Polymorph is one of the so called "smart materials" now starting to be used in school science and technology. Many lab suppliers sell Polymorph in different quantities and may be listed as a 'smart plastic'. Polymorph is one of a class of polymers known as caprolactones which has unusual but useful properties.
At room temperature, Polymorph resembles a tough, clear plastic but it becomes easily mouldable at around 62°C, allowing it to be shaped as required. The mouldable temperature can be reached by either immersing into hot water or heated using a hairdryer. As long as the Polymorph remains at the mouldable temperature, it will remain in a putty-like state. As soon as it starts to cool, it returns to its plastic like state. Heating in a microwave is not recommended.
Polymorph is usually supplied in pellet form and sold by weight and has been designed to provide a useful solution to prototype design and orthopaedic products. Polymorph is often used in school technology departments to make ergonomic products such as hand tools and component mountings. Because of the safe handling temperatures, polymorph is a safe alternative to plaster of paris or traditional plastic moulding techniques.
Once cooled, Polymorph is very similar in appearance and physical properties to many polythenes, in fact it is stronger and tougher than most polythene used in domestic products. Polymorph is a true thermoplastic and can therefore be re-heated and thermoformed many times without deterioration.
Polymorph should never be heated above the 60°C-65°C temperature range as it will not only become a sticky treacle-like mass but may cause burns if handled. It is recommended that Polymorph is only fused in water whose temperature is monitored with a thermometer. It is not necessary to use boiling water which in itself presents a scalding hazard. With a molecular weight of 80,000, Polymorph sinks in water and will collect at the bottom of a container. When fused, the granules will adhere to each other but not to the container. The mass can be removed with tongs and squeezed to remove trapped water.
- Chemical name: Caprolactone polymer or Oxepanone polymer
- Commercial designation: CAPA 680 (specification 118310)
- Fusing point: 60-62° centigrade
- Tensile strength: 580 kg/cm2
- General Hazards: Non-hazardous [manufacturer's safety data sheet]
- Colour: Hazen
- Disposal: Biodegradable in soil