Ultradrawing properties of ultrahigh‐ molecular‐weight polyethylene/carbon nanotube fibers prepared at various formation temperatures

Abstract

The influence of formation temperature on the ultradrawing properties of ultrahigh‐molecular‐weight polyethylene/carbon nanotube (UHMWPE/CNT) fiber specimens is investigated. Gel solutions of UHMWPE/CNT with various CNT contents were gel‐spun at the optimum concentration and temperature but were cooled at varying formation temperatures in order to improve the ultradrawing and tensile properties of the UHMWPE/CNT composite fibers. The achievable draw ratio (Dra) values of UHMWPE/CNT as‐prepared fibers reach a maximum when they are prepared with the optimum CNT content and formation temperature. The Dra value of UHMWPE/CNT as‐prepared fibers produced using the optimum CNT content and formation temperature is about 33% higher than that of UHMWPE as‐prepared fibers produced using the optimum concentration and formation temperature. The percentage crystallinity (Wc) and melting temperature (Tm) of UHMWPE/CNT as‐prepared fiber specimens increase significantly as the formation temperature increases. In contrast, Wc increases but Tm decreases significantly as the CNT content increases. Dynamic mechanical analysis of UHMWPE and UHMWPE/CNT fiber specimens exhibits particularly high α‐transition and low β‐transition, wherein the peak temperatures of α‐transition and β‐transition increase dramatically as the formation temperature increases and/or CNT content decreases. In order to understand these interesting drawing, thermal and dynamic mechanical properties of the UHMWPE and UHMWPE/CNT as‐prepared fiber specimens, birefringence, morphological and tensile studies of as‐prepared and drawn fibers were carried out. Possible mechanisms accounting for these interesting properties are proposed. Copyright © 2010 Society of Chemical Industry

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

“…Presumably, incorporation of uniformly dispersed and aligned CNTs in polymer matrix can provide polymer composites with dramatically improved strength and modulus in their machine direction. These expectations have recently been confirmed by a number of studies [26][27][28][29][30][31][32][33][34][35]. Our recent investigation [32][33][34] found that the achievable draw ratios (D ra ) of UHMWPE/carbon nanotubes (CNTs) asprepared fibers prepared near the optimal UHMWPE concentration improve consistently and reach a maximal value as their CNT and/or functionalized CNT contents increase up to an optimal value, respectively.…”

“…These expectations have recently been confirmed by a number of studies [26][27][28][29][30][31][32][33][34][35]. Our recent investigation [32][33][34] found that the achievable draw ratios (D ra ) of UHMWPE/carbon nanotubes (CNTs) asprepared fibers prepared near the optimal UHMWPE concentration improve consistently and reach a maximal value as their CNT and/or functionalized CNT contents increase up to an optimal value, respectively. As evidenced by DSC thermal analysis, CNTs with extremely high specific surface areas can serve as efficient nucleation sites and facilitate the crystallization of UHMWPE molecules into crystals but with low melting temperatures and/or evaluated smaller crystal thickness during their crystallization processes.…”

“…The maximal achievable draw ratios of FA mx as-prepared series fiber specimens and the tensile strengths of the drawn FA mx fiber specimens are significantly higher than those of the corresponding FA x drawn fiber specimens prepared at the same draw ratios and ATPs contents but without purification by sodium hexametaphosphate. The ultimate tensile strength values of the UHMWPE/purified ATPs drawn fibers prepared at the optimal ATP content using one-stage drawing process at 95°C can reach around 3.9 GN m −2 , which is even higher than most of those UHMWPE/functionalized CNTs drawn fibers prepared at the same drawing condition in our previous study [32][33][34]41]. These results clearly suggest that nanofillers with extremely high specific surface areas can act as efficient nucleation sites and significantly improve the achievable draw ratios and ultimate tenacity properties of nanofillers added UHMWPE fibers.…”

Ultradrawing properties of ultrahigh‐molecular weight polyethylene/functionalized carbon nanotube fibers and transmittance properties of their gel solutions

“…Most recently, Ruan et al reported [12] that the tensile strength and elongation at break of 5‐wt% MWCNTs‐filled UHMWPE gel‐spun composite fiber specimen reached 4.2 GPa and 5%, respectively, which are 18.8 and 15.4% higher than that of the pure UHMWPE fiber with the same draw ratios, respectively. As presented in our recent investigation [15], it was found that the UHMWPE/CNTs fiber specimens prepared at lower formation temperatures always exhibit lower values of percentage crystallinity, birefringence, and melting temperature but higher achievable draw ratios than those prepared at higher formation temperatures.…”

Effect of Heat Drawing Process on Mechanical Properties of Dry-Jet Wet Spun Fiber of Linear Low Density Polyethylene/Carbon Nanotube Composites

“…Because of high Young's modulus of 1-5 TPa and anisotropic properties, CNTs have been proposed as a material that can increase the elastic modulus and tensile strength of composite materials [20,21]. In addition, PE has been used as a matrix for preparing composites with CNTs using UHMWPE [22][23][24][25], HDPE [26,27], and LDPE [19,28] and as a thin film [29][30][31].…”