Mechanochemistry offers a promising approach for sustainable polymer degradation, enabling the controlled breakdown of both newly designed polymers and existing plastics. This review highlights the historical development and current applications of mechanochemistry in polymer degradation, emphasizing the role of mechanical forces in breaking polymer bonds. It discusses the challenges and opportunities in this field, including the limitations of mechanophores, the potential of trituration mechanochemistry, and the need for interdisciplinary research to advance sustainable polymer recycling. The review also explores the theoretical and computational frameworks that can aid in understanding and predicting mechanochemical reactions. Key examples include the development of polymers with force-responsive bonds that degrade under mechanical stress, the use of trituration to break down polymers, and the application of in situ observation techniques to study mechanochemical processes. The review emphasizes the importance of controlling the degradation process to achieve efficient and sustainable polymer recycling, while addressing challenges such as the need for scalable technologies and the thermodynamic constraints of polymer depolymerization. Computational methods, including isometric and isotensional simulations, are discussed as tools to predict and understand mechanochemical reactivity. The review concludes with a discussion of the potential of mechanochemistry in transforming bulk polymers into small molecules, highlighting the advantages of this approach over traditional chemical recycling methods.Mechanochemistry offers a promising approach for sustainable polymer degradation, enabling the controlled breakdown of both newly designed polymers and existing plastics. This review highlights the historical development and current applications of mechanochemistry in polymer degradation, emphasizing the role of mechanical forces in breaking polymer bonds. It discusses the challenges and opportunities in this field, including the limitations of mechanophores, the potential of trituration mechanochemistry, and the need for interdisciplinary research to advance sustainable polymer recycling. The review also explores the theoretical and computational frameworks that can aid in understanding and predicting mechanochemical reactions. Key examples include the development of polymers with force-responsive bonds that degrade under mechanical stress, the use of trituration to break down polymers, and the application of in situ observation techniques to study mechanochemical processes. The review emphasizes the importance of controlling the degradation process to achieve efficient and sustainable polymer recycling, while addressing challenges such as the need for scalable technologies and the thermodynamic constraints of polymer depolymerization. Computational methods, including isometric and isotensional simulations, are discussed as tools to predict and understand mechanochemical reactivity. The review concludes with a discussion of the potential of mechanochemistry in transforming bulk polymers into small molecules, highlighting the advantages of this approach over traditional chemical recycling methods.