Review on processing ultra high tenacity fibers from flexible polymer

Abstract

The various efforts up to date on the processing of ultra high tenacity fibers from flexible polymer have been summarized in this report. Some significant parameters correlating well with ultra high tenacity have been found through consideration of experimental results of polyethylene, despite the wide diversity in the processing techniques, degrees of drawing, thermal conditions, and molecular weight characteristics. It has been concluded from those parameters that ultra high tenacity fibers can be only attained by processing techniques satisfying the following structural principles simultaneously: ultra drawing with draw ratio above 20 for increasing the number of tie molecules and the degree of molecular orientation. reduction of the small angle x‐ray scattering intensity, correlating to an increase in the number of tie molecules. increase in molecular chain length for reducing the intermolecular chain slip at polymer chain ends. increase the slope of the Griffith plot, a manifestation of reducing defeets and flaws in microfibrils.

Influence of two-stage drawing conditions on ultradrawing behavior of gel films of ultrahigh-molecular-weight polyethylene and low-molecular-weight polyethylene blends

“…This method of ultradrawing the gel specimens spun or cast from gel solutions of UHMWPE is referred to as the gel-deformation method. As reported by several authors, [12][13][14][15][16][17][18][19][20] the tensile strengths and moduli of the drawn gel specimens were found to improve consistently with their draw ratios, although their orientation and crystallinity values increased slowly at draw ratios above about 30. 16,20 The drawability of the gel specimens was found to depend principally on the compositions of the solutions from which the gels were made.…”

An analysis of deformation process on poly-p-phenylenebenzobisoxazole fiber and a structural study of the new high-modulus type PBO HM+ fiber

“…We may think that the electron density fluctuation in the HM fiber comes from the presence of contrast between ordered and disordered regions; the ordered region forms threedimensional lattice and disordered region may include defects such as molecular chain ends, conformational irregularity and so on. In a study of polyethylene fiber, 22,23 fiber modulus strongly depends on SAXS intensity, which may support the absence of the four-point pattern in the HMϩ pattern. Combining TEM high-resolution electron microscopic (HREM) and a defocus-contrast technique, we have already proved that the density fluctuation pattern in the HM fiber is accord with the presence of the lattice in a HREM image.…”

“…There is a study to relate small-angle X-ray scattering intensity with fiber modulus in polyethyelene fiber. 22,23 A long period structure including alternatives of crystal and amorphous gives the SAXS intensity. Normally PBO fiber is spun with the dry-jet wet spinning method through an aqueous coagulation bath.…”

Ultradrawing properties of ultra-high molecular weight polyethylene/hydrochloric acid treated attapulgite fibers

“…Tensile strengths (GPa) The mechanical properties of the drawn specimens are generally believed to depend mainly on the degree of orientation of the drawn specimens, as their molecular weights are constant [48,49]. As evidenced by the orientation analysis, at a fixed draw ratio, the orientation factor values of the drawn F 100 A 0.05 and F 100 A xM-0.025 fiber specimens prepared at the optimal purified and acid treated ATP contents are always higher than those of other F 100 A y and/or F 100 A xM-y fiber specimens prepared at ATP and/or acid treated ATP contents deviating from their optimal values, respectively.…”