Structure and properties evolution of UV crosslinked ultra‐high molecular weight polyethylene fiber during processing

Abstract

With the development of heat and creep‐resistant UHMWPE fiber via UV crosslinking, its structure‐properties evolution during processing needs attention. The structures of UHMWPE fiber in different forms, the pre‐oriented yarn (POY), the full stretch yarn (FDY) and UV crosslinked FDY (UVFDY), obtained from our pilot line were systematically studied with differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), small‐angle X‐ray scattering (SAXS), and solid‐state 13C NMR. Additionally, the heat and creep resistance of UVFDY were evaluated by the temperature at break (Tb), glass transition temperature (Tg), time at break (tb) for a given aging temperature, and creep elongation (Lc). The results demonstrated that UVFDY possessed high gel content (89.0%), high crystallinity (84.2%), and high orientation (91.7%). These characteristics caused UVFDY not only with excellent mechanical properties but also process extraordinary heat and creep resistance, especially for its much higher Tb (220 °C), Tg (−75.7 °C) and tb (20 h) while lower Lc (7.8%), comparing with FDY (Tb = 158 °C, Tg = −86.8 °C, tb = 1.3 h and Lc = 38.2%). This work provides insights into the structure‐properties relationship of UVFDY, which will aid in the development of UV crosslinked UHMWPE fiber with better heat and creep resistance.

Feasibility of Repairing Concrete with Ultra-High Molecular Weight Polyethylene Fiber Cloth: A Comprehensive Literature Review

“…Better physical properties of UHMWPE fiber depend on higher molecular weight and long-chain crystallization. Ultra-high molecular weight diminishes the amorphous regions between chain termini, augments intermolecular attraction, and engenders a higher abundance of crystalline phases characterized by favorable mechanical properties [76][77][78][79]. Molecules arranged in elongated chains demonstrate a consistent capacity for energy absorption, thus reducing vulnerability to damage and facilitating the optimization of their mechanical properties [78][79][80][81][82][83].…”