This report outlines the evaluation for replacing an absorption glass mat (AGM) with a polymer mat to be used in a valve regulated lead acid (VRLA) battery. AGMs are expensive and exhibit low tensile strength, so polymers were investigated to both decrease cost and improve the properties of the mat. Initially the important properties of the mat were assumed to be chemical inertness in aqueous acid, stability towards oxidation and heat, wettability and contact angle, porosity, and tensile strength. The processes of making the various polymers were then considered to determine any additional complexities that could arise during manufacturing. The best material was found to be a hydrophobic polymer exhibiting the physical properties of the AGM, but containing a hydrophilic material to induce wettability. Through this analysis the final recommendation is to replace the AGM with a composite polymer mat composing of 95% polypropylene (PP) and 5% polytetrahydrofuran (PTHF) which has a cost of $1.3/lb of polymer composite and an annual profit upper bound (PUB) of $2,000,000. This is based...
Fire and thermal properties of PA 66 resin treated with poly-N- aniline- phenyl phosphamide as a flame retardant
In this work, the mechanical and barrier properties were examined for Polypropylene (PP) film in which the surface of the film was modified by Oxygen plasma treatment. The PP film was treated in various intervals of time of 60 s, 120 s, 180 s, 240 s and 300 s with three various RF power settings of 7.2 W, 10.2 W, 29.6 W. The contact angle was measured to characterize the wettability. The oxygen functional groups were generated on the surface of oxygen modified PP which was observed by Fourier transform infrared spectroscope and it was resulted in the improvement of wettability. The surface morphology and roughness of the PP films before and after the oxygen plasma treatment was analyzed by Atomic Force Microscopy (AFM). It was found that the roughness of
GLASS written by ellen hopkins intermenes the real life struggles that teenagers face everyday, from love to drugs to destructive relationships. Ellen really hits home showing the life of a once 4.0 honors student Kristina; whose life easily got turned upside down from one toxic summer at her fathers that will show the darkest side possible of life. An estimated 12 percent of children in the United States live with a parent who is dependent on or abuses alcohol or other drugs. Based on data from 2002 through 2007, it was to be reported that 8.3 million children under the age of 18 lived with at least one substance-dependent or substance-abusing parent according to Substance Abuse and Mental Health Services Administration (Paragraph 4). The bond between a child and their parents is so pure yet
Z Qin et al modified ammonium polyphosphate (APP) and compared the effect of modification on flame retardant properties of polypropylene along with dipentaerythritol (DPER). The incorporation of modified ammonium polyphosphate (IMAPP) with dipentaerythritol (DPER) at 25 % loading produced LOI 32% with V-0 rating while unmodified APP had LOI 26% and V-1 rating. IMAPP also significantly decreased the PHRR and THR and contributed to the formation of compact intumescent
Today, polyvinyl chloride (PVC) is used in many different products across the world. According to the APHA (2011), the material can be found in toys, medical supplies, floors, and even food wrapping. (p. 1) I believe that this material has made it possible for a lot of products to be made that have benefited the human population, but I believe there are many drawbacks to using this material.
STRUCTURE Kevlar Aramid Fiber is a synthetic (man-made) material known as Polymer. A polymer is a chain that is made up of many similar molecular groups, better known as ‘monomers’ that are bonded together. The ‘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. A group of polymer chains can be organised together in a fiber.
In an “electrolytic solution”, if two electrodes, one being positive and the other negative, are placed in the solution then ions have the ability to transport free electrons to and from both of the electrodes. Acids in a solution are good electrolytes since the acids supply the solution with hydrogen ions. If a solution contains organic compound has sugar or starch, then that solution won’t conduct electricity well since organic compounds are contributing as many hydrogen ions as acids. The most familiar electrolytes would be elements such as potassium, calcium, sodium, and magnesium. Lithium-ion batteries are commonly used in many household as a source of energy, however the battery relies heavily on liquid electrolytes which are flammable and are prone to fires.Researchers at Oak Ridge National Laboratory has created a solid electrolytes that is made out of lithium triphosphate to try to overcome the safety issues presented by lithium-ion
...commend this to my friend, but to the whole world. It’s a great and helping opportunity if you have the chance.
Denture teeth can be made of acrylic poly(methyl methacrylate) (PMMA) or composite resins. PMMA is a polymer - a material made the from joining of methyl methacrylate monomers. Properties of PMMA include resistance to abrasion, chemical stability and a high boiling point. (Jun Shen et al. 2011). However, weak flexure and impact strength of PMMA are of concern as they account for denture failure. (Bolayir G, Boztug A and Soygun K. 2013). Composite denture teeth are made of a three distinct phases - filler, matrix and coupling agents. Out of the types of composite teeth available, nano-filled composite teeth are preferred. Composite teeth have a PMMA coating around the tooth and a high content of filler particles. This gives them strength, higher resistance to forces than acrylic teeth and provides compete polymerization due to the PMMA coating. (Anusavice, K. J., Phillips, R. W., Shen, C., & Rawls, H. R, 2012). If the interface between the PMMA denture base and PMMA or composite teeth was weak, the denture will not be able to sustain occlusal forces, making the base-teeth interface, an entity of significance.
These reasons are why Lithium-Ion Batteries are some of the most viable options when designing new gadgets. But, the structure of these batteries are why these batteries are being used for new gadgets. A Lithium-Ion Batt...
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
All polymer host has some major advantages for which their application in electrochemical devices are still continuing. Also these polymer have some disadvantages and to improve the
Hydrogels are defined as networks made up of polymer chains which are hydrophilic. They are in some cases found as a solid dispersed in a liquid. where water acts as the medium dispersed. Hydrogels are natural, highly porous or artificial polymeric networks. The hydrophilic structure allows hydrogels to hold the significant amount of water within their three-dimension structural systems. The extensive employment of hydrogel products in some environmental and industrial areas of applications are very high importance. As time passed, natural hydrogels were replaced with artificial ones. This was due to their long service life, the wide variety of the raw chemical resources, high capacity of water absorption, and their stability. Artificial polymers have structures that are well defined and can be modified to produce tailor powerful functionality and degradability. The artificial of hydrogels can also occur from purely artificial components. The artificial hydrogels are stable in conditions of high and sharp temperature fluctuations. Recent research describes hydrogels as a two- or multi-component systems that are made of three-dimensional
The battery separator plays an important role by regulating cell kinetics, allowing ionic flow, preventing electronic contact between the two electrodes, and sometimes by acting as a safety device. Because the separator is pressed between the two electrodes and filled with electrolyte, it is in contact with all of the active cell components. By regulating electrolyte distribution, it limits ionic diffusion and recombination rates, and thereby significantly impacts cell capacity, cell power, and available energy. Consequently, much work has been carried out to determine optimal separator character- istics, such as porosity and tortuosity.1-3 Separator degradation has been often observed in certain types of batteries, and shown to be responsible for battery failure or power loss. [R Kostecki, L Norin, X Song, F McLarnon, Diagnostic Studies of Polyolefin Separators in High-Power Li-Ion Cells. Journal of The Electrochemical Society (2004) vol. 151 (4) pp. A522-A526]
The name of the structure doesn’t matter as much as the pleasure received; some may call them glass rooms or greenhouses. The uses of these glass structures vary as the weather they see. The structures all contain glass allowing people a place to view the natural environment inside. These structures are mediums in which outside and inside environments are connected. For many people myself included, there is a fantasy of being in an environment that is exotic and surreal.