Synthetic Lubricants Derived from Plastic Waste and their Tribological Performance

Abstract

The energy efficiency, mechanical durability, and environmental compatibility of all moving machine components rely heavily on advanced lubricants for smooth and safe operation. Herein an alternative family of high-quality liquid (HQL) lubricants was derived by the catalytic conversion of pre-and post-consumer polyolefin waste. The plastic-derived lubricants performed comparably to synthetic base oils such as polyalphaolefins (PAOs), both with a wear scar volume (WSV) of 7.5 × 10 À 5 mm À 3 . HQLs also performed superior to petroleum-based lubricants such as Group III mineral oil with a WSV of 1.7 × 10 À 4 mm À 3 , showcasing a 44 % reduction in wear. Furthermore, a synergistic reduction in friction and wear was observed when combining the upcycled plastic lubricant with synthetic oils. Life cycle and techno-economic analyses also showed this process to be energetically efficient and economically feasible. This novel technology offers a cost-effective opportunity to reduce the harmful environmental impact of plastic waste on our planet and to save energy through reduction of friction and wearrelated degradations in transportation applications akin to synthetic oils.

Scalable Synthesis of Pt/SrTiO3 Hydrogenolysis Catalysts in Pursuit of Manufacturing-Relevant Waste Plastic Solutions

“…The dispersity of the product of the SEA-Pt/STO catalyst decreased below 1.1, similar to our prior work producing upcycled liquid products from polyolefins with Pt/STO. 21,22 Notably, the dispersity decreased below 1.1 while the M w was above 2000 Da, which we have not previously observed. This narrow dispersity demonstrates that SEA-derived Pt/STO is a selective catalyst for waste plastic hydrogenolysis.…”

“…9−22 To that effect, Celik et al and Hackler et al recently investigated a system of platinum (Pt) nanoparticles deposited onto SrTiO 3 (STO) nanocuboids (Pt/STO) that catalyze the hydrogenolysis of high-density polyethylene (HDPE) into lubricant materials. 21,22 In addition to demonstrating superior catalytic performance to a conventional catalyst, Pt on γ-Al 2 O 3 , several properties of Pt/STO make it an attractive model system for catalytic study. STO nanocuboids are highly crystalline, have high thermal stability, and have well-defined {100} facets, among other properties.…”

“…Activity experiments were performed under solvent-free conditions at 170 psi and 300 °C, unless otherwise noted. For the Parr reactor, the conditions were 300 mg Pt/ STO, 3 g HDPE, Sigma-Aldrich, M w = 35 kDa, Đ = 3.11, 300 °C, 170 psi H 2 , 96 h, with a glass liner in the reactor, as per Hackler et al 22 Gel Permeation Chromatography (GPC). Samples were analyzed by GPC as per Hacker et al 22 Solutions A + B were mixed and stirred for 10 min in a 2000 mL Erlenmeyer flask; 276.85 g of 10 M NaOH solution was injected into the AB solution for 28 min at a flow rate of 10 mL/min using a syringe pump.…”

“…For the Parr reactor, the conditions were 300 mg Pt/ STO, 3 g HDPE, Sigma-Aldrich, M w = 35 kDa, Đ = 3.11, 300 °C, 170 psi H 2 , 96 h, with a glass liner in the reactor, as per Hackler et al 22 Gel Permeation Chromatography (GPC). Samples were analyzed by GPC as per Hacker et al 22 Solutions A + B were mixed and stirred for 10 min in a 2000 mL Erlenmeyer flask; 276.85 g of 10 M NaOH solution was injected into the AB solution for 28 min at a flow rate of 10 mL/min using a syringe pump. The AB−OH solution was stirred using a magnetic stirrer at the maximum stir rate of the stir plate; no gelation was observed.…”

Synthesis and Characterization of Mesoporous Silica Nanoparticles Loaded with Pt Catalysts

“…To address this issue, a series of materials have been introduced. For example, carbon support [16], SrTiO 3 perovskite nanocuboid [17][18][19], atomic layer deposition (ALD) overcoats [20][21][22], mesoporous silica nanoparticles [23], mesoporous aluminosilica spheres [24], and many other materials have been studied as the support and protective layer to prevent deactivation of the catalysts. Among the above materials, mesoporous silica nanoparticles are an excellent candidate to stabilize catalysts.…”