Structure and properties development in poly(phenylene sulfide) fibers, part I: Effect of material and melt spinning process variables

Abstract

The detailed research study of manufacturing PPS fibers using melt spinning and further enhancement of tensile properties by drawing and annealing experiments, a study lacking as of today in open scientific literature, was the focus of this research. This article discusses the effect of polymer molecular weight (MW) and melt spinning process variables on the structure and properties development in melt spun fibers manufactured from proprietary FortronV R linear PPS resins. Structure-properties relationship was studied using several characterization tools like tensile testing, differential scanning calorimetry, polarized light optical microscopy, and wide-angle x-ray scattering. Changes in dynamic mechanical behavior of asspun fibers manufactured from resins of varying MW and different melt spinning take-up speeds were also studied. The study showed that by a combination of higher MW of the polymer and spinning at higher take-up speeds, tensile properties of as-spun PPS fibers can be improved.

Structure and properties development in poly(phenylene sulfide) fibers. II. Effect of one‐zone draw annealing

“…Differences in the MW of the PPS resins used were discussed in our earlier publication9 in terms of the melt flow index (MFI). For the majority of the results discussed next, unless otherwise stated specifically, the as‐spun fibers used were manufactured at a take‐up speed of 1750 mpm with a throughput of 12 g/min/12 holes and at an extrusion temperature (ET) of 315°C.…”

“…14), with a substantial decrease, particularly in the amorphous regions. The probable cause for a loss of molecular orientation may have been slippage of the chains past each other and coiling thereafter, as could be deduced from the increasingly viscous flowlike behavior of the chains with increasing temperature 9. Above a certain temperature, the long period (Fig.…”

“…The details of characterization of the fiber properties, such as the denier, tensile strength, breaking elongation, tensile modulus, overall molecular orientation, and degree of crystallinity as determined by differential scanning calorimetry (DSC), were discussed in detail in our earlier publication 9…”

“…WAXS pinhole patterns of the draw‐annealed fiber samples that were obtained as discussed in our earlier publication9 were converted into 2θ versus intensity data with Polar software (Precision Works NY, Inc., East Setauket, NY). Because the calculation of the crystallinity index by this technique requires the knowledge of the contribution due to the amorphous fraction, an amorphous film was made from polymer 3P by hot pressing at 325°C and then by cooling rapidly using an ice‐water bath.…”

“…The overall orientation was determined by birefringence (Δ n ) with a polarized optical microscope (Prior Scientific Inc., Rockland, MA) equipped with compensator. The details of Δ n measurement were reported in our earlier publication 9…”