A method of manufacturing acetylhyaluronate comprises the steps of suspending hyaluronic acid powder in an acetic anhydride solvent and then adding concentrated sulfuric acid thereto to effect acetylation. A method of purifying acetylhyaluronate comprises the steps of adding raw acetylhyaluronate to an ...
The invention discloses a preparation method of low-molecular-weight acetyl-terminated allyl alcohol polyether. The method comprises the steps of using low molecular weight allyl alcohol polyether and acetic anhydride as the raw materials, carrying out esterification, bubbling deacidification, hydrolysis ...
This method estimates the molecular weight of a polymer by measuring its effect on solvent vapor pressure. The decrease in the vapor pressure of a polymer in a solvent varies depending on how much it dissolves the solvent vapor, and the molecular weight of the polymer can be calculated from t...
molecular weightpermeabilitypolymer filmspolymer structurepolymerisationtensile strengthX-ray diffraction/ biopolymer filmsAn increase in the depolymerization of chitosan was found with an increased concentration of sodium perborate. Acetic anhydride was added to reacetylated chitosan in a molar ratio per gul...
respectively.Results Chitosans with the molecular weight of 5×105 g/mol,1×106 g/mol and DA of 95% can promote the survival and outgrowth of cells,and they have better hydrophilicity and can keep integrity even after 8 to 16 weeks.All of the above meet the requirement of tissue ...
Not only are low molecular weight amines abundantly distributed in nature, but numerous drugs, synthetic probes and other molecules of interest also contain amino groups. The sensitive detection, identification and quantitation of amines...
A: Powder 5Tablets,mix with 20mLof water,and filter:the filtrate responds to the tests for Potassium á191ñ. B: Aportion of powdered Tablets containing about 50mg of potassium citrate responds to the test for Citrate á191ñ,20mLof the mixture of pyridine and acetic anhydride being used...
methylated aldiol acetates (PMAA25) after 2 h hydrolysis with 2 M (v/v) TFA at 121 °C, overnight reduction with NaBD4and acetylation with acetic anhydride and pyridine. GLC-MS analysis was performed on an HP-5890 GC interfaced to a mass selective detector 5970 MSD using a ...
The molecular weight distribution of polytetrahydrofuran and of copolymers of tetrahydrofuran and alkylene oxides are narrowed by a process in which low molecular weight fractions are distilled off fr
A method of efficiently removing a low molecular weight substance from a polyimide precursor or polyimide in which the low molecular weight substance is dispersed as micro-domains, without using a lar