And why is mens and womens shampoo so different.
In: Chemistry
Soap is basically a salt of various fatty acids. If you mix acid and base, you will get salt. You can only use sodium hydroxide or potassium hydroxide as a base. They say you can use another strong bases but you can’t get useful soap with them. You get different soap salts as you mix the base with different oils. For example, if you mix NaOH with coconut oil, you get sodium cocoate, if you mix NaOH with olive oil, you get sodium oliveate. Every soap salt has different properties. For example, if you add sodium oliveate, your soap will be conditioning. But if you want your soap cleaning, you should add coconut oil, palm kernel oil, or tallow. If you don’t have these in your soap, your soap won’t clean your body. Fabrication soaps usually use sodium palm kernelate for cleansing, and sodium palmate for conditioning and creamy bubbles.
You will say why we need other detergents. That’s simple. If you try to make your soap acidic(like adding citric acid), you will notice your soap won’t lather anymore. That’s why we may need other detergents. Human skin pH is between 4.5 and 5.5, and soap pH is between 8 and 10. So, technically, when you rub your skin with the soap, you hurt your body. Your skin may be itchy, and turn red over time(it doesn’t happen to me except my hair, by the way). If you can’t make the soaps acidic, you need another detergent. That’s why sodium lauryl sulfate came out.
Sodium lauryl sulfate has very detergent-like odor, and it comes with pellets. You can easily change its pH with various acids and bases(I use citric acid). You can make the pH of product around 4 or 5, and you can use it without any damage to the skin. But sodium lauryl sulfate has very high cleaning properties(like you are using a hundred percent of sodium cocoate in a soap), so it needs some oils and humectants like glycerin. Shower gels, liquid soaps and shampoo all share this ingredient. There are mild surfectants, but since I have oily skin, I hate all of them. Long live sodium lauryl sulfate.
Men’s and women’s shampoo is different, because usually women have more fragile hair. So men easily use their shower gel as shampoo, but women may have a hard time. Women’s shampoo should contain more silicone and humectants.
You can make the soap more mild by adding high amounts of glycerin, and your soap will be translucent, but the soap will be little bit soft and meltable.
Also you don’t need a preservative in a soap, because bad microorganisms can’t live in high pH. But you need a preservative like methylparaben in a shower gel or shampoo, because pH is now acidic(because you added citric acid to it). My favorite preservative is sodium benzoate and potassium sorbate, but they are highly reactive. Using parabens like methylparaben would extend the shelf life of the product big amount. That’s why they quit using parabens. They should sell you more products. Also methylchloroisothiazolinone is effective, but it’s only usable in wash-off products like shower gels. You can’t use them in lotions. You can also use high amounts of propylene glycol to preserve the product. Lush uses that.
Latest Answers