The present invention relates to a method for preparing a catalyst, and in particular provides a method for preparing a catalyst suitable for the polymerisation of ethylene and/or propylene, said catalyst comprising a compound of yttrium, neodymium or scandium supported on a silica support, and wherein the method comprises: a) Treating a silica support by heating at a temperature of at least 550° C., b) Contacting the treated silica support with a complex of the following formula: D.sub.mMX.sup.1X.sup.2R wherein M is selected from Y, Sc and Nd, R is a hydrocarbyl group, X.sup.1 and X.sup.2 are anionic groups, D is a neutral donor group, and m is 0 or greater.

Method for the preparation of dried polymer pellets in a facility having a dryer with a first chamber and a mechanical agitator, and the facility further having a degassing silo with a second chamber, the method includes the steps of guiding a drying gas flow made from or containing a first gas mixture for drying wet polymer pellets into the first chamber, transferring the dried polymer pellets into the second chamber, guiding a second gas mixture for degassing the dried polymer pellets into the second chamber thereby transforming the second gas mixture into a third gas mixture and guiding a portion of the third gas mixture into the first chamber; and process for manufacturing LDPE pellets.

Method for the preparation of dried polymer pellets in a facility having a dryer with a first chamber and a mechanical agitator, and the facility further having a degassing silo with a second chamber, the method includes the steps of guiding a drying gas flow made from or containing a first gas mixture for drying wet polymer pellets into the first chamber, transferring the dried polymer pellets into the second chamber, guiding a second gas mixture for degassing the dried polymer pellets into the second chamber thereby transforming the second gas mixture into a third gas mixture and guiding a portion of the third gas mixture into the first chamber; and process for manufacturing LDPE pellets.

The present invention provides a class of halogen-containing synthetic base oils, and preparation method and use thereof. The synthetic base oils have introduced with halogen, especially fluorine, wherein the dipole motion of the halogen groups results in dipole interaction between the dipoles of other components and the base oil molecules of dipole-dipole and dipole-induced halogen (especially fluorine), and the interaction force is stronger and more localized than the dispersion force between the molecules of pure hydrocarbon synthetic oils, and thus the performance of the base oils is directly affected. It solved the problem of oil solubility of pure hydrocarbon synthetic oils, and also improved the properties of oxidation resistance and thermal stability.

The present invention provides a class of halogen-containing synthetic base oils, and preparation method and use thereof. The synthetic base oils have introduced with halogen, especially fluorine, wherein the dipole motion of the halogen groups results in dipole interaction between the dipoles of other components and the base oil molecules of dipole-dipole and dipole-induced halogen (especially fluorine), and the interaction force is stronger and more localized than the dispersion force between the molecules of pure hydrocarbon synthetic oils, and thus the performance of the base oils is directly affected. It solved the problem of oil solubility of pure hydrocarbon synthetic oils, and also improved the properties of oxidation resistance and thermal stability.

Disclosed herein are methods for removing acetylene from an ethylene gas stream wherein a catalyst reacts with the acetylene to polymerize said acetylene forming an ethylene gas stream substantially free of acetylene.

Disclosed herein are methods for removing acetylene from an ethylene gas stream wherein a catalyst reacts with the acetylene to polymerize said acetylene forming an ethylene gas stream substantially free of acetylene.

The present disclosure provides a composition. In an embodiment, the composition is an ethylene-based polymer composition formed by high pressure (greater or equal to 100 MPa) free radical polymerization. The ethylene-based polymer composition includes ethylene monomer and a mixture of hydroxyl-terminated polybutadiene molecules (PB-OH). Each PB-OH molecule includes internal alkene groups and terminal alkene groups. Each PB-OH molecule has more internal alkene groups than terminal alkene groups.

The present disclosure provides a composition. In an embodiment, the composition is an ethylene-based polymer composition formed by high pressure (greater or equal to 100 MPa) free radical polymerization. The ethylene-based polymer composition includes ethylene monomer and a mixture of hydroxyl-terminated polybutadiene molecules (PB-OH). Each PB-OH molecule includes internal alkene groups and terminal alkene groups. Each PB-OH molecule has more internal alkene groups than terminal alkene groups.

The present disclosure relates to a polyethylene composition capable of producing a molded product having excellent environmental stress crack resistance, and improving total volatile organic compound (TVOC) properties that can be generated by a low molecular weight polymer, and a method for preparing the same.