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931.
Li-Piin Sung Joan Jasmin Xiaohong Gu Tinh Nguyen Jonathan W. Martin 《Journal of Coatings Technology and Research》2004,1(4):267-276
Laser scanning confocal microscopy (LSCM) has been used to characterize the changes in film thickness and local surface morphology
of polymer coatings during the UV degradation process. With the noninvasive feature of LSCM, one can obtain thickness information
directly and nondestructively at various exposure times without destroying the specimens or deriving the thickness values
from IR measurement by assuming uniform film ablation. Two acrylic polymer coatings were chosen for the study, and the physical
and chemical changes of the two systems at various exposure times were measured and analyzed. Those measurable physical changes
caused by UV exposure include film ablation, formation of pits and other surface defects, and increases in surface roughness.
It was found in both coatings that changes in measured film thickness by LSCM were not correlated linearly to the predicted
thickness loss using the changes in the CH band obtained by the Fourier Transform Infrared (FTIR) spectroscopy measurements
in the later degradation stages. This result suggested it was not a uniform film ablation process during the UV degradation.
At later stages, where surface deformation became severe, surface roughness and profile information using LSCM were also proven
to be useful for analyzing the surface degradation process
Presented at the 81st Annual Meeting of the Federation of Societies for Coatings Technology, November 13–14, 2004 in Philadelphia,
PA. 相似文献
932.
本文浅述了含氟高分子材料的特性及其在汽车,建材方面的应用状况,分析了含氟材料对汽车、建筑业的支持作用和发展方向。 相似文献
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The effects of oxyen plasma treatment on the surface chemistry of Spectra 1000® high modulus polyethylene fibers and on the mechanical properties of fiber-reinforced composites of the fibers in a Bis-GMA based acrylic resin have been studied. X-ray photoelectron spectroscopy and diffuse reflectance FTIR spectroscopy have been used to show that the majority of oxygen on the fiber surface exists mostly in the form of ether and/or epoxy linkages, with carbonyl-, carboxylic- and ester-containing compounds accounting for less than 10 percent of the total. While the untreated and plasma-treated fibers have similar chemical compositions, the surfaces of the plasma-treated fibers are more polar and the oxygen is chemically bonded instead of being merely physisorbed. The interfacial shear strength between the fibers and the acrylic resin is increased by a factor of 2.3 by the plasma treatment indicating the presence of a weak boundary layer on the surface of the untreated fibers. The hydrolytic stability of the composite interfaces was investigated for fibers sized with several Bis-GMA-based adhesives. Maximum stability was attained by sizing with Bis-GMA containing a peroxide catalyst or an amine accelerator. The flexural properties of composites utilizing plasma-treated and untreated fibers were compared in three-point bending. The ultimate bending loads for composites using treated fibers were much higher than those for composites with untreated fibers, but only a fraction of that for glass or Kevlar®-reinforced materials. 相似文献
939.
发展玻璃纤维产业纺织品 总被引:2,自引:0,他引:2
本文层层深入地介绍产业用纺织品发展与应用、玻璃纤维纺织品发展与应用,以及它们的国内外概况并给出一些意见,以期待玻璃纤维产业纺织品有更好的发展. 相似文献
940.
An isotactic polypropylene hollow microfiber was continuously produced by using a carbon dioxide (CO2) laser‐thinning method. To prepare the hollow microfiber continuously, the apparatus used for the thinning of the solid fiber was improved so that the laser can circularly irradiate to the hollow fiber. Original hollow fiber with an outside diameter (OD) of 450 μm and an internal diameter (ID) of 250 μm was spun by using a melt spinning machine with a specially designed spinneret to produce the hollow fiber. An as‐spun hollow fiber was laser‐heated under various conditions, and the OD and the ID decreased with increasing the winding speed. For example, when the hollow microfiber obtained by irradiating the CO2 laser to the original hollow fiber supplied at 0.30 m min?1 was wound up at 800 m min?1, the obtained hollow microfiber had an OD of 6.3 μm and an ID of 2.2 μm. The draw ratio calculated from the supplying and the winding speeds was 2667‐fold. The hollow microfibers obtained under various conditions had the hollowness in the range of 20–30%. The wide‐angle X‐ray diffraction patterns of the hollow microfibers showed the existence of the highly oriented crystallites. Further, the OD and ID decreased, and the hollowness increased by drawing hollow microfiber obtained with the laser‐thinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2600–2607, 2006 相似文献