Biomod/2014/UANL/Jesus
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</head> <body> <h1>Chemical Resistance of Polycarbonate Sheets<br></h1> The mechanism of chemical attack on polycarbonate sheets differs significantly from the mechanism of corrosion of metals.<br> Corrosion of metals results in a gradual loss of surface material as a result of electrolytic action by the relevant chemicals.<br> In the cases where chemical attack on polycarbonate sheet occurs, all or a portion of a range of effects can be observed.<br> Ethylene choride, chloroform, tetrachloroethane, m-cresol, pyridine and other chemicals can cause partial dissolution of<br> polycarbonate. Swelling agents include benzene, chlorobenzene, tetralin, acetone, ethyl acetate, acetonitrile and carbon<br> tetrachloride. Additional effects include color change and/or whitening. These effects may not always lead to product<br> failure, especially for non-loaded sheets. Nevertheless, the level of measured mechanical properties will be reduced.<br> The most critical effect of chemical attack is stress cracking or crazing, which may range in size from being visible to the<br> naked eye to being only observable under a microscope. Stress cracks will always result in sheet failure which will eminate<br> from areas of greatest stress (screws, fixings, bends, etc.)<br> Polycarbonate sheets are generally not recommended for use with acetone, ketones, ethers, and aromatic and chlorinated<br> hydrocarbons in addition to aqueous or alcoholic alkaline solutions, ammonia gas and its solutions and amines.<br> Polycarbonate is resistant to mineral acids, many organic acids, oxidizing and reducing agents, neutral and acid salt solutions,<br> many greases, waxes and oils, saturated, aliphatic and cycloaliphatic hydrocarbons and alcohols, with the exception of<br> methyl alcohol. The resistance of polycarbonate to water may be described as good up to approximately 60°C. At higher<br> temperatures, degradation occurs, the extent of which depends on time and temperature. Polycarbonate should therefore<br> not be exposed for long periods of time to hot water. However, brief contact with hot water has no effect. For example,<br> polycarbonate tableware can be washed over 1000 times in a dishwashing machine with no adverse effects being observed.<br> <br>
<h1>Physicochemical properties</h1> <br> <table style="text-align: left; height: 116px; width: 1033px;"
border="1" cellpadding="2" cellspacing="2"> <tbody> <tr> <td style="width: 94px;">Enzyme</td> <td style="width: 245px;">Some inhibitors</td> <td style="width: 93px;">KM value mM</td> <td style="width: 85px;">pH optimum</td> <td style="width: 86px;">pH range</td> <td style="width: 153px;">Temperature optimum</td> <td style="width: 156px;">Temperature range</td> </tr> <tr> <td style="width: 94px;">Urease<br> <span style="color: rgb(51, 51, 51); font-family: Helvetica,Arial,'lucida grande',tahoma,verdana,arial,sans-serif; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 17.94px; text-align: left; text-indent: 0px; text-transform: none; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(255, 255, 255);">Canavalia
ensiformis</span></td>
<td style="width: 245px;"><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">(2-[[(2-[[2-(hydroxy-kappaO)ethyl]amino-kappaN]ethyl)<br>
imino-kappaN]methyl]-4-nitrophenolato-kappaO)<br> (methoxymethanolato-kappaO)zinc<br>
<br> </span><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(245, 245, 245);">(2-[[(2-[[2-(hydroxy-kappaO)ethyl]amino-kappaN]ethyl)<br>
imino-kappaN]methyl]-4-nitrophenolato-kappaO)<br> (nitrato-kappaO)copper</span><br>
<br> <span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">(2E)-3-(1,3-benzodioxol-5-yl)-1-(2-hydroxyphenyl)<br>
prop-2-en-1-one</span></td>
<td style="width: 93px; text-align: center;">2.7</td> <td style="width: 85px; text-align: center;">5.5</td> <td style="width: 86px; text-align: center;">5.5-7</td> <td style="width: 153px; text-align: center;">25</td> <td style="width: 156px; text-align: center;">NR</td> </tr> <tr> <td>Catalase<br>
Bos taurus</td>
<td><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">2-mercaptoethanol, </span><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(245, 245, 245);">3-amino-1H-1,2,4-triazole, </span><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">dinitrosyl
iron complex, </span><span
style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">Glutaraldehyde,
</span><span
style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">hydroxylamine,
</span><span
style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(245, 245, 245);">NaCN</span><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);"></span></td> <td style="width: 93px; text-align: center;">28.6</td> <td style="width: 85px; text-align: center;">7</td> <td style="width: 86px; text-align: center;">6-7.5</td> <td style="text-align: center;">25</td> <td style="width: 156px; text-align: center;">25-35</td> </tr> <tr> <td style="width: 94px;">Uricase<br>
Arthrobacter globiformis<br>
</td> <td style="width: 245px;"><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(233, 233, 233);">8-Azaxanthine, </span><span style="color: rgb(25, 25, 112); font-family: arial,helvetica,sans-serif; font-size: 12px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; float: none; background-color: rgb(245, 245, 245);">Cu2+,</span></td> <td style="width: 93px; text-align: center;">0.075</td> <td style="width: 85px; text-align: center;">8.5-9.5</td> <td style="width: 86px; text-align: center;">6-9.5</td> <td style="width: 153px; text-align: center;">30</td> <td style="width: 156px; text-align: center;">25-40</td> </tr> </tbody>
</table> <br>
References <br> <a href="http://www.palramhort.com/pdffiles/PC_Products_General_Info/PC_Chemical_Resistance.pdf">Polycarbonate membranes</a>
<a href="http://brenda-enzymes.org/">Enzymes proerties</a><br>
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