Physical Properties of Nomex Yarns Pretreated with Various Amines

Abstract

In this study, we pretreat aramid (Nomex®) yarns with ethylene diamine (EDA), diethylene triamine (DETA), and triethylene tetramine (TETA) under different conditions and study some physical properties. The values of changes in tensile strength retention ΔTSR increase and then decrease, and basic dye uptake [D] f and wicking height WH increase with increased pretreating temperature, time period, and amine concentration. The rank of the minus values of Δ TSR for the pretreated fibers is EDA > DETA > TETA. but the tendencies of the plus values of ΔTSR and of [ D] f, WH, and shrinkage are inverse at a given pretreating temperature, time period, and amine concentration. The glass transition temperatures and densities of the crystals are ranked as EDA > DETA > TETA. Surface etching on TETA pretreated fibers is more obvious than on EDA pretreated fibers. The polymer chains of aramid fibers may rearrange through shrinkage of the fibers during pretreatment, and some degradation of the Nomex polymer chains may occur at higher amine concentrations.