Synthetic Lubricants Derived from Plastic Waste and their Tribological Performance

Area of Science:

• Materials Science
• Tribology
• Green Chemistry

Background:

• Advanced lubricants are crucial for the energy efficiency, mechanical durability, and environmental compatibility of machine components.
• Polyolefin waste represents a significant environmental challenge, with limited recycling options.
• Developing sustainable lubricant alternatives is essential to reduce reliance on fossil fuels and mitigate plastic pollution.

Purpose of the Study:

• To derive high-quality liquid (HQL) lubricants from catalytic conversion of polyolefin waste.
• To evaluate the tribological performance of these novel plastic-derived lubricants.
• To assess the environmental and economic feasibility of the upcycling process.

Main Methods:

• Catalytic conversion of pre- and post-consumer polyolefin waste to produce HQL lubricants.
• Tribological testing, including wear scar volume (WSV) measurements, comparing HQLs with synthetic base oils (PAOs) and Group III mineral oil.
• Friction and wear testing of HQLs blended with synthetic oils.
• Life cycle and techno-economic analyses of the lubricant production process.

Main Results:

• Plastic-derived HQL lubricants demonstrated comparable performance to polyalphaolefins (PAOs) with a WSV of 7.5×10^-5 mm^-3.
• HQLs outperformed Group III mineral oil, achieving a 44% reduction in wear (WSV of 1.7×10^-4 mm^-3).
• Synergistic reductions in friction and wear were observed when HQLs were combined with synthetic oils.
• The upcycling process was found to be energetically efficient and economically feasible.

Conclusions:

• Novel high-quality liquid lubricants can be successfully derived from polyolefin plastic waste.
• These upcycled lubricants offer a sustainable and high-performance alternative to conventional lubricants, reducing wear and friction.
• This technology presents a cost-effective strategy to mitigate plastic waste and enhance energy efficiency in transportation applications.