Step-grow th polymerisation It refers to a type of polymerisation mechanism in which bi-functional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long chain polymers. ● Nylon-6,6 is type of polyamide or nylon. It and nylon-6, are the most common for textile and plastic industries. It is formed by step-growth polymerisation by polycondensation of hexamethylene diamine and adipic acid. n(HOOC−(CH2)4−COOH)