The present invention relates to an amphiphilic block copolymer represented by formula I, a preparation method thereof, and a nanomicelle drug delivery system formed from the copolymer and a poorly soluble drug. The amphiphilic block copolymer includes a hydrophilic chain segment, a hydrophobic chain segment, and a linker for linking the hydrophilic chain segment to the hydrophobic chain segment. The linker contains an unsaturated structure, which can enhance the interaction between the poorly soluble drug and the copolymer to improve the drug loading ability and stability of the nanomicelle. The invention also relates to a nanomicelle drug-loading system, a preparation method thereof, and the use of the nanomicelle drug-loading system for preparing medicines for treating tumors, inflammation, diabetes, central nervous system diseases, cardiovascular diseases, and psychological disorders.

##STR00001##

The present invention relates to an amphiphilic block copolymer represented by formula I, a preparation method thereof, and a nanomicelle drug delivery system formed from the copolymer and a poorly soluble drug. The amphiphilic block copolymer includes a hydrophilic chain segment, a hydrophobic chain segment, and a linker for linking the hydrophilic chain segment to the hydrophobic chain segment. The linker contains an unsaturated structure, which can enhance the interaction between the poorly soluble drug and the copolymer to improve the drug loading ability and stability of the nanomicelle. The invention also relates to a nanomicelle drug-loading system, a preparation method thereof, and the use of the nanomicelle drug-loading system for preparing medicines for treating tumors, inflammation, diabetes, central nervous system diseases, cardiovascular diseases, and psychological disorders.

##STR00001##

A catalyst for use in esterification reaction is provided. The catalyst is formed by reacting a mixture including at least one first compound and at least one second compound. The at least one first compound is a metal alkoxide, an inorganic metal salt, a metal carboxylate salt, an inorganic metal compound, or a combination thereof, and each foregoing compound has titanium, aluminum, zirconium, hafnium, zinc, or bismuth. The at least one second compound is an alpha hydroxyl acid, an alkyl ester formed by an alpha hydroxyl acid and an alcohol, an alkyl amide formed by an alpha hydroxyl acid and an amine, an amino acid, an alkyl ester formed by an amino acid and an alcohol, an alkyl amide formed by an amino acid and an amine, or a combination thereof.

The invention relates to the cold curing and warm curing of unsaturated polyester resins, such as polyester resins and methyl methacrylate resins using mercaptans as reaction accelerators.

The invention relates to the cold curing and warm curing of unsaturated polyester resins, such as polyester resins and methyl methacrylate resins using mercaptans as reaction accelerators.

A polyethylene terephthalate resin composition which is characterized by having a manganese element content of 30 to 60 ppm, a potassium element content of 2 to 10 ppm, an antimony element content of 70 to 150 ppm, a molar ratio of metal elements to phosphorus element (M/P=(M1+M2/2)/P) satisfying formula (1), and a gelation ratio of 5% by weight or less:
0.6(M1+M2/2)/P1.3(1)
wherein M1 represents the content (mol/t) of a bivalent metal element selected from the group consisting of Mg, Mn, and Ca; M2 represents the content (mol/t) of a monovalent metal element selected from the group consisting of Li, Na, and K; and P represents the content (mol/t) of phosphorus element.

A polyethylene terephthalate resin composition which is characterized by having a manganese element content of 30 to 60 ppm, a potassium element content of 2 to 10 ppm, an antimony element content of 70 to 150 ppm, a molar ratio of metal elements to phosphorus element (M/P=(M1+M2/2)/P) satisfying formula (1), and a gelation ratio of 5% by weight or less:
0.6(M1+M2/2)/P1.3(1)
wherein M1 represents the content (mol/t) of a bivalent metal element selected from the group consisting of Mg, Mn, and Ca; M2 represents the content (mol/t) of a monovalent metal element selected from the group consisting of Li, Na, and K; and P represents the content (mol/t) of phosphorus element.

This invention relates to catalysts for polyesterol synthesis and the use of a di-thio compound as catalyst for the production of polyester-polyols.

The invention relates to a method for adding a compound (A) to an H-functional starting compound (BH) in the presence of a catalyst, wherein the at least one compound (A) is selected from at least one group consisting of alkylene oxide (A-1), lactone (A-2), lactide (A-3), cyclic acetal (A-4), lactam (A-5), cyclic anhydride (A-6) and oxygen-containing heterocyclic compound (A-7) different from (A-1), (A-2), (A-3), (A-4) and (A-6), wherein the catalyst comprises an organic, n-protic Brnsted acid (C), wherein n2 and is an element of the natural numbers and the degree of protolysis D is 0<D<n, with n as the maximum number of transferable protons and D as the calculated proton fraction of the organic, n-protic Brnsted acid (C). The invention further relates to an n-protic Brnsted acid (C) having a degree of protolysis D of 0<D<n, wherein n is the maximum number of transferable protons, with n=2, 3 or 4, and D is the calculated proton fraction of the organic, n-protic Brnsted acid (C).

The invention relates to a method for adding a compound (A) to an H-functional starting compound (BH) in the presence of a catalyst, wherein the at least one compound (A) is selected from at least one group consisting of alkylene oxide (A-1), lactone (A-2), lactide (A-3), cyclic acetal (A-4), lactam (A-5), cyclic anhydride (A-6) and oxygen-containing heterocyclic compound (A-7) different from (A-1), (A-2), (A-3), (A-4) and (A-6), wherein the catalyst comprises an organic, n-protic Brnsted acid (C), wherein n2 and is an element of the natural numbers and the degree of protolysis D is 0<D<n, with n as the maximum number of transferable protons and D as the calculated proton fraction of the organic, n-protic Brnsted acid (C). The invention further relates to an n-protic Brnsted acid (C) having a degree of protolysis D of 0<D<n, wherein n is the maximum number of transferable protons, with n=2, 3 or 4, and D is the calculated proton fraction of the organic, n-protic Brnsted acid (C).