Preparation method of biodegradable polyphosphazene grafted APC-Polyols

Abstract

The invention discloses a preparation method of biodegradable polyphosphazene grafted APC-Polyols, and the preparation method comprises the following steps: mixing and uniformly stirring hydroxyl-containing side group substituted linear polyphosphazene and APC-Polyols, adding a toughening agent, and then heating; adding a catalyst, vacuumizing, carrying out ester exchange reaction under a vacuum condition, and then heating to carry out polymerization reaction; and adding nitrogen to recover normal pressure, and discharging to obtain the polyphosphazene graft modified APC-Polyols material. According to the invention, the polyphosphazene is grafted and modified on the APC-Polyols, so that the biocompatibility of the APC-Polyols is enhanced, the PC product has good biodegradability and biocompatibility, and meanwhile, the PC has excellent strength and chemical inertness, so that the PC is more suitable for positioning of medical products.

Description

Technical Field

[0001] The invention relates to a polyester graft modification method, in particular to a preparation method of biodegradable polyphosphazene grafted APC-Polyols. Background Art

[0002] w,w'-Hydroxyl-Ended Aliphatic Polycarbonatepolyols (APC-Polyols for short) refers to aliphatic polycarbonate resins with a molecular weight of less than 10,000 and two or more hydroxyl groups at the end. Its main chain contains aliphatic alkylene and carbonate repeating units, which is quite different from traditional polycarbonate materials, but similar to aliphatic polyester polyols and polyether polyols. Their properties are between aliphatic polyesters and polyethers, with lower T g , good room temperature compliance, some also have some unique properties, such as good oxygen barrier, low decomposition temperature and no residue after decomposition. Some varieties also have good biodegradability. APC-Polyols has a wide range of uses and can be used to prepare various types of polyurethane materials, prepare surfactants with biodegradability, and prepare ceramic and metal materials with special structures and uses. In addition, APC-Polyols can also be used in the biomedical field, oil and gas extraction field, etc.

[0003] Polyphosphazenes can adjust the hydrolysis performance, mechanical properties and surface properties of polymers by changing the structure of their side groups, changing in a wide range and giving the materials good biocompatibility. More importantly, the purpose of promoting cell adhesion and proliferation can be achieved by changing the side groups. So far, more than 700 kinds of polyphosphazene materials have been studied and reported, and polyphosphazene materials substituted with amino acid esters, hydroxy acid esters, alkoxy groups, glucose units, glyceryl groups, etc. alone or in combination have been proven to have good biocompatibility and are widely used in drug controlled release research. Because polyphosphazenes have such unique properties, compared with traditional biodegradable materials (polyesters, polyanhydrides, etc.), polyphosphazenes will have potential application prospects and advantages that cannot be ignored in the research of tissue engineering.

[0004] Among all types of plastics, polycarbonate is not the most used in medical products, but as a typical engineering plastic, PC has excellent heat and radiation resistance, which is unmatched by other commonly used plastics. Especially in surgical operations, the materials used have high requirements for hygiene, and PC's excellent strength and chemical inertness make it suitable for this environment.

[0005] "Synthesis and Characterization of Biodegradable Polyphosphazene Grafted Polyester Copolymers" discloses polyphosphazene grafted polycaprolactone copolymers substituted with diglycine ethyl ester; however, this technology can only achieve good ester exchange efficiency under conditions such as good thermal stability of the polyester material itself, low melting point or viscosity flow temperature, and low melt viscosity. At the same time, the strength of the obtained polymer is not high.

[0006] Chinese patent CN111205619A "A flame-retardant composite material of polycarbonate, phosphaphenanthrene and polyphosphazene with synergistic effect, and its preparation method and application" discloses the process of melt-blending and granulating polycarbonate, phosphaphenanthrene, polyphosphazene, antioxidant and compatibilizer; however, in essence, the polyphosphazene is used as a flame retardant only through physical blending, and no grafting reaction occurs.

[0007] Chinese patent CN113166531A "SiCoPC blends containing phosphazenes and silicone / acrylate impact toughness modifiers" discloses a process of melt-blending and granulating polycarbonate, polysiloxane-polycarbonate block co-condensate, rubber-modified grafted polymer, phosphazene and additives; however, in essence, the phosphazene is used as a flame retardant only through physical blending, and no grafting reaction occurs.

[0008] Chinese patent CN111133053A "Polycarbonate composition" discloses a method of melt-blending and granulating polycarbonate, polysiloxane carbonate copolymer and cyclic phosphazene; however, in essence, the phosphazene is used as a flame retardant only through physical blending, and no grafting reaction occurs.

[0009] Chinese patent CN107735448A "Flame-retardant polycarbonate-polyester composition" discloses a method of melt-blending polycarbonate, polyester and phosphazene into granules; however, in essence, the phosphazene is used as a flame retardant only through physical blending, and no grafting reaction occurs. Summary of the invention

[0010] The present invention provides a preparation method for grafting polyphosphazene onto APC-Polyols to improve the performance of existing materials. By grafting polyphosphazene onto APC-Polyols, the biocompatibility of APC-Polyols is enhanced, so that the PC product has good biodegradability and biocompatibility. At the same time, the excellent strength and chemical inertness of PC itself make it more suitable for the positioning of medical products.

[0011] To achieve the above object, the present invention provides a method for preparing biodegradable polyphosphazene grafted APC-Polyols, the preparation method comprising the following steps:

[0012] 1) mixing the linear polyphosphazene containing hydroxyl side groups and APC-Polyols and stirring them evenly, adding a toughening agent, and then heating;

[0013] 2) adding a catalyst, evacuating the air, carrying out an ester exchange reaction under vacuum conditions, and then raising the temperature to carry out a polymerization reaction to obtain a polyphosphazene graft-modified APC-Polyols material.

[0014] Preferably, in step 1), the weight ratio of the linear polyphosphazene substituted with hydroxyl side groups to APC-Polyols is (1-3): 1. The material ratio of the linear polyphosphazene substituted with hydroxyl side groups to APC-Polyols during the preparation process can be calculated based on the degree of substitution of hydroxyl groups in the target polymer and the length of the side chain.

[0015] Preferably, in step 1), the amount of the toughening agent used is 1-5% of the total weight of the reaction materials.

[0016] Preferably, in step 2), the amount of the catalyst used is 0.001-2%, preferably 0.005-1.0%, of the total weight of the reaction materials.

[0017] Preferably, the APC-Polyols is at least one of polyhexamethylene carbonate diol, 1,6-hexanediol homopolymerized aliphatic polycarbonate diol, polyhexamethylene carbonate diol, and poly(1,4-butylene carbonate) ester diol, preferably polyhexamethylene carbonate diol.

[0018] Preferably, the linear polyphosphazene substituted with hydroxyl side groups is at least one of: polyphosphazene substituted with 50% polyethylene glycol and 50% methoxy polyethylene glycol at the terminal, polyphosphazene substituted with polyethylene glycol at the terminal, and polyphosphazene substituted with methoxy polyethylene glycol at the terminal.

[0019] Preferably, the catalyst is at least one of butyl titanate, stannous isooctanoate, isopropyl titanate, and zinc acetate, preferably butyl titanate.

[0020] Preferably, the toughening agent is at least one of EM500 and PC powder.

[0021] Preferably, the APC-Polyols are obtained by transesterification of small molecule polyols and aliphatic carbonates or aromatic carbonates.

[0022] Preferably, the preparation process of APC-Polyols at least includes:

[0023] a. Mix small molecule polyol and aliphatic carbonate or aromatic carbonate in a weight ratio of (1-3):1 and stir evenly, raise the temperature to 90-110°C and exhaust the air in the system;

[0024] b. Add a catalyst, the amount of which is 0.001-2% of the total weight of the reaction materials, then raise the temperature to 160-190°C and react for 2-6 hours;

[0025] c. Evacuate the mixture and carry out polycondensation reaction under vacuum conditions below 0.1 MPa for 2 to 10 hours to prepare APC-Polyols with a molecular weight of 1000 to 5000.

[0026] Preferably, the small molecule polyol is at least one of a polyol having a carbon number between hydroxyl groups greater than 3 and a modified product thereof.

[0027] Preferably, the polyol having a carbon number between hydroxyl groups greater than 3 is at least one of 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1,4-dihydroxymethylcyclohexane, 1,4-butanediol, polyether polyol, and polyester polyol.

[0028] Preferably, the aliphatic carbonate is at least one of dimethyl carbonate, ethyl methyl carbonate and methyl propyl carbonate.

[0029] Preferably, the aromatic carbonate is diphenyl carbonate.

[0030] Preferably, in step b), the catalyst is at least one of alkaline hydroxides, alkaline metal carbonates, alkaline metal oxides, metal alcoholates, organic amine homogeneous catalysts, quaternary ammonium salt compounds, organic peptide compounds, heterogeneous catalysts, and enzyme catalysts.

[0031] Preferably, in step b), the catalyst is KOH, K 2 CO 3 , NaOH, Mg(OH) 2 MgCO 3 , CaO, NaCH 3 At least one of OH, triethylamine, tri-n-butylamine, triphenylamine, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutyl titanate, bimetallic (Mg-Al) hydrotalcite, and trimetallic (Mg-Zn-Al) hydrotalcite.

[0032] Preferably, in step 1), the temperature is raised to 60-100°C.

[0033] Preferably, in step 2), the vacuum is lower than 15 Pa, the temperature is raised to 130-190° C., and the polymerization reaction time is 8-48 hours.

[0034] The biodegradable polyphosphazene grafted APC-Polyols obtained by the preparation method of the present invention has excellent biodegradability, biocompatibility and non-toxicity, improves and regulates the hydrophilicity and biodegradation rate of aliphatic polycarbonate; the degradation product of the biodegradable polyphosphazene grafted APC-Polyols has self-neutralization, because the alkaline degradation product of polyphosphazene can neutralize the acidic degradation product of polycarbonate to a certain extent, and can reduce the aseptic inflammation that may be caused by the accumulation of the acidic degradation product of polycarbonate, and is a new type of biodegradable polymer with a wide range of biomedical uses. In addition, the preparation method of the present invention uses a non-toxic, commercialized, and approved catalyst for medical materials (such as butyl titanate or stannous isooctanoate), so it is not only conducive to large-scale production, but also conducive to the use of the copolymer synthesized by the method in the preparation of medical products. DETAILED DESCRIPTION

[0035] The present invention is described in detail below through specific embodiments. It is necessary to point out that the embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention.

[0036] In the specification and claims, "including" and "comprising" should be understood as meaning "including, but not limited to", and the specific details disclosed are intended to make the present invention easier to understand. The technical solution of the present invention is also that adopted by technicians in the relevant field to implement the present solution using one or more technical details.

[0037] Unless otherwise specified, the reagents used in the examples can be purchased from the market.

[0038] Preparation Example 1:

[0039] Preparation of polyhexamethylene carbonate diol:

[0040] a. Mix 1,6-hexanediol and diphenyl carbonate in a weight ratio of 2:1 and stir evenly, then heat to 100°C and exhaust the air in the system;

[0041] b. Add tetrabutylammonium bromide in an amount of 0.005% of the total weight of the reaction materials, then raise the temperature to 160°C and react at normal pressure for 6 hours;

[0042] c. Evacuate the mixture and carry out polycondensation reaction under vacuum conditions below 0.1 MPa for 4 hours;

[0043] d. Add nitrogen to restore the normal pressure and discharge the material to prepare polyhexamethylene carbonate diol with a molecular weight of 1000 to 5000.

[0044] Preparation Example 2:

[0045] Preparation of polyhexamethylene carbonate diol:

[0046] a. Mix 1,5-hexanediol and diphenyl carbonate in a weight ratio of 3:1 and stir evenly, then heat to 110°C and exhaust the air in the system;

[0047] b. Add tetrabutylammonium bromide in an amount of 2% of the total weight of the reaction materials, then raise the temperature to 190°C and react at normal pressure for 2 hours;

[0048] c. Evacuate the mixture and carry out polycondensation reaction under vacuum conditions below 0.1 MPa for 2 hours;

[0049] d. Add nitrogen to restore the normal pressure and discharge the material to prepare polyhexamethylene carbonate diol with a molecular weight of 1000 to 5000.

[0050] Preparation Example 3:

[0051] Preparation of poly (1,4-butylene carbonate) ester diol:

[0052] a. Mix 1,4-butanediol and diphenyl carbonate in a weight ratio of 1:1 and stir evenly, then heat to 90°C and exhaust the air in the system;

[0053] b. Add tetrabutyl titanate in an amount of 0.001% of the total weight of the reaction materials, then raise the temperature to 180°C and react at normal pressure for 4 hours;

[0054] c. Evacuate the mixture and carry out polycondensation reaction under vacuum conditions below 0.1 MPa for 10 hours;

[0055] d. Add nitrogen to restore the normal pressure and discharge the material to prepare poly(1,4-butylene carbonate) ester diol with a molecular weight of 1000 to 5000.

[0056] Embodiment 1:

[0057] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl terminal and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred at a mass ratio of 1.02:1, and EM500 was added in an amount of 3% of the total weight of the reaction materials under the protection of an inert atmosphere (argon or nitrogen), and the mixture was heated to 100°C for pulping, and butyl titanate was added in an amount of 1% of the total weight of the reaction materials, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 24 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 50%. The tensile strength of the product can reach 80MPa, and the bending strength can reach 120MPa.

[0058] Embodiment 2:

[0059] The polyphosphazene substituted with methoxy polyethylene glycol having a hydroxyl terminal and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred uniformly in a mass ratio of 2:1, and PC powder was added for toughening under the protection of an inert atmosphere (argon or nitrogen) in an amount of 1% of the total weight of the reaction material, and the temperature was raised to 100°C for slurrying, and stannous isooctanoate was added in an amount of 1% of the total weight of the reaction material, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 24 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 40%. The tensile strength of the product can reach 70MPa, and the bending strength can reach 100MPa.

[0060] Embodiment 3:

[0061] The polyphosphazene substituted with polyethylene glycol having a hydroxyl terminal and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred uniformly in a mass ratio of 3:1, and EM500 was added in an amount of 1% of the total weight of the reaction materials under the protection of an inert atmosphere (argon or nitrogen), and the mixture was heated to 100°C for pulping, and butyl titanate was added in an amount of 0.5% of the total weight of the reaction materials, and then reacted at 190°C under vacuum conditions (less than 15Pa) for 8 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 42%. The tensile strength of the product can reach 90MPa, and the bending strength can reach 130MPa.

[0062] Embodiment 4:

[0063] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl end and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred in a mass ratio of 1:1, and PC powder was added for toughening under the protection of inert atmosphere (argon or nitrogen) in an amount of 2% of the total weight of the reaction materials, and the temperature was raised to 100°C for pulping, and stannous isooctanoate was added in an amount of 0.5% of the total weight of the reaction materials, and then reacted at 130°C under vacuum conditions (less than 15Pa) for 48 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 55%. The tensile strength of the product can reach 75MPa, and the bending strength can reach 125MPa.

[0064] Embodiment 5:

[0065] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl end and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred at a mass ratio of 1.5:1, and PC powder was added for toughening under the protection of inert atmosphere (argon or nitrogen) in an amount of 3% of the total weight of the reaction materials, and the temperature was raised to 100°C for pulping, and butyl titanate was added in an amount of 0.005% of the total weight of the reaction materials, and then reacted at 130°C under vacuum conditions (less than 15Pa) for 48 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 35%. The tensile strength of the product can reach 82MPa, and the bending strength can reach 132MPa.

[0066] Embodiment 6:

[0067] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl terminal and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 2 were mixed and stirred uniformly in a mass ratio of 2.5:1, and EM500 was added in an amount of 5% of the total weight of the reaction materials under the protection of an inert atmosphere (argon or nitrogen), and the mixture was heated to 100°C for pulping, and butyl titanate was added in an amount of 0.5% of the total weight of the reaction materials, and then reacted at 130°C under vacuum conditions (less than 15Pa) for 48 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 50%. The tensile strength of the product can reach 78MPa, and the bending strength can reach 130MPa.

[0068] Embodiment 7:

[0069] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl terminal and 50% substitution of methoxy polyethylene glycol and the poly (1,4-butylene carbonate) ester diol obtained in Preparation Example 3 were mixed and stirred at a mass ratio of 2.5:1, and EM500 was added in an amount of 4% of the total weight of the reaction materials under the protection of an inert atmosphere (argon or nitrogen), and the temperature was raised to 100°C for slurrying, and butyl titanate was added in an amount of 0.001% of the total weight of the reaction materials, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 12 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 48%. The tensile strength of the product can reach 85MPa, and the bending strength can reach 132MPa.

[0070] Embodiment 8:

[0071] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl end and 50% substitution of methoxy polyethylene glycol and the poly (1,4-butylene carbonate) ester diol obtained in Preparation Example 3 were mixed and stirred in a mass ratio of 2:1, and PC powder was added for toughening under the protection of inert atmosphere (argon or nitrogen) in an amount of 1% of the total weight of the reaction materials, and the temperature was raised to 100°C for slurrying, and butyl titanate was added in an amount of 0.05% of the total weight of the reaction materials, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 12 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 60%. The tensile strength of the product can reach 76MPa, and the bending strength can reach 128MPa.

[0072] Embodiment 9:

[0073] The polyphosphazene substituted with methoxy polyethylene glycol having a hydroxyl terminal and the poly (1,4-butylene carbonate) ester diol obtained in Preparation Example 3 were mixed and stirred uniformly in a mass ratio of 2:1, and PC powder was added for toughening under the protection of an inert atmosphere (argon or nitrogen) in an amount of 1% of the total weight of the reaction material, and the temperature was raised to 100°C for slurrying, and stannous isooctanoate was added in an amount of 1% of the total weight of the reaction material, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 24 hours to obtain polyhexylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexylene carbonate polyol is 40%. The tensile strength of the product can reach 80MPa, and the bending strength can reach 121MPa.

[0074] Embodiment 10:

[0075] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl terminal and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 1 were mixed and stirred at a mass ratio of 2.5:1, and EM500 was added in an amount of 4% of the total weight of the reaction materials under the protection of an inert atmosphere (argon or nitrogen), and the mixture was heated to 100°C for pulping, and butyl titanate was added in an amount of 0.001% of the total weight of the reaction materials, and then reacted at 160°C for 12 hours under vacuum conditions (less than 15Pa) to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 45%. The tensile strength of the product can reach 76MPa, and the bending strength can reach 132MPa.

[0076] Embodiment 11:

[0077] The polyphosphazene with 50% substitution of polyethylene glycol with hydroxyl terminal and 50% substitution of methoxy polyethylene glycol and the polyhexamethylene carbonate diol obtained in Preparation Example 1 were mixed and stirred in a mass ratio of 2:1, and PC powder was added for toughening under the protection of inert atmosphere (argon or nitrogen) in an amount of 1% of the total weight of the reaction materials, and the temperature was raised to 100°C for slurrying, and butyl titanate was added in an amount of 0.05% of the total weight of the reaction materials, and then reacted at 160°C for 12 hours under vacuum conditions (less than 15Pa) to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 55%. The tensile strength of the product can reach 80MPa, and the bending strength can reach 140MPa.

[0078] Embodiment 12:

[0079] The polyphosphazene substituted with methoxy polyethylene glycol having a hydroxyl terminal and the polyhexamethylene carbonate diol obtained in Preparation Example 1 were mixed and stirred uniformly in a mass ratio of 2:1, and PC powder was added for toughening under the protection of an inert atmosphere (argon or nitrogen) in an amount of 1% of the total weight of the reaction material, and the temperature was raised to 100°C for pulping, and stannous isooctanoate was added in an amount of 1% of the total weight of the reaction material, and then reacted at 160°C under vacuum conditions (less than 15Pa) for 24 hours to obtain polyhexamethylene carbonate polyol grafted polyphosphazene. The grafting rate of polyhexamethylene carbonate polyol was 40%. The tensile strength of the product can reach 79MPa, and the bending strength can reach 142MPa.

[0080] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field can make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing biodegradable polyphosphazene grafted APC-Polyols, characterized in that: The following steps are involved: 1) mixing the linear polyphosphazene containing hydroxyl side groups and APC-Polyols and stirring them evenly, adding a toughening agent, and then heating; 2) adding a catalyst, evacuating the air, carrying out an ester exchange reaction under vacuum conditions, and then raising the temperature to carry out a polymerization reaction to obtain a polyphosphazene graft-modified APC-Polyols material.

2. The preparation method according to claim 1, characterized in that: In step 1), the weight ratio of the linear polyphosphazene substituted with hydroxyl side groups to APC-Polyols is (1-3):

1.

3. The preparation method according to claim 1, characterized in that: In step 1), the amount of the toughening agent used is 1-5% of the total weight of the reaction materials.

4. The preparation method according to claim 1, characterized in that: The amount of the catalyst used is 0.001-2% of the total weight of the reaction materials.

5. The preparation method according to claim 1, characterized in that: The APC-Polyols is at least one of polyhexamethylene carbonate diol, 1,6-hexanediol homopolymerized aliphatic polycarbonate diol, polyhexamethylene carbonate diol, and poly(1,4-butylene carbonate) ester diol.

6. The preparation method according to claim 1, characterized in that: The linear polyphosphazene substituted with hydroxyl side groups is at least one of: polyphosphazene substituted with 50% polyethylene glycol and 50% methoxy polyethylene glycol at the terminal hydroxyl group, polyphosphazene substituted with polyethylene glycol at the terminal hydroxyl group, and polyphosphazene substituted with methoxy polyethylene glycol at the terminal hydroxyl group.

7. The preparation method according to claim 1, characterized in that: The catalyst is at least one of butyl titanate, stannous isooctanoate, isopropyl titanate and zinc acetate.

8. The preparation method according to claim 1, characterized in that: The toughening agent is at least one of EM500 and PC powder.

9. The preparation method according to claim 1, characterized in that: The APC-Polyols are obtained by transesterification of small molecule polyols and aliphatic carbonate or aromatic carbonate.

10. The preparation method according to claim 9, characterized in that: The preparation process of the APC-Polyols at least includes: a. Mix small molecule polyol and aliphatic carbonate or aromatic carbonate in a weight ratio of (1-3):1 and stir evenly, raise the temperature to 90-110°C and exhaust the air in the system; b. Add a catalyst, the amount of which is 0.001-2% of the total weight of the reaction materials, then raise the temperature to 160-190°C and react for 2-6 hours; c. Evacuate the mixture and carry out polycondensation reaction under vacuum conditions below 0.1 MPa for 2 to 10 hours to prepare APC-Polyols with a molecular weight of 1000 to 5000.

11. The preparation method according to claim 9 or 10, characterized in that: The small molecule polyol is at least one of a polyol having a carbon number between hydroxyl groups greater than 3 and a modified product thereof.

12. The preparation method according to claim 11, characterized in that: The polyol having a carbon atom number greater than 3 between hydroxyl groups is at least one of 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1,4-dihydroxymethylcyclohexane, 1,4-butanediol, polyether polyol and polyester polyol.

13. The preparation method according to claim 9 or 10, characterized in that: The aliphatic carbonate is at least one of dimethyl carbonate, ethyl methyl carbonate and methyl propyl carbonate.

14. The preparation method according to claim 9 or 10, characterized in that: The aromatic carbonate is diphenyl carbonate.

15. The preparation method according to claim 10, characterized in that: In step b), the catalyst is at least one of alkaline hydroxides, alkaline metal carbonates, alkaline metal oxides, metal alcoholates, organic amine homogeneous catalysts, quaternary ammonium salt compounds, organic peptide compounds, heterogeneous catalysts, and enzyme catalysts; the catalyst is at least one of KOH, K2CO3, NaOH, Mg(OH)2, MgCO3, CaO, NaCH3OH, triethylamine, tri-n-butylamine, triphenylamine, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutyl titanate, bimetallic (Mg-Al) hydrotalcites, and trimetallic (Mg-Zn-Al) hydrotalcites.

16. The preparation method according to claim 1, characterized in that: In step 1), the temperature is raised to 60-100° C.; in step 2), the vacuum is lower than 15 Pa, the temperature is raised to 130-190° C., and the polymerization reaction time is 8-48 hours.