Ultradrawing properties of ultrahigh‐molecular‐weight polyethylene/attapulgite fibers

Abstract

An investigation of the influence of the contents of original and modified attapulgite (ATP) on the ultradrawing properties of ultrahigh-molecular-weight polyethylene (UHMWPE)/ATP (FA x ) and UHMWPE/modified ATP (FA mx ) as-prepared fibers is reported. Similar to what is found for the orientation factor values, the achievable draw ratios (D ra ) of the FA x and FA mx as-prepared fibers approach a maximum value as the original ATP and/or modified ATP contents reach their corresponding optimum values. The maximum D ra value obtained for FA mx as-prepared fiber specimens is significantly higher than that for FA x as-prepared fiber specimens prepared at the optimum original ATP content. Similar to what is found for the orientation factors and achievable drawing properties, the tensile strength (σ f ) and initial modulus (E) of both drawn F 2 A x and F 2 A mx fiber series specimens with a fixed draw ratio reach maximum values as the original and/or modified ATP contents approach the optimum values, respectively. The σ f and E values of the F 2 A mx fiber specimens are always significantly higher than those of the corresponding F 2 A x fiber specimens prepared at the same draw ratios and ATP contents but without being modified. To understand the interesting ultradrawing, orientation and tensile properties of FA x and FA mx fiber specimens, Fourier transform infrared spectral, specific surface area, transmission electron microscopic and elemental analyses of the original and modified ATPs were performed.

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

“…Similar to those found in our previous study [41], D ra values of F 100 A y as-prepared fibers are significantly higher than that of the F 100 as-prepared fiber specimen without addition of purified ATP nanofibers. The D ra values of F 100 A y as-prepared fiber series specimens increase significantly with the initial increase in purified ATP contents and then reach a maximal value at 145 as their purified ATP contents approach an optimal value at 0.05 phr.…”

“…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.…”

“…At HCl concentrations higher than 5 M or treating time more than the optimal value at 60 min, the specific surface areas of the acid treated ATP nanofibers reduce significantly with the further increase in the HCl concentration or treating time. For instance, the maximal specific surface areas of the ATP nanofibers acidtreated for an optimal amount of time at 60 min reduce from 282 m , which were generally ascribed to the motions of Ti-O bending, carbonate bending, Mg-O stretching, carbonate bending, absorbed water bending, Al-Mg-OH bending and Al 2 -OH bending, respectively [41,46]. After purification, the Ti-O and carbonate bending bands nearly disappeared, while demarcated Mg-O stretching, absorbed water bending, Al-Mg-OH bending and Al 2 -OH bending bands were found centering at 1,195, 1,657, 3,583 and 3,616 cm -1 of the FT-IR spectrum of purified ATP specimen (see Fig.…”

“…Its structure scheme was firstly proposed by Bradly in 1940 [37], who described a theoretical formula of (Mg, Al, Fe) 5 Si 8 O 20 (Al)(HO) 2 (OH 2 ) 4 ·4H 2 O. In our recent study [41], natural and purified attapulgite (ATP) minerals were added in UHMWPE gel-spinning solutions to improve the ultradrawing and ultimate tensile properties of UHMWPE/ATPs fibers. Similar to those found for UHMWPE/CNTs or UHMWPE/functionalized CNTs as-prepared fibers, the achievable draw ratios of the UHMWPE/ATPs (FA x ) and UHMWPE/purified ATPs (FA mx ) as-prepared fibers and tensile strength values of their drawn fibers approach a maximal value as their ATPs and/or purified ATPs contents reach the optimal values at 0.02 and 0.015wt%, respectively.…”

Stiffening mechanisms in vermiculite–amorphous polyamide bio-nanocomposites

“…Polymer nanocomposites are high performance materials promising to meet new application requirements and to replace existing materials [1][2][3]. Adding clay-based nanoparticles can significantly improve properties such as heat resistance, stiffness, strength, toughness, impact resistance, barrier properties, rheological properties, flame retardancy, etc.…”