Development of a gel spinning process for high‐strength poly(ethylene oxide) fibers

Abstract

This article describes a new gel-spinning process for making high-strength poly(ethylene oxide) (PEO) fibers. The PEO gel-spinning process was enabled through an oligomer/polymer blend in place of conventional organic solvents, and the gelation and solvent-like properties were investigated. A 92/8 wt% poly(ethylene glycol)/PEO gel exhibited a melting temperature around 45 C and was highly stretchable at room temperature. Some salient features of a gel-spun PEO fiber with a draw ratio of 60 are tensile strength at break 5 0.66 6 0.04 GPa, Young's modulus 5 4.3 6 0.1 GPa, and a toughness corresponding to 117 MJ/m 3 . These numbers are significantly higher than those previously reported. Wide-angle x-ray diffraction of the high-strength fibers showed good molecular orientation along the fiber direction. The results also demonstrate the potential of further improvement of mechanical properties. POLYM. ENG. SCI., 54:2839-2847, 2014. V C 2014 Society of Plastics Engineers

Gel spinning of UHMWPE fibers with polybutene as a new spin solvent

“…A. The formation of this solid structure is consistent with the crystallization temperature measured by DSC for the same 2% PE/PB gel; therefore, the solid structure formed during quenching of the PE/PB fiber should be consistent with a network of polymer molecules swollen in solvent and mechanically supported by crystalline regions, which behave like physical crosslinks .…”

“…The lack of C‐axis orientation of the precursor fiber is anticipated due to free falling without jet stretch of the gel fiber. The negative small orientation factor may infer some small vertical orientation, as also seen in previous studies . The peak melting temperature of the precursor fiber is ∼124°C, determined from the corresponding DSC thermogram in Fig.…”

“…A. The blend shows single melting and crystallization peaks at reduced temperature compared to the neat UHMWPE, suggesting complete miscibility and similarity to paraffin oil/UHMWPE . The similarity is supported by the solubility parameters of the materials, which are 7.9, 7.5, and 8.05 (cal/cm 3 ) 1/2 for PE, paraffin oil and PB, respectively .…”

“…According to Flory‐Huggins’ theory, PE can be miscible in the two solvents. Thus, this gel also benefits from the polymer/oligomer blend with solution‐like behavior . The melting temperature of neat UHMWPE is reduced from ∼140°C to 115°C after mixing 2% wt.…”

“…Hence, the objective of the hot drawing process is to achieve a large draw ratio and obtain fibers with the possibly smallest diameter. In the previous studies of gel spun PE fibers with paraffin oil and decalin , drawing in two stages seems to be especially effective to obtain high draw ratios compared with other methods. Thus, in this study, the PE fibers spun with PB were also drawn in two stages using the same hot drawing conditions.…”