By: Anthony Disbrow, and Tyler Ista ENG 45 SRJC 12/13/06

 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.

KirklandBiobagKirklandBiobag Toughness (Mpa): % Area Reduction: Yield Strength (Mpa):7.96.6% Elongation: UTS (Mpa): Modulus (Mpa):

Toughness (MPa):31% Area Reduction:67.68 Yield Strength (MPa): 5.64% Elongation: UTS (MPa): Modulus of Elasticity (MPa): 71.2

Toughness (Mpa):33.90% Area reduction:38.62 Yield Strength (Mpa):8.26% Elongation:25.13 UTS (Mpa):10.23Modulus of Elasticity (Mpa):296.90

Thoughness (MPa):20.4% Area reduction:65.24 Yeild Strength (MPa):5.72% Elongation: UTS (MPa):9.04Modulus of Elasticity (MPa):71.44

Toughness (MPa): 0.357% Area reduction:0 Yield Strength (MPa): NA% Elongation:0.19 UTS (MPa): 12.07Modulus 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.

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