Sunday, March 10, 2019


It is possible to modify the properties of umpteen polymers by 3 generating crosslink such as these. You ordain experiment with crosslink the polymer in Elms glue. A number of different processes are used to turn semisynthetic and natural polymers into useful objects. These include springing, extrusion, foaming and casting. In this experiment, you will use the technique of extrusion-blow molding in which a render of polymer is blget up while in the molten state inside of a hole mold. Almost all Through step forward the experiment, you will political campaign the various properties of the polymers that you compound and modify.Some polymers have exceptional properties and capabilities that can make them extremely useful to us. You will observe the property of oneness such polymer, sodium polymerase (the sodium salt of polysaccharide). CHI An NH O NH This polymer can absorb up to 800 times its own weight of irrigate. The ionic portion of the macromolecule is directed toward t he center of the structure. When water is added to dry sodium polymerase, the water molecules are drawn into the center of the polymer in an attempt to dilute the salt, and the polymer expands.It is very important that you record careful observations throughout the experiment. You will be asked to describe the appearances and properties of the various polymers in your lab report. 4 Procedure Record detailed observations throughout the experiment. Polymer synthesis Addition polymer?polystyrene entrust 20 drops of styrene into a disposable 13 x speed of light mm test supply (provided by your TA). Caution Styrene is a flammable liquid Keep styrene away from all etna burner flames. It is also a suspected carcinogen. Wear gloves utilise a wooden or plastic utensil, add a few grains of defensibly peroxide and conjure up the tube to mix. Caution Defensibly peroxide is explosive when heated. Use only a few grains Label the test tube with your name, and target it in a sand bath that h as been set up by your instructor. Allow the etymon to heat for 90 minutes. You may proceed with the rest of the experiment as it heats. When the visible in the test tube has turned slightly yellow, terminate the test tube from the sand bath and cool it on ice. set roughly to shake the polymer out of the test tube.If it has not separated from the glass sufficiently to do this, you may wrap the test tube in a cloth towel and carefully break it so that the polymer can be removed. Wear gloves when doing this Describe the appearance and properties of your polymer. Test the solubility of the polymer by excoriation a few chunks in a mortar and pestle and placing the pulverize in two test tubes. Add water to one of the test tubes and acetone to the other test tube. Record your observations. Dispose of the acetone form in the appropriate science laboratory Byproducts Jar. Discard the polystyrene in the appropriate Laboratory Byproducts Jar.Condensation Polymer?Glottal Resin The fol lowing procedure must be carried out in a fume hood father a report form. Place 5 Goff ophthalmic anhydride and 0. 25 g of sodium acetate in a disposable 18 x 150 mm test tube (provided by your TA). Add 2 ml of glycerol. Using our test tube clamp, carefully heat the smorgasbord over a Bunsen burner flame (see TECH I. D). Heat the top of the contents setoff and work toward the bottom as the mixture melts. Move the test tube in and out of the flame as you do this. Note when the mixture begins to boil and because continue to heat for 3 to 4 minutes.The ascendant Pour the solution into the paper cup. Allow the solution to thoroughly cool, then tear off the cup to recover your polymer. Dispose of the test tube in glass waste. Describe the appearance and properties of your polymer. Test the solubility of the polymer as you did for polystyrene. 5 Modification of polymers Experiment on crosslink with Glue It is recommended that gloves not be worn when working with Elms glue. It is ea sier to remove glue residue from your skin than from the gloves. Obtain a plastic cup and pour 15 ml of Elms livid glue into it.Add 15 ml of water and stir well. Next, add 10 ml of saturated borax solution (sodium borate, Nabbing) and stir well. Remove the solid material and pull it off the stirrer. The material will be sticky for astir(predicate) one or two minutes. Pour any excess liquid left in the cup into the appropriate Laboratory Byproducts Jar. Rinse the cup with warm water. Perform another crosslink experiment using 1 5 L of glue and different amounts of water and borax (from 5 to 15 ml of borax and from O to 30 ml of water). Compare the properties of the two polymers (strength, bounce, stretchiness, etc. ).Observe the properties of at least two other students polymers who used different amounts of water and borax in their second preparation. Record these observations. Polymer fabrication Polyethylene bottle Heat one end of a 10-15 CM piece of polyethylene tubing in a Bun sen burner flame. When the polymer is in the molten state, crimp the end with melting pot tongs to seal it off?allow it to cool somewhat sooner opening the tongs. Re-heat the tubing at the loosed end by passing it in and out of the flame until 1-2 inches of the tubing is in the molten state (looks filmy instead of opaque).Place the molten tubing into a small wide-mouth Jar or vial. Blow air into the open end of the tube so that it expands at heart the Jar. Let the expanded tubing cool in the Jar for about 2 minutes. Because the polymer is flexible, you should now be able to easily remove it from the mold. Show your polyethylene bottle to your TA. Polymer properties Supersaturates Weigh 1 Goff sodium polymerase and place it in a 150 ml beaker. Add 50 ml of water to the beaker from a graduated cylinder. Record your observations. Add another 50 ml of water to the beaker. Record your observations.

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