Polypropylene carbonate (PPC) – a completely biodegradable, eco-friendly plastic

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I. Product Definition: Polypropylene carbonate (PPC), also known as polymethyl ethylene carbonate, is a completely biodegradable and environmentally friendly plastic that is produced through a copolymerization reaction using carbon dioxide (CO₂) and propylene oxide (PO) as the main raw materials, in the presence of catalysts. The weight percentage of carbon dioxide in PPC is over 40%, making it the currently cheapest artificially synthesized biodegradable material. Approximately 0.42 tons of CO₂ can be sequestered per ton of PPC produced, and it can be completely decomposed into CO₂ and water within 6–12 months. Product quality is in line with GB/T 31124-2014 Polypropylene carbonate (PPC). II. Performance Parameters 1. Thermal properties: The glass transition temperature (Tg) is approximately 23–45°C, while the thermal decomposition temperature (T5%) is ≥200°C. The processing window is narrow, requiring precise temperature control. 2. Mechanical properties: Tensile yield stress of 15–20 MPa, elongation at break of 400–650%, offering both flexibility and moderate stiffness. 3. Barrier properties: Its oxygen barrier property is 6 times that of PLA and 24 times that of PBAT, approaching the level of PET. 3. Biodegradability: The relative biodegradation rate after 180 days is ≥60% (as required by national standards). 4. Water resistance: PPC has a polycarbonate structure, giving it excellent water resistance; it does not suffer from the hydrolysis problem associated with polyester-based materials such as PLA and PBAT. III. Applications 1. Biodegradable plastic film: PPC plastic film possesses insulation and moisture-retention properties closest to those of LLDPE, making it the most suitable material for producing biodegradable plastic films. The cost of covering each mu with plastic film can be reduced to 150 yuan, making it the cheapest biodegradable plastic film. Qin County in Shanxi has issued a tender for the procurement of 150 tons of biodegradable permeable membranes ； The 1,000-mu demonstration area in Huguan County, Shanxi Province, has become a site for observing dryland farming practices in nine provinces and regions. Over 60 tons have been promoted in Changzhi and Lüliang, Shanxi. The PPC plastic mulch produced by Shandong Lianchuang Company was used in cotton fields in Xinjiang; after 60 days, its field degradation rate reached 80%. The PPC-based fully biodegradable permeable plastic film promoted in Jiaxian County, Northern Shaanxi, resulted in a 32.82% increase in yield in corn pilot fields compared to conventional plastic films. PPC-degradable plastic mulch can degrade in the soil; there is no need for manual recovery after use, as it can be directly plowed into the soil, making it efficient and environmentally friendly. The degradation rate reaches 87% at the time of autumn harvest, and it will be 100% degraded by the time of spring sowing next year. 2. Packaging sector: PPC can be used in food preservation films and eco-friendly packaging. It can also be used as a modifier for PLA and PBAT, providing effective barrier properties while reducing the cost of the products. 3. Polyurethane elastomers and foaming materials: PPC polyols can be used as foaming materials in eco-friendly car seat cushions, automotive sound insulation materials, high-end bedding, flame-retardant foam panels, etc ； It can also be used to make water-based polyurethane coatings, water-based paints, water-based adhesives, etc. 4. Medical field: The PPC surgical suture developed by the Institute of Chemistry, Chinese Academy of Sciences, has a degradation rate of over 90% within 28 days in the body, and has obtained CFDA classification III medical device certification. 5. Other applications: 3D printing consumables, disposable tableware, disposable medical and food packaging materials, etc. V. Production Process and Technical Origin 1. The core of the PPC production process is the copolymerization reaction of carbon dioxide and propylene oxide, with the coordination polymerization method being the predominant approach used worldwide. Catalyst systems: Three technical approaches coexist, namely dual-metal cyanide (DMC), rare earth complexes (such as Salen-Co), and zinc-glycerol complexes. 2. Technical breakthrough: The aliphatic polycarbonate (APC) material developed by Zhang Xinghong’s team at Zhejiang University has an estimated production cost of less than 8,000 yuan per ton, which is close to the current cost of petroleum-based polyethylene (around 7,400 yuan per ton). The 200-ton/year pilot plant under construction has been operating stably for over a year, and the cost effects of scaling up will be comprehensively evaluated once the 10,000-ton production line is built. 3. Domestic technology leaders: The PPC production technology developed by the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, is the best in the world, enabling the production of PPC products with a molecular weight of over 150,000. Jilin Province has built a 50,000-ton/year PPC production facility in the Chemical Industry Circular Economy Demonstration Park in Jilin City. VI. Major Manufacturers and Production Capacity 1. By 2024, domestic PPC production capacity is set to approach 40,000 tons. However, due to various factors such as catalytic technology, reaction processes, and relatively low market demand, the operational rate of the entire industry remains low; nonetheless, the production growth rate has been close to 20% over the past five years. In 2024, production reached 48,100 tons, while demand stood at 46,100 tons. The market size was 848 million yuan. 2. The main manufacturer, Changchun Institute of Applied Chemistry: a PPC production facility with an annual capacity of 50,000 tons, along with a production line dedicated to producing PPC packaging film with an initial annual capacity of 3,000 tons. Jiangsu Zhongke Jinlong: a production line with an annual capacity of 50,000 tons for polycarbonate propylene oxide polyol, and a production line with an annual capacity of 10,000 tons for fully biodegradable plastic masterbatches. Shanxi Luxin Xinnong: The PPC biodegradable plastic film production line has an annual output of 2,000 tons. BoDa DongFang: The first phase of the PPC project with an annual production capacity of 50,000 tons has been successfully commissioned, with a planned total capacity of 300,000 tons per year. Zhejiang Wenling Bangfeng: Currently has a production capacity of 30,000 tons per year, with plans to increase this to 100,000 tons per year. Lianhong New Materials: The 50,000-ton/year production facility is expected to come online in the second quarter of 2026. 3. Regarding future production capacity planning, it is initially estimated that the growth rate of production capacity over the next five years will be around 20%, while the growth rate of output is expected to exceed 50%. VII. Market Supply, Demand and Prices 1. Market Size By 2025, the market size for biodegradable materials is expected to exceed 48 billion yuan. As the lowest-cost variety among them, PPC has broad market prospects. Currently, domestic PPC consumption is concentrated in three main areas: agricultural films, packaging materials, and polyurethane elastomers, which together account for around 82% of the total usage. 2. Cost advantage: The production cost at a scale of 10,000 tons is approximately 7,824 yuan per ton, which is close to the 7,400 yuan per ton cost of petroleum-based polyethylene. Of this, the raw material cost is approximately 6,224 yuan (including 5,024 yuan for propylene oxide, 200 yuan for CO₂, and 1,000 yuan for additives and other items), while other costs amount to about 1,600 yuan. 3. Supply and demand outlook: With policy support in the field of biodegradable materials and the advancement of **carbon neutrality strategies, the use of PPC products in areas such as plastic mulch and food packaging is expected to increase steadily. 8. Industry development trends: 1. Accelerated replacement of traditional agricultural plastics. With the increase in PPC production capacity, a bio-degradable agricultural plastic film industry capable of producing 100,000 tons per year will be established. This will not only help to address the issue of \"white pollution\" in farmlands but also contribute to the upgrading of the agricultural plastics industry. 2. Costs continue to decline. The production cost has dropped below 8,000 yuan per ton, bringing it within reach of petroleum-based polyethylene. Technologies such as fourth-generation catalysts and supercritical polymerization will be gradually put into use to further reduce costs. 3. Technological iteration is accelerating. Continuous breakthroughs are being made in catalyst innovation, process integration, composite modification, etc. 4. Promotion by the “dual carbon” strategy. As the only scalable bioplastic that achieves a negative CO₂ carbon footprint, PPC holds unique value in carbon neutrality strategies. The shift from an \"open carbon cycle\" to a \"closed carbon cycle\" is the core strategic advantage that distinguishes PPC from other biodegradable materials.