Retrobright refers to
H2O2 (hydrogen peroxide) based processes used to remove yellowing from ABS plastics. The usage has also expanded to other retro restoration applications, such as classic and collectible sneaker restoration, where it is referred to by collectors as "sole sauce".
Yellowing in ABS plastic occurs when it is exposed to UV light or excessive heat, which causes
photo-oxidation of polymers
In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. It is the most significant factor in the weathering of plastics. Photo-oxidatio ...
that breaks polymer chains and causes the plastic to yellow and become brittle.
One method of reversing the yellowed discoloration coined the term (stylized as retr0bright or Retrobrite
) was first discovered in 2007 in a German retrocomputing forum, before spreading to an English blog where it was further detailed. The process has been continually refined since.
The long-term effectiveness of these techniques is questioned. Some have discovered the yellowing reappears, and there are concerns that the process weakens and only bleaches the already damaged plastic.
Alternatives
Certain beauty salon products that are primarily composed of hydrogen peroxide can also be used as an alternative to retrobright, as it has been discovered to be almost identical in effect, and already viscous so that it can be applied less wastefully to yellowed plastics (especially large devices such as computer panels or monitors).
While this eliminates the difficulty of having to put together a batch directly from the instructions,
one must be careful to apply the cream and wrap consistently and evenly to avoid streaks in the final product.
Sodium percarbonate
Sodium percarbonate is a chemical substance with formula . It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 · 3 . I ...
may also be used by dissolving it in water and following the usual steps for hydrogen peroxide, as it is sodium carbonate and hydrogen peroxide in a crystalline form.
can also be used for retrobrighting, as long as an ozone generator, a suitable container of sufficient size and a source of UV are available, but can take longer than other methods.
Retrobright
Retrobright consists of
hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%†...
, a small amount of the "active oxygen" laundry booster
TAED
Tetraacetylethylenediamine, commonly abbreviated as TAED, is an organic compound with the formula (CH3C(O))2NCH2CH2N(C(O)CH3)2. This white solid is commonly used as a bleach activator in laundry detergents and for paper pulp. It is produced by ...
as a catalyst, and a
source of UV.
The optimum mixture and conditions for reversing yellowing of plastics:
* A hydrogen peroxide solution (oxigenated water).
* A source of
ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
,
from sunlight or a UV lamp.
Xanthan gum
Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple sugars u ...
or
arrowroot can be added to the mixture, creating an easier-to-apply gel. In addition to homemade gel mixtures, hydrogen peroxide-based hair bleaching creams available at beauty supply stores can also be used as a ready-made mix.
References
Cleaning products
Plastics
Hacker culture
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