What is meant by photodegradation?
Photodegradation is degradation of a photodegradable molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light, and ultraviolet light.
Why is photodegradation a problem?
Photodegradation is a major problem also for thermochromic materials, since solar radiation causes polymer chain breaking, altering chemical and mechanical properties as well as leading to a loss of the reversible thermochromic effect [13].
What are the effects of photodegradation?
Photodegradation causes chain scission in the polymer material which results in the loss of important physical properties such as impact strength, tensile strength, elongation at break, etc. and can be observed as cracking, chalking and color changes.
Does plastic react with oxygen?
Thermal oxidation is the degradation of a polymeric material through contact with a chemical oxidizer. Most polymers are subject to oxidation, and it is the most common form of plastic degradation (consider Table 2). These free radicals react with oxygen to attack the polymer backbone covalent bonds.
How do I speed up photodegradation?
By incorporating metal salts like cobalt, iron and nickel, the polymers absorb more ultraviolet (UV) light and become significantly weaker. Then, the elements (wind, rain, etc.) work on the remaining weakened plastic structure over a concerted period of time, steadily wearing it down.
How can we prevent photodegradation of drugs?
For this, amber glasses like Fiolax amber and Corning 51-L are commonly used to protect the pharmaceutical from UV radiations. Iodine (in the form of Lugol’s solution) and colloidal silver are universally used in packaging that lets through very little UV light so as to avoid degradation.
What chemicals can dissolve plastic?
Melting Plastic with Chemicals. Purchase acetone to use for melting plastic. Acetone is a solvent that is often used for stripping paint or cleaning off nail polish but it can be used for melting some types of plastic. It is available at most hardware and beauty supply stores, as well as from online retailers.
Does the sun break down plastic?
Sunlight oxidizes the plastic, breaking down the polymers into highly soluble organic molecules called oligomers. Other types of non-aromatic plastic, like polypropylene and polyethylene, take much longer – from years to decades – to dissolve.
What is the meaning of the term photodegradation?
Photodegradation is the change, typically undesirable, in the properties of a material. Quite literally, it means the degradation of a material due to photon exposure. Photo degradation is a major concern with some polymers and other materials, where ultraviolet (UV) light causes the polymer to oxidize, thus making them brittle.
How is photodegradation used in disinfection technology?
It is however partly responsible for remineralization of biomass and is used intentionally in some disinfection technologies. Photodegradation does not apply to how materials may be aged or degraded via infrared light or heat, but does include degradation in all of the ultraviolet light wavebands.
How can we reduce the amount of photodegradation?
To reduce the amount of degradation that occurs, several prevention methods can be used. One is coating the polymer with a substance that does not photodegrade. Shielding the polymer from the sun or ultraviolet light source is another option.
How is photodegradation of polymers caused by light?
Photodegradation of polymers is induced by the action of light and is attributed to photochemical reactions arising from the absorption of UV radiation by carbonyl groups present on the polymer backbone.
