Polyester Fibres Indtroduction: Polyester are polymers made by a condensation reaction taking place between small molecules, in which the linkage of the molecules occurs through the formation of estes groups. Polyesters are commonly made by interaction of a dibasic acid with a dihydric alcohol: HOOC-X-COOH+HO-Y-OH OC-X-COO-Y-OCO-X-COO-Y-OCO The formation of polyester was studied by Wallace H. Carothers of du Point during the investigation of polyesters which lead eventually to the discovery of nylon. Development of the polyesters was overshadowed, however, by the polyamide research, and it was not until 1941 that a valuable polyester fibre was discovered. in that year, J. T. Dickson and J. R. Winfield of the Calico Printers'
INTRODUCTION Figure 1: Molecular Structure of PET PET (or PETE) is also known as polyethylene terephthalate or (C10H8O4)n. Its natural state is a colorless, semi-crystalline resin when combined with other materials like glass fiber or carbon nanotubes, it increases the material’s strength. Polyethylene terephthalate melts at 260°C and Amorphous density (at 25oC) is 1.33 g/cm3. PET can be produced by 2 different reactions as a product of polymerization. The first reaction is between ethylene glycol with terephthalic acid. The second one is the reaction of ethylene glycol with dimethyl terephthalate in acid catalyst.
Dehydration Synthesis, or condensation reaction, is when we can take these single-ring structures and combine them by taking away water, or H2O. This combining of molecules by removing water is a chemical reaction called dehydration synthesis. • Maltose is created from the linkage of glucose + glucose. Maltose is commonly referred to as malt sugar, and it is the sugar that we get
Other disaccharides are broken down by other carbohydrase enzymes. Carbohydrates (starch)are broken down in the oral cavity by saliva amylose. They are made up of 3 elements, carbon (C), hydrogen(H) and oxygen(O) and can be found together in three different forms. Either as a monosaccharide, disaccharide or a polysaccharide they are differentiated by the number of rings in their chemical compound. There chemical formation is C6,H12,O6 and due to their bond angles between the carbons, tend to form a pentose of hexoses, stable ring structure.
Alternative 3 Another solution that Garland Chocolates can look at is to buy a machine that costs less or does half of the work and outsource to finish the product. By doing half the work they are saving time and money. Advantages Buying a machine that can do half the work will cost less for the company. It will take them less time to produce the candy. Outsourcing the rest of the production will create more jobs in an undeveloped country as well as save money for Garland Chocolates.
Local practitioners also use powder of stem bark of Jujube to cure Aphthous. There for, it was decided to prepare of a mocuadhesive disc from Jujube stem bark extract. The strategy for designing is principally based on the utilization of mixture of polymers with suitable excipients such as Carbopol and PVP k30. 1.1. The present work includes the following
A piece of evidence to support this detail is “Wood bats are much less expensive to replace than metal or composite ones”( Phoenix Bats). Many wooden bats are cheap and are less costly than aluminum bats. Having less money on baseball helps increase colleges money to go to other causes like safety of other sports and other activities around the college besides the baseball team. Another piece of evidence that proves that wooden bats should be allowed in college baseball is “Woods bats usually cost less than $90 for a good quality bat. Aluminum bats can cost up to $250 and can go any higher than $400.” Wooden bats being less expensive by a few hundred dollars can save the college more money than buying eight to nine aluminum or composite bats for a whole season.
One of the reasons is that, chocolate milk is healthy. It may contain more sugar and fat, but it contains the “nutrients of concern.” The nutrients of concern include most of the Vitamins, Calcium, Potassium, and Iron. Normal milk contains 12 grams of sugar while chocolate milk contains 20 grams of sugar. Now there is chocolate milk with fewer amounts of sugar, fat, and calories. “One serving of milk is equal to two ounces of cheese, one medium egg, one cup of fortified orange juice, and half a cantaloup over the course of the week.” says Buzzfeed.com.
Based on the data from the amount of carbon used in paper cups in 5 years, it is slightly less than the carbon stored in Shanghai American School tree field, which proves that paper cups do not contribute to the issue of global warming as much. Yet we still need to be aware of that paper cups are not the only factor Shanghai American School use. There are other factors of human activities that have an impact on global warming, such as electricity, transportation, paper, and even tissue. Out of all these factors, electricity and transportation have a higher percentage for damaging our environment. While by only counting the amount of carbon that is been used from paper cups, it is already so close to surpass the carbon that is been stored in trees.