Composite polymers, which are nylon6 materials with aluminum powders dispersed homogeneously, are prepared. Influences of water absorption on Charpy impact value of composite polymers have been investigated. Although the aluminum dispersion from zero to 40 vol%Al decreases the impact value, the water absorbing treatment for 10 5 s at boiling point largely increases the impact values of all composite polymers. It is explained that water molecules in nylon6 mainly relaxes the impact force. If the water absorption also enhances the interfacial energy to form the crack in nylon6 and its composites, the high impact value with smooth undulating surface can be explained.
In order to generate the bending motion operated by pressure change in hydrogen gas, soft uni-morph composites were prepared, in which composites dispersed with not only driving particles of LaNi 5 hydrogen storage alloy with Pd-Al 2 O 3 catalyst powders to get high responsiveness, were piled up on a simple polyurethane sheet. Since the highest values of irreversible bending strain at the first hydrogenation (" 1) under 0.3 MPa H 2 gas and the maximum irreversible bending strain during hydrogenation cycles (" m) were remarkably obtained at the 35 vol% of LaNi 5 powders dispersed in polyurethane composites, the bending strain of reversible motion was detected from the first to the 8th hydrogenation (" r 1 and " r 8) under 0.2 MPa H 2 gas. The bending strain of reversible motion of polyurethane composites sheet is more than 2000 ppm, which was approximately equal to that of silicone rubber composites and is extremely larger than that (300 ppm) of ABS resin composites. Responsiveness (d"=dt) of cyclic motion of elastic deformed mover composites, which were constructed with 35 vol%LaNi 5 dispersed powder and matrix of polyurethane or silicone rubber, were more than 10 times higher than that of ABS composite.
Foam can be created within the interstices of a porous medium by displacing a resident surfactant solution with a gas. This process of in-situ foam formation has a number of potential applications. Thus, it is of interest to establish those properties of surfactants which improve the performance of a given process.Both anionic and nonionic surfactants were studied. Each was characterized by its surface tension, surface viscosity, foaming ability, foam stability, bulk viscosity and wettability.I.
Bio-adaptable 2-layer polyurethane/polytetrafluoroethylene (PU/PTFE) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of: (1) applying low dose <0.65 MGy homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the PU and PTFE layers, respectively, prior to: (2) hot-press under 5 MPa and 403 K. Although the adhesion of the PU/PTFE sheets cannot be observed without the new double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance ( o F p ). Based on the 3-parameter Weibull equation, the lowest o F p value at P p of zero (F s ) could be estimated. An increasing trend in F s occurs by the double-step treatment applying HLEBI up to 0.43 MGy reaching a maximum at 0.38 Nm ¹1 , improving the safety level without radiation damage. When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in PU and PTFE, the created adhesion between the laminated sheets can be explained. Based on X-ray photoelectron spectrometer (XPS) surface analysis of the PU/PTFE laminated sheets after the peeling tests, fluorine (F) was detected on the PU peeled surface, indicating the strong chemical bonding generated by the double-step treatment. For these reasons, double-step treatment is a useful method for quick lamination of PU and PTFE with sterilization without the use of glue.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.