Manual for Polymerization Station

ChE 401/402

Group F

Jessie Abbotts

Jordan Atlas

Kendell Jillson

Last Updated: May 15, 2002
Detailed Experimental Procedure

  1. Setup
  1. Preheat paraffin oil baths to desired temperatures, between about 58oC and 70o, two hours in advance of laboratory session. Note that the left oil bath maintains a more consistent temperature than the right.
  2. Dry molecular sieve in oven for 15 min.
  1. Methyl Methacrylate (MMA) Preparation (Keep ALL open MMA containers inside the hood with the window below the green arrows at all times)
  1. Weigh out 1.2 gm of Sodium Hydroxide (NaOH).
  2. Combine NaOH with 600mL of distilled H2O to make a 0.05 M NaOH solution in a 2000mL Erlenmeyer flask.
  3. Add 600mL of MMA into the inverted flask (with stopcock closed)
  1. Add approximately 200 mL of NaOH solution
  2. After the addition of NaOH, shake thoroughly for roughly a minute
  1. When shaking, be sure to cover the stopper to prevent leaking
  2. After shaking, allow the mixture to separate into an organic and an aqueous phase.
  3. Open the stopcock to decant the lower aqueous phase into a beaker, and use the vacuum pump to dispose of this. Make sure to remove the stopper of the inverting flask when decanting
  1. Repeat with two successive runs of 200 mL of NaOH solution
  2. Add molecular sieves and shake for approximately three minutes
  3. Use a piece of filter paper in a Buchner funnel, pour the MMA and the sieves over the filter paper into the 1-L filter flask. Also attach the vacuum tube to the suction port of the filter flask to facilitate the separation. After allowing sieves and filter paper to dry in the hood, return them to the oven
  4. Dispose of all the aqueous waste with the vacuum pump into the collection bottle
  5. Clean the 2000mL Erlenmeyer flask with acetone, water, and then with acetone again and dry with vacuum pump.
  1. Store the MMA in the refrigerator in the filter flask, using a rubber stoppers on the top and a smaller rubber cover on the suction port, when not in use
  1. Clean inverted flask with acetone, water, and acetone again, and then dry
  1. Making Run Solutions (Perform A-C, F in fume hood with the window below the green arrows)
  1. Combine quantities of MMA and solvent to equal 70 mL in a 250mL beaker in case of spilling during transfer to the dilatometer (See following page for MMA and solvent quantities).
  2. Add appropriate amount of AIBN to the MMA solution and mix thoroughly using the magnetic stirrer
  3. Fill the dilatometer with the MMA solution. Make sure to note which dilatometer was used
  1. Fill up a pipette with appropriate solution. Expel the solution into the flask once to wash the pipette walls with the new mixture.
  2. Refill the pipette and transfer the solution into the dilatometer with the stopcock open. Fill the dilatometer until the level of the capillary is about to that of the lower horizontal bar of the dilatometer. Use the thin wire near the baths to get rid of any air bubbles.
  1. Clamp dilatometer into position in the oil bath.
  1. Submerge bulb completely in oil bath.
  2. Absorb overflowing MMA solution with a paper towel.
  1. Setup cathetometer to collect data.

1. Set cathotometers to 40 cm and adjust level of capillary by using the stop cock

2. Record the elapsed time when the solution height changes by 1cm.

  1. Record until about 9 cm on the cathetometer or until the capillary height is obscured
  2. Remove dilatometer from oil bath.
  1. Immediately clean the dilatometer after each run, before the PMMA solidifies.
  1. Use vacuum to remove the PMMA solution from dilatometer.
  2. Using vacuum, clean dilatometer with successive runs of acetone, acetone, water, and acetone.
  1. Repeat A – F for desired number of runs.
  2. Note that the bath at the lower temperature will run slower than the other. Typically at temperatures around 60 oC, the run will last about 20-25 minutes, at temperatures close to 70 oC will last near 10-15 minutes
  1. Cleanup
  1. Clean all glassware used with acetone and dry. DO NOT clean any glassware the contained any MMA or any solvents in the sink. Clean ALL glassware that held these chemicals inside the hood by rinsing with acetone. Do not pour MMA or other poisonous chemicals down the drain. Do not rinse glassware that contained MMA or other poisonous chemicals and then pour that rinse down the drain. These rinses must be vacuumed into the waste storage bottle and disposed of as hazardous waste.
  2. Place all waste (including leftover MMA) into the appropriate waste containers at the end of the day. Transfer the contents of the collection bottle (attached to the vacuum pump) into the appropriate waste containers. Notify lab technicians when bottle is full.
  3. Shutdown the oil bath heating coils and mixers when done.