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Substituted 4,4,4-trifluoro-3-(indole-3-)butyric acids (TFIBAs), novel fluorinated plant growth regulators, were easily synthesized from substituted 2,2,2-trifluoro-l-(indole-3-)ethanols. The synthetic substituted TFIBAs showed marked root growth-promoting activity toward Chinese cabbage, lettuce, and rice plants. 5-MeO-2-Me-TFIBA (2d) had especially strong promoting activity toward Chinese cabbage, while 5-Me-TFIBA (2b) markedly promoted the root growth of all three plants. The promoting activity of TFIBAs halogenated at the 5-position in the indole nucleus of the molecule (5-Brand 5-CI-TFIBA (2e and 2g» was also greater than the activity of TFIBA, the original non-substituted compound. 5-N0 2-TFIBA (2h) with a strong electron-withdrawing group showed only very weak root growth-promoting activity.

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In this research work, the effects of sodium carbonate and hydrogen peroxide treatment of hemp fiber on the water absorption, mechanical, and tribological properties of hemp fiber reinforced epoxy composites (HFREC) were investigated. The change in surface roughness and fiber size after chemical treatment was confirmed by the scanning electron microscopy (SEM) images. Fourier transform infrared analysis confirmed the removal of hemicellulose and lignin content of the fiber after both the chemical treatment. X-ray diffraction analysis showed an increase in the crystallinity index of the chemically treated fiber.The experimental results also revealed that both sodium carbonate and peroxide modification have resulted in enhancement of water resistance and mechanical properties such as tensile strength and tensile modulus and reduction in impact properties of treated HFREC. Tribological test results revealed that the treated HFREC have improved wear and frictional properties in comparison with untreated HFREC. The best tribological and mechanical properties were exhibited by peroxide treated HFREC, which was also confirmed through the SEM images of worn and fractured surfaces of the composites.