Copolymers having linked internal polyether blocks and internal polyamideblocks have advantageous physical properties and solvent-gelling abilities.The copolymer may be prepared from a reaction mixture that contains 1,4-cyclohexane dicarboxylic acid (CHDA) and poly(alkyleneoxy) diamine (PAODA).Optionally, the reaction mixture contains no monofunctional compound reactivewith either amine or carboxylic acid groups, however some of thismonofunctional compound may be present. Dimer diamine and/or dimer acid may bepresent in the reaction mixture. A copolymer may also be prepared from areaction mixture containing dimer acid and at least two diamine compound(s)including PAODA and short-chain aliphatic diamine having 2-6 carbons (SDA),wherein: a) the reaction mixture comprises x grams of PAODA and y grams ofSDA, and x/(x+y) is 0.8-0.98； b) the reaction mixture weighs z grams, and x/zis at least 0.25； and c) the reaction mixture contains either no co-diacid, orcomprises a small amount of co-diacid, wherein, if the reaction mixturecomprises a small amount of co-diacid, then acid equivalents from co-diacidcontribute less than 25% of the total acid equivalents present in the reactionmixture.
