Introduction

What if polymerization, the process that gave us the age of plastics, became the key to ending plastic waste? Polymers shape nearly every aspect of modern life, from lightweight composites in transportation to biodegradable packaging and advanced biomedical materials. Yet, this same material class that defines modern convenience is detrimental to the environment if our vision stops at synthesis. Understanding how monomers transform into long-chain polymers is fundamental to designing materials that meet today’s industrial and environmental challenges.

Polymerization lies at the heart of polymer science, determining the structure, properties, and performance of polymeric materials. Traditional mechanisms such as step-growth, chain-growth, and ring-opening polymerization remain essential for producing diverse materials, from synthetic fibers to engineering plastics. Yet, the demand for precisely engineered materials has led to the development of advanced controlled polymerization techniques, most notably Atom Transfer Radical Polymerization (ATRP) and Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization. These technologies allow chemists to manipulate molecular weight, sequence, and architecture with exceptional precision, enabling the creation of polymers tailored for applications in biomedicine, electronics, and green manufacturing. In 2022, we produced roughly 400 million tons of synthetic polymers/plastics (Houssini et al., 2025). Advancing effective recycling technologies is crucial for preserving the advantages of polymeric materials while minimizing their environmental impact. For graduate students and researchers, this chapter connects chemistry, materials science, and sustainability.

The chapter titled “The Principles and Technologies of Polymerization” will provide a comprehensive overview of polymerization techniques, existing polymer recycling methods, and the current challenges of effective recycling. The first section will include an introduction to fundamental polymerization mechanisms, including step-growth, chain-growth, and ring-opening polymerization. Following this, we delve into advanced controlled polymerization techniques, such as ATRP and RAFT, exploring how these methods enable control over polymer synthesis and properties. Then the chapter includes a general idea of how different products, such as textiles, packaging, and electronics, are made from raw polymers to understand their recycling opportunities and challenges. The second section will focus on the detailed existing recycling techniques of specific polymers, their degradation behavior, and advanced waste management. Together, these sections create a roadmap for understanding both the polymer synthesis and its recycling techniques to meet the global responsibility of sustainable waste management.

The Polymer Life Cycle: Synthesis to Sustainability

References:

Houssini, K., Li, J., & Tan, Q. (2025). Complexities of the global plastics supply chain revealed in a trade-linked material flow analysis. Communications Earth & Environment, 6, Article 2169. https://doi.org/10.1038/s43247-025-02169-5