By: Anthony Disbrow, and Tyler Ista
ENG 45
SRJC
12/13/06
 Reflection
 Ambient
temperature
 Humidity
 Impurities
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Any UV radiation can cause photochemical
effect within polymers.
This effect can be either a benefit, or a
detriment.
With respect to plastics, UVC is more likely to
have an effect.
Surface of plastics may undergo a color shift,
appear chalky, or become brittle.
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Certain polymer systems are able to be cured
under UV light at room temperature.
UV curing can also be used on some glasses,
semiconductors, optical fibers, dental fillings,
inks, paper finishes, and much more.
UV curing can take place in a matter of
seconds.
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UV energy can excite photons, which result in
free radicals (atoms or molecules with unpaired electrons).
Small impurities (ppb) can act as free radical
receptors, leading to degradation.
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One ton of recycled plastic saves:
5,774 Kwh of energy
 16.3 barrels (685 gallons) of oil
 98 million Btu's of energy
 30 cubic yards of landfill space

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Recycled plastic saves 88% of the energy used
to produce plastic from raw materials.
Only 26% of HDPE plastic are recycled
Plastics cannot be naturally degraded.
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No polyethylene is used .
Made from cornstarch, vegetable oil and other
renewable resources.
The Mater-Bi process is protected by more than 70
patents.
Compostable, disposable

Cut plastic bag into a strip 1” x 12”.
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Record initial thickness using micrometer.
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Record initial width with Verneir calipers.
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Clamp one end of bag allowing the strip to hang.
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Clamp the other end such that weights can be hung from the clamp.
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Measure the initial length of the specimen.
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Add weight in 50g increments, record the length after each increment.
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Continue the previous step until the specimen breaks.
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After breakage record the final length, thickness and width.
Stress vs. Strain for Kirkland and Biobag Control
12
Stress (MPa)
10
8
6
4
2
0
0
0.2
0.4
0.6
0.8
1
1.2
Strain (m/m)
Kirkland
Biobag
Toughness (Mpa):
9.24
2.4
Yield Strength (Mpa):
7.9
10.64
UTS (Mpa):
Kirkland
Biobag
% Area Reduction:
91.81
53.52
6.6
% Elongation:
49.55
55.93
7.17
Modulus (Mpa):
53.56
43.9
Stress vs. Strain For Kirkland Bag exposed to
UV light for 140 hours
Stress (MPa)
16
14
12
10
8
6
4
2
0
0
1
2
Strain(m/m)
3
4
Toughness (MPa):
31
% Area Reduction:
67.68
Yield Strength (MPa):
5.64
% Elongation:
214.64
UTS (MPa):
14.77
Modulus of Elasticity (MPa):
71.2
Stress vs. Strain for Biobag exposed to UV light for 140
hours
Stress (MPa)
12
10
8
6
4
2
0
0
0.1
0.2
0.3
Strain (m/m)
Toughness (Mpa): 33.90
Yield Strength (Mpa): 8.26
UTS (Mpa): 10.23
% Area reduction: 38.62
% Elongation: 25.13
Modulus of Elasticity (Mpa): 296.90
0.4
Stress vs. Strain for Kirkland Bag Exposed to Soil for 118
hours
12
Stress (MPa)
10
8
6
4
2
0
0
0.5
1
1.5
2
2.5
Strain (m/m)
Thoughness (MPa): 20.4
Yeild Strength (MPa): 5.72
UTS (MPa): 9.04
% Area reduction: 65.24
% Elongation: 151.79
Modulus of Elasticity (MPa): 71.44
3
Stress vs. Strain for Biobag Exposed to Soil for 118 hours
14
Stress (MPa)
12
10
8
6
4
2
0
0
0.1
0.2
0.3
Strain (m/m)
Toughness (MPa): 0.357
Yield Strength (MPa): NA
UTS (MPa): 12.07
% Area reduction: 0
% Elongation: 0.19
Modulus of Elasticity (MPa): 471.5
0.4
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Just the tensile test alone was not enough to
reach a solid conclusion.
The creep properties of the plastic appeared to
be affected.
The stress strain curve alone cannot show the
elongation for a given time period.
We observed the samples exposed to more UV
light crept the slowest.
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http://www.zeusinc.com/cgibin/search.exe?q=UV
http://www.masterbond.com/wbarticles/wb
uv.html
http://en.wikipedia.org/wiki/Ultraviolet
http://www.biogroupusa.com/catering.htm
http://www.biobag.at/produkte/bio_bag/ba
g_4_life/
http://www.greenerchoices.org/products.cfm
?product=plastic&pcat=homegarden
http://www.deq.state.ms.us/MDEQ.nsf/page
/Recycling_RecyclingTrivia?OpenDocument