The tribological properties under abrasive wear conditions, the tensile properties, the thermal properties and the structure have been investigated on the polyamide 6 (PA6) fibers dispersed with vapor-grown carbon fibers (VGCF's) in order to analyze the effects of dispersing VGCF's on the wear resistance of PA6 fibers. The wear resistance of the fibers have been determined using a method previously proposed by the present authors. The coefficient of friction decreased by dispersing a small amount of VGCF's but increased with increasing VGCF fraction at large VGCF fractions. The wear resistance increased with increasing VGCF fraction. Under the experimental conditions adopted in this study, the dispersion of VGCF's more effectively increased the wear resistance of PA6 fibers than the heat treatment. These experimental results have been analyzed based on a model with which the coefficient of friction (μ) and the wear rate (W s) have been related to the microhardness (H), the resistance against sliding (σ s), the fracture probability (f) the shape factor (g) and a constant (k) as μ = gσ s /(kH) and W s = gf/(kH).

Organic material characteristics of volume change and stress generation have attracted the attention of many researchers aiming to develop chemomechanical systems such as artificial muscles and polymer engines having the advantages of high energy density and silent operation. Although polymer gels offer a relatively large actuator stroke, their mechanical properties are relatively poor and the working temperature is relatively low, often limited by the evaporation of liquid if contained. We have developed an iodine-treated poly(vinyl alcohol) having extraordinarily large vapor-induced deswelling stress reaching 59 MPa, which is one to two orders of magnitude greater than those of ordinary polymer gels. Furthermore, this material has extremely large volumetric and gravimetric energy densities reaching 1.3 × 106 J m−3 and 9.6 × 102 J kg−1, respectively, and an elastic modulus of a few GPa and is heat-resistant to at least 200 °C. The high performance of this material can be demonstrated by a jump of a film. © 2014 The Authors. Journal of Polymer Science Part B: Polymer Physics published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1357–1365

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