Polyethylene-Matrix Composites with Halloysite Nanotubes with Enhanced Physical/Thermal Properties

Abstract

The aim of the present work is to investigate the effect of halloysite nanotubes (HNT) on the mechanical properties of low-density polyethylene composites modified by maleic anhydride-grafted PE (PE-graft-MA). Polyethylene nanocomposites were prepared using an injection molding machine, Arburg Allrounder 320 C 500–170; the HNT content was varied at 0 wt %, 2 wt %, 4 wt % and 6 wt %, and the PE-graft-MA content was varied at 5 wt %. The composites were examined for their ultimate tensile stress, strain at ultimate stress, hardness, impact strength, melt flow rate, heat deflection temperature, Vicat softening temperature, crystallinity degree and phase transition temperature. It was found that the addition of halloysite nanotubes to low-density polyethylene (LDPE) led to an increased heat deflection temperature (HDT, up to 47 °C) and ultimate tensile strength (up to 16.00 MPa) while the Vicat softening temperature, strain at ultimate stress, impact strength and hardness of examined specimens slightly decreased. Processing properties of the materials specified by the melt flow rate (MFR) deteriorated almost twice. The results have demonstrated that the nanoparticles can reinforce enhance LDPE at low filler content without any considerable loss of its ductility, but only when halloysite nanotubes are superbly distributed in the polyethylene matrix.

Preparation and Characterization of Alumina HDPE Composites

“…The values of tensile strength decreased due to the weak interaction between the filler and the polymer matrix, which was not strong enough to transfer the stress from HDPE to P3 and MG5 efficiently [22]. This finding is in line with the result reported by Sikora et al (2019) [17]. It is noteworthy that the tensile strength of nanocomposites can be negatively affected by the filler content since the possibility of nanoparticles agglomeration increases with the higher filler concentration [12].…”

“…Based on the previous findings of several studies, it can be concluded that the influence of nanofiller's type and concentration on the properties of the obtained composites should be evaluated independently for every matrix and type of filler [14][15][16][17]. The present research aims to fabricate two types of alumina PNCs without neither performing any kind of surface treatment/modification nor using coupling agents.…”

Modern Biodegradable Plastics—Processing and Properties: Part I

“…where ∆H m is the melting enthalpy and ∆H 0 m is the melting enthalpy of 100% crystalline PE (293 J/g) [36], and PLA (93 J/g) [60], respectively. In the TPS test specimens the degree of crystallinity was determined for the PE matrix.…”

“…DSC measurement results for granulates. The values of T g (below −110 • C) revealed that LDPE [36] was one of the additives, and a polymer that is not biodegradable. The values of T g were approximately at −30 • C as read from the DSC curves plotted for PLA, TPS-C, and TPS-P, and partial to presence of other processing additives in the tested bioplastics.…”

“…Pre-treatment of native starch into TPS (thermoplastic starch) is a complex process with multiple preconditions, in order to obtain a material with specified properties. These preconditions include: An optimum procedure of native starch drying [33], the quantities and types of plasticizers [34], an optimum technology for processing TPS and optimized processing conditions [29,35], and an optimum selection of the structural parts for the extrusion machine's plasticizing system [36,37] to ensure a satisfactory homogenization level. Reference literature provides many examples of plasticizers with a proven effectiveness in application with native starch and which perform in compliance with internal or external plasticizing mechanisms.…”