Polymers are everywhere in our daily life. From the daily necessities to the cutting-edge materials and even the life itself are made of polymers. The video, Polymers and plastics, is a brief introduction of polymers. What follows are mainly based on the contents of the video, combining with the reflective thoughts from my own perspective.
Polymers and plastics is one of the episodes of an education TV program called Atoms of Fire, an introduction to organic chemistry. This series of educational video clips use stories, demonstrations, diagrams and documentaries to explain the basic facts of organic chemistry and so do the Polymers and plastics. The video introduced some important polymers such as cellulose, nitrocellulose, celluloid, bakelite
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Taking the polyethylene, the polymer of the ethylene, as an example, millions of ethylene molecules join together to built this strong material. However, the main question is: Why is it so strong? Then the video gives us the answer. It is because the amazing combining power of carbon atoms. Since its situation in the periodic table, carbon have 4 outermost electrons, it need to gain four more electrons to form a stable state, like neon. Whereas, carbon can also loss 4 outermost electrons to form another stable structure, like helium. As the result of that, carbon have the same chance to loss and gain the electrons, which enable it to conjoin with itself or other atoms endlessly in the shape of chains, sheets or even blocks. Diamond is the best demonstration of this properties. Every carbon atom in the diamond shares four outermost electrons with the atoms nearby to form four 2-electron bonds. In this way every atom set in an exact position and gets a perfect structure, that they all have 8 outmost electrons. Therefore, the carbon atom could combine with itself tightly, which is the basis of how carbon chain can be the skeleton of most …show more content…
In 1860s, an American inventor, John Wesley Hyatt, wanted to find a substitute material for ivory to make the billiard ball [1]. He took the collodion, which is the solution of nitrocellulose in alcohol and ether, and then dissolved it under pressure and high temperatures in camphor to form celluloid under low temperatures [2]. Not only is the celluloid an appropriate material in billiard ball manufacture, but also an admirable material for forming the Ping-Pong balls, combs or photographic films. The celluloid is the first thermoplastic, which means it is hard under room temperatures and becomes soft when you hat it. However, due to this property, celluloid still have the eager to born. So latter came the synthetic polymer. In 1909, Leo Baekeland developed bakelite, a three dimensional thermoset plastic. The synthesis reaction is that in the presence of alkaline catalyst, a molecule of formaldehyde joins the two phenols with a methylene and form a molecule of water. It is because its three dimensional structure, that bakelite won’t melt before burn. After that the modern year of polymer began. In the early 1930th, the first breakthrough of modern polymers, nylon, a thermoplastic, was discovered. Concerning the thermoplastics and thermoset plastics that mentioned above, the different between them is because the degree of crosslinking
Carbon is one of the 115 chemical elements discovered on Earth which is part of the nonmetals group with other elements such as nitrogen, oxygen, and hydrogen. Carbon as an element has good stability, it is very light, very stable, and has many types of forms such as graphite, and coal. Carbon fiber is just another form of carbon, basically has filaments between five to ten micrometers in diameter of pure carbon or at least 90% of carbon. Thousand carbon fibers are twisted together to form a long chain, which can then be used in a variety of raw forms, including yarns, weaves, and braids, which are in turn mixed with synthetic resins to create the carbon fiber as a composite material. Based on different characteristics carbon fibers can be divided into three principals groups: according to carbon fiber tensile modulus, according to precursor fiber materials, and according to final heat
rapid development of polymer chemistry after World War II a host of new synthetic fibers
Stiffness In terms of stiffness this additive is hard and stiff. This affects the polymers in a good way because it acts like a protective shield for the polymer to stop any polymer oxidation on the polymer.
The first term that I noted during the movie was Conductive Polymers. Conductive polymers are almost always organic meaning a large class of chemical compounds whose molecules contain carbon. These polymers have extended delocalized bonds which are bonds found in a molecule that do not belong to a single atom or covalent bond. They are conjugated systems of double bonds and in a aromatic systems. The conjugated systems are atoms covalently bonded with alternating single and double bonds. When the electrons are removed or added into the valence bands the electrical conductivity increases. The conductive polymer has a low conductivity until the electron is removed from the valence band called (p-doping) or (n-doping) until it becomes more conductive. The movement of the charges is what is responsible for electrical conductivity. These polymers are plastic which are organic polymers and with mechanical properties such as flexibility and elasticity.
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.
According to the American Council of Chemistry, plastics, which are otherwise known as polymers, are comprised of carbon, hydrogen, chlorine, nitrogen, sulfur, oxygen, and other elements that are combined through the conversion of natural products like oil, natural gas, or coal (ACA, n.d.). Between 7 and 8 % of the oil and natural gasses produced annually are used either directly in the conversion of such fossil fuels to plastics, or in powering the processes to produce plastics (Hopewell, Dvorak & Kosior, 2009). Plastic combinations can either form as thermoplastics, which are plastics whose atoms are connected in long chains that can be melted and reused, or thermosets, which are plastics whose atoms are arranged in three dimensional patterns that cannot be melted or reused (ACC, n.d.). Plastics are used in a wide range of products. For example, polyesters are used in textiles and fabrics, polyvinylidene chlorides are used for food packaging, polycarbonates are used for glasses and disks, and more. By the United States energy averages of 2015, each kg of plastic produced requires 62-108 mega joules of energy. The plastic requiring the largest amount of energy per kg is silicon which required about 235 mega joules of energy per kg. Three hundred and twenty two million metric tons of plastic produced in 2015 alone, and that value continues to raise, (Global plastic production,
The most commonly produced PVC structure by addition polymerisation is the atactic PVC. As seen in Figure #, the chlorine atoms are branched randomly and asymmetrically along the carbon backbone. Unlike the other two structures, the random orientation prevents the polymers from packing closely together and is described to be ‘amorphous’.
Every year, an estimated 8 million tons of plastic waste enters our environment, severely polluting oceans, beaches, forests, and even the towns and cities we live in. In the ocean alone, it is believed that 5.25 trillion pieces of plastic pollutes the waters (“Plastic Statistics”, Ocean Crusaders).The majority of plastic pollution can be traced back to single-use items, such as grocery bags, bottles, and plastic packaging. According to United Nations Environment, “At the rate we are dumping items such as plastic bottles, bags and cups after a single use, by 2050 oceans will carry more plastic than fish…” (“UN Declares War on Ocean Plastic”, UN Environment). This pollution is a major problem and endangers not only the environment, but human
The purpose of this experiment was to create a polymer by reacting a mixture of decanedioyl dichloride and dichloromethane with a mixture of water, 1,6-hexadiamine and sodium carbonate. Specifically, we created the polymer Nylon-6,10. Nylon-6,10 polymers are used in a vast majority of things we use in everyday life such as zippers, the bristles in brushes, and even car parts. This experiment was different from the industrial method of making nylon because that takes place at a much higher temperature. A polymer is a substance that has a structure made of similar or identical units bonded together. All polymerizations fall into two categories: step-growth and chain-growth (both of which we used to form our polymer). Step growth polymerization
Ever since I began studying science and mathematics at all levels of educations I have always had an interest in the production of useful materials. In the growing turmoil of today; a world full of global warming and diminishing resources, questions often arise in my mind such as, "can we make a more efficient, more durable and a renewable resource that will overshadow fossil fuels? and have less of an impact on our environment?" Up to now, I have not found a solution to these questions and answering these questions is a personal aspiration of mine which I aim to fulfil by achieving a degree in Chemical engineering and eventually I will contribute to the field in my own unique way. The debate surrounding sustainable energy fascinates me, having recently learned from personal research I have understood what an authoritative role chemists and chemical engineers play in the industry at the present time and how, by working as a team, they contribute to an improved future for the whole world. However, one of the main reasons that has single-mindedly driven me this far to want to study chemical engineering is a book I have read, “Beyond the Molecular Frontier: Challenges for Chemistry and Chemical Engineering” While reading this book, I had solidified my understandings of what chemical engineering is all about. Also, one of the main processes mentioned was polymerisation and is something I already study in A-level chemistry, it is something that not only interests me, but is a personal career aspiration of mine. Reading this book gave me a determination to be the person who helps improve the future of the industry and provide an answer to the questions I always ask myself by studying this degree.
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...
chains instead of hydrogen atoms. Cross-linking is another way in which the polymer can be made stronger. This involves ultraviolet radiation that bombards the polymer with electrons and formulates bonds between the molecular chains of the polymers. This is like linear polyethylene but different in that it is more impact resistant, and it has a much higher density. This allows it to be stored or be used with different chemicals that would normally cause the polymer to desolve.3 This can start to become a problem because as the polymer continues to become chemically enhanced. So the ways of dissolving and recycling the polymer become more difficult.
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.
My main aim during my undergraduate studies was to get an overview of the various fields in chemical engineering and identify a field of interest in which I could pursue my research career. Because of their vast applications, Materials & Polymer Sciences, in general, have attracted m...