Lab Report 2 Chem 221 Essay

Submitted By kelbru
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Chem 221
Section 9
10 February 2015
Lab 8: Thermal Depolymerization and Polymerization of Styrofoam
Purpose
The purpose of this experiment was to implement the technique of distillation in order to depolymerize polystyrene and to subsequently implement various methods of a reflux system in order to re-polymerize Styrofoam from the monomer styrene.
Results
Type
Solvent
Monomer
Boiling point
51oC
170oC
Specific gravity
8.08g/13mL = 0.62g/mL
9.77g/12.0mL= 0.81 g/mL
Miscibility
Miscible
Not miscible

Mass/ Volume
Solvent
Monomer
V0
20-25mL

Vf
13.0 mL

Mo

15.77g
Mf

9.77g

Percent recovery acetone= (13.0mL/ 20.0-25.0 mL) * 100% = 65.0-52.0%
Percent recovery styrene= (9.77g/ 15.77g) * 100% = 61.95%
Three different polymers were synthesized by using different polymerization techniques: traditional reflux and the simple heating by reflux in a test tube. Before the first reflux setup, the styrene was washed multiple times with NaOH and water. The aqueous layers were removed each time and the styrene was again washed with water. It was then dried with sodium sulfate and decanted. This decanted, pure styrene was then mixed with xylene and tert-butyl peroxybenzoate and refluxed in a reflux setup using a sand bath to maintain the temperature of 190oC. Half of the refluxed styrene was then placed on filter paper to evaporate and solidify, and the other half was vacuum filtrated with methanol. The evaporated styrene formed a polymer that left a very thin film on the filter paper. It was also very shiny and colorless. The vacuum filtrated styrene formed a polymer that resembled tiny, sugar crystals. They were whitish or clear. This precipitate was in a crystal form. Lastly, more of the decanted pure styrene was again mixed with tert-butyl peroxybenzoate and refluxed in a very simple setup in a test tube with a sand bath that heated the system for about ten minutes. Once the solution become more viscous over time and with heat, the polymer formed, once poured on filter paper from the test tube, resembled sugar when it turns into taffy. It was very stringy and colorless.

Discussion
Substance
Acetone
Styrene
State of Matter
Liquid
Oily liquid
Color
Colorless
Colorless to dark
Odor
Sweetish odor
Aromatic odor
Boiling point
56oC
145-146 °C
Miscibility
Water soluble
Insoluble in water
Specific Gravity
0.791 g/mL
0.909 g/mL
 References: www.chemicalbook.com
Substance
Acetone
Styrene
State of Matter
Liquid
Liquid
Color
Colorless
Part 1: Peach, light orange (due to the pink Styrofoam solids used)
Part 2: Colorless (used common styrene provided in lab)
Odor
Strong odor, nail polish remover
Strong odor, gasoline-like odor
 The above data was collected during lab.
Based on the amount recovered and the purity of both samples, I can conclude that the distillation was somewhat successful. I recovered more than half of both acetone and the monomer styrene. Other properties that were observed during the experiment such as color, state of matter, specific gravity, and miscibility agree with the published data for both acetone and styrene. The observations regarding odor during the experiment do not match the published data, but I believe that is due to the way I described the odor. I compared it to other familiar odors, whereas the published data did not do so. On the other hand, the area where my experimental data and the published data did not match was regarding boiling point. During the experiment, the
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