Polymeriza-tion

Done by: Cindy & Jack

During INTERNSHIP AT MAHIDOL

PolymerizationIs a process of reacting monomer mol-

ecules together reacting in a chemical

reaction to form 3-D networks or

polymer chains.

Monomers & Polymers

MONOMERS are atoms or a small mol-

ecule that may bind chemically to

other to form polymers.

Polymers are large molecules com-

posed of repeating structural units.

Atomic Transfer Rad-ical Polymeriza-tionATRP is a type of polymerization that

can control the length of a polymer

There are 3 components, which in-

cludes a monomer, catalyst, and a ini-

tiator

In this Experi-ment...We used Two monomers: - Methyl Methacrylate (MMA) - Styrene

Two catalysts: - Copper Bromide (CuBr) - Liquid TRENFCIMTwo initiator: - 1-Bromoethylrenzene - Ethyl 2-Bromoisobuthylate(??)

1) Polymerization of MMA2) Polymerization of Styrene3) Polymerization of MMA and Styrene

at the same time4) Copolymerization of MMA + Styrene5) Copolymerization of Styrene + MMA

Order of exper-imentation

- First two were to let us be familiarized with polymerization

PurposeCheck whether the theory and the experiment

matches or not.

To find out which monomer the catalyst suits

more.

To study properties of polymer products and

copolymer products

Hypothesis

We could have hypothesized,

however, we knew nothing about

polymerization, so we had no

idea what would happen. There-

fore, we could not hypothesize.

Materials Used High vacuum grease Trap Parafilm (30) Argon Gas Argon (g) Medium size towel (2) Stand Vacuum pump Thermostat container Styrene (l) Ethyl-2-bromoisobuthyl (l) CuBr (s) Ligand TRFNFclm (s) Mask Aluminum Oxide (s) Stopper Column Cotton

THF Plastic Spoon Spatula short Eyedropper Long eyedropper Square Dry Ice (10) Acetone (l) Hammer MMA (l) Goggles Weighing papers Gloves Magnetic bar Funnel Anti-bump Stirrer Magnetic stirrer

ProcedureThe step by steps in the ex-

periment weren’t complicated

but it just took a lot of time

and had us ending up like

this..

Setting Trap Apply grease to the cap of the trap Put the trap on the stand Connect the 2 tubes from the vacuum to the trap Use parafilm to wrap around the tubes to prevent leakage Turn on the vacuum machine Open the argon gas tank Wait for 30 minutes Put the trap in a thermostat container Get dry ice and put it in the container Once its full, pour acetone in the container slowly Cover the top with a rag

Setting Side-Arm flask

Get a side-arm flask from the ovenQuickly set it on the standAdjust the stopper cock onto the flaskStick the rubber stopper on the openingVacuum it for 5 minutesChange it to argon gas for 20 secondsRepeat the last two steps 2 more times

Weighing Catalyst Get the catalyst needed from the desiccator Put the weighing paper in the weighing scale and zero it Using a spatula get the amount of catalyst needed Do it again using a different spatula and weighing paper if

there are more catalysts Quickly open the rubber stopper and put the catalysts

needed Vacuum it 3 times

Injecting the monomer

Bring out the monomer from the fridge Store it at room temperature Get a needle from the oven and stick it on a plastic syringe Using the needle pump the argon out 3 times Using the needle with the syringe take 2mL out of the monomer Using tissue, adjust the amount of monomer needle by flipping the

needle backwards Inject it in the flask Get a glass stopper from the oven Apply grease on it Quickly replace it with the rubber stopper

Freeze Pump Thaw Put the side arm flask in a thermostat container Add dry ice into the container Slowly pour in acetone into the container Wait till the liquid solution freezes Vacuum it for 10 minutes Close the valve on the flask Take the flask out of the container Leave it for it to melt After it turns to liquid, put it back in the container When it freezes, open the valve Vacuum it for 10minutes Repeat steps 6~11 again Close the valve Take the flask out and let it melt Change the glass stopper to a rubber stopper before

it melts

Stirring Get a magnetic stirrer Set the flask on top of it Place a piece of tissue under the flask Set it to 300rpm Stir it for 5minutes

Injecting the Initiator Go to the oven and get needle syringe and a glass bottler(idk how

to call) Get the initiator from the desiccator (1-bromoethylrenzene) Pour a little bit initiator into the glass bottle Get the needle and pump the argon out 3 times Put it in the flask Move it to the magnetic stirrer with heat ( temperature depends on

the catalyst) Stir it Add THF to stop the reaction

Removing Catalyst Wear a mask Get a column with a stopper and fix it on a stand Put a small piece of cotton in the column enough to block the bot-

tom Get 20 spoons of aluminum oxide in a beaker Pour in THF enough to cover the aluminum oxide Mix it well using Pour it down the column Using THF let most of aluminum oxide go in the column Let all the aluminum oxide on the walls of the column go to the bot-

tom Hit the column with a tube so that it’ll be packed Place a beaker under the column and open the valve

Removing Catalyst When a little bit of THF is left, close the valve Using a dropper drop THF in the column along the walls Repeat the steps until the THF in the column is clear When it gets clear, close the valve Get the solution in the side arm flask Using another magnetic bar, take the magnetic bar inside out Get a long dropper and use it to drop towards the wall of the col-

umn When done, using THF rinse the side arm flask and pour it in the

column (twice) Use a dropper with THF to rinse the walls of the column too Get a flask and replace it with the beaker under the column Open the valve, and make it a drop per 2 seconds Pour THF in the column if the opening near the stopper cock isn’t

transparent

Removing Solvent Pour the solution in the flask using a funnel into a 250mL round bot-

tom flask Open the vacuum machine Set it to 40 degrees Connect the anti-bump to the machine Right next to the anti-bump connect the round bottom flask Close the top(??) to reduce pressure Lock the anti-bump and the round bottom flask using a blue clip Rotate it for 20~30 minutes

Removing Solvent Open the top(??) to increase pressure back Take the blue clip out and take out the round bottom flask Using a dropper drop 2 droppers of dichloromethane into the round

bottom flask Pour 50mL of methanol into the round bottom flask Leave it for 5 minutes Pour the methanol in the round bottom flask out into a beaker Using a spatula gather all the precipitate in the flask into a ball Vacuum it for __ hours

Results (MMA)

Results (styrene)

Results (MMA then Styrene)

Results (Styrene then MMA)

Results (ran-dom)

ConclusionTo conclude, we had to compare between the the-ory and the real experiment. We have an answer to this which is that the theory’s expected num-bers are not same as the one’s in the real experi-ment. In the theory, the polydispersity number should be 1 for all, however, we got 1.3 or even higher, 2. Therefore, we could say that those two things are two different things.

It has been concluded that the catalyst we used was more suitable for styrene than mma because in the results the polydispersity of styrene was closer to 1; and others it was more than 1.5 which means the catalyst can’t control the process.

The polydispersity of MMA was about 1.92 and for Styrene was about 1.3 . According to the the-ory, they both should have approx-imately 1. These are the proper-ties that is the most important.

A BIG THANKS TO…

P’ Dear – for helping us throughout the experiment

P’ Man – for taking us to Mahidol Salaya campus

Dr. Ekasith – for allowing the in-ternship to Mahidol

& so many other people for help-ing…