You can bleach polyester provided you use the correct type of bleach. There are three basic categories of bleach.
These work by breaking chemical bonds within the molecule that contributes the color. This type of molecule is called a chromophore. Breaking the bonds of the chromophore alters its structure so that it has either no color at all or what color it does reflect is outside the visual spectrum. Chlorine and peroxide are examples of oxidizing agents. Most common bleaches are oxidizing agents.
These convert double bonds within a molecule into single bonds, thereby changing the optical properties of the molecule. Sodium dithionite is an example of a reducing agent.
Sometimes adding energy to a substance containing a chromophore can disrupt the energy contained within its chemical bonds. High-energy ultraviolet rays, for example, can destabilize chemical bonds. Sunlight is an example of this and explains why hanging diapers outdoors on a clothesline can help disinfect them.
What Is Polyester?
Polyester is made from the polymerization of individual ester molecules. Polyesters occur naturally and they can also be synthesized. Polymerization is a chemical reaction in which individual subunits, called monomers, react with one another to form chains or three-dimensional networks. Polyesters are found in soccer uniforms and in white net curtains.
How Can I Bleach Polyester?
The important thing is not to use chlorine bleach. This type of bleach is ineffective with polyester and may even damage the fabric. Instead, use an oxygen-based bleach. You can obtain the best results if you soak the fabric for an hour before laundering.