Polymorph plastics

Polycaprolactone (PCL) is a biodegradable polyester with a low melting point of around 60°C and a glass transition temperature of about −60 °C.

Polycaprolactone is also used for splinting, modeling, and as a feedstock for prototyping systems such as a RepRap, where it is used for Fused Filament Fabrication (similar to the Stratasys' Fused Deposition Modeling or FDM technique).PCL has been approved by the Food and Drug Administration (FDA) in specific applications used in the human body as (for example) a drug delivery device. A variety of drugs have been encapsulated within PCL beads for controlled release and targeted drug delivery which have been peer reviewed.

In odontology or dentistry (as composite named Resilon), it is used as a component of "night guards" (dental splints) and in root canal filling. It performs like gutta-percha, has the same handling properties, and for retreatment purposes may be softened with heat, or dissolved with solvents like chloroform. Similar to gutta-percha, there are master cones in all ISO sizes and accessory cones in different sizes available.

PCL also has many applications in the hobbyist market. It has physical properties of a very tough, nylon-like plastic that melts to a putty-like consistency at only 60 °C. PCL's specific heat and conductivity are low enough that it is not hard to handle at this temperature. This makes it ideal for small-scale modeling, part fabrication, repair of plastic objects, and rapid prototyping where heat resistance is not needed. Though molten PCL readily sticks to many other plastics, if the surface is cooled, the stickiness can be minimized while still leaving the mass pliable.

Source: en.wikipedia.orgAdded: 13 November 2012