We’ve had a look at some general principles. Now let’s dig into it a bit.
Today we’ll look at the chemistry of clothes.
Broadly speaking we can classify clothes into two categories, natural fibres and synthetic fibres.
Natural fibres are cotton, linen, wool, leather, silk, and perhaps one or two others.
Synthetic fibres number in their hundreds and possibly thousands and include any material with the word “poly” in it, as well as many others. Some of the more common ones would be nylon, polyester, rayon, polyviscose and so on.
In general, natural fibres feel better to wear, which is why we still have them available, as they have significant disadvantages practically in comparison to synthetic materials.
The first disadvantages is that they stain more easily.
The reason for this is that the only reason that they can be made into clothes is that someone worked out that they could be. In other words, the chemical structure of these materials is simply the way they exist – they were never designed to be used for clothing in the same way that synthetic fibres were.
As a result they contain many functional groups that synthetic fibres don’t, and that bind quite strongly to many stains. And remember that the only reason that we have stains in clothes, is that something in the molrcular structure of the stain material somehow binds or interacts with the molecules in the garment. If there was no interaction they would just wash straight out.
The second disadvantage of natural fibres is that they are more prone to attack by aggressive chemical cleaning agents such as bleaches.
There are several different types of bleach, which is a topic for another day, but all of them are more likely to attack the structure of natural fibres than synthetic fibres.
The third disadvantage of natural fibres, particularly cotton, is that it crumples more easily, unlike certain synthetic fibres such as microfibre which essentially never crumple and never need to be ironed
In functional terms, there are only two advantages that natural fibres have over synthetic fibres. Firstly, cotton if exposed to fire burns. Now you may wonder why that is an advantage, but synthetic fibres when exposed to fire have a tendency to melt.
This is why cotton is by far the more common choice of material for industrial clothing – it’s better to just have burns (and by the way cotton will withstand a higher temperature than will most synthetics) than to have your clothes melted onto your skin.
The other advantage of natural fibres is that wool really has no synthetic equivalent in terms of either its insulating properties (the same is true of silk by the way), or its water resistant properties. If you get caught in a shower with a woollen jumper on, it dries very quickly, as it has a natural coating of lanolin which repels water.
Tomorrow, we will look at the chemistry of stains.