Degradable polyesteramide block copolymer and synthesis method thereof

Abstract

The invention belongs to the field of polymer synthetic chemistry, and discloses a method for preparing a degradable polyesteramide block copolymer. The invention provides a method for preparing a degradable polyesteramide block copolymer, which is characterized by comprising the following steps: adding caprolactam monomer, deionized water and a hydrolysis catalyst into a reaction kettle, reacting under the protection of inert gas flow, adding polyester and a polycondensation catalyst into the reaction kettle, and carrying out polycondensation to obtain the degradable polyesteramide block copolymer. The degradable polyesteramide block copolymer is obtained. The polyesteramide block copolymer polymerization method is suitable for industrial production, and has the advantages of simple operation, mild conditions, easy processing, easily available raw materials, stable yield and the like, and the copolymer has good thermodynamic properties, mechanical properties and processability.

Description

Technical Field

[0001] The invention belongs to the field of polymer synthetic chemistry, and particularly relates to a degradable polyester amide block copolymer and a synthesis method thereof. Background Art

[0002] Polyesteramides are a class of polymer materials with a combination of polyester and polyamide structures. Through the synergistic effect of ester and amide bonds, they combine the superior properties of both. The ester groups in their molecular chains impart flexibility and processability, while the amide groups provide high mechanical strength and thermal stability. Compared to single polyesters or polyamides, polyesteramides exhibit a more balanced combination of properties: high chemical resistance, excellent impact resistance, good biocompatibility, and, in some systems, biodegradability. These properties hold great potential for application in engineering plastics, biomedical materials, and environmentally friendly packaging.

[0003] The synthesis of polyesteramides is primarily based on polycondensation reactions, with common methods including melt polycondensation and solution polycondensation. For example, linear polyesteramides can be prepared using adipic acid, ethylene glycol, and hexamethylenediamine as monomers by precisely controlling the molar ratio and reaction conditions. Another approach is ring-opening polymerization, such as the copolymerization of ε-caprolactone and caprolactam, which achieves controlled polymerization under the action of a catalyst. In recent years, green synthesis technologies such as enzyme catalysis have also been explored to reduce energy consumption and improve product selectivity. Different methods affect the molecular weight distribution and segment sequence, which in turn determine the material properties. For example, melt polycondensation easily produces high molecular weight products, while enzyme methods are more suitable for functional modification.

[0004] Polyester amides can be divided into two categories: random copolymers and block copolymers, and their structural differences lead to differentiated performance. In random copolymers, ester and amide units are randomly distributed, the molecular chain is highly disordered, and the mechanical strength and thermal stability are limited. Block copolymers can better maintain the physical and chemical properties of the two blocks, can achieve mutual solubility at the molecular level, and can be used to adjust photovoltaic, electrical and optical applications. However, the synthesis of block copolymers requires precise control of monomer sequence and degree of polymerization, and the difference in the reactivity of ester and amide monomers often leads to uneven distribution of chain segments, which makes the synthesis of block copolymers a serious challenge. This patent prepares polyester amide block copolymers through a two-step method, which has the advantages of simple operation, mild conditions, and stable yield, and this type of copolymer has good thermodynamic properties, mechanical properties and good processability. Summary of the Invention

[0005] Purpose of the invention: The problem to be solved by the present invention is to provide a degradable polyester amide block copolymer and a synthesis method thereof in view of the shortcomings of existing polyester amides.

[0006] In order to solve the above problems, the present invention designs a degradable polyester amide block copolymer and a synthesis method thereof, the general formula of which is shown in Formula I:

[0007]

[0008] wherein R is selected from poly(ε-caprolactone), poly(δ-valerolactone) and poly(L-lactide);

[0009] Wherein, n and m are independently selected from any integer between 10 and 500;

[0010] According to the degradable polyester amide block copolymer, it is characterized in that the copolymer is any one of the structures shown in Formulas Ia, Ib, and Ic;

[0011]

[0012] The method is characterized in that, under inert gas protection, a cyclic amide monomer, deionized water, and a hydrolysis catalyst are first added to an autoclave. The autoclave temperature is raised to temperature A1 under pressure condition P1, and a prepolymerization reaction is carried out for B1 time. The pressure is then released in stages, and the polyester and polycondensation catalyst are added to the autoclave. After replacing the inert gas, the autoclave is stirred for a period of time. The temperature is adjusted to T2, and a negative pressure is applied while stirring for B2 time. After the reaction is completed, the autoclave is cooled in deionized water to obtain a degradable polyesteramide block copolymer. The copolymer comprises segments or links of polyamide and polyester. Such copolymers have excellent thermodynamic and mechanical properties, as well as good processability.

[0013] The cyclic amide monomer is caprolactam, the polyester is any one of poly(ε-caprolactone), poly(δ-valerolactone) and poly(L-lactide), and the molecular weight of the polyester is preferably 500 to 20,000 g / mol.

[0014] Wherein, the mass ratio of the caprolactam monomer to deionized water is 1:(0.01-0.2); the mass ratio of the caprolactam monomer to the polyester monomer is (1-100):(1-100).

[0015] The prepolymerization catalyst is nylon 66 salt, γ-aminobutyric acid, 6-amino-1-hexanoic acid, stannous octoate or 4-dimethylaminopyridine, preferably 6-amino-1-hexanoic acid, and the mass ratio of caprolactam monomer to prepolymerization catalyst is 1: (0.001-0.01).

[0016] The polycondensation catalyst is tetrabutyl titanate, antimony trioxide, antimony glycol, stannous octoate or 4-dimethylaminopyridine, preferably tetrabutyl titanate, and the mass ratio of caprolactam monomer to polycondensation catalyst is 1:(0.001-0.01).

[0017] Wherein, the A1 temperature is 140-270° C., the B1 reaction time is 0.1-3 h, and the P1 pressure is 0.5-10 MPa.

[0018] Wherein, the T2 temperature is 200-290° C., and the B2 reaction time is 1-24 h.

[0019] The biodegradable polyester amide block copolymer and the synthesis method thereof of the present invention have the following characteristics: (1) the synthesized polymer product is biodegradable, which is beneficial to solving the environmental pollution problem faced by the traditional polyamide industry; (2) the biodegradable polyester amide block copolymer synthesized by chemical synthesis has excellent thermal stability and mechanical properties, and low water absorption; (3) the patent adopts a one-pot two-step feeding synthesis method, which has a simpler process route and lower production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0021] Figure 1 The polyester amide product of Example 3 1 H NMR spectra;

[0022] Figure 2 This is the TGA diagram of the polyester amide product of Example 3;

[0023] Figure 3 This is the DSC diagram of the polyester amide product of Example 3;

[0024] Figure 4 This is the GPC chart of the polyester amide product of Example 3.

[0025] Figure 5 This is the WAXD diagram of the polyester amide product of Example 3.

[0026] Figure 6 WAXD diagrams of PA6, polyesteramide product of Example 3, polyesteramide product of Comparative Example 3 and PCL DETAILED DESCRIPTION

[0027] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0028] In the following examples, a 400 MHz Bruker nuclear magnetic resonance instrument was used to measure the products: 6 mg of polyester amide sample was placed in a nuclear magnetic resonance tube, deuterated trifluoroacetic acid was added, and the sample was measured after shaking until it was completely dissolved.

[0029] The sample decomposition temperature was obtained by TGA 550 equipment testing. 5-10 mg of sample was weighed on a platinum plate. Under the protection of inert gas nitrogen, the temperature was increased at a rate of 20°C / min. The measurement temperature range was 30°C to 650°C.

[0030] The melting temperature of the sample was determined using a DSC 250 instrument. 5-10 mg of sample was weighed onto a platinum pan and, under an inert nitrogen atmosphere, the program was set to heat up, then cool down, and finally heat up again. The starting temperature was -50°C, and the final temperature was the temperature at which the sample degraded by 0.5% under thermogravimetric analysis. The cooling process was performed from the highest temperature back to -50°C at a rate of 10°C min-1. The melting point was obtained from the second temperature scan.

[0031] The mechanical properties of the samples were tested by an electronic universal testing machine (TMG104). The tensile test conditions were in accordance with the national standard GB / T 1040.1-2006, with a tensile rate of 20 mm / min and a test temperature of room temperature.

[0032] The method for detecting the relative viscosity of the degradable polyester amide block copolymer in the present invention is the Ubbelohde viscometer method.

[0033] In the water absorption test, the polyester amide prepared in the example was first placed in a vacuum drying oven at 60°C for 12 hours, then moved to a desiccator for cooling. After cooling, it was immediately weighed and recorded as m1. The sample was placed in deionized water at 23°C and kept at this temperature for 48 hours. The sample was then taken out, wiped dry with a lint-free cloth, and weighed and recorded as m2. The saturated water absorption rate of the sample is:

[0034]

[0035] Example 1

[0036] 72g of caprolactam, 7.2mL of deionized H2O, and 0.288g of γ-aminobutyric acid were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2MPa. The autoclave was heated to 260°C and maintained at this temperature for 2 hours for prepolymerization. The pressure was then gradually released to atmospheric pressure. 8g of polycaprolactone (molecular weight: 2000g / mol) and 0.072mL of tetrabutyl titanate were then added to the autoclave, which was then sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 1 hour. Finally, the autoclave was heated to 280°C and stirred under negative pressure for 10 hours.

[0037] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 1.323.

[0038] Example 2

[0039] 64 g of caprolactam, 6.4 mL of deionized H2O, and 0.256 g of 6-amino-1-hexanoic acid were sequentially added to an autoclave, and the reactor was sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2 MPa. The autoclave was heated to 270°C and maintained at this temperature for 1 hour for prepolymerization. Then, staged pressure relief was initiated, reducing the pressure in the autoclave to atmospheric pressure. 16 g of polyvalerolactone (molecular weight: 4000 g / mol) and 0.064 mL of antimony trioxide were added to the autoclave, and the reactor was sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 0.5 h. Finally, the autoclave was heated to 270°C and stirred under negative pressure for 8 hours.

[0040] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.986.

[0041] Example 3

[0042] 56 g of caprolactam, 5.6 mL of deionized H₂O, and 0.224 g of 6-amino-1-hexanoic acid were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2 MPa. The autoclave was heated to 250°C and maintained at this temperature for 0.5 hours for prepolymerization. The pressure was then gradually released to atmospheric pressure. 24 g of polycaprolactone (molecular weight: 1540 g / mol) and 0.056 mL of tetrabutyl titanate were then added to the autoclave, which was then sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 0.5 hours. Finally, the autoclave was heated to 260°C and stirred under negative pressure for 10 hours.

[0043] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.772.

[0044] Example 4

[0045] 48g of caprolactam, 4.8mL of deionized H2O, and 0.192g of 4-dimethylaminopyridine were sequentially added to an autoclave, and the reactor was sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2MPa. The reactor was heated to 220°C and maintained at this temperature for 3 hours for prepolymerization. Then, staged pressure relief was initiated, reducing the pressure in the autoclave to atmospheric pressure. 32g of polylactide with a molecular weight of 15,000g / mol and 0.048mL of antimony ethylene glycol were added to the autoclave, and the reactor was sealed. After nitrogen displacement at room temperature, the reaction mixture was stirred at atmospheric pressure for 1.5 hours. Finally, the reactor was heated to 290°C and stirred under negative pressure for 16 hours.

[0046] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.667.

[0047] Example 5

[0048] 40 g of caprolactam, 4 mL of deionized H₂O, and 0.16 g of 6-amino-1-hexanoic acid were sequentially added to an autoclave, and the reactor was sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2 MPa. The reactor was heated to 240°C and maintained at this temperature for 0.5 hours for prepolymerization. Then, the pressure was gradually released to atmospheric pressure. 40 g of polycaprolactone (MW 8000 g / mol) and 0.04 mL of 4-dimethylaminopyridine were added to the autoclave, and the reactor was sealed. After nitrogen displacement at room temperature, the reaction mixture was stirred at atmospheric pressure for 0.5 hours. Finally, the reactor was heated to 270°C and stirred under negative pressure for 12 hours.

[0049] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.555.

[0050] Example 6

[0051] 32g of caprolactam, 3.2mL of deionized H2O, and 0.128g of stannous octoate were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2MPa. The autoclave was heated to 210°C and maintained at this temperature for 0.5 hours for prepolymerization. Staged pressure relief was then initiated, reducing the pressure in the autoclave to atmospheric pressure. 48g of polyvalerolactone (molecular weight: 500g / mol) and 0.032mL of tetrabutyl titanate were then added to the autoclave, which was then sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 2 hours. Finally, the autoclave was heated to 260°C and stirred under negative pressure for 24 hours.

[0052] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.462.

[0053] Example 7

[0054] 24 g of caprolactam, 2.4 mL of deionized H₂O, and 0.096 g of 6-amino-1-hexanoic acid were sequentially added to an autoclave, and the reactor was sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2 MPa. The autoclave was heated to 250°C and maintained at this temperature for 0.5 hours for prepolymerization. Staged pressure relief was then initiated, reducing the pressure in the autoclave to atmospheric pressure. 56 g of polycaprolactone (molecular weight: 1540 g / mol) and 0.024 mL of stannous octoate were then added to the autoclave, and the reactor was sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 0.5 hours. Finally, the autoclave was heated to 260°C and stirred under negative pressure for 10 hours.

[0055] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.356.

[0056] Example 8:

[0057] 16g of caprolactam, 1.6mL of deionized H2O, and 0.064g of nylon 66 salt were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2MPa. The autoclave was heated to 190°C and maintained at this temperature for 0.5 hours for prepolymerization. The pressure was then gradually released to atmospheric pressure. 64g of polycaprolactone (MW 20,000 g / mol) and 0.016mL of antimony trioxide were then added to the autoclave, which was then sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 2 hours. Finally, the autoclave was heated to 280°C and stirred under negative pressure for 2 hours.

[0058] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.312.

[0059] Example 9

[0060] 8g of caprolactam, 0.8mL of deionized H2O, and 0.032g of antimony ethylene glycol were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2MPa. The autoclave was heated to 200°C and maintained at this temperature for 0.5 hours for prepolymerization. Then, the pressure was gradually released to atmospheric pressure. 72g of polylactide with a molecular weight of 10,000g / mol and 0.008mL of tetrabutyl titanate were added to the autoclave, which was then sealed. After nitrogen displacement at room temperature, the autoclave was stirred at atmospheric pressure for 0.5 hours. Finally, the autoclave was heated to 250°C and stirred under negative pressure for 4 hours.

[0061] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed with anhydrous ethanol three times, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide block copolymer with an intrinsic viscosity of 0.276.

[0062] Comparative Example 1

[0063] 72 g of caprolactam, 8 g of polyvalerolactone (molecular weight: 1540 g / mol), 7.2 mL of deionized H2O, 0.288 g of nylon 66 salt, and 0.072 mL of antimony trioxide were sequentially added to an autoclave, which was then sealed. The atmosphere was replaced with nitrogen at room temperature for 10 minutes, then pressurized to 1 MPa. The autoclave was heated to 190°C and maintained at this temperature for 1 hour for prepolymerization. Staged decompression was then initiated, reducing the pressure in the autoclave to atmospheric pressure. The autoclave was then heated to 280°C and stirred under negative pressure for 12 hours.

[0064] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide random copolymer with an intrinsic viscosity of 1.094.

[0065] Comparative Example 2

[0066] 60 g of caprolactam, 20 g of polycaprolactone (530 g / mol), 6 mL of deionized H2O, 0.24 g of γ-aminobutyric acid, and 0.056 mL of antimony glycolate were sequentially added to an autoclave, which was then sealed. The atmosphere was nitrogen-displaced at room temperature for 10 minutes, then pressurized to 1.5 MPa. The autoclave was heated to 290°C and maintained at this temperature for 2 hours for prepolymerization. Staged pressure relief was then initiated, reducing the pressure in the autoclave to atmospheric pressure. The autoclave was then heated to 250°C and stirred under negative pressure for 15 hours.

[0067] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide random copolymer with an intrinsic viscosity of 0.634.

[0068] Comparative Example 3

[0069] 72 g of caprolactam, 24 g of polycaprolactone (molecular weight: 1560 g / mol), 5.6 mL of deionized H2O, 0.224 g of 6-amino-1-hexanoic acid, and 0.056 mL of tetrabutyl titanate were sequentially added to an autoclave, which was then sealed. The atmosphere was replaced with nitrogen at room temperature for 10 minutes, then pressurized to 2 MPa. The autoclave was heated to 250°C and maintained at this temperature for 0.5 hours for prepolymerization. Staged pressure relief was then initiated, reducing the pressure in the autoclave to atmospheric pressure. The autoclave was then heated to 260°C and stirred under negative pressure for 10 hours.

[0070] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide random copolymer with an intrinsic viscosity of 0.713.

[0071] Comparative Example 4

[0072] 60 g of caprolactam, 20 g of polylactide with a molecular weight of 5000 g / mol, 6 mL of deionized H2O, 0.24 g of stannous octoate, and 0.056 mL of 4-dimethylaminopyridine were sequentially added to an autoclave, which was then sealed. After nitrogen displacement at room temperature for 10 minutes, the pressure was increased to 2 MPa. The autoclave was heated to 280°C and maintained at this temperature for 3 hours for prepolymerization. Then, staged pressure relief was initiated, reducing the pressure in the autoclave to atmospheric pressure. The autoclave was then heated to 260°C and stirred under negative pressure for 24 hours.

[0073] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60°C, and dried for 12 hours to obtain a degradable polyester amide random copolymer with an intrinsic viscosity of 1.348.

[0074] Comparative Example 5

[0075] 60 g of caprolactam, 20 g of caprolactone monomer, 6 mL of deionized H2O, 0.24 g of 4-dimethylaminopyridine, and 0.056 mL of stannous octoate were sequentially added to an autoclave, which was then sealed. The atmosphere was replaced with nitrogen at room temperature for 10 minutes, then pressurized to 3 MPa. The autoclave was heated to 250°C and maintained at this temperature for 1.5 hours for prepolymerization. Staged pressure relief was then initiated, reducing the pressure in the autoclave to atmospheric pressure. The autoclave was then heated to 290°C and stirred under negative pressure for 8 hours.

[0076] After the polycondensation was completed, stirring was stopped, the polymer product was discharged into cooling water, washed three times with anhydrous ethanol, placed in an oven at 60° C., and dried for 12 hours to obtain a degradable polyester amide random copolymer with an intrinsic viscosity of 0.718.

[0077] Test Example 1

[0078] The melting point, initial and maximum decomposition temperature, tensile strength and elongation at break of the polymers of Examples 1-9 and Comparative Examples 1-5 were measured using DSC, TGA and an electronic universal testing machine. The test results are shown in Table 1.

[0079]

[0080]

[0081] Table 1 Physical and chemical parameters of polyester amides prepared in Examples 1-9 and Comparative Examples 1-5

[0082] Degradation experiment

[0083] The polyester amide block copolymer prepared in the example was immersed in a tartaric acid-sodium tartrate buffer solution with a pH of 2.40, a PBS buffer solution with a pH of 7.20, and a borax-sodium hydroxide buffer solution with a pH of 12.00 at 37±0.5°C for degradation. The copolymer sample was taken out every 15 days, washed three times with deionized water, and dried in a vacuum drying oven at 60°C to a constant weight before being weighed. In the above experiment, the buffer solution was replaced every 15 days to maintain a constant pH value. W0 and Wt are the initial mass and the remaining mass after a certain period of degradation, respectively. The degradation rate is calculated as follows:

[0084]

[0085] The degradation rates of the polyester amides prepared in Examples 1-5 were measured respectively, and the degradation rates were 80.12%-97.05%. The specific test results are shown in Table 2.

[0086]

[0087] Table 2 Degradation rates of degradation examples 1-5 at different pH

[0088] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A degradable polyester amide block copolymer, characterized in that: The copolymer is shown in Formula I: wherein R is selected from poly(ε-caprolactone), poly(δ-valerolactone) and poly(L-lactide); wherein n and m are independently selected from any integer between 10 and 500.

2. The degradable polyester amide block copolymer according to claim 1, characterized in that: The copolymer is any one of the structures shown in Formula Ia, Ib, and Ic:

3. The method for preparing the degradable polyester amide block copolymer according to claim 1, characterized in that: Under the protection of inert gas, caprolactam, deionized water and a hydrolysis catalyst are added to a high-pressure reactor. The temperature of the reactor is raised to temperature A1 under pressurized condition P1. After a prepolymerization reaction is carried out for B1 time, the pressure is released in stages. The polyester and the polycondensation catalyst are added to the high-pressure reactor. After replacing the inert gas and stirring for a period of time, the temperature is adjusted to T2, vacuumed under negative pressure and stirred for B2 time. After the reaction is completed, the reactor is cooled in deionized water to obtain a degradable polyester amide block copolymer.

4. The method according to claim 1, characterized in that The cyclic amide monomer is caprolactam, the polyester is any one of poly(ε-caprolactone), poly(δ-valerolactone) and poly(L-lactide), and the molecular weight of the polyester is preferably 500 to 20,000 g / mol.

5. The method according to claim 1, characterized in that: The mass ratio of the caprolactam monomer to deionized water is 1:(0.01-0.2); the mass ratio of the caprolactam to the polyester is (1-100):(1-100).

6. The method according to claim 1, characterized in that The prepolymerization catalyst is nylon 66 salt, γ-aminobutyric acid, 6-amino-1-hexanoic acid, stannous octoate or 4-dimethylaminopyridine, preferably 6-amino-1-hexanoic acid, and the mass ratio of caprolactam monomer to prepolymerization catalyst is 1:(0.001-0.01).

7. The method according to claim 1, characterized in that: The polycondensation catalyst is tetrabutyl titanate, antimony trioxide, antimony glycol, stannous octoate or 4-dimethylaminopyridine, preferably tetrabutyl titanate. The mass ratio of caprolactam monomer to polycondensation catalyst is 1:(0.001-0.01).

8. The method according to claim 1, characterized in that: A1 temperature is 140-270°C, B1 reaction time is 0.1-3h, and P1 pressure is 0.5-3MPa.

9. The method according to claim 1, characterized in that: The T2 temperature is 200-290°C, and the B2 reaction time is 1-24h.

10. Use of claim 1 or 2 in preparing degradable materials.

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