, microcellular formation, porosity, and microphase separation of different polymer and polymer composites for several applications. Several research and review articles are also available with an emphasis on the synthesis and processability of scCO 2 graphene composites for a myriad range of applications, mostly concentrating on single-step autoclave techniques. ,,− ,− A number of researchers have also reported the continuous industrial standard processing of graphene-based composite three-dimensional foams. ,− However, the effects of reprocessing once scCO 2 assisted processed composite has not been described elsewhere. Usually, when processing composites using extrusion, the extrudates are processed twice to attain even dispersion.…”