Description
Poly(acrylic acid) (PAA; trade name Carbomer) is a polymer with the formula (CH2-CHCO2H)n. It is a derivative of acrylic acid (CH2=CHCO2H). In addition to the homopolymers, a variety of copolymers and crosslinked polymers, and partially deprotonated derivatives thereof are known and of commercial value. In a water solution at neutral pH, PAA is an anionic polymer, i.e., many of the side chains of PAA lose their protons and acquire a negative charge. Partially or wholly deprotonaated PAAs are polyelectrolytes, with the ability to absorb and retain water and swell to many times their original volume. These properties - acid-base and water-attracting - are the bases of many applications.
Chemical Properties
"wets" very quickly
Uses
cosmetic uses e.g., clear gels, hydro-alcoholic gels, lotions and creams
Uses
Poly(Acrylic Acid) is a thickening, suspending, dispersing, emulsifying agent. In the cosmetic and textile printing fields, in printing inks, in emulsion-based lubricants, in pharmaceuticals, polishes, waxes, paints, waterproof and oil-proof coatings, in industrial specialties.
Application
Carbomers are thickening agents that help control the viscosity and flow of cosmetic products. They also help distribute and suspend insoluble solids into liquid, and prevent the oil and liquid parts of a solution from separating. They have the ability to absorb and retain water, and can swell up to 1000 times their original volume when dispersed in water. Generally, this class of ingredients is used in gel-like formulations because it forms a colloidal, mucilage-like consistency when mixed in water.
This ingredient is contained in a wide range of personal care products such as styling gel, facial moisturizer, sunscreen, shampoo, anti-aging treatment, eye cream, cleanser and scrubs.
Brand name
Carbopol 934P (Noveon); Carbopol
974P (Noveon).
Side effects
irritation. Uncommon side effects (may affect up to 1 in 100 people): eye swelling, eye pain, itchy eye, eye redness, increased tear production.
Safety
The safety of carbomers has been assessed by the Cosmetic Ingredient Review Expert Panel, a group responsible for evaluating the safety of skincare and cosmetics. Carbomer polymers demonstrated a low potential for phototoxicity, photo-contact allergenicity, skin irritation and sensitization at concentrations up to 100%. Upon evaluation of the scientific data, the CIR Expert Panel concluded that carbomer polymers were safe as ingredients in cosmetics and personal care products.
Synthesis
Precipitation polymerization: Carbomers are synthesized by free radical precipitation polymerization conducted in organic solvents. The solvents for this process are selected such that the monomers, initiators and other additives are soluble in the reaction medium, but the resulting polymer product is not.
