German Chemist Hans von Pechmann first synthesized Polyethylene by accident in 1898 by heating diazomethane. His colleagues characterized the waxy substance polyethylene due to the fact that they recognized that it consisted of long ethene chains. It was then first industrially synthesized by accident in 1933 by applying extremely high pressure to ethylene and benzaldehyde. Over the years, development of polyethylene has increased due to the additions of catalyst. This makes ethylene polymerization possible at lower temperatures and pressures.1
Polyethylene is a polymer that is made of a long chain of CH2 monomers bonded together. It is one of the most commonly used polymers in everyday items. Grocery bags, soap bottles, children’s toys, and even bullet proof vests are all made from polyethylene.2 This polymer is very versatile and can be used in many materials but this all depends on the way that the polymer is chemically made or enhanced. There are many different types of polyethylene classified by density and branching. 2
Higher density polyethylene is very linear and has no branching. Lower density polyethylene is a result of some of the carbon atoms bonding with other polyethylene
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.
Other alterations such as dying the polymer are less cost efficient to recycle and can be more difficult as well. There are certain types of HDPE (high density polyethylene) that are blown into shapes such as bottles. Different chemicals are used in this process and therefore have to be separated into their own category when recycling. The reason people have moved away from landfill dumping and moved towards recycling is due to the fact that it is much more cost effective to recycle compared to paying engineers and environmentalist to designing landfills.4 The HDPE can also be mechanically recycled through curb side pick ups.
rapid development of polymer chemistry after World War II a host of new synthetic fibers
In the early morning hours of January 12th 1981, twenty-five detonations were heard coming from the ramp at Muñiz Air National Guard Base, located in the Luis Muñoz Marín International Airport in San Juan, Puerto Rico (PR). It was a terrorist attack. The result? Ten A-7D aircrafts and a single F-104 destroyed, with a total of $45,000,000 in damages. It was the largest attack on the US military since the Vietnam War. The culprits? All members of a separatist domestic terrorist group called Ejercito Popular Boricua (English: Boricua Popular Army or BPA, EPB) more commonly known as Los Macheteros (“The Machete Wielders”); a nickname that conjures images of the improvised group of Puerto Ricans that banded together to defend and fight the United States Army when they invaded during the Spanish-American War. BPA’s main ideology is a free Puerto Rico, free from the colonial status that United States has on PR, and for PR to become its own sovereign state. Although BPA is not as active as it once was, they still promote and will fight for PR’s independence. But to understand the history and origins, ideologies, and goals of BPA we must go back in time to recognize why such a group even exists.
Service life The effect of fillers on polymers is that they are very beneficial because they don’t get ruined for a long time. Glass fillers are the most commonly used fillers in polymers. This is because they last longer and their service life is longer.
Polymer chains are long, individual chains, although they behave as if they are attached to each other. The individual chains are actually held together by ‘Electrostatic Forces’ between molecules, also known as ‘Hydrogen Bonds’. Scientists discovered this, by using a special type of X-ray microscopy called ‘XANES’. This was able to reveal the orientation of molecules in materials. It has also been discovered that the components of Kevlar fiber, have a radial orientation that is in a crystal. The crystal-like regularity is the largest contributing factor in the strength of Kevlar fiber.
Before using ethylene to produce polyethylene, the compound needs to be purified to almost 100%. In order to reach this level of purity the ethylene needs to be freed of olefins, acetylenes, dienes and water through several processes such as: driers are used to take out the water, a demethanizer is used to remove methane, etc. ...
spaced –CONH– amide groups. Nylon 6-6, or poly(hexamethylneadipamide), is composed of. two structural monomers (hexamethylendiamine (H2N(CH2)6NH2) and adipic acid. (HOOC(CH2)4COOH), whereas Nylon 6, or poly(6-caprolactam), is composed of a single structural unit (either 6-aminocaproic acid (H2N(CH2)4COOH) or caprolactam). Ultimately, the answer is yes.
Plastic materials have become so numerous that you cannot go through a single day without touching something made of plastic. Toothbrushes, ballpoint pens, unbreakable dishes, cabinets and knobs for machines and appliances, light switches – all of these things and many more are made of plastic.
Polystyrene is a thermoplastic polymer which is the third most important polymer which is synthetically prepared from the styrene of monomers which is petrochemical liquid. It can be hard or can b soft foamed. It is inexpensive resin that’s why it is clear, brittle and hard. The excellent processing and physical properties make this thermoplastic material very suitable that’s why it is used in many applications. It is a vinyl polymer which has long hydrocarbon chain and phenyl group attached to every other carbon atom. It is formed or produced by polymerization of vinyl which should be a free radical. This polystyrene is a component of type of hard rubber which is also called poly(styrene-butadiene-styrene). Polystyrene will take more volume in landfill than paper and enter the environment again and again when water or any mechanical force breach landfills. We can also say that it performed many functions as a monomer which is to be found in many different polymers. As estimated that the 17-21 million tons of polystyrene is produced yearly.
With new technology and different resources that make human life easier, there are increased problems for the environment and wildlife. Plastic was a huge discovery and it has changed everyday life since then. Plastic has a low cost and has replaced many traditional products such as wood and glass. Because of their wide variety of uses, plastics are used throughout the entire world. This poses problems with how to safely dispose of plastics and the damage they cause when they are not disposed of properly.
Many people believe that we should not recycle anymore, but this is not the case. We, the people of the world, need to continue to recycle because we do not want our children to grow up in a world where there are no certain species of animals due to recycling failures. We also do not want our children to grow up thinking that it is okay that they throw their garbage on the ground, and not have to pick it up. We need to teach our children that they need to take care of the earth that they are living on, because they only get one. Recycling is one of the most beneficial environmental issues that we have here on this earth. Recycling saves energy, limits pollution and supports several environmental factors of the economy. “In 2003, the savings from recycling 54 billion aluminum cans exceeded the energy equivalent of 15 million barrels of crude oil- or the amount of gas the U.S. uses in one day,” according to the U.S. Environmental Protection Agency. The EPA estimates that 200 million gallons of used oil are not disposed of properly, and if we were to dispose the oil properly then we could keep the oil from polluting the ground and the fresh water source. According to E. Takatori, “… While on-going societal regulation treats material recycling as the dominant cycle, the properties of recycled plastic remain the most port
The future for these products is also quite often over looked. The components are not made to be detachable, so the different materials cannot be recycled correctly or recycled at all, which leads to landfills and pollution. Every material, from wood to steel to carbon fibre has an environmental story behind it and these can all be reused, however there is quite often not enough thought into this design aspect. These components are not labelled correctly for recycling and the result is a scarred landscape. However recycling these days has now turned into a way of life for us. Bins are now everywhere marked with the unmistakeable ‘three-green-arrow’ (another remarkable graphic design – now playing a huge role in the way we live), which lets members of the public kn...
One huge aspect of recycling is that it gives the recycler the fulfillment of helping the environment. W. Kip Viscusi a professor at Vanderbilt University said, “The warm glow environmental benefit that a person receives from recycling will be greater for those who place a higher value on the environment .” Therefore, the benefit of helping our environment is the greatest benefit of all. Although it might seem as if plastic is thrown away than it can not harm the environment, however, that is incorrect. Plastic is not biodegradable, therefore, it will never be able to completely decompose into the earth. With plastic not being able to decompose it takes up a large amount of space while also being capable of traveling through the air. Sati Manrich, the author of Plastic Recycling said, “The mounting volume of plastic residues, coupled with their extremely low biodegradability, generated a serious problem regarding the amount of space they took up.” Therefore, when plastic is thrown away it will last for at least four-hundred and fifty years before degrading in the landfills; thus allowing all the plastic that was thrown away in the last four-hundred and fifty years to start a stockpile in the landfills or even travel somewhere else.(Manrich
from different resins. In order to recycle plastics, the different types must be kept separate.
Recycling is important in the effort to preserve our environment for future generations. We are running out of locations to put landfills. Recycling is a simple and effective way to reduce the amount of waste stored in landfills, yet many people do not know how easy it can be. For example, whenever I go to Shoprite® and I b...