Part of the betaine can also be used as a thickener. The thickening principle is similar to the thickening principle of other small molecules, and with the mass fraction of 10%-20% of the hydroxyl groups, they are thickened by interacting with surface-active micelles. Soaps can be used for thickening in stick cosmetics. Natural gums mainly include collagen and polysaccharides. Betaine is mainly used in surfactant water systems. Water-soluble polymer thickeners: Many systems thickened by polymer thickeners are not affected by the pH value of the solution. (Pyrrolidone) In addition, the polymer thickener needs a small amount to achieve the required viscosity, and only 0.5% of the cellulose polymer is required to achieve the same. Most water-soluble polymer compounds are used not only as thickeners in the cosmetics industry, but also as suspending agents, dispersing agents, and setting agents.
Cellulose is an effective thickener in water-based systems. Cellulose is a natural product. It contains repeating glucoside units. Each glucoside unit contains 3 hydroxyl groups. Various types of hydroxyl groups can be formed through these hydroxyl groups. Derivatives. Cellulosic thickeners thicken by hydrating and swelling long chains, and the cellulose thickened system exhibits a pseudoplastic rheological form. (Pyrrolidone) is generally used in a mass fraction of about 1%. Polyacrylic acid thickeners have 40 years of history since Coodrich introduced Carbomer 934 to the market in 1953. Now this series of thickeners have more choices (see Table 1). There are two thickening mechanisms of polyacrylic acid thickeners, namely, neutralization thickening and hydrogen bonding thickening.
Neutralization and thickening is the neutralization of acidic polyacrylic thickeners to ionize the molecules and generate negative charges along the main chain of the polymer. The repulsion between the same charges causes the molecules to stretch out and form a network. The structure is thickened; the hydrogen bond thickening is that the polyacrylic thickener first combines with water to form hydrated molecules, and the donor (such as a nonionic surfactant with 5 or more ethoxy groups) combines to make it curl. The molecules unravel in the aqueous system to form a network structure to achieve thickening. (Pyrrolidone) Different pH values, different neutralizers and the presence of soluble salts have a greater impact on the viscosity of the thickening system. When the pH value is less than 5, the pH value increases and the viscosity increases; the pH value is 5-10 , The viscosity is almost unchanged; but as the pH value continues to rise, the thickening efficiency will drop again. Monovalent ions are only the thickening efficiency of the system. Divalent or trivalent ions can not only make the system thinner, but also produce insoluble precipitates when the content is sufficient.