Method for preparing polyglycolic acid

Abstract

The invention discloses a method for preparing polyglycolic acid. According to the method, with glycolide serving as a monomer and di-n-butyl magnesium as a catalyst, a molecular weight adjustment agent is added to adjust the characteristic viscosity number of the polyglycolic acid, so as to obtain the polyglycolic acid with proper molecular weight distribution width. The method is low in time consumption and low in energy consumption; the catalyst is a metal magnesium compound, so that toxic metal element residues are avoided; the metal magnesium compound is harmless to a human body; and therefore, the polyglycolic acid can be used as a raw material of a food package material and a medical material.

Description

technical field

[0001] The invention relates to a preparation method of polyglycolic acid, belonging to the technical field of polyglycolic acid preparation. Background technique

[0002] Polyglycolic acid (PGA for short, also known as polyglycolic acid and polyglycolide) is an aliphatic polyester polymer with the least number of unit carbon atoms, a completely decomposable ester structure, and rapid degradation in the natural environment. Material. The special molecular structure of polyglycolic acid endows this material with many excellent properties, such as: excellent gas barrier properties, excellent mechanical properties, excellent biodegradability and good biocompatibility, etc. Therefore, it has broad application prospects in food packaging materials, biomedical materials and other fields. Polyglycolic acid has been known around 1950, but due to the complicated production process, the production cost of high-quality polyglycolic acid is extremely high. In recent y...

Examples

Embodiment 1

[0021] A preparation method of polyglycolic acid, glycolide: lauryl alcohol: di-n-butyl magnesium in a molar ratio of 10000: 1: 2, respectively weighing 40g of glycolide and lauryl alcohol with a purity greater than 99.5%. 0.0064g and 0.0096g of di-n-butylmagnesium were added to the reactor, the reactor was evacuated, and then replaced with nitrogen, the operation of vacuuming and nitrogen replacement was carried out twice, and finally the vacuum was evacuated to make the pressure inside the reactor to 120Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a heating rate of 3°C / min, and finally keep the temperature at 230°C, react for 60 minutes and then discharge the material to produce Get polyglycolic acid.

Embodiment 2

[0023] A preparation method of polyglycolic acid, the glycolide: lauryl alcohol: di-n-butyl magnesium molar ratio is 20000: 3: 2 proportioning, respectively weighing 40g of glycolide and lauryl alcohol with a purity greater than 99.5% Add 0.0096g and 0.0048g of di-n-butylmagnesium into the reactor, vacuumize the reactor, and then replace it with nitrogen, carry out the operations of vacuuming and nitrogen replacement twice, and finally evacuate again to make the pressure inside the reactor to 125Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a rate of 1°C / min, and finally keep the temperature at 230°C, react for 120min and then discharge the material to produce Get polyglycolic acid.

Embodiment 3

[0025] A preparation method of polyglycolic acid, the glycolide: lauryl alcohol: di-n-butyl magnesium molar ratio is 20000: 1: 2 proportioning, respectively weighed 40g of glycolide and lauryl alcohol with a purity greater than 99.5%. Add 0.0032g and 0.0048g of di-n-butylmagnesium into the reactor, vacuumize the reactor, and then replace it with nitrogen, carry out the operations of vacuuming and nitrogen replacement twice, and finally pump the vacuum to make the pressure inside the reactor to 110Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a rate of 2°C / min, and finally keep the temperature at 230°C, react for 80 minutes and then discharge the material to produce Get polyglycolic acid.

technical field

[0001] The invention relates to a preparation method of polyglycolic acid, belonging to the technical field of polyglycolic acid preparation. Background technique

[0002] Polyglycolic acid (PGA for short, also known as polyglycolic acid and polyglycolide) is an aliphatic polyester polymer with the least number of unit carbon atoms, a completely decomposable ester structure, and rapid degradation in the natural environment. Material. The special molecular structure of polyglycolic acid endows this material with many excellent properties, such as: excellent gas barrier properties, excellent mechanical properties, excellent biodegradability and good biocompatibility, etc. Therefore, it has broad application prospects in food packaging materials, biomedical materials and other fields. Polyglycolic acid has been known around 1950, but due to the complicated production process, the production cost of high-quality polyglycolic acid is extremely high. In recent y...

Examples

Embodiment 1

[0021] A preparation method of polyglycolic acid, glycolide: lauryl alcohol: di-n-butyl magnesium in a molar ratio of 10000: 1: 2, respectively weighing 40g of glycolide and lauryl alcohol with a purity greater than 99.5%. 0.0064g and 0.0096g of di-n-butylmagnesium were added to the reactor, the reactor was evacuated, and then replaced with nitrogen, the operation of vacuuming and nitrogen replacement was carried out twice, and finally the vacuum was evacuated to make the pressure inside the reactor to 120Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a heating rate of 3°C / min, and finally keep the temperature at 230°C, react for 60 minutes and then discharge the material to produce Get polyglycolic acid.

Embodiment 2

[0023] A preparation method of polyglycolic acid, the glycolide: lauryl alcohol: di-n-butyl magnesium molar ratio is 20000: 3: 2 proportioning, respectively weighing 40g of glycolide and lauryl alcohol with a purity greater than 99.5% Add 0.0096g and 0.0048g of di-n-butylmagnesium into the reactor, vacuumize the reactor, and then replace it with nitrogen, carry out the operations of vacuuming and nitrogen replacement twice, and finally evacuate again to make the pressure inside the reactor to 125Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a rate of 1°C / min, and finally keep the temperature at 230°C, react for 120min and then discharge the material to produce Get polyglycolic acid.

Embodiment 3

[0025] A preparation method of polyglycolic acid, the glycolide: lauryl alcohol: di-n-butyl magnesium molar ratio is 20000: 1: 2 proportioning, respectively weighed 40g of glycolide and lauryl alcohol with a purity greater than 99.5%. Add 0.0032g and 0.0048g of di-n-butylmagnesium into the reactor, vacuumize the reactor, and then replace it with nitrogen, carry out the operations of vacuuming and nitrogen replacement twice, and finally pump the vacuum to make the pressure inside the reactor to 110Pa, then close the reactor for stirring reaction, firstly heat the temperature of the reactor to 150°C, then raise the temperature at a rate of 2°C / min, and finally keep the temperature at 230°C, react for 80 minutes and then discharge the material to produce Get polyglycolic acid.

Images