The synthesis of polymers starts with ethylene, (or ethene). Ethylene is obtained as a by-product of petrol refining from crude oil or by dehydration of ethanol. Ethylene molecules compose of two methylene units (CH2) linked together by a double carbon
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
very special polymer that is unique in its characteristics, functions, and use in the modern
After this compound is formed, then comes the polymerisation stage1. In the polymerisation stage the compound that is produced is heated at a temperature of 260oC and at a low pressure1. A catalyst is required at this stage to speed up the reaction - there are many options for catalysts such as antimony (iii) oxide1. After this step the polyester is formed and half of the ethane1,2- diol is restored which is removed1.
Recycling is the process by which a waste material is converted again into reusable process and disposal is a process by which we get rid of something. Polymers are not very reactive so this property makes them very useable for storing food but this property makes it difficult to recycle or dispose of polymer. This difficulty in recycling and disposing of polymer is a major cause of environment hazard. Since the waste of polymer is increasing day by day so proper measurement should be taken to reduce the use of polymer and different method should be made to properly dispose and recycle waste. Following are the process by which a polymer is recycled or disposed.
Plastic, like most inventions, was accidentally invented. Charles Goodyear was a perfect example of how things accidently started. He started the process of making plastic by dropping India-rubber mixed with sulfur on a hot stove. The in the late 1930s, chemist Wallace Carruthers invented nylon, which is a synthetic polymer. Polymers have a high melting and boiling point. Synthetic polymers are also known by the word we use today, plastic. The evolution of plastic started during World War II. Ever since then, plastic has been remolded and created to be used for our convenience in our everyday lives. For example, using a plastic cup or plate is more convenient than using a glass cup or bowl. People encounter many different types of plastic each day and may not be aware of it. In fact, during the first two hours of a typical morning, a female college student might encounter the following products which contain plastics: her alarm clock, mirror frame, the tape used to hang her posters, the toilet seat, the shower curtains, her deodorant, her toothbrush, her shampoo and conditioner bottles, her blow dryer, the light switch, bottled water, her refrigerator, a bread bag, her roommate's glasses, her fan, and phone.
Scifun. (date unknown) Chemical of the week – polymers, date accessed 18th August 2010, http://scifun.chem.wisc.edu/chemweek/polymers/polymers.html
There are six classifications of plastics, each assigned a number. Numbers 1 and 2 are commonly recycled, 4 is recycled less, and the others are generally not recycled. The first is polyethylene terephthalate (PET). PET is commonly used in making liquid containers such as plastic soda and water bottles and has many other applications. Recycled PET also has many applications, including textiles, sheets for tapes, and the bottle market. The second type of plastic is high-density polyethylene (HDPE). HDPE is used in milk, detergent, and oil bottles and plastic bags. It is crushed into flakes and washed, then dried and shaped into pellets. Some uses for recycled HDPE are trash cans, flower pots, lumber, and other non-food applications. The third type of plastic is vinyl or poly vinyl chloride (PVC). Low-density polyethylene (LDPE) is the fourth type of plastic, and is used in many plastic bags and shrink wraps. It has the same chemical makeup as HDPE but is less dense and more flexible. Recycled LDPE is used for plastic trash bangs and grocery sacks and plastic lumber, as well as several other applications. The fifth type of plastic is polypropylene (PP), which is used in food wrap, some carpets, and bottle tops. P...
The most common form of polyethylene is petroleum based or olefins based; as before mentioned polyethylene compounds have a wide commercial applicability and are made from non-renewable resources (Harding, Dennis, von Blottnitz, Harrison, & S.T.L., 2007). Its manufacturing processes are regarded as energy intensive and release significant amount of CO2 and heat into the atmosphere (Broderick, 2008). Next a little more detailed description of polyethylene’s production processes will be presented, with a focus on the way the material inputs are extracted and synthesized.
Kevlar Aramid Fiber is a synthetic (man-made) material known as a Polymer. A polymer is a chain that is made up of many similar molecular groups, better known as ‘monomers’ that are bonded together. ‘Monomers’ are made up of fourteen Carbon atoms, two Nitrogen atoms, two Oxygen atoms and ten Hydrogen atoms. A single Kevlar polymer chain could possibly have anywhere from one to five million monomers bonded together.