Experimental Evaluation of Wear and Coefficient of Frictional Performance of Zirconium Oxide Nanoparticle–Reinforced Polymer Composites for Gear Applications

Table of Contents:

S. Sathees Kumar and B. Sridhar Babu

CMR Institute of Technology

Introduction

Polymer composites are as a rule progressively utilized in the plastic industry due to their great qualities and low densities (Nie et al., 2010). Particularly short fiber- strengthened thermoplastic polymer composites are broadly utilized in many fields, for example, airplane, aviation, and car industry (Molnar et al., 1999; Botelho et al., 2003). Among the thermoplastic polymers, polyamide 6 (PA6) has become a solid contender grid inferable from its great warm security, low dielectric steady, and high elasticity (Botelho and Rezende, 2006; Li, 2008).

The primary drawbacks of polyamides (PAs) is their high moisture retention, which brings down the checked on mechanical properties and dimensional solidness (Ebewele, 2000; Strong, 2006). Additionally, research shows that PA materials lose their mechanical properties at high temperatures (Mao, 2007). To overcome the above limitation, some researchers have reported that the mechanical and wear resistances can be improved when the polymers are reinforced with fillers (Sung and Suh. 1979; Li et al., 2000; Chen et al., 2008; Kowandy et al., 2008). Usually, adding fillers to the polymers will increase some properties like mechanical, tribological, and thermal stabilities of the polymer (Unal and Mimaroglu, 2012). Fillers are fundamentally basic inorganic mineral powders added to improve handling, rigidity, and dimensional constancy as expressed (Brydson, 1966).

The various reinforcements used in PA materials are graphite, carbon, wax, polytetraflouroethylene, polyethylene terephthalate, silica, carbon nanotube, carbon fiber, and high-density polyethylene. In this experiment, to improve the tribological properties of the pure PA6, it is decided to reinforce with the filler zirconium dioxide (ZrO,) in different weight proportions. ZrO, is one of the most capable nanoparticles utilized in anticorrosion coatings. Nanometric Zr02 particles are an innovatively significant class of materials with a wide scope of uses. ZrO, exposes amazing properties, for example, better strength, maximum break toughness, good wear resistance, high hardness, and great substance opposition. Not many works were carried out in the past about the impact of ZrO, on the properties of thermoplastics. A few studies have detailed that ZrO, nanoparticles indicated better biocompatibility when compared with different nanomaterials, including ferric oxide, titanium dioxide, and zinc oxide

In concurrence with these outcomes, others have announced that ZrO, nanoparticles could prompt gentle (Karunakaran et al., 2013) or no cytotoxic impacts.

Polyamides

A point-by-point investigation of the impact of these boundaries on the composite properties reveals that PAs are a significant gathering of the thermoplastic polycondensates. The amide gathering occurs by the polymerization of lactams (polylactams) or by the buildup of diamines with nylons. Hardly any creators expressed that PAs continually pull in more extensive intrigue on account of their interesting mechanical, thermal, and morphological properties. PAs are notable for their fantastic mechanical performances. The two substantial sorts of PAs are polyamide 66 (PA66) and PA6. PA66 is made out of two basic units, each with six carbon atoms, in particular the residues of hexamethylenediamine and adipic acid (Hatke et al., 1991; Spiliopoulos and Mikroyannidis 1998; Liaw et al., 2003).

PA6 or poly 6-caprolactam, another significant polymer, involves a single structural unit, to be specific the clear residue of 6-aminocaproic acid. PAs do uncover an inclination to creep under applied load. Likewise, the properties of PAs are extensively influenced by moisture. PAs have a few advantages over different classes of polymers. The thermoplastic polymers are a class of engineering materials that develop commercial outcome because of their simplicity of assembling and great thermomechanical properties (Benaarbia et al., 2014).

Polyamide 6

PA6 is a polymer created by Paul Schlack at Interessen—Gemeinschoft Farben to reproduce the properties of PA66 without disregarding the patent of its creation. In contrast to most different PAs, PA6 is not a buildup polymer, rather it is encircled by ring-opening polymers. PA6 begins as a crude caprolactam. As caprolactam has 6 carbon molecules, it has the name Nylon 6. When caprolactam is warmed at 533K in an inert environment of nitrogen for around 4-5 h, the ring breaks and encounters polymerization. By at that point, the liquid mass has encountered the spinners to shape fiber of Nylon 6.

 
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