CHEM 211
Experiment 9
Minyan Wang
5292561
ChEM 211 D Lab
Locker #2
Experimental
Materials used
- Test tubes
- Phthalic anhydride
- Sodium acetate
- Glycerol
- Heating mantle
- 1, 6 diaminohexane
- Sodium hydroxide
- Decanedioyl chloride
- Diethyl ether
- Dichlorodimethylsilane
- Water
- Sodium bicarbonate
- Sodium chloride
- Anhydrous sodium sulphate
- Boric acid
Experimental procedure
Part 1 – 2g of phthalic acid, 0.1g of sodium acetate and 0.6mL of glycerol are added
together. Heat is applied until the melt starts to turn yellow. The hot liquid is poured into
a mold and cooled. Solubility of the final product in water and acetone are tested.
Part 2 – 1, 6 diaminohexane and 2 drops of sodium hydroxide are added. Decanedioyl
chloride is then added. The nylon formed is hooked out and wrapped around a test tube.
The mixture is continuously stirred until no more nylon is formed. The final product is
washed then dried before it was weighed.
Part 3 – Water is slowly added to a mixture of 25 mL diethyl ether and 12 mL of
dichlorodimethylsilane. The HCl/water phase is then extracted and disposed. The ether
phase is washed with 5mL of water and 10mL of sodium bicarbonate. The ether is then
washed with saturated sodium chloride solution. The solution is then dried with
anhydrous sodium sulphate, and then filtered into a round bottom flask. The ethers are
removed using rotary evaporation. Boric acid is then added to the silicone fluid, and
heated to about 1800C for around 5 minutes. The product is cooled and its properties are
examined.
Results
Weight of silicone flask: 46.186g
Weight of silicone flask + silicone fluid: 51.390g
Weight of silicone: 51.390g – 46.186g = 5.204g
Yield of nylon: 0.246/(0.05 x 2mL x 0.93g/mL + 0.09 x 2 x 1.12 g/mL) x 100% = 83.5%
Yield of Silicon polymers: 5.204/(12 x 1.07g/mL) x 100% = 40.5%
Product
Glyptal Resins
Weight
0.114 ± 0.002 g
Percent yield
Nylon
0.246 ± 0.002 g
83.5%
Silicon Polymer
5.204 ± 0.002 g
40.5%
Appearance
Hard plastic-like and
translucent. Soluble in
Acetone, insoluble in
water.
Opaque, light, threadlike
Soft, a bit sticky,
translucent, bouncy
Discussion
The sodium acetate help delay the vulcanization of glyptal resins, allowing it to be fluid
enough to be poured out into the mold. Sodium acetate decomposes quickly, and as it
decomposes the polymer becomes harder. That explains why the polymer starts out soft
and hardens as the reaction continues.
H2N(CH2)6NH2 + ClCO(CH2)8COCl  -[-NH(CH2)6NHCO(CH2)8CO-]- + 2HCl
The NaOH added reacts with the product HCl, and in effect neutralizes the solution.
Unlike the glyptal polymer, the repeating units join together on the ends, making it a
linear macromolecule. Because of the way the monomers connect the resulting product is
also observed to be linear. The adjacent bonds are single bonds allowing the molecules to
twist and turn. There are also no hydrogen bonds holding the structure in place making it
a soft material.
A higher B concentration would result in a higher amount of cross-linkage. This would
harden the resulting product since more cross-linkage allows more structure, and it could
result in harder and bouncier putty. The addition of sodium bicarbonate gives rise to CO2
gas because in that step sodium bicarbonate is used to neutralize the acid residues in the
solution. When sodium bicarbonate neutralizes one of its product is carbon dioxide:
HCO3- → CO2 + OHThe results were consistent with theory in that all of the products formed are consistent
with the everyday materials that are made of the same thing. Glyptal resins had a plasticlike texture and hardness. Nylon was string shaped which is consistent with everyday
nylons used in clothing. Bouncing putty felt the same and mechanically behaved the same
to the commercial bouncing putties. However, there were still errors that affected the
yield of the final product. If liquid glyptal was not poured out fast enough it would have
solidified inside the test tube, therefore causing an error in the measure of the final weight
of glyptal product. The nylon might not have been completely dry when its weight was
measured, which can cause an overestimate of the weight of the final product. Also, if not
all the nylon was obtained from the solution it would decrease the amount of product
made. Finally, the extraction of the ether phase in the production of silicone polymers
was not perfect and therefore caused impurity in the final product. That would increase
the amount of yield.
Reagent
Phthalic anhydride
Sodium acetate
Glycerol
1, 6 diaminohexane
Sodium hydroxide
Sebacoyl Chloride
Dichlorodimethylsilane
Diethyl ether
Sodium bicarbonate
Boric Acid
MW
(g/mol)
148.1
82.03
92.09382
Mp (oC)
Bp (oC)
131
324
18
284
Decomposes
290
116.24
23-41
199-205
1.261
0.93
39.997
239.14
129.07
318
−2.5
-86
1390
220
70
2.1
1.12
1.07
74.12
84.007
61.832
−116.3
50
169
34.6
0.7134
Decomposes. 2.159
Decomposes 1.435
Density
g/ml
1.53
1.45
Harzardous
properties
irritant
corrosive
corrosive
Hydrolises
to give HCl
gas
irritant