In this article, hybrid analytical hierarchy process (AHP) and complex proportional assessment (COPRAS) approach was proposed to optimize automotive brake friction materials. Sixteen formulations based on phenolic resin, barium sulfate, Kevlar fiber, Lapinus fiber, multiwall carbon nanotube (MWCNT), nanoclay and graphite were formulated and evaluated for tribological properties. The tribo‐evaluation parameters such as coefficient of friction, friction‐fluctuations, friction‐variability, friction‐fade, wear, friction‐recovery, friction‐stability and disc temperature rise were considered as criterion for the performance optimization. The optimization of formulations was carry out in two steps: (1) finding the weight of each criterion by AHP method and (2) ranking the formulations with COPRAS method. The AHP‐COPRAS results show that the formulation of 50 wt% barium sulfate, 15 wt% phenolic resin, 2.5 wt% graphite, 5 wt% Kevlar fiber, 25 wt% Lapinus fiber with 2.5 wt% MWCNT exhibits the optimal tribological properties. POLYM. COMPOS., 40:1602–1608, 2019. © 2018 Society of Plastics Engineers

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Composite materials are emerging as a vital entity for the sustainable development of both humans and the environment. Polylactic acid (PLA) has been recognized as a potential polymer candidate with attractive characteristics for applications in both the engineering and medical sectors. Hence, the present article throws lights on the essential physical and mechanical properties of PLA that can be beneficial for the development of composites, biocomposites, films, porous gels, and so on. The article discusses various processes that can be utilized in the fabrication of PLA-based composites. In a later section, we have a detailed discourse on the various composites and nanocomposites-based PLA along with the properties’ comparisons, discussing our investigation on the effects of various fibers, fillers, and nanofillers on the mechanical, thermal, and wear properties of PLA. Lastly, the various applications in which PLA is used extensively are discussed in detail.

In this article, multiwalled carbon nanotube (MWCNT) filled and lapinus‐Kevlar fiber reinforced friction composite material have been fabricated and characterized for their chemical, physico‐mechanical and tribological properties. The experimental results indicated that the density, hardness, impact energy, tensile, and flexural strengths decreases, whereas compressibility, void, and ash content of the friction composites increases with increase in MWCNT content. Further, Taguchi design of experiment technique was applied to study the tribological properties of the fabricated friction composites by taking four input parameter at‐a‐time such as composition, speed, distance and load, respectively, by using a pin on disc machine. An orthogonal array L16 has been applied to optimize the parameter settings to get performance output such as: coefficient of friction (COF) and specific wear rate (WR). The study reveals that the composition contributes mainly towards COF and WR with contribution ratio (CR) of 55.16 and 30.18% followed by speed with CR of 24.16 and 29.30%, respectively. Finally, confirmation experiment has been performed to verify the experimental results and is strongly correlated with the predicted results. POLYM. COMPOS., 39:E1109–E1117. © 2017 Society of Plastics Engineers

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Hemp-sisal natural fiber-reinforced hybrid epoxy composites containing a varying proportion of silica nanoparticles (0, 1, 2, 3, and 4 wt%) were manufactured and subsequently evaluated for physical, mechanical, and sliding wear properties. The density of the composite was found to increase, whereas void content was found to decrease with the increase of silica nanoparticles content. The composites containing 2 wt% silica nanoparticles exhibit maximum tensile strength, impact strength, and hardness, whereas the composite with 3 wt% silica nanoparticles showed the highest flexural strength. Dry sliding wear tests of the manufactured composites were carried out on a pin-on-disc machine under different sliding speeds, distances and applied loads at room temperature. Taguchi based L 16 orthogonal array design was used to find the optimum combination of control factors resulting in higher wear resistance. The analysis reveals that the silica nanoparticles contribute the most towards wear performance with a contribution ratio of 32.61% and a combination of 2 wt% of silica nanoparticles, 10 N normal load, 1.5 m/s sliding speed and 500 m sliding distance resulted in higher wear resistance.

In polymer composites, synthetic fibers are primarily used as a chief reinforcing material, with a wide range of applications, and are therefore essential to study. In the present work, we carried out the erosive wear of natural and synthetic fiber-based polymer composites. Glass fiber with jute and Grewia optiva fiber was reinforced in three different polymer resins: epoxy, vinyl ester and polyester. The hand lay-up method was used for the fabrication of composites. L16 orthogonal array of Taguchi method used to identify the most significant parameters (impact velocity, fiber content, and impingement angle) in the analysis of erosive wear. ANOVA analysis revealed that the most influential parameter was in the erosive wear analysis was impact velocity followed by fiber content and impingement angle. It was also observed that polyester-based composites exhibited the highest erosive wear followed by vinyl ester-based composites, and epoxy-based composites showed the lowest erosive wear. From the present study, it may be attributed that the low hardness of the polyester resulting in low resistance against the impact of erodent particles. The SEM analysis furthermore illustrates the mechanism took place during the wear examination of all three types of composites at highest fiber loading. A thorough assessment uncovers brittle fractures in certain regions, implying that a marginal amount of impact forces was also acting on the fabricated samples. The developed fiber-reinforced polymer sandwich composite materials possess excellent biocompatibility, desirable promising properties for prosthetic, orthopaedic, and bone-fracture implant uses.

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