<i>In Vitro</i> Mechanical Properties of Metallocene Linear Low Density Polyethylene (mLLDPE) Nanocomposites Incorporating Montmorillonite (MMT)

Abstract

The viability of metallocene linear low density polyethylene (mLLDPE) nanocomposites is being investigated as a new material for biomedical application. The effect of filler loadings on the ambient andin vitro(after being exposed in oxidizing condition, 37°C) mechanical properties was studied. We observed that, the mLLDPE nanocomposites have higher mechanical property values as compared to the neat mLLDPE. Furthermore, these properties were less affected by thein vitroconditions. The best ambient andin vitromechanical properties were achived when 3wt% of organically modified MMT (organo-MMT) was added into the mLLDPE. It was postulated that the presence of MMT layered structure introduced a more tortous path for the diffusing of oxidant molecules, thereby decreasing their permeability towards mLLDPE molecular chains. The smaller amount of oxidants entering the molecular chains resulted in greater retention of mechanical properties when testedin vitro. This preliminary biostability studies show promising properties of the mLLDPE nanocomposite which possess the potential to be further developed for biomedical devices.

Pre‐dispersing of montmorillonite nanofiller: Impact on morphology and performance of melt compounded ethyl vinyl acetate nanocomposites

“…The shear energy provided by the twin screw extruder during the compounding with the polymer may not be enough to produce fully exfoliated organo‐MMT structure, especially when the nanofiller loading is greater than 2 wt %. This was proved by several studies . Therefore, this project has introduced the pre‐dispersing technique to increase the organo‐MMT exfoliation efficiency prior to melt compounding with the EVA.…”

“…The nanoclays are attracting considerable interest as nanofiller material as they can provide vastly superior reinforcement efficiency due to their high aspect ratio and a greater surface area to mass ratio. The incorporation of nanoclays into the host polymeric materials were reported to result in enhanced mechanical and barrier properties, biostability, biocompatibility, thermal stability, and flame retardancy when compared with neat polymer.…”

“…Consequently, the exfoliation and dispersion of the nanoclay can be facilitated inside the host polymer . Even though this ion exchanged method may enhance the compatibility between the clay and the polymer matrix, previous researches suggest that fully exfoliated structure is difficult to achieve, even when surface modified . Direct melt compounding methods such as extrusion and internal mixing could not promise the production of fully exfoliated nanoclays with appreciable dispersion quality, even though the screw or mixing blade is capable to provide shear forces to break up large tactoids .…”

Effects of Hydrolytic and Oxidizing Agents on the Properties of Low Density Polyethylene/Halloysite Nanocomposites for Biomedical Applications

“…However, these qualities were negatively affected upon increasing the nanofiller content from 3 to 5%, probably due to the inferior HNT dispersion characteristics should be noted that the tensile properties of NCs can be affected by the dispersion, orientation, content of the nanofiller, as well as the filler-polymer interaction. 20,21 The achieved reinforcement by the dispersed halloysite nanotubes is responsible for the increased tensile strength of the polymer NC. Because of the increased contact surface area and polymer-nanotubes interactions, better dispersed HNTs may improve tensile strength.…”

Effects of Ultrasonication Time on Thermal Stability and Swelling Behaviour of The Commercial Organo-Montmorillonite (O-MMT)

“…The thickness of an individual layer is around 1 nm, but the lateral dimensions of nano layers may vary from 100 nm to several microns [4]. An interesting behavior of MMT is its ability to swell in both polar and nonpolar molecules, as their inter-galleries is sensitive to the absorption of both types of ancillary molecules [5,6]. In its pristine state, MMT possesses high surface area and surface reactivity of platelets.…”