Relevant textbook readings - Pavia, expt 49 (addition polymers only), Smith chap 13.13-13.14
Overview - We are carrying out the same reaction as that described in Experiment 49C but with substantial modifications. You will then obtain an IR spectrum of the resulting polymer as described in Expt 49D.
Procedures for Expt 49C
1. Place a small piece of cotton in a Pasteur pipet and fill the pipet with alumina to a height of approx 3-4 cm. Use this alumina column to filter 2 mL of styrene into a small disposable test tube (do not use one of the reaction tubes out of the micro kit!).
2. Add 50 mg of benzoyl peroxide or AIBN and and place a wood applicator stick into the tube to serve as a boiling aid and to allow monitoring of the reaction.
3. Heat on a sand bath to around 135°C observing carefully for the onset of polymerization as indicated by yellowing , bubbling, and/or increasing viscosity of the solution. Once polymerization begins the reaction will generate its own heat so you will want to lower the applied heat by removing the tube somewhat from the hot sand.
4. Remove the wood stick from the solution periodically. When the fibers so formed are brittle (can be cleanly snapped in two) after cooling, the polymerization is done.
5. Pour some of the hot polymer onto a warm watch glass or glass plate. Spread it out so that when it hardens you will get a thin film . Allow it to cool and use this thin film to obtain the IR spectrum.
Assigned questions. Do numbers 2-5 on p 413 of Pavia in addition to the question below.
1. Why was it necessary to filter the styrene through alumina prior to running this reaction?