CN-122011345-A - Biodegradable polyester material and preparation method thereof

CN122011345ACN 122011345 ACN122011345 ACN 122011345ACN-122011345-A

Abstract

The invention relates to the technical field of biomedical materials, in particular to a biodegradable polyester material and a preparation method thereof, and the preparation method of the biodegradable polyester material comprises the following steps of carrying out bulk polymerization reaction on a monomer, an initiator and a tin catalyst to obtain a crude product; dissolving the crude product in a first organic solvent to obtain a crude product solution, adding pretreated iminodiacetic acid type chelating resin into the crude product solution for adsorption, wherein the total exchange capacity of the iminodiacetic acid type chelating resin is more than or equal to 1.95mmol/g, and the dosage of the pretreated iminodiacetic acid type chelating resin is 5-15% of the mass of the crude product. The preparation method of the biodegradable polyester material provided by the invention can stably obtain the high-quality polyester material with high molecular weight, narrow molecular weight distribution and extremely low tin catalyst residue while ensuring high-efficiency production.

Inventors

PAN LONG
WANG YUBO
LI YAN
ZHANG CHEN
ZHANG WANYU

Assignees

天津普立美特科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (10)

1. A method for preparing a biodegradable polyester material, which is characterized by comprising the following steps: carrying out bulk polymerization reaction on a monomer, an initiator and a tin catalyst to obtain a crude product; Dissolving the crude product in a first organic solvent to obtain a crude product solution, adding pretreated iminodiacetic acid type chelating resin into the crude product solution for adsorption, wherein the total exchange capacity of the iminodiacetic acid type chelating resin is more than or equal to 1.95mmol/g of chelating copper; Wherein the amount of the pretreated iminodiacetic acid type chelating resin is 5-15% of the mass of the crude product.
2. The method for preparing biodegradable polyester material according to claim 1, characterized in that the pretreatment method comprises reflux-extracting the iminodiacetic acid type chelate resin with a second organic solvent as an extraction solvent at 70-90 ℃ for 12-36h, and with a third organic solvent as an extraction solvent at 70-80 ℃ for 12-36h; preferably, the second organic solvent is selected from one or more of methanol, ethanol and isopropanol, and the third organic solvent is selected from tetrahydrofuran and/or acetone.
3. The preparation method of the biodegradable polyester material according to claim 1 or 2, wherein the skeleton of the iminodiacetic acid type chelating resin is a styrene-divinylbenzene skeleton, the iminodiacetic acid type chelating resin comprises 40-50% by mass of iminodiacetic acid groups, the total volume exchange capacity of the iminodiacetic acid type chelating resin is more than or equal to 0.60 mmol/ml, the water content is 50-60%, the wet apparent density is 0.70-0.80g/ml, the wet true density is 1.15-1.25g/ml, the particle size is 0.4-1.25mm, the proportion is more than or equal to 95%, and the uniformity coefficient is less than or equal to 1.6.
4. A process for the preparation of biodegradable polyester material according to any one of claims 1 to 3, characterized in that said adsorption is carried out at a temperature of 20 to 30 ℃ for a time of 3 to 5 hours and at a stirring speed of 100 to 300rpm.
5. The method for producing a biodegradable polyester material according to any one of claims 1 to 4, characterized in that said first organic solvent is selected from one or more of methylene chloride, chloroform and tetrahydrofuran, and that the mass volume percentage of said crude product in said crude product solution is 10 to 20%.
6. The method for producing a biodegradable polyester material according to any one of claims 1 to 5, characterized in that the tin catalyst is added in an amount of 0.01 to 0.05% by mass of the monomer; Preferably, the tin catalyst is selected from one or more of stannous octoate, tri-n-butyl methoxy tin and dioctyl tin dilaurate; And/or the addition amount of the initiator is 0.1-1% of the mass of the monomer, preferably the initiator is one or more selected from dodecanol, 1-butanol and glycollic acid; And/or the monomer is selected from one or more of D, L-lactide, caprolactone, glycolide, and L-lactide.
7. The method for producing a biodegradable polyester material according to any one of claims 1 to 6, characterized in that said bulk polymerization reaction temperature is 120 to 180 ℃ for a period of 6 to 10 hours.
8. The method for producing a biodegradable polyester material according to any one of claims 1 to 7, characterized by further comprising the steps of separating the chelate resin after the completion of the adsorption, and extracting the biodegradable polyester material from the filtrate with a poor solvent; preferably, the poor solvent is selected from one or more of ethanol, methanol, n-heptane and methyl tertiary butyl ether, and the volume of the poor solvent is 5-15 times of that of the filtrate.
9. A biodegradable polyester material prepared by the method of any one of claims 1 to 8.
10. The biodegradable polyester material according to claim 9, characterized in that the residual tin content of the biodegradable polyester material is <20ppm, the weight average molecular weight of the biodegradable polyester material is 200-500kDa, and the molecular weight distribution PDI of the biodegradable polyester material is not more than 1.8.

Description

Biodegradable polyester material and preparation method thereof Technical Field The invention relates to the technical field of biomedical materials, in particular to a biodegradable polyester material and a preparation method thereof. Background Biodegradable polyester materials, such as polylactic acid (PLA), polycaprolactone (PCL), polylactic acid-glycolic acid copolymer (PLGA) and copolymers thereof, have been widely used in biomedical fields such as surgical sutures, orthopedic fixation materials, drug sustained release carriers, etc., due to their excellent biocompatibility and in vivo degradable absorption characteristics. Currently, stannous octoate (Sn (Oct) 2) is commonly used in industry as a catalyst to synthesize such polyester materials. Stannous octoate acts as a heavy metal catalyst and the residual tin element in the final product must be tightly controlled. For medical implant grade applications in particular, industry standards generally require that the residual tin element must be below 150 ppm or even lower. In conventional work-up processes, the polymer is generally purified by precipitation in a poor solvent (e.g., methanol, ethanol or water) after dissolution of the polymerization product. Although this method is effective in removing unreacted monomers and oligomers, it is extremely poor in removing tin catalyst residues in the form of chemical bonds or physical entrapment. In order to meet the stringent requirements of the final product for tin residues, the prior art is generally forced to resort to a source-controlled compromise strategy in which the amount of catalyst added is severely limited during the initial stages of the polymerization reaction (e.g., the catalyst to monomer mass ratio is typically controlled to a level of 1/10000 or less). Although the strategy can control the final tin content to a certain extent, a series of serious technical defects are brought to the polymerization process per se, namely (1) the reaction rate is slow, the extremely low catalyst concentration leads to the great extension of the polymerization reaction time, and the problems of low production efficiency, increased energy consumption and high production cost are directly caused. (2) The molecular weight is difficult to increase, the effective concentration of active centers in a polymerization system is difficult to maintain due to the too low concentration of the catalyst, the polymer chain is difficult to grow, and the required high molecular weight (for example, the weight average molecular weight Mw is more than 20 ten thousand) product is difficult to stably obtain, so that the mechanical property and the application range of the material are limited. (3) The molecular weight distribution is broad-at low catalyst concentrations, the competition of side reactions with the main reactions, which are caused by thermal effects or impurities in the system, is exacerbated, which leads to a broadening of the molecular weight distribution of the final polymer product (i.e. an increase in the polydispersity index PDI value). The broad molecular weight distribution affects the batch stability of the mechanical properties of the material and the uniformity and predictability of degradation rates. Thus, the prior art has a contradiction between efficient production of high quality biodegradable polyesters and control of catalyst residues in the final product, which is difficult to reconcile. The field needs a new technical scheme for effectively removing tin residues in the final product while realizing efficient polymerization reaction, so as to prepare the high-performance polyester material meeting medical implantation standards. Disclosure of Invention The invention provides a biodegradable polyester material and a preparation method thereof, which are used for solving the problem that the high polymerization efficiency and the high purity of a final product (namely, low catalyst tin residue) are difficult to be simultaneously achieved when medical grade biodegradable polyester is prepared in the prior art, and realizing that the high-performance medical grade polyester material with three excellent characteristics of high molecular weight, narrow molecular weight distribution and ultra-low tin residue (< 20 ppm) is stably obtained while the polymerization rate is greatly improved and the production period is shortened. According to a first aspect of the present invention, there is provided a method of preparing a biodegradable polyester material, comprising the steps of: carrying out bulk polymerization reaction on a monomer, an initiator and a tin catalyst to obtain a crude product; Dissolving the crude product in a first organic solvent to obtain a crude product solution, adding pretreated iminodiacetic acid type chelating resin into the crude product solution for adsorption, wherein the total exchange capacity of the iminodiacetic acid type chelating resin is more than or equal to 1.95mm