With the rapid expansion of the degradable plastic market, starch-based plastics, oxo-degradable plastics and bio-based PLA have become mainstream environmentally friendly plastic products. However, differences in material technology, degradation principles and terminal environmental effects have led to significant gaps in industry adaptability, compliance and sustainable value among the three types of materials. Compared with traditional starch-based and oxo-degradable plastics, bio-based PLA has become the optimal solution for high-quality and long-term environmental protection by virtue of pure biodegradation attributes, stable product performance and compliant environmental standards, thoroughly solving the industry pain points of traditional degradable materials such as incomplete degradation, secondary pollution and performance defects.
In terms of degradation principles and environmental effects, oxo-degradable plastics are essentially petroleum-based plastics that achieve "pseudo-degradation" by adding oxidative degradation additives to traditional plastics such as PET, PE and PP, rather than real biodegradation. Its degradation logic is to break the macromolecular chains of plastics through light, oxygen and high temperature, which only decomposes large plastic blocks into microplastics at micron and nanometer levels, without harmless elimination. These residual microplastics remain in soil, water and atmosphere for a long time, causing continuous ecological pollution. Currently, oxo-degradable plastics have been clearly restricted by the EU and many national environmental protection agencies, failing to meet the compliance requirements of high-end environmental protection markets.
Starch-based degradable plastics are mainly made of starch mixed with plastic additives and adhesives. Although plant raw materials are incorporated, pure starch has poor mechanical properties and is prone to moisture damage, so the products still contain a large amount of non-degradable polymer components. In the process of actual use and waste degradation, only the starch component can decompose naturally, and the remaining plastic matrix cannot be degraded, still causing plastic residues and microplastic pollution. Meanwhile, starch-based plastics have poor water resistance and stability, are prone to mildew and damage with short service life, and cannot adapt to complex scenarios such as high temperature and humidity, which greatly limits their application scope.
Bio-based PLA is a pure biodegradable material completely synthesized from plant raw materials with a pure and efficient degradation mechanism. Under industrial composting conditions, PLA can be completely degraded through microbial action, and finally converted into carbon dioxide, water and biomass without microplastic residues or harmful substance precipitation, realizing genuine harmless and resource recycling. It can also achieve progressive degradation in natural soil and seawater environments without secondary pollution throughout the process, fully complying with the new standards and export compliance requirements of degradable materials worldwide.
In terms of product performance and industrial adaptability, traditional oxo-degradable and starch-based plastics generally have performance defects. Oxo-degradable plastics have uncontrollable degradation cycles and unstable service life, prone to premature aging and damage; starch-based plastics have insufficient toughness, poor waterproofness and strict storage conditions, making it difficult to meet the needs of large-scale industrial production and high-end product applications. In contrast, PLA has uniform and stable material properties, excellent toughness, transparency, temperature resistance and moisture resistance. Its processing performance is comparable to traditional petroleum-based plastics, suitable for various processing technologies such as injection molding, film blowing and blister molding, and widely applied in high-end food packaging, disposable catering consumables, maternal and infant products, medical packaging, outdoor supplies and other fields.
With the upgrading of industry compliance, the market has increasingly higher requirements for degradable materials featuring "real degradation, zero residue and high performance". The hidden danger of microplastic pollution of oxo-degradable plastics and the incomplete degradation and performance shortcomings of starch-based plastics can no longer adapt to the needs of high-end markets and policy compliance. By virtue of the core advantages of full-chain greenness, complete biodegradation, stable performance and strong compliance, bio-based PLA has broken through the technical bottlenecks of traditional degradable materials and become the core mainstream material for the standardization, high-end and sustainable development of the degradable plastic industry.
