To prepare Nylon 6,6, adipic acid and hexamethylene diamine are heated to 553 K under pressure. Nylon 6,6 is obtained by condensation polymerisation.
nHOOC−(CH2)2−COOH+nH2N−(CH2)6−NH2553K−−−−−−−−→high pressure[−CO−(CH2)−4−CO−NH−(CH2)6−NH−]n+(2n−1)H2O