SURFACE-AREA OF AQUEOUS SODIUM-HYDROXIDE HYDROLYZED HIGH-SPEED SPUN POLY(ETHYLENE-TEREPHTHALATE) FIBERS

The specific surface area (SSA) of delustered undrawn and drawn high-s peed spun PET fibers hydrolyzed in aqueous NaOH was measured using thr ee methods: (1) geometric, based on fiber diameter; (2) gas adsorption using N-2 and the BET equation; and (3) adsorption of a nonionic surf actant. Increasing the spinning speed had little effect on the SSA of the untreated fibers, while drawing resulted in considerably larger SS A. For the hydrolyzed fibers, both adsorption methods resulted in larg er SSAs than that predicted geometrically due to surface pitting. Afte r hydrolysis, the higher spinning speed resulted in a greater increase in SSA over the untreated sample, whereas the increase in SSA was les s for the drawn fibers compared to the undrawn. The kinetics of hydrol ysis are also discussed. (C) 1995 John Wiley & Sons, Inc.