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21.
Effects of coupling agents on mechanical and morphological behavior of the PP/HDPE blend with two different CaCO3 总被引:1,自引:0,他引:1
《European Polymer Journal》2002,38(12):2465-2475
The main purpose of incorporating fillers, such as calcium carbonate, into blends of polyolefins is to decrease costs and change tensile and impact properties. Structural differences between both components give rise to the formation of large filler agglomerates in the polymer matrix, which influence the mechanical response of the material. Therefore, the coupling agents of the Lica 12 type at various concentrations was used to facilitate the link between filler and matrix (the latter consisting of PP/HDPE 80/20 wt). Filler was added to the PP/HDPE blend at a 30 wt.% concentration. Two types of calcium carbonate (CaCO3) were used. These have different average sizes (3.0 and 1.8 μm) which were determined by means of laser diffraction techniques. In addition other coupling agents of the titanate type, such as Lica 09, Lica 01, zirconates ZN 12, and a 1:1 mixture of Lica 12 and Lica 01, were used. This study clearly demonstrated that the addition of the coupling agent to CaCO3 modifies the mechanical properties of the PP/HDPE/CaCO3 composites. Values of the mechanical properties indicate that due to its characteristics, each coupling agent gives rise to increases in a particular mechanical property. In the case of Lica 01 an increase was verified in Young’s modulus at 0.7 wt.% and in elongation at break at both concentrations (0.3 and 0.7 wt.%), whereas ZN 12 brought about an increase in elongation at break. The 1:1 mixture of Lica 12 and Lica 01 caused impact resistance of the blend of PP/HDPE with CaCO3 to increase considerably. 相似文献
22.
The benzamide-derived P,O-ligands efficiently promoted the Pd-catalyzed Suzuki cross-coupling reactions of aryl bromides with phenylboronic acid at 0.01 mol % of Pd loading at 60-80 °C to form biaryls in excellent yields. A sterically hindered arylboronic acid gave a quantitative yield of the coupling product at 110 °C with 1 mol % Pd. 相似文献
23.
Masahiro Yoshida 《Tetrahedron letters》2004,45(29):5573-5575
The direct coupling of propargylic alcohols with arylboronic acids has been achieved using palladium catalyst. Various propargylic alcohols and arylboronic acids can be coupled to afford the corresponding allenic and propargylic arenes, which are selectively produced depending on the substituent on the propargylic alcohol, respectively. 相似文献
24.
Kamaladin Gharanjig Mokhtar Arami Shohre Rouhani Hajir Bahrami Barahman Movassagh Niyaz Mohammad Mahmoodi 《中国化学会会志》2007,54(4):1021-1028
Five novel monoazo disperse dyestuffs based on N‐ester‐1,8‐naphthalimide were synthesized. Acenaphthene was nitrated, then oxidized to 4‐nitro‐1,8‐naphthalic anhydride. 4‐Nitro‐1,8‐naphthalic anhydride was reacted with methyl and ethyl glycinate in alcoholic media, followed with reduction. 4‐Amino‐N‐methyl and ethyl glycinate‐1,8‐naphthalimide were obtained. These products were diazotized and coupled with appropriate aromatic amines to give bluish‐red or violet dyestuffs. All intermediates and dyestuffs were purified and characterized by 1H‐NMR, FTIR, DSC, UV‐VIS and Elemental Analysis. Dispersion of dyestuffs was prepared in water and applied to polyester fabrics. The dyed fabrics showed that four of the synthesized dyestuffs were suitable for coloring polyester fibers, producing deep bluish red with very good build up properties. 相似文献
25.
S. L. Prunty 《International Journal of Infrared and Millimeter Waves》1985,6(6):471-479
This paper presents a simple theory based on the diffraction integral approach for calculating the coupling efficiency in waveguide lasers which employ plane or spherical mirrors. The results obtained differ only slightly from a full rigorous approach, due to the fact that only less than one percent of the beam energy lies outside the waveguide aperture. The infinite aperture approximation employed here leads to an explicit compact formula for the coupling efficiency, whereas exact calculations lead to expressions requiring numerical integration for their evaluation. 相似文献
26.
《Tetrahedron》2004,60(3):529-534
Cyclodextrin glucosyltransferase (CGTase) from Thermoanaerobacter sp. was covalently immobilized on Eupergit C and used for the synthesis of maltooligosyl fructofuranosides employing soluble starch as donor and sucrose as acceptor. Using a weight ratio starch-sucrose of 1:2, the conversion of starch into acceptor products catalyzed by soluble and immobilized CGTases was higher than 80% in 48 h. Under these conditions, the reaction was selective for the formation of maltosyl fructofuranoside. 相似文献
27.
Copper-catalyzed N-arylation of diazoles can be accomplished using air-stable CuI as a copper source and 1,10-phenanthroline in the presence of KF/Al2O3 as a base. This is a simple and efficient method for the coupling of aryl bromide with diazoles. Different functionalized aryl bromides were coupled with diazoles using this system. 相似文献
28.
María Fernanda Martínez-Esperón 《Tetrahedron》2006,62(16):3843-3855
N,N′-aryl- and N,N′-alkyl-buta-1,3-diyne-1,4-ditosylamides have been synthesized for the first time, in good to excellent yields, by copper-catalyzed dimerization of the corresponding N-aryl or N-alkyl tosylynamides. Negishi coupling of N-ethynylzinc tosylamides derivatives with (hetero)aryl iodides in the presence of Pd2dba3 and triphenylphosphine affords N-aryl and N-alkyl arylynamides in yields of up to 90%. Intramolecular [4+2] cycloaddition reactions of N-ethynylphenyl ynamides and arylynamides allow the synthesis of carbazoles and benzannulated and heteroannulated carbazoles in moderate-to-good yields. 相似文献
29.
Mecheril V. Nandakumar 《Tetrahedron》2005,61(41):9775-9782
A Pd2dba3/P(i-BuNCH2CH2)3N catalyzed one-pot synthesis of unsymmetrically substituted trans-4-N,N-diarylaminostilbenes and both symmetrically and unsymmetrically substituted N,N-diarylaminostyrene derivatives is reported. The procedure involves two or more palladium catalyzed sequential coupling reactions (an amination and an inter-molecular Heck reaction) in one-pot using the same catalyst system with two different aryl halides, including aryl chlorides and hetero aryl halides as the coupling partners. 相似文献
30.
Alessandro Ferrali 《Tetrahedron letters》2004,45(27):5271-5274
A δ-valerolactam-derived vinyl triflate has been converted into the corresponding vinyl boronate by Pd-catalyzed coupling with bis(pinacolato)diboron, which results in an umpolung. This boronate efficiently couples under Pd catalysis with aryl and heteroaryl bromides to give the corresponding 2-substituted piperidines in excellent yields. 相似文献