Polycaprolactone

Polycaprolactone (PCL) is a synthetic, semi-crystalline, biodegradable polyester with a melting point of about 60 °C and a glass transition temperature of about −60 °C. The most common use of polycaprolactone is in the production of speciality polyurethanes. Polycaprolactones impart good resistance to water, oil, solvent and chlorine to the polyurethane produced. This polymer is often used as an additive for resins to improve their processing characteristics and their end use properties (e.g., impact resistance). Being compatible with a range of other materials, PCL can be mixed with starch to lower its cost and increase biodegradability or it can be added as a polymeric plasticizer to polyvinyl chloride (PVC). Polycaprolactone is also used for splinting, modeling, and as a feedstock for prototyping systems such as fused filament fabrication 3D printers. PCL is prepared by ring opening polymerization of ε-caprolactone using a catalyst such as stannous octoate. A wide range of catalysts can be used for the ring opening polymerization of caprolactone. Low molecular weight alcohols are commonly added to regulate the molecular weight of the polymer. PCL is degraded by hydrolysis of its ester linkages in physiological conditions (such as in the human body) and has therefore received a great deal of attention for use as an implantable biomaterial.