Polytetrafluoroethylene Research Paper

One of the polymers used is polyvinylpyrrolidine, which is also used to glue the layers of wood in plywood together. An non-water soluble polymer called polydimethylsiloxane is added to make the hold last a bit longer (the polyvinylpyrrolidine is water soluble).

Hydrofluorcarbons (HFC’s) are a new class of recently developed propellants, they share many of the same properties as CFC’s but are less polluting. Several popular HFC’s include 1,1-difluoroethane and 1,1,1,2,-tetrafluoromethane. These propellants are relatively expensive but formulate fast drying. Currently the most commonly used propellant is dimethyl ether (DME).

Persistent organic pollutants (POPs) have been a public health and environmental concern for many years given their persistence in the environment, tendency to bioaccumulate, and toxic, carcinogenic, and endocrine-disrupting potentials (Bonefeld-Jorgensen 2014). Perfluoroalkyl Chemicals (PFCs) is one such family, chemically characterised by a fluorinated linear carbon chain with a hydrophilic head (Volkel 2008). Due to its stability, amphiphilicity, and non-flammability (Lau 2007, Kotthoff 2015), PFCs are commonly used to aid the industrial production of textiles, food packages, and cookware (Kotthoff 2015, Humblet 2014). PFCs can remain in the environment and bioconcentrate in animals (Lau 2007).

He was working at DuPont Jackson Laboratory in New Jersey and had been trying to invent a new type of Freon for cooling purposes. Roy Plunkett had no idea that he would come across “a material that would eventually become an indispensable part of everything from space capsules to heart valves to frying pans--and one that had absolutely nothing to do with refrigeration” (Friedel, 1996). To test out his hypothesis, he first needed to obtain large quantities of TFE. After Plunkett made a hundred pounds of TFE he placed the “canisters on top of dry ice so that the TFE inside would liquefy and the pressure inside the cans would be kept low” (Friedel,

The first step of the synthesis is to take pure methyl salicylate and hydrolyzed into salicylic acid,

Polybutylene commonly bears a stamp with “PB” and a series of numbers. The most common was stamped “PB2110”.

Fluorine hits its boiling point at -188°C and hits its melting point at -219.6°C (“Lenntech”). It is thermally conductive, but not electrically conductive (“Rsc”). Fluorine has a density of 0.001696 g/cm cubed at -20°C (“Chemicool”). Due to being a gas, fluorine has no ductility, hardness, or malleability. Fluorine only has one stable naturally occurring isotope, 19F, which in turn has a natural abundance of 100% (“Rsc”). None of its eleven other known isotopes occur naturally, or are stable enough.

Increasing the rocket fuel, refrigeration, air condition, and bug insecticide. Additionally, hydrofluoric acids can be used or engraving the glass of light bulbs.

Perfluorocarbons (PFCs) are lab made chemical compounds that are linear and cyclic hydrocarbons who have a low molecular weight. Liquid Perfluorocarbons are formed when hydrogen ions in hydrocarbons have been replaced with fluorine atoms since they are neutral chemical compounds (Veni et al. 39). Perfluorocarbons are also chemically inert—not chemically reactive—due to the strength of the carbon-fluorine bonds (Anilkumar et al. 478). Perfluorocarbons are made into Perfluorocarbon artificial blood by adding water, salt and phospholipid surfactants to it, then the solution is then emulsified through high pressure homogenization—when two non-soluble liquids are turned into an emulsion—the solutions is then purified through a high temperature

dummies. (2018). The Process of Natural Radioactive Decay - dummies. [online] Available at: http://www.dummies.com/education/science/chemistry/the-process-of-natural-radioactive-decay/ [Accessed 27 Mar. 2018].

Experimentation continued, with most of the hundreds of new plastics created over the next several decades failing commercially. PET was developed in 1941, but it wasn't until the early 1970s that the plastic soda bottle became a reality. Nathaniel C. Wyeth, son of well-known painter N. C. Wyeth and an engineer for the Du Pont Corporation, finally developed a usable bottle after much experimentation.

First of all, it may be prudent to explain exactly what Teflon is. Teflon, is the registered trademark of a man-made chemical known as polytetrafluorothylene (PTFE), and has been in commercial use since the mid-1940s.

W.L. Gore & Associates is an American manufacturing company that specializes in making products derived from polytetrafluoroethylene, or simply PTFE. The company is best known for its Gore-Tex fabric coating, which makes fabric waterproof and windproof, but yet breathable. The company evolved from the late Wilbert L. Gore’s experiences personally, organizationally, and technically. Mr. Gore moved to E. I. du Pont de Nemours in 1945 where he was part of a team that worked on the development of applications for PTFE. Wilber Gore, or Bill to his coworkers, became knowledgeable in the development of computers and transistors. He believed that PTFE had the ideal insulating characteristics that would make PTFE useful in such equipment. A breakthrough happened in the basement in his house when Mr. Gore and his son Bob successfully created PTFE-coated ribbon by using PTFE sealant tape made by 3M. Because Du Pont wanted to remain a supplier of raw materials and not a fabricator, Bill was unsuccessful in convincing Du Pont to make his PTFE-coated ribbon cable. On January 1, 1958, Bill and his wife Vieve founded W.L. Gore & Associates in the basement of their house. The company took off when the Gores secured an order for $100,000. W.L. Gore continued to grow and manufacture products made from PTFE. Bill Gore died in 1986 while backpacking in the Wind River Mountains of Wyoming. Before he died, he had become chairman and his son, Bob, president. Vieve was

Of the 11 ODF formulations, formulation F1, F5 exhibited faster disintegration time (11 sec, 13 sec) than other formulations and a drug release of 102.12%, 98.27% respectively.

Polylactic acid polymers (PLA) appear to be a very promising material for use as a