By: Anthony Disbrow, and Tyler IstaENG 45

SRJC12/13/06

Reflection Ambient temperature

Humidity Impurities

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.

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.

UV energy can excite photons, which result in free radicals (atoms or molecules with un-paired electrons).

Small impurities (ppb) can act as free radical receptors, leading to degradation.

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

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.

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”.

Record initial thickness using micrometer.

Record initial width with Verneir calipers.

Clamp one end of bag allowing the strip to hang.

Clamp the other end such that weights can be hung from the clamp.

Measure the initial length of the specimen.

Add weight in 50g increments, record the length after each increment.

Continue the previous step until the specimen breaks.

After breakage record the final length, thickness and width.

Kirkland Biobag Kirkland Biobag

Toughness (Mpa): 9.24 2.4 % Area Reduction: 91.81 53.52

Yield Strength (Mpa): 7.9 6.6 % Elongation: 49.55 55.93

UTS (Mpa): 10.64 7.17 Modulus (Mpa): 53.56 43.9

Stress vs. Strain for Kirkland and Biobag Control

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0 0.2 0.4 0.6 0.8 1 1.2

Strain (m/m)

Str

ess

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a)

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0 1 2 3 4

Str

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Pa

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Strain(m/m)

Stress vs. Strain For Kirkland Bag exposed to UV light for 140 hours

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

Toughness (Mpa): 33.90 % Area reduction: 38.62

Yield Strength (Mpa): 8.26 % Elongation: 25.13

UTS (Mpa): 10.23 Modulus of Elasticity (Mpa): 296.90

Stress vs. Strain for Biobag exposed to UV light for 140 hours

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2

4

6

8

10

12

0 0.1 0.2 0.3 0.4

Strain (m/m)

Str

ess

(MP

a)

Thoughness (MPa): 20.4 % Area reduction: 65.24

Yeild Strength (MPa): 5.72 % Elongation: 151.79

UTS (MPa): 9.04 Modulus of Elasticity (MPa): 71.44

Stress vs. Strain for Kirkland Bag Exposed to Soil for 118 hours

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0 0.5 1 1.5 2 2.5 3

Strain (m/m)

Str

ess (

MP

a)

Stress vs. Strain for Biobag Exposed to Soil for 118 hours

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14

0 0.1 0.2 0.3 0.4

Strain (m/m)

Str

ess

(MP

a)

Toughness (MPa): 0.357 % Area reduction: 0

Yield Strength (MPa): NA % Elongation: 0.19

UTS (MPa): 12.07 Modulus of Elasticity (MPa): 471.5

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.

http://www.zeusinc.com/cgi-bin/search.exe?q=UV

http://www.masterbond.com/wbarticles/wbuv.html

http://en.wikipedia.org/wiki/Ultraviolet http://www.biogroupusa.com/catering.htm http://www.biobag.at/produkte/bio_bag/

bag_4_life/ http://www.greenerchoices.org/products.cfm?

product=plastic&pcat=homegarden http://www.deq.state.ms.us/MDEQ.nsf/page/

Recycling_RecyclingTrivia?OpenDocument