Year 11 ChemistryIntroductionThroughout these thousands of years, mankind have been using naturalplastics. These plastics come from natural resins of nature. The use ofplastics date back to when the Egyptians soaked burial wrappings in naturalresins to help preserve their dead, and people had also used animals hornsand shell for centuries to make spoons and combs. The development of plastics was invented in about 1860, when Phelan andCollander, 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 naturalivory. Throughout those entrants, a person name John Wesley Hyatt althoughwasn’t the winner, but had developed a cellulose derivative for thatcontest. Later on, his product was named Celluloid, which resulted in asuccessful organization of product, where companies had began using hisproduct in order to produce a range of items. Later on in 1920, a German scientist name Hermann Staudinger had orderedout a advance information of plastic materials. He stated that plastic weremade up of very large molecules held together by a strong force. From histheory, in the 1920’s and 1930’s plastic research had raised, manufacturingnew 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 veryown characteristics and purpose of use. Plastic bucketsTypes of PlasticsPlastics are believably made of natural/synthetic materials. Plastics areproduced by chemically modified natural substance or either is synthesizedfrom organic raw materials. Due to the different physical characteristics,plastics are positioned into either thermosets, elastomers orthermoplastics. These group differ through the difference in molecularstructure, having plastic falling into their groups with different thermalbehaviour.
Thermosets- Thermosets have a very tight scaled branched molecularstructure making the material very hard. After the process of shaping thedesire shape, the plastic will no longer allow any reshaping, even if thematerial is again heated. The only method to reshaping the material isperformed by machinery. Thermoset plastic are used for making items like;light switches, the handle of a kettle, plastic bins, and the knob of asaucepan. Elastomers- Elastomers have a more looser mesh molecular structure thenthermosets, giving the plastic the ability to stretch to a degree.
However,in terms of shaping the plastic, it is exactly like thermoset plastic wherethe plastic no longer allow any reshaping after the final process. It isused for vehicle tires. Thermoplastics- Thermoplastic are plastic in which can have a linear orbranched molecular structure. At room temperature it is flexible, but oncereaching a limitation of temperature is begins to melt into a liquid. Thistype of plastic are used for packaging and shopping nags.
picThe molecular structure of thermoset plasticpicThe molecular structure of elastomerspicThe molecular structures (branch and linear) of the two kind ofthermoplasticsIn the world, there are a huge variety of different plastics, each possesswith their own useful properties and characteristics. Generally, allplastics are lighter then many other materials of comparable strengths,where unlike metal plastic doesn’t rust. Most plastics can be produced inalmost any colour as well can be manufactured to an extent where it isidentical 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 areresistant to heat, while there are others are easy to melt. Some polymeralso has the ability to be molded over and over again, while there are manythat stay in formation. These characteristics all depend on the molecularstructure of the plastics. Nowadays, with the use of advance technology and intelligence, chemist canproduce plastic in order to suit specific needs by controlling the polymersproperties.
This include the determination of size of the molecule and thestructure, either having it be branched or linear. The reason for the different molecular structure of different types ofplastics is to suit our requirements. For example if we were to designing aoutdoors water tank, we require a suitable plastic in which has ability towithstand heat, durable, flexible, and long lasting. The Use of plasticsSince the development of plastic earlier this century, it has become one ofthe most popular material used. The uses of plastics are essentiallylimitless.
Plastic is found almost everywhere. Although for these many pastyears of producing and usage, we are not aware of how we are harming theworld. Today plastic is used to make or wrap around many of the items
