hillenkamp f and giessman u anal chem 64 1992 908 for pure nylon 66 polymer as rv increases the number of amine ends and acid ends decreases in the following set of examples we demonstrate that by adding more propylene oxide to nylon 66 salt the rv of the produced polymer is increased and also the number of amine ends and acid ends increase into a small autoclave set at 120 u00b0 c was added 59 07 gms of 51 5 aqueous solution of hexamethylenediamine adipic acid salt nylon salt 0 08 gms of hexamethylenediamine hmd and an amount of propylene oxide po the autoclave was equipped with a pressure relief valve set at 250 psi the temperature of the autoclave was increased from 120 u00b0 c to 240 u00b0 c over a period of 100 min over the following period of 60 min the autoclave temperature was increased from 240 u00b0 c to 275 u00b0 c and the pressure was reduced to atmospheric pressure the temperature was maintained at 275 u00b0 c for an additional period of 60 min the nylon polymer was removed from the autoclave and analyzed the polymer amine and acid end equivalent per million grams of polymer where measured in the following set of examples we demonstrate that by adding more 1 2 epoxybutane to nylon 66 salt the rv does not change much and the number of amine ends and acid ends increase into a small autoclave.