Filling the Gaps: Tracing 12 Types of Non-commodity Plastics in China’s Plastic Socioeconomic Metabolism

Recent plastic flow research has largely focused on commodity plastics (PE, PP, PVC, PS, ABS), yet a sizable share of other polymer types remains understudied. These non-commodity plastics suffer from inconsistent definitions, complex classifications, and data gaps, which hinder accurate assessment of their production, use, and end-of-life management. This study develops dynamic material flow analysis to investigate 12 key “non-commodity” plastics in Chinaincluding PET, PU, seven engineering plastics, and three thermosetting plasticsand addresses these knowledge gaps. Our results show that in 2022, China produces approximately 85 million tonnes of these polymers, a volume comparable to commodity plastics, with 35% used in plastic products and the remainder in non-plastic applications (e.g., fibers, rubber). PET is predominantly employed in short-lifespan packaging, whereas PU, engineering plastics, and thermosetting plastics find use in longer-lifespan applications, underscoring the need for targeted recycling strategiesparticularly chemical recycling for PU and thermoset products. Revisiting the scope of “plastics” using scientific criteria can help mitigate definitional ambiguities and guide more effective policymaking. By improving data availability and tracking this underexplored non-commodity category, our study lays the groundwork for more accurate assessments and interventions to reduce plastic pollution.近年来塑料物质流研究多聚焦于通用塑料（commodity plastics，即PE、PP、PVC、PS、ABS），但其余大量聚合物品类仍未得到充分研究。此类非通用塑料存在定义不统一、分类复杂及数据缺失等问题，阻碍了对其生产、使用及生命周期末端管理的精准评估。本研究采用动态物质流分析（dynamic material flow analysis）方法，针对中国12种关键“非通用”塑料展开研究——包括聚对苯二甲酸乙二醇酯（PET）、聚氨酯（PU）、7种工程塑料（engineering plastics）以及3种热固性塑料（thermosetting plastics）——并填补了相关知识空白。研究结果显示，2022年中国此类聚合物产量约达8500万吨，规模与通用塑料相当，其中35%用于塑料制品生产，剩余部分则应用于非塑料领域（如纤维、橡胶制品）。聚对苯二甲酸乙二醇酯（PET）主要用于短寿命包装场景，而聚氨酯（PU）、工程塑料及热固性塑料则多用于长寿命应用场景，这凸显了制定针对性回收策略的必要性——尤其针对聚氨酯及热固制品的化学回收（chemical recycling）。基于科学标准重新界定“塑料”的范畴，有助于减少定义歧义，助力制定更高效的政策。本研究通过提升数据可得性并追踪这一未被充分探索的非通用塑料品类，为更精准的评估及塑料污染治理干预措施奠定了基础。