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91.
Cuttlebone was proved to be a biomass for new reinforcing filler for natural rubber (NR). The cuttlebone particles were obtained by crushing cuttlebone and followed by sieving. Density and crystal structure of the cuttlebone were 2.70 g/cm3 and an aragonite form of CaCO3, respectively. The surface area and average diameter of the cuttlebone particles were measured and the reinforcement effect as filler for NR was investigated. The cuttlebone particles did not prevent a peroxide cross-linking reaction of NR, and mechanical properties of peroxide cross-linked NR filled with cuttlebone particles were found to be comparable with those of peroxide cross-linked NR filled with commercial CaCO3 filler. Presence of chitin on the surface of the cuttlebone particles was speculated to result in a good interaction between cuttlebone particles and NR, which may be ascribed to the mechanical properties of cuttlebone filled NR samples. 相似文献
92.
Fuminori Hiramatsu Tetsuya Murayama Takuya Koseki Katsuhide Okada Yoshihito Shiono 《Helvetica chimica acta》2008,91(8):1595-1603
New cadinane sequiterpenoids, strobilols E–K ( 5 – 11 , resp.) have been isolated from a liquid culture of Strobilurus ohshimae. Their structures have been established on the basis of spectral analyses. 相似文献
93.
Nectrianolins A,B, and C,new metabolites produced by endophytic fungus Nectria pseudotrichia 120-1NP
Nanang Rudianto Ariefta Priska Kristiana Handojo Hadi Nurjanto Hiroyuki Momma Eunsang Kwon Tatsuya Ashitani Keitaro Tawaraya Tetsuya Murayama Takuya Koseki Hiroshi Furuno Narandulam Usukhbayar Ken-ichi Kimura Yoshihito Shiono 《Tetrahedron letters》2017,58(43):4082-4086
Two sesquiterpene-epoxycyclohexenone conjugates, nectrianolins A (1) and B (2), together with a sesquiterpene, nectrianolin C (3), were isolated from the brown rice culture of Nectria pseudotrichia 120-1NP, an endophytic fungus isolated from Gliricidia sepium. Their structures were determined on the basis of 1D-/2D-NMR spectroscopy and HRESIMS data analyses in combination with chemical means. Nectrianolins A–C (1–3) exhibited cytotoxic activity against both HL60 and HeLa cells. 相似文献
94.
95.
Summary: Propylene polymerization was conducted at 0 °C in heptane or chlorobenzene (CB) by an ansa‐fluorenylamidodimethyltitanium complex combined with dried, modified methylaluminoxane that had been treated by dilution with heptane and successively repeatedly vacuum dried to remove any free trialkylaluminiums. The post‐polymerizations testified that the living polymerization proceeded irrespective of the solvent used. The heptane system gave the syndiotactic poly(propylene)s (PPs), whereas the CB system gave almost atactic PPs. After the first polymerization in heptane had been completed, the same amounts of propylene and CB were added for the second polymerization. This procedure gave the syndiotactic‐atactic stereoblock PP with narrow molecular‐weight distributions.
96.
A completely aspecific catalyst was prepared by supporting TiCl3 on MgCl2. The catalyst isospecificity could be drastically converted from aspecific into isospecific either by adding ethyl benzoate or by changing the cocatalyst from Al(C2H5)3 to Cp2Ti(CH3)2. On the other hand, the catalyst system composed of SiO2-supported CpTiCl3 and methylaluminoxane (MAO) gave atactic polypropylene as well as a random copolymer of ethylene and propylene with frequent chemical inversion of propylene units. It was also found that the CpTiCl3/SiO2-MAO catalyst system can afford poly(ethylene-co-1-hexadecene) containing a large amount of 1-hexadecene. The mechanisms of stereochemical control(isospecificity and regiospecificity) are discussed from these results. 相似文献
97.
Yuushou Nakayama Masaya Tanimoto Takeshi Shiono 《Macromolecular rapid communications》2007,28(5):646-650
A series of pentavalent tantalum and niobium complexes with aryloxy ligands was prepared, and their catalytic behavior for the ROMP of norbornene was studied in the presence of an alkylaluminum cocatalyst. Tantalum complexes 1 – 4 showed very high activity for the ROMP of NBE in combination with iBu3Al to give high‐molecular‐weight polymers. In contrast, the niobium complexes 5 and 6 , as well as NbCl5, exhibited very high activity upon activation with Me3Al to give high‐molecular‐weight polymers.
98.
Hideaki Hagihara Takeshi Shiono Tomiki Ikeda 《Macromolecular rapid communications》1999,20(4):200-202
Propene polymerization was conducted with the [t‐BuNSiMe2Flu]TiMe2/B(C6F5)3 catalyst at –50°C at various concentrations of propene. The polymerization proceeds in a living manner regardless of the propene concentration employed. Molecular weight of polymer obtained in a certain polymerization time with low monomer conversion increases with increasing concentration of propene. The logarithmic plot of molecular weight against propene concentration gives a straight line with a slope of 1.8, which indicates that the propagation rate is almost of second order with respect to propene concentration. 相似文献
99.
Jizhu Jin Toshiya Uozumi Tsuneji Sano Toshiharu Teranishi Kazuo Soga Takeshi Shiono 《Macromolecular rapid communications》1998,19(7):337-339
The copolymerization of ethylene and propene was conducted at −40°C with the [ethylene(1-indenyl)(9-fluorenyl)]zirconium dichloride-methylaluminoxane catalyst system, and the microstructure of the resulting copolymers was analyzed in detail by 13C NMR. The content of alternating [EP] sequences increased markedly with an increase in the feed ratio of propene to ethylene. A poly(ethylene-co-propene) with a proportion of [EP] sequences over 95% was thus obtained under appropriate copolymerization conditions. It was also demonstrated that the alternating ethylene-propene copolymer is stereoregular and isotactic. 相似文献
100.