Mechanical and tribological behaviors of PA66/PVDF blends filled with calcium sulphate whiskers

Abstract

The mechanical and tribological performance of the PA66/PVDF blends filled with various amount of calcium sulphate whiskers (CSW) was investigated. The whiskers improve the tensile and flexural performance of the PA66/PVDF blends. Meanwhile, the addition of CSW obviously decreases friction coefficient and improves the wear resistance of the blends. With the further increase of CSW, friction coefficient of the blends relatively keeps stable and the wear resistance of the blends slightly decreases. The PA66/PVDF blends filled with 5 wt% CSW exhibited the best anti‐wear ability. FTIR analysis shows that the chemical change has not occurred in the debris. XPS analysis shows that some tribo‐chemical reactions have occurred during friction process and produces some compounds such as FeF2, Fe2O3 on the transfer film surfaces. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers

Influence of Alkyl Trimethyl Ammonium Bromides on Hydrothermal Formation of α-CaSO4·0.5H2O Whiskers with High Aspect Ratios

“…Figure 4 presents the variations of Fourier transform infrared (FT-IR) spectra and zeta potentials of the α-CaSO 4 ·0.5H 2 O whiskers with CTAB concentration. As shown in Figure 4a, the peak at 660 cm −1 corresponded to the bending (ν 4 ) mode of SO 4 2− , while the peaks at 1620 cm −1…”

“…The lower surface energy implied the increased stability of the side facets, which reduced the growth tendency of the whiskers along the direction normal to the lateral facets. In summary, the adsorption of CTAB on the side facets of the whiskers not only provided a strong steric hindrance preventing the addition of Ca 2+ and SO 4 2− , but also reduced the surface energy of the side facets. Both aspects inhibited the growth of the whiskers along the direction normal to the lateral facets and led to the formation of α-CaSO 4 ·0.5H 2 O whiskers with high aspect ratios.…”

“…The distribution of SO 4 2− ions on the side facets as (200), (400), and (020) is denser than that of Ca 2+…”

“…[1][2][3][4], showing excellent thermal stability and mechanical strength [5][6][7]. Calcium sulfate whiskers can be produced by preparing α-CaSO 4 ·0.5H 2 O whiskers through hydrothermal, acidification, reverse micro-emulsion, and microwave-assisted approaches [8][9][10][11][12][13] followed by calcination of the α-CaSO 4 ·0.5H 2 O whiskers above 600 • C [14,15].…”

Preparation of calcium sulfate whiskers using waste calcium chloride by reactive crystallization

“…As promising reinforcement materials, inorganic whiskers have attracted considerable interests of scientists and engineers since they exhibit high strength and stiffness, and are nearly free from internal defects such as dislocations owing to their small diameter [1][2][3][4][5][6][7][8]. There are various prospective inorganic whiskers that can be used to reinforce the composite materials, such as silicon carbide (SiC) [9], calcium carbonate [10], potassium titanate (K 2 Ti 6 O 13 ) [2], aluminum borate (Al 18 B 4 O 13 ) [11], titanium boride (TiBw) [12] and calcium sulphate (CaSO 4 ) whiskers [13]. They are reckoned as more effective reinforcements than traditional fibers, such as carbon fiber and glass fiber.…”