Wednesday, October 9, 2019
Polyeurethanes Research Paper Example | Topics and Well Written Essays - 750 words
Polyeurethanes - Research Paper Example Some of these chains can be very small, while others can extend to incorporate many monomers on orders of hundreds to thousands. The length and complexity of the chain also affects the chemistry and how the compound will interact under specific conditions. For example, as the chains get longer, chemical properties such as melting point and boiling point increase with resistance and hardening, but chain mobility decreases (Mark 3-24). As a result, this impacts the mold ability of the polymer. One of these polymers that our society has adopted across many industrial and commercial applications is Polyurethane. Polyurethane is a polymer, which consists of repeating units of a core structure containing: urethane groups in addition to benzene rings and the carbon chain. The polymer was first synthesized in Germany by chemist, Otto Bayer, in 1937. The primary complex of chemicals, which are used, is isocynate and polyol. These chemicals size, purity, and quality all influence how fast the reaction will go to completion, as well as the chemical forces will affect the properties of the compound. The reaction is catalyzed to begin the polymerization reaction by tertiary amine compounds. Polyurethane is classified in a group of other compounds known as reaction polymers. The properties of polyurethane can change based on the types of monomers, which are substituted into the carbon chain. When in a solid form, polyurethane is a flammable material and can have some side effects with exposure to humans. It can cause eye and lung irritation, but is not a known carcinogen (Ashida 5-9). Commercially, polyurethane has become an important type of epoxy, which is used in a wide variety of applications in the manufacturing industry as well as products and services. Because of the multiple substituents that can occur in the polymer, it can have the properties of rubber, but still be tough enough to withstand great amounts of force as well as endure high temperatures. It was origina lly designed to supplement rubber, and eventually replace it. Now, it is used in many commercial applications. It is used to help hold upholstery and dashboards in vehicles. The ââ¬Å"harderâ⬠variants of this material are used in shoes, as adhesives and coatings as well. One of the more typical applications of this was the discovery that this polymer could be used as foam. The synthesizing of the foam compound of polyurethane is a bit different than the standard compound. It involves a reaction with carbon dioxide and water, which is what it gives it the high degree of mold ability. One important fact that has to be noted about this particular reaction is that it is an exothermic reaction, meaning that high amounts of heat are released upon the catalyzation of the polymerization reaction. As a result the use of the foam polymer has seen the most widespread use in terms of the other variations. Itââ¬â¢s most common application is through the use of insulation in houses. Bec ause the foam is form fitting, it can block holes and unusual spaces, which conventional materials would fail to block. This has also made it a good sealant for tires. The use of the foam type of polyurethane also extends to use on airplanes, as soundproofing, use in electrical equipment, etc (Moore). Polymers and the basis of polymer science have had a large impact not only on industrial and commercial companies, but also in the daily lives of our
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.