Investigation of the ultradrawing properties of gel spun fibers of ultra‐high molecular weight polyethylene/carbon nanotube blends

The carbon nanotubes (CNTs) contents, ultrahigh‐molecular‐weight polyethylene (UHMWPE) concentrations and temperatures of UHMWPE, and CNTs added gel solutions exhibited significant influence on their rheological and spinning properties and the drawability of the corresponding UHMWPE/CNTs as‐prepared fibers. Tremendously high shear viscosities (ηs) of UHMWPE gel solutions were found as the temperatures reached 140°C, at which their ηs values approached the maximum. After adding CNTs, the ηs values of UHMWPE/CNTs gel solutions increase significantly and reach a maximum value as the CNTs contents increase up to a specific value. At each spinning temperature, the achievable draw ratios obtained for UHMWPE as‐prepared fibers prepared near the optimum concentration are significantly higher than those of UHMWPE as‐prepared fibers prepared at other concentrations. After addition of CNTs, the achievable draw ratios of UHMWPE/CNTs as‐prepared fibers prepared near the optimum concentration improve consistently and reach a maximum value as their CNTs contents increase up to an optimum value. To understand these interesting drawing properties of the UHMWPE and UHMWPE/CNTs as‐prepared fibers, the birefringence, thermal, morphological, and tensile properties of the as‐prepared and drawn fibers were investigated. Possible mechanisms accounting for these interesting properties are proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008