Mould gutta percha

Gutta peavha in its pure fium is white, and in crude form can be brown or black. It has the same chemical formula as rubber but a di rent physical state. It was not vulcanised as it was for too valuable a material and was prized for its elasticity and plasticity, and would have been ruined by vulcanisation. It was very easy to mould and could take intricate patterns, but to be made into jewellery, it would have needed to be hardened in some way. Gutta percha was less durable than vulcanite, and cracked and deteriorated when closed to air over a lot period of time. Instead it kept... 

Charles Goodyear [1], an American scientist, worked with gutta-percha, a gum from natural tropical trees, and Thomas Hancock, a British scientist who simultaneously and independently developed a process for the vulcanisation of rubber (1839) by reacting it with sulphur and heat, are credited with the first deliberate attempt to chemically modify a natural polymer to produce a moulding material. Gutta-percha was used to protect and insulate the first submarine telegraph cables. The combined and independent efforts of these men helped to lay the foundation for the manufacture of synthetic materials using chemistry. 

The first plastic materials to be utilised were natural materials, or modifications of them. As early as the seventeenth century, decorative mouldings were produced firom the natural polymer, horn. In the eighteenth century, rubber and gutta percha, both gums from tropical trees, were first exploited. Around 1841 Charles Goodyear... 

Plastics are made up of polymers and other materials that are added to them to give the desired characteristics. Natural polymeric materials such as mbber, shellac and gutta percha have a long history as raw materials for man. The first thermoplastic, celluloid, was also manufactured from a natural product, from cellulose. Even today, there are still some cellulose based plastics, i.e., the cellulose acetates (CA). Cellulose is already composed of the large molecules that are characteristic of plastics (macromolecules). However, to manufacture CA plastics, they still have to be prepared with acetic acid. The first injection moulding machine was built and patented in 1872 in order to mould cellulose materials. 

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