摘要:
The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 μm in length. The carbon nanotube agglomerates, ranged between 1˜1000 μm, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20˜800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.
摘要:
The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 μm in length. The carbon nanotube agglomerates, ranged between 1˜1000 μm, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20-800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.
摘要:
A catalyst for homopolymerizing and copolymerizing propylene and its preparation and use. The catalyst component includes titanium compound containing at least one Ti-halogen bond and at least two kinds of electron donor compounds A and B supported on MgCl2.nROH adduct, wherein the electron donor compound A is a compound of formula (I), the electron donor compound B is ester or ether compound; the molar ratio between compound A and compound B is 0.1-5; the molar ratio between the total amounts of the two kinds of electron donors and MgCl2.nROH is 0.01-1, based on the amount of MgCl2.nROH; and the molar ration between the titanium compound containing Ti-halogen bond and MgCl2.nROH is 1-200. The catalyst has high activity, high stereospecificity and good copolymerization performance. In addition, the morphology of the polymer obtained therefrom is good.
摘要:
Disclosed is a catalyst for the polymerization of olefins comprising thienyl-substituted silanes, which comprises a solid titanium catalyst component containing titanium, magnesium and a halogen as the main components, an alkylaluminum compound, and a component of organosiloxane compound comprising two thienyl as substituents represented by general formula (I). The molar ratio of each catalyst component is 1:50-150:5-50 based on titanium:aluminum:silicon. When the catalyst is used in the polymerization of propylene, the polymerisate obtained has a very high degree of isotacticity, and the yield is high.
摘要:
An olefin polymerization catalyst and preparation method and use thereof are provided. The components of the catalyst comprise an active magnesium halide, a titanium compound containing at least one Ti-halide bond loaded on the active magnesium halide, and an internal electron donor selected from one or more silicon esters compounds having formula (I). The method for preparing the catalyst components is that: adding spherical magnesium chloride alcoholate particles and the electron donor into the solution of titanium compound in sequence, and processing with the titanium compound for one or more times to obtain the catalyst. The catalyst system used for the olefin polymerization comprises the catalyst components, a cocatalyst and an external electron donor. The catalyst has high activity for the propylene polymerization, and the activity is 4399 gPP/gTi·h(50° C., 1 h, slurry polymerization at atmospheric pressure), and the isotacticity of the polymer is 98%.
摘要:
An olefin polymerization catalyst and preparation method and use thereof are provided. The components of the catalyst comprise an active magnesium halide, a titanium compound containing at least one Ti-halide bond loaded on the active magnesium halide, and an internal electron donor selected from one or more silicon esters compounds having formula (I). The method for preparing the catalyst components is that: adding spherical magnesium chloride alcoholate particles and the electron donor into the solution of titanium compound in sequence, and processing with the titanium compound for one or more times to obtain the catalyst. The catalyst system used for the olefin polymerization comprises the catalyst components, a cocatalyst and an external electron donor. The catalyst has high activity for the propylene polymerization, and the activity is 4399 gPP/gTi·h(50° C., 1 h, slurry polymerization at atmospheric pressure), and the isotacticity of the polymer is 98%.
摘要:
Disclosed is a catalyst for the polymerization of olefins comprising thienyl-substituted silanes, which comprises a solid titanium catalyst component containing titanium, magnesium and a halogen as the main components, an alkylaluminum compound, and a component of organosiloxane compound comprising two thienyl as substituents represented by general formula (I). The molar ratio of each catalyst component is 1:50-150:5-50 based on titanium:aluminum:silicon. When the catalyst is used in the polymerization of propylene, the polymerisate obtained has very high degree of isotacticity, and the yield is high.
摘要:
A catalyst for homopolymerizing and copolymerizing propylene and its preparation and use. The catalyst component includes titanium compound containing at least one Ti-halogen bond and at least two kinds of electron donor compounds A and B supported on MgCl2.nROH adduct, wherein the electron donor compound A is a compound of formula (I), the electron donor compound B is ester or ether compound; the molar ratio between compound A and compound B is 0.1-5; the molar ratio between the total amounts of the two kinds of electron donors and MgCl2.nROH is 0.01-1, based on the amount of MgCl2.nROH; and the molar ration between the titanium compound containing Ti-halogen bond and MgCl2.nROH is 1-200. The catalyst has high activity, high stereospecificity and good copolymerization performance. In addition, the morphology of the polymer obtained therefrom is good.