Crosslinking of Synthetic Fibers by Peroxides Part 2. Crosslinking of Nylon 66 Fiber by t-Butyl Perbenzoate.

Abstract

Commercial nylon 66 fibers were dipped in a chloroform solution of t-butyl perbenzoate (TBP) at 60_??_65 °C under nitrogen for a predetermined period and then crosslinked at 150°C for 2h. When the time of dipping in a 30% TBP solution exceeded 2h, the crosslinked fibers became partially insoluble in hot formic acid. Density and gel content of crosslinked fibers increased and then decreased with the increase in time of dipping, which corresponded to the increase and decrease in TBP content in dipped fibers measured by DTA. X-Ray analysis showed that degree of crystallinity of crosslinked fibers decreased with the increase in time of dipping due to the cleavage of smaller crystallites. Young's modulus of crosslinked fibers increased with prolonged time of dipping up to 10 days in spite of the decreases in density and gel content, suggesting that the effective crosslinking occurred as a result of the penetration of TBP into the more inner part of fibers.