Carbomer

(9007-20-9) A cross-linked polymer of acrylic acid; it contains a large proportion (56% to 68%) of carboxylic acid (COOH) groups after drying at 80° for 1 hour. Average relative molecular mass about 3 × 10⁶.

pH (2.2.3) : about 3 for a 1.0% w/v suspension.