The Plastic Industry


Year 11 Chemistry


Introduction


Throughout these thousands of years, mankind have been using natural plastics. These plastics come from natural resins of nature. The use of plastics date back to when the Egyptians soaked burial wrappings in natural resins to help preserve their dead, and people had also used animals horns and shell for centuries to make spoons and combs.


The development of plastics was invented in about 1860, when Phelan and Collander, a U.S. pool and billiard ball company, was offering a prize of $10,000 to the person who could design the best substitute for natural ivory. Throughout those entrants, a person name John Wesley Hyatt although wasn’t the winner, but had developed a cellulose derivative for that contest. Later on, his product was named Celluloid, which resulted in a successful organization of product, where companies had began using his product in order to produce a range of items.


Later on in 1920, a German scientist name Hermann Staudinger had ordered out a advance information of plastic materials. He stated that plastic were made up of very large molecules held together by a strong force. From his theory, in the 1920’s and 1930’s plastic research had raised, manufacturing new plastic every year. Some of these include nylon, methyl methacrylate, Plexiglas, and polytetrafluoroethylene.


Every since, new types of plastic have been produced, with each their very own characteristics and purpose of use.



Plastic buckets


Types of Plastics


Plastics are believably made of natural/synthetic materials. Plastics are produced by chemically modified natural substance or either is synthesized from organic raw materials. Due to the different physical characteristics, plastics are positioned into either thermosets, elastomers or thermoplastics. These group differ through the difference in molecular structure, having plastic falling into their groups with different thermal behaviour.


Thermosets- Thermosets have a very tight scaled branched molecular structure making the material very hard. After the process of shaping the desire shape, the plastic will no longer allow any reshaping, even if the material is again heated. The only method to reshaping the material is performed by machinery. Thermoset plastic are used for making items like; light switches, the handle of a kettle, plastic bins, and the knob of a saucepan.


Elastomers- Elastomers have a more looser mesh molecular structure then thermosets, giving the plastic the ability to stretch to a degree. However, in terms of shaping the plastic, it is exactly like thermoset plastic where the plastic no longer allow any reshaping after the final process. It is used for vehicle tires.


Thermoplastics- Thermoplastic are plastic in which can have a linear or branched molecular structure. At room temperature it is flexible, but once reaching a limitation of temperature is begins to melt into a liquid. This type of plastic are used for packaging and shopping nags.


The molecular structure of thermoset plastic


The molecular structure of elastomers



The molecular structures (branch and linear) of the two kind of thermoplastics


In the world, there are a huge variety of different plastics, each possess with their own useful properties and characteristics. Generally, all plastics are lighter then many other materials of comparable strengths, where unlike metal plastic doesn’t rust. Most plastics can be produced in almost any colour as well can be manufactured to an extent where it is identical to glass, having to be translucent, and opaque.


Some plastic polymers are very hard and rigid like bowling balls, helmets, while others are soft and flexible like foam mattresses. Some polymers are resistant to heat, while there are others are easy to melt. Some polymer also has the ability to be molded over and over again, while there are many that stay in formation. These characteristics all depend on the molecular structure of the plastics.


Nowadays, with the use of advance technology and intelligence, chemist can produce plastic in order to suit specific needs by controlling the polymers properties. This include the determination of size of the molecule and the structure, either having it be branched or linear.


The reason for the different molecular structure of different types of plastics is to suit our requirements. For example if we were to designing a outdoors water tank, we require a suitable plastic in which has ability to withstand heat, durable, flexible, and long lasting.


The Use of plastics


Since the development of plastic earlier this century, it has become one of the most popular material