A recyclable poly(methyl methacrylate) (PMMA) is synthesized by incorporating a minimal amount of an α-methylstyrene (AMS) analogue into the polymer structure. This P(MMA-co-AMS) copolymer retains the essential mechanical strength and optical clarity of PMMA, crucial for its use in various industries. Doping with AMS significantly enhances the thermal, catalyst-free depolymerization efficiency of PMMA, enabling the recovery of methyl methacrylate (MMA) with high yield and purity at temperatures ranging from 150 to 210 °C, nearly 250 K lower than current industrial standards. This low temperature allows for the isolation of pure MMA from a mixture of common plastics. PMMA, known as Plexiglas, is a synthetic material widely used in construction, automobiles, and electronics. It is transparent, lightweight, and shatterproof, making it a cost-effective alternative to glass. However, nearly 90% of PMMA ends up in landfills, a trend expected to rise with increasing plastic demand. Mechanical recycling is not effective due to the need for rigorous sorting and quality loss after multiple cycles. Chemical recycling of PMMA back to its monomer, MMA, offers a sustainable solution for a circular economy. PMMA is typically produced from MMA via radical polymerization at temperatures between 50 and 90 °C. This process can be tuned to favor depolymerization at higher temperatures, but conventional pyrolysis requires temperatures above 400 °C, which is energy-intensive and leads to impure MMA. Recent advancements aim to reduce the temperature required for PMMA depolymerization by incorporating functional groups with low bond dissociation energies. However, these methods often require transition metal catalysts or expensive photocatalysts. The study introduces a "doping" strategy by incorporating a small amount of AMS into PMMA, introducing a weak bond in the carbon-carbon backbone. This enables main-chain scission at moderate temperatures, facilitating efficient and selective depolymerization to MMA. The study demonstrates that doping PMMA with 3% AMS allows for efficient and selective thermal reversion to MMA under mild conditions, maintaining PMMA's desirable properties. The copolymers exhibit high thermal stability and efficient depolymerization, with P(MMA-co-AMS) 6 and 7 showing high MMA yields at 150 °C. The method is suitable for bulk synthesis and does not require precious metals or specific end-groups. The study also shows that the recovered MMA can be repolymerized without further purification, and the copolymers maintain optical and mechanical properties similar to PMMA. The mechanism involves weak bonds in the polymer backbone and rapid formation of AMS monomers, suggesting depolymerization is initiated by random scission of AMS-containing linkages. This approach offers a significant step toward a circular economy by enabling theA recyclable poly(methyl methacrylate) (PMMA) is synthesized by incorporating a minimal amount of an α-methylstyrene (AMS) analogue into the polymer structure. This P(MMA-co-AMS) copolymer retains the essential mechanical strength and optical clarity of PMMA, crucial for its use in various industries. Doping with AMS significantly enhances the thermal, catalyst-free depolymerization efficiency of PMMA, enabling the recovery of methyl methacrylate (MMA) with high yield and purity at temperatures ranging from 150 to 210 °C, nearly 250 K lower than current industrial standards. This low temperature allows for the isolation of pure MMA from a mixture of common plastics. PMMA, known as Plexiglas, is a synthetic material widely used in construction, automobiles, and electronics. It is transparent, lightweight, and shatterproof, making it a cost-effective alternative to glass. However, nearly 90% of PMMA ends up in landfills, a trend expected to rise with increasing plastic demand. Mechanical recycling is not effective due to the need for rigorous sorting and quality loss after multiple cycles. Chemical recycling of PMMA back to its monomer, MMA, offers a sustainable solution for a circular economy. PMMA is typically produced from MMA via radical polymerization at temperatures between 50 and 90 °C. This process can be tuned to favor depolymerization at higher temperatures, but conventional pyrolysis requires temperatures above 400 °C, which is energy-intensive and leads to impure MMA. Recent advancements aim to reduce the temperature required for PMMA depolymerization by incorporating functional groups with low bond dissociation energies. However, these methods often require transition metal catalysts or expensive photocatalysts. The study introduces a "doping" strategy by incorporating a small amount of AMS into PMMA, introducing a weak bond in the carbon-carbon backbone. This enables main-chain scission at moderate temperatures, facilitating efficient and selective depolymerization to MMA. The study demonstrates that doping PMMA with 3% AMS allows for efficient and selective thermal reversion to MMA under mild conditions, maintaining PMMA's desirable properties. The copolymers exhibit high thermal stability and efficient depolymerization, with P(MMA-co-AMS) 6 and 7 showing high MMA yields at 150 °C. The method is suitable for bulk synthesis and does not require precious metals or specific end-groups. The study also shows that the recovered MMA can be repolymerized without further purification, and the copolymers maintain optical and mechanical properties similar to PMMA. The mechanism involves weak bonds in the polymer backbone and rapid formation of AMS monomers, suggesting depolymerization is initiated by random scission of AMS-containing linkages. This approach offers a significant step toward a circular economy by enabling the