Polylactic acid

Polylactic acid (CAS 26100-51-6), commonly known as PLA, is a bio-based, compostable thermoplastic derived from renewable feedstocks such as corn starch or sugarcane.

Where is Polylactic acid used?

• Packaging: films, trays, cups, and rigid containers where end-of-life compostability is a requirement
• Medical devices and pharmaceuticals: resorbable sutures, drug delivery matrices, implantable scaffolds
• 3D printing: filament for FDM and FFF processes
• Food contact: disposable cutlery, cold-drink cups, produce packaging
• PLA degrades predictably in biological environments during use.
• Shrink-wrap material, as it constricts under heat.
• Solvent welding using dichloromethane.

Good to know: Grades are differentiated by molecular weight, D/L-lactide ratio, and melt flow index, allowing the material to suit injection molding, extrusion, or fiber spinning. Medical-grade specifications typically meet USP or ISO 13485-aligned quality standards.

Formulation notes

• With acrylated epoxidized soybean oil as a chain extender, parts containing 2.5–7.5 wt% chain extender showed increased mechanical properties and thermal stability.
• Relatively low glass transition temperature of about 55–65 °C, which can limit use in high-temperature applications unless stabilized by blending or additives.
• Undergoes thermal degradation by specific scission above 200 °C.

Typical specification

• Available in Technical, Pharmaceutical, and Drug Delivery grades.
• Exists in three stereochemical forms: poly(L-lactic acid), poly(D-lactic acid), and poly(D,L-lactic acid).
• Grade 3D850 from NatureWorks has a typical melt flow rate of 7.00–9.00 g/10 min and a maximum melt temperature of 165–180 °C, used for highly transparent 3D printing monofilaments.

Regulatory status

• ASTM D6400 certified, meeting standards for industrial composting with 90% biodegradation within 180 days.
• FDA approved for food contact in the US, safe for direct food packaging applications.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.