Thermal Degradation and Chemical Recycling of Polymers

Thermal degradation and chemical recycling represent a concerted effort to divert polymer waste from landfills and incineration by breaking macromolecular chains into reusable monomers or value-added chemicals. Thermal degradation encompasses a range of heat-induced pathways, including random chain scission, unzipping depolymerisation and char formation, each governed by the polymer’s chemical structure, molecular weight distribution and reaction environment. Chemical recycling leverages these degradation mechanisms—often via pyrolysis, solvolysis or catalytic depolymerisation—to recover monomers such as methyl methacrylate or to generate feedstocks for new polymer synthesis. Advances in reactor design, from fluidised-bed systems to micro-electromechanical thermal analysers, have improved heat transfer, residence-time control and product selectivity. Kinetic modelling and in-situ spectroscopic techniques now enable precise mapping of reaction pathways, facilitating closed-loop processes that can achieve high monomer yields with minimal by-product formation. These developments have global significance as industries seek circular-economy solutions for packaging, automotive and construction polymers. By integrating fundamental thermal-degradation studies with scalable recycling processes, researchers are charting pathways to sustainable polymer management and reducing reliance on virgin petrochemical feedstocks.

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Thermal Degradation and Chemical Recycling of Polymers publication trend

The graph below shows the total number of articles in thermal degradation and chemical recycling of polymers across all publications each year (not limited to Nature Index journals).

Technical terms

Thermal degradation: Breakdown of polymer chains under heat, leading to smaller molecules, monomers or char.

Chemical recycling: Process of recovering chemical building blocks from polymer waste for reuse in new material synthesis.

Pyrolysis: Thermal decomposition in an inert atmosphere that converts polymers into gaseous, liquid and solid fractions.

Depolymerisation: Reversal of polymerisation involving the unzipping of chains to regenerate monomers.

Thermogravimetric analysis (TGA): Technique that measures weight change of a sample as a function of temperature or time to study decomposition kinetics.

References

1. Experimental determination of quantitative yields from polymethyl methacrylate (PMMA) flash pyrolysis in a fluidized bed reactor via online FTIR gas analysis. Fuel (2025).
2. Recycled PMMA prepared directly from crude MMA obtained from thermal depolymerization of mixed PMMA waste. Waste Management (2023).
3. MEMS Resonant Cantilevers for High-Performance Thermogravimetric Analysis of Chemical Decomposition. Sensors (2023).
4. Depolymerization of PMMA-Based Dental Resin Scraps on Different Production Scales. Energies (2024).