Personal care compositions, particularly hair care products, include a polymer mixture made from (A) a derivatized polymer of maleic anhydride having defined repeat units of a monomer (e.g. -olefin) maleic anhydride alkyl half-ester or full acid, maleamic acid and maleimide, and (B) a compound or polymer having a carboxylic acid functionality. These compositions exhibit excellent high humidity curl retention properties, as well as an advantageous blend of toughness and cohesiveness, and a strong affinity to natural fibers such as keratin-based fibers, e.g. hair, skin, or textiles, such as cotton or wool; and they are also water-soluble and water-resistant.