The present invention is directed to composite nanoparticles comprising a metal, a rare earth element, and, optionally, a complexing ligand. The invention is also directed to composite nanoparticles having a core-shell structure and to processes for preparation of composite nanoparticles of the invention.

The present invention discloses an ultra-low shrinkage polyester industrial yarn and its preparation method. The ultra-low shrinkage polyester industrial yarn is prepared by subjecting a polyester to dissolution, washing and solid state polycondensation followed by spinning. The ultra-low shrinkage polyester industrial yarn has a dry heat shrinkage rate of 1.80.25% under test conditions of 177 C.10 min0.05 cN/dtex. The polycondensation catalyst consists of magnesium ethylene glycol and antimony ethylene glycol, has a small thermal degradation coefficient. The present invention reduces oligomers during polymerization, reduces thermal degradation during processing, and as a result the invention greatly reduces impurities and nucleating agent in the polyester, leading to an increase in the probability of homogeneous nucleation based on the reduction of heterogeneous nucleation. The dissolution and washing of polyester further decreases oligomer content, facilitating the growth of the grain size and the optimization of crystal perfection in the ultra-low shrinkage polyester industrial yarn.

The present invention discloses an ultra-low shrinkage polyester industrial yarn and its preparation method. The ultra-low shrinkage polyester industrial yarn is prepared by subjecting a polyester to dissolution, washing and solid state polycondensation followed by spinning. The ultra-low shrinkage polyester industrial yarn has a dry heat shrinkage rate of 1.80.25% under test conditions of 177 C.10 min0.05 cN/dtex. The polycondensation catalyst consists of magnesium ethylene glycol and antimony ethylene glycol, has a small thermal degradation coefficient. The present invention reduces oligomers during polymerization, reduces thermal degradation during processing, and as a result the invention greatly reduces impurities and nucleating agent in the polyester, leading to an increase in the probability of homogeneous nucleation based on the reduction of heterogeneous nucleation. The dissolution and washing of polyester further decreases oligomer content, facilitating the growth of the grain size and the optimization of crystal perfection in the ultra-low shrinkage polyester industrial yarn.

A polyester obtained by the esterification of terephthalic acid and ethylene glycol and the polycondensation catalysed by a mixture of magnesium ethylene glycol and antimony ethylene glycol followed by granulation. In the polyester sections, the carboxyl end group is less than 15 mol/t, the mass percentage of oligomer is lower than 0.5%, and weight percentage of diethylene glycol is lower than 0.5%.

A flame-retardant polyester fiber obtained by spinning flame-retardant polyester and irradiating with ultraviolet light and having a limiting oxygen index value of greater than 30. Flame retardant 2-carboxyethylphenylphosphinic acid to improve the flame retardant properties of polyester, the use of polyester containing unsaturated double bond in UV irradiation, the double bond opens to form a crosslinking point, the formation of a certain amount of the network structure improves the heat-resistant temperature of the poly-fiber and improves the anti-dripping performance of the polyester fiber.

The present invention is directed to composite nanoparticles comprising a metal, a rare earth element, and, optionally, a complexing ligand. The invention is also directed to composite nanoparticles having a core-shell structure and to processes for preparation of composite nanoparticles of the invention.

A method for creating a metal-carbon composite. In one embodiment, the method includes the steps of providing a polymer Schiff base transition metal film precursor having a chemical structure of the formula [M(Schiff)].sub.n and a recurring unit and a transition metal selected from the group consisting of nickel, palladium, platinum, cobalt, copper, iron; Schiff is a tetradentate Schiff base ligand selected from the group consisting of Salen (residue of bis(salicylaldehyde)-ethylenediamine), Saltmen (residue of bis(salicylaldehyde)-tetramethylethylenediamine, Salphen (residue of bis-(salicylaldehyde)-o-phenylenediamine), a substituent in a Schiff base is selected from the group consisting of H, and carbon-containing substituents, preferably CH.sub.3, C.sub.2H.sub.5, CH.sub.3O, C.sub.2H.sub.5O, and Y is a bridge in a Schiff base depositing the polymer Schiff base transition metal precursor film onto a support substrate; and heating the polymer Schiff base transition metal precursor film and support substrate in a furnace in an inert atmosphere.