Polycaprolactone[2]
Overview
Polycaprolactone (PCL) is a synthetic biodegradable polyester derived from ε-caprolactone monomer via ring-opening polymerization. First developed in the 1930s, it gained industrial significance in the 1970s due to its unique combination of biodegradability and mechanical properties. PCL is particularly valued for its slow degradation rate (2-4 years) compared to other biodegradable polymers like PLA, making it suitable for long-term medical implants. Its low glass transition temperature (-60°C) and melting point (58-64°C) enable easy processing through extrusion, injection molding, or solvent casting.
Physical and Chemical Properties
PCL exhibits semi-crystalline morphology with typical crystallinity of 45-55%. The polymer's flexibility stems from its aliphatic ester structure, yielding an elongation at break of 300-1000%. Its low melt viscosity facilitates processing at relatively low temperatures (60-100°C). Chemically, PCL is stable at room temperature but undergoes hydrolytic degradation in aqueous environments or compost conditions. The degradation rate depends on molecular weight, crystallinity, and environmental factors like temperature and pH. PCL shows good compatibility with many organic solvents and can be blended with starch, cellulose, or other polyesters to modify properties.
Main Applications
In the medical field, PCL is used for resorbable sutures, drug-eluting stents, and tissue engineering scaffolds due to its FDA-approved biocompatibility. Its slow degradation matches the timeline for tissue regeneration in orthopedic and dental applications. The packaging industry utilizes PCL films for biodegradable food wraps and agricultural mulch films. In additive manufacturing, PCL filaments are preferred for low-temperature 3D printing of flexible prototypes. Recent developments include PCL-based shape-memory polymers for smart textiles and PCL nanocomposites with enhanced mechanical strength for automotive parts.
Safety and Storage
PCL is classified as non-hazardous under normal handling conditions. Dust formation during grinding or machining should be controlled through local exhaust ventilation to prevent respiratory irritation. Processed PCL products are generally safe for skin contact and medical implantation. Proper storage requires moisture-proof packaging (preferably vacuum-sealed) to prevent hydrolysis. Bulk material should be stored in a cool (<30°C), dry environment away from oxidizing agents. Shelf life typically exceeds 2 years when stored correctly. For critical medical applications, gamma irradiation sterilization is recommended over heat methods to avoid polymer degradation.
B2B Procurement Guide
Industrial buyers should specify key parameters: molecular weight (typically 10,000-80,000 g/mol), melt flow index (2-25 g/10min at 80°C), and residual monomer content (<0.5%). Medical-grade PCL requires additional documentation including USP Class VI certification and endotoxin testing reports. Leading manufacturers include Perstorp (Capa™), Daicel, and BASF. Prices vary significantly based on quantity (bulk discounts available for >1 ton orders) and specialty formulations. For prototyping needs, small-quantity suppliers like Filamentive offer pre-compounded PCL filaments with diameter tolerances of ±0.05mm. Always verify biodegradation certificates (EN 13432 or ASTM D6400) for packaging applications.