Against the backdrop of carbon peaking and carbon neutrality policies and global environmental upgrading, traditional petroleum-based plastics are increasingly criticized for high carbon emissions, resource consumption and poor degradability. Polylactic Acid (PLA), a core bio-based material, is comprehensively replacing mainstream petroleum-based general plastics including PET, PP and PS, becoming a key green solution and driving the transformation and upgrading of the plastic industry toward low-carbon, renewable and circular development.
In terms of raw materials, PET, PP and PS are typical petroleum-based plastics refined from non-renewable fossil resources such as crude oil and natural gas. Their production process is highly dependent on fossil energy, which aggravates global resource depletion and generates massive greenhouse gas emissions. Industry test data shows that producing 1kg of PET resin emits 3.4kg of carbon dioxide, while the carbon emission of 1kg of PLA resin is only 0.75kg, achieving a carbon reduction rate of 77%. Compared with various petroleum-based general plastics, PLA can reduce carbon dioxide emissions by 75%-90% and save 35%-60% of production energy consumption. In contrast, PLA is made from renewable plant starches such as corn, cassava and crop straws. The renewable raw materials completely eliminate reliance on fossil resources and form a sustainable resource utilization loop.
In terms of product performance and application scenarios, petroleum-based general plastics have long dominated packaging, daily necessities, catering consumables and industrial injection molding fields due to stable physical properties. PET features high transparency and excellent barrier properties, widely used in beverage packaging; PP has good heat resistance and toughness, commonly applied in lunch boxes and injection molded products; PS boasts high hardness and light transmittance, suitable for disposable tableware and packaging buffer materials. However, all three materials have fatal defects: they cannot be biodegraded in the natural environment and take hundreds of years to decompose after disposal, easily causing white pollution to soil and water. In addition, their recycling cost is high with prominent secondary pollution problems.
The performance of bio-based PLA can be optimized through modification processes to adapt to various application scenarios accurately. Modified PLA has a heat resistance of up to 95°C, balancing transparency, hardness and air permeability. It not only meets the usage requirements of food packaging and disposable catering supplies, suitable for fresh breathable packaging and beverage containers, but also achieves 100% complete degradation through industrial composting, complying with the international degradable standard EN 13432. In terms of terminal user experience, PLA can perfectly replicate the transparent effect of PET and PS and match the structural stability of PP, fully adapting to civil and industrial general plastic scenarios.
From the perspective of full life cycle value, petroleum-based plastics feature high carbon emissions and high energy consumption throughout the whole chain of "exploitation-production-use-disposal", and are difficult for harmless disposal after abandonment, leading to rising annual environmental governance costs. In contrast, PLA is low-carbon and environmentally friendly throughout the whole process from plant planting and raw material processing to product use and terminal degradation. It only decomposes into carbon dioxide and water without residues or pollution, and has dual attributes of recyclability and compostability. With the normalization of global plastic restriction and prohibition policies, PLA has gradually replaced high-pollution petroleum-based general plastics by virtue of its core advantages of renewability, low emission and complete degradability, becoming the preferred material for green upgrading in packaging, catering, light industry and daily necessities industries.
