WO2023236862A1 - Method for synthesizing biodegradable block copolyester and block copolyester - Google Patents

Abstract

The present invention provides a method for synthesizing a biodegradable block copolyester. The method comprises the following steps: (1) reacting a first aliphatic dicarboxylic acid or a dialkyl ester thereof with a first aliphatic diol in the presence of a first catalyst to prepare prepolymer 1 as an aliphatic diol-dicarboxylate ester prepolymer; (2) reacting a second aliphatic dicarboxylic acid or a dialkyl ester thereof, an aromatic dicarboxylic acid or a dialkyl ester thereof, and a second aliphatic diol in the presence of a second catalyst to prepare prepolymer 2 as an aliphatic-aromatic diol-dicarboxylate ester prepolymer; and (3) connecting prepolymer 1 and prepolymer 2 by using a chain extender to give the block copolyester. The present invention also provides a block copolyester obtained by using the method. The block copolyester prepared by the method of the present invention has good mechanical properties, especially bending resistance and impact resistance, and thus has good mechanical property balance.

Description

Synthesis method of biodegradable block copolyester and block copolyester

This application claims priority from Chinese Patent Application No. 202210630140.1 submitted on June 6, 2022. The disclosure of the above-mentioned Chinese Patent Application is hereby cited in its entirety as part of this application.

Technical field

The present invention relates to the field of polymers. Specifically, the present invention relates to a synthesis method of a biodegradable block copolyester (also known as a polyester block copolymer) with excellent bending resistance and impact resistance, and a block copolymer obtained by this method. ester.

Background technique

Polybutylene succinate (PBS) is one of the most promising biodegradable polymer materials at present. PBS has a high heat distortion temperature, which can reach over 95°C without special treatment. Its heat resistance is better than other biodegradable materials, and it has great application potential in the field of disposable tableware. At the same time, PBS has excellent mechanical properties and processing performance, fully adaptable to current polyethylene (PE) and polypropylene (PP) processing equipment. In addition, PBS can pass household composting degradation certification, and its synthetic raw materials have broken through 10,000-ton industrial biological fermentation technology, with the potential to be completely bio-based. However, PBS itself has shortcomings such as poor impact resistance and low elongation at break, which restricts its promotion and application.

Patent CN1796435 reports a method of modifying PBS by introducing rigid maleopimaric anhydride for copolymerization. The resulting copolymer has good elongation at break and bending strength, but the improvement in impact strength is limited.

Patent CN106221139 reports a method of modifying PBS by melt blending with aliphatic polyester elastomer. The elongation at break of the blend-modified PBS is increased to 100-300%, and the impact strength is increased to 8.2-41.3KJ/M ² , but the toughening effect tends to decline rapidly with the phase separation of the two blended phases.

Therefore, there is still a need to provide a polyester synthesis method that can improve the mechanical properties of biodegradable polyester, especially the impact resistance and/or the bending resistance.

Contents of the invention

The present invention aims to overcome the above-mentioned defects in the prior art.

Therefore, an object of the present invention is to provide a method for synthesizing biodegradable block copolyesters. The block copolyester products synthesized by this method have good mechanical properties, especially impact resistance and/or Bending resistance.

Another object of the present invention is to provide a method for synthesizing biodegradable block copolyester. The block copolyester product synthesized by this method has a good balance of mechanical properties, especially in impact resistance and/or or a good balance between bending resistance.

A further object of the present invention is to provide a copolyester obtained by the above method.

In particular, the present invention is implemented as follows:

1. A synthesis method of biodegradable block copolyester, which includes the following steps:

(1) Reacting a first aliphatic dibasic acid or a dialkyl ester thereof and a first aliphatic diol in the presence of a first catalyst to prepare a prepolymer as an aliphatic dibasic acid diol ester prepolymer object 1;

(2) Reacting a second aliphatic dibasic acid or a dialkyl ester thereof, an aromatic dibasic acid or a dialkyl ester thereof, and a second aliphatic diol in the presence of a second catalyst to prepare an aliphatic- Prepolymer 2 of aromatic dibasic acid glycol ester prepolymer;

The second aliphatic dibasic acid may be the same as or different from the first aliphatic dibasic acid;

The second aliphatic glycol is the same as or different from the first aliphatic glycol;

(3) Connect prepolymer 1 and prepolymer 2 using a chain extender to obtain block copolyester.

2. The method according to item 1, wherein the weight average molecular weight of prepolymer 1 is 50000-150000, which is determined by gel permeation chromatography.

3. The method according to any one of items 1-2, wherein the weight average molecular weight of prepolymer 2 is 20000-80000, which is determined by gel permeation chromatography.

4. The method according to any one of items 1 to 3, wherein with respect to the second aliphatic dibasic acid or dialkyl ester thereof and the aromatic dibasic acid or dialkyl ester thereof used in step (2) The total number of moles, the amount of aromatic dibasic acid or its dialkyl ester used in step (2) is 1.0%-25.0% mole.

5. The method according to any one of items 1 to 4, wherein with respect to the first aliphatic dibasic acid or dialkyl ester thereof used in step (1) and the second aliphatic dibasic acid used in step (2) The total number of moles of dibasic acid or dialkyl ester thereof and aromatic dibasic acid or dialkyl ester thereof, the amount of aromatic dibasic acid or dialkyl ester used in step (2) is 0.45% - 10.0% mol.

6. A method according to any one of items 1-5, wherein:

The first aliphatic dibasic acid is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably succinic acid , adipic acid, sebacic acid, oxalic acid, or a mixture of any two or more thereof, preferably succinic acid;

The alkyl groups in the dialkyl ester of the first aliphatic dibasic acid are each independently selected from C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the dialkyl ester of the first aliphatic dibasic acid The alkyl ester is selected from dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or a mixture of any two or more thereof, preferably dimethyl succinate. ester.

7. The method according to any one of items 1 to 6, wherein the first aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, Or a mixture of any two or more thereof; preferably selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3-propanediol, Or a mixture of any two or more thereof, more preferably 1,4-butanediol.

8. The method according to any one of items 1 to 7, wherein the molar ratio of the first aliphatic diol to the first aliphatic dibasic acid or dialkyl ester thereof is 1.0 to 3.0, preferably greater than 1.0 to 3.0 , preferably 1.1-2.0, preferably 1.2-1.5.

9. A method according to any one of items 1 to 8, wherein:

The first aliphatic dibasic acid or its dialkyl ester is a first aliphatic dibasic acid, and the prepolymer 1 is made by subjecting the first aliphatic dibasic acid to a first aliphatic diol through an esterification reaction. , and then prepared by prepolymerization; or

The first aliphatic dibasic acid or its dialkyl ester is the dialkyl ester of the first aliphatic dibasic acid, and the prepolymer 1 is prepared by making the dialkyl ester of the first aliphatic dibasic acid and the third An aliphatic diol is prepared by transesterification and then prepolymerization.

10. The method according to any one of items 1-9, wherein the first catalyst is selected from organic compounds, metal oxides, metal salts of elements such as zirconium, cobalt, titanium, manganese, tin, zinc, germanium, or any combination thereof , preferably selected from tetrabutyl titanate, tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctate, germanium oxide, cobalt acetate, zirconium oxide or any combination thereof.

11. The method according to any one of items 1 to 10, wherein the addition amount of the first catalyst is 0.01% to 1.0% of the mass of the first aliphatic dibasic acid or its dialkyl ester.

12. A method according to any one of items 1-11, wherein

The second aliphatic dibasic acid is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably selected from Succinic acid, adipic acid, sebacic acid, oxalic acid, or a mixture of any two or more thereof, preferably succinic acid;

The alkyl groups in the dialkyl ester of the second aliphatic dibasic acid are each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the alkyl groups of the second aliphatic dibasic acid The dialkyl ester is selected from the group consisting of dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or a mixture of any two or more thereof, preferably dimethyl succinate. Methyl ester.

13. A method according to any one of items 1-12, wherein

The aromatic dicarboxylic acid is selected from C6-C20 aromatic dicarboxylic acid, or a mixture of any two or more thereof, preferably phthalic acid, terephthalic acid, isophthalic acid, or any two or more thereof. More mixtures, more preferably terephthalic acid;

The alkyl groups in the dialkyl ester of the aromatic dibasic acid are each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the alkyl groups of the aromatic dibasic acid The dialkyl ester is selected from dimethyl phthalate, diethyl phthalate, dimethyl terephthalate, diethyl terephthalate, dimethyl isophthalate, isophthalic acid Diethyl ester, or a mixture of any two or more thereof, preferably dimethyl terephthalate, diethyl terephthalate or a combination thereof, more preferably dimethyl terephthalate.

14. The method according to any one of items 1 to 13, wherein the second aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, Or a mixture of any two or more thereof, preferably, it is selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3- Propylene glycol or any combination thereof, more preferably 1,4-butanediol.

15. The method according to any one of items 1 to 14, wherein the second aliphatic diol is with respect to the second aliphatic dibasic acid or dialkyl ester thereof and the aromatic dibasic acid or dialkyl ester thereof The molar ratio of the sum is 1 to 3:1, preferably greater than 1 to 3, preferably 1.1-2.0, preferably 1.2-1.5.

16. A method according to any one of items 1 to 15, wherein:

In step (2), the second aliphatic dibasic acid or dialkyl ester thereof is a second aliphatic dibasic acid, and the aromatic dibasic acid or dialkyl ester thereof is an aromatic dibasic acid. , and the prepolymer 2 is prepared by subjecting the second aliphatic dibasic acid, the aromatic dibasic acid and the second aliphatic diol to an esterification reaction, and then performing a prepolymerization reaction; or

In step (2), the second aliphatic dibasic acid or dialkyl ester thereof is a dialkyl ester of a second aliphatic dibasic acid, and the aromatic dibasic acid or dialkyl ester thereof is A dialkyl ester of an aromatic dibasic acid, and prepolymer 2 is prepared by making a dialkyl ester of a second aliphatic dibasic acid, a dialkyl ester of an aromatic dibasic acid and a second aliphatic diol. Prepared by transesterification and then prepolymerization;

Preferably, the alkyl group in the dialkyl ester of the second aliphatic dibasic acid is the same alkyl group as the alkyl group in the dialkyl ester of the aromatic dibasic acid.

17. The method according to any one of items 1 to 16, wherein the second catalyst is selected from organic compounds, metal oxides, metal salts of elements such as zirconium, cobalt, titanium, manganese, tin, zinc, germanium, or any combination thereof , preferably selected from tetrabutyl acid, tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctanoate, germanium oxide, cobalt acetate, zirconium oxide or its random combination.

18. The method according to any one of items 1 to 17, wherein the addition amount of the second catalyst is the total of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester. 0.01% to 1.0% of mass.

19. The method according to any one of items 1-18, wherein the chain extender is selected from the group consisting of diisocyanates, dioxazolines, diperoxides, diepoxides, dianhydrides, or diacid chlorides;

The chain extender is preferably selected from toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4 , 4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate (sometimes also referred to as hexamethylene diisocyanate in this article), isophorone diisocyanate; 2,2'-bis( 2-oxazoline), bis(2-oxazolinyl)methane, 1,2-bis(2-oxazolinyl)ethane, 1,3-bis(2-oxazolinyl)propane, 1 ,4-bis(2-oxazolinyl)butane, 1,4-bis(2-oxazolinyl)benzene, 1,2-bis(2-oxazolinyl)benzene, 1,3-bis (2-oxazolinyl)benzene; benzoyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy) peroxy)methylcyclododecane, 4,4-bis(butylperoxy)n-butyl valerate, dicumyl peroxide, tert-butyl peroxybenzoate, dibutyl peroxide, α,α-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2 ,5-di(tert-butylperoxy)hex-3-yne, tert-butylperoxycumylbenzene; hydroquinone, diglycidyl ether, resorcinol diglycidyl ether, 1,6-hexanedi Alcohol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether;

Preferably, the chain extender is selected from: toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or any mixture thereof;

Preferably, the chain extender is 1,6-hexamethylene diisocyanate.

20. The method according to any one of items 1 to 19, wherein the added amount of the chain extender is 0.01% to 1.0% of the total mass of prepolymer 1 and prepolymer 2.

21. Block copolyester obtained by the method of any one of items 1 to 20.

Detailed ways

In one aspect, the invention provides a synthesis method of biodegradable block copolyester, which includes the following steps:

(1) Reacting a first aliphatic dibasic acid or a dialkyl ester thereof and a first aliphatic diol in the presence of a first catalyst to prepare a prepolymer as an aliphatic dibasic acid diol ester prepolymer object 1;

(2) Reacting a second aliphatic dibasic acid or a dialkyl ester thereof, an aromatic dibasic acid or a dialkyl ester thereof, and a second aliphatic diol in the presence of a second catalyst to prepare an aliphatic- Prepolymer 2 of aromatic dibasic acid glycol ester prepolymer;

The second aliphatic dibasic acid may be the same as or different from the first aliphatic dibasic acid;

The second aliphatic glycol is the same as or different from the first aliphatic glycol;

(3) Connect prepolymer 1 and prepolymer 2 using a chain extender to obtain block copolyester.

About step (1)

In one embodiment, the first aliphatic dibasic acid is selected from: linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or any two or more thereof A mixture of species, preferably linear C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably an even number of carbon atoms (such as C2, C4, C6, C8, C10, C12, C14, C16, C18, C20) aliphatic dibasic acid, or a mixture of any two or more thereof, preferably succinic acid, adipic acid, sebacic acid, oxalic acid, or a mixture of any two or more thereof, preferably succinic acid.

In one embodiment, the alkyl groups in the dialkyl ester of the first aliphatic dibasic acid can be the same or different from each other, preferably the same, and are preferably each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl. Preferably, the dialkyl ester of the first aliphatic dibasic acid is selected from dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or any two or more thereof. A variety of mixtures, preferably dimethyl succinate.

In one embodiment, the first aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, or any two or more thereof A mixture of, preferably linear C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diol, or a mixture of any two or more thereof, preferably an even number of carbon atoms (such as C2, C4, C6 , C8, C10, C12, C14, C16, C18, C20) aliphatic diol, or a mixture of any two or more thereof; Preferably, it is selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3-propanediol, or any two or more thereof mixture, more preferably 1,4-butanediol.

In one embodiment, the molar ratio of the first aliphatic diol to the first aliphatic dibasic acid or dialkyl ester thereof is greater than 1.0, that is, there is an excess of hydroxyl groups relative to carboxyl groups.

In one embodiment, the molar ratio of the first aliphatic diol to the first aliphatic dibasic acid or dialkyl ester thereof is 1.0 to 3.0, preferably greater than 1.0 to 3.0, preferably 1.1-2.0, preferably 1.2- 1.5. , 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, or the range limited by any two of them.

In one embodiment, the first aliphatic dibasic acid or dialkyl ester thereof is a first aliphatic dibasic acid, and the prepolymer 1 is prepared by mixing the first aliphatic dibasic acid with the first aliphatic dibasic acid. The glycol is prepared by esterification reaction and then prepolymerization (polycondensation) reaction.

In one embodiment, the first aliphatic dibasic acid or dialkyl ester thereof is a dialkyl ester of the first aliphatic dibasic acid, and the prepolymer 1 is prepared by making the first aliphatic dibasic acid The dialkyl ester is prepared by transesterification with the first aliphatic diol and then prepolymerization (polycondensation) reaction.

In one embodiment, in step (1), the esterification or transesterification and prepolymerization reactions are carried out in the presence of a first catalyst.

In one embodiment, the first catalyst is selected from organic compounds, metal oxides, metal salts of elements such as zirconium, cobalt, titanium, manganese, tin, zinc, germanium, or any combination thereof, and is preferably selected from tetrabutyl titanate. ester, tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctanoate, germanium oxide, cobalt acetate, zirconium oxide or any combination thereof.

In one embodiment, the addition amount of the first catalyst is 0.01% to 1.0% of the mass of the first aliphatic dibasic acid or its dialkyl ester, for example, it can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21% , 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38 %, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71% ,0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92% , 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.0%, or a range limited by any two of them.

In one embodiment, the esterification or transesterification reaction in step (1) is carried out under reduced pressure, preferably under an (absolute) pressure of 1000-100000 Pa. For example, the pressure can be 1000Pa, 2000Pa, 3000Pa, 4000Pa, 5000Pa, 6000Pa, 7000Pa, 8000Pa, 9000Pa, 10000Pa, 20000Pa, 30000Pa, 40000Pa, 50000Pa, 60000Pa, 70000Pa, 80000Pa, 90000Pa , 100000Pa or any two of them limited scope.

In one embodiment, the esterification or transesterification reaction in step (1) is carried out at any suitable temperature, for example, at a temperature of 140-230°C. For example, the reaction temperature can be 140°C, 145°C, 150°C ℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃, 230℃, or a range limited by any two of them.

In one embodiment, the esterification or transesterification reaction in step (1) can be carried out for any suitable reaction time according to the reaction temperature and the desired molecular weight of the prepolymer 1, for example, the reaction time can be 0.5-24 hours or Longer time, such as 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24 hours, or a range limited by any two of them.

In one embodiment, the prepolymerization reaction in step (1) is carried out under reduced pressure, preferably at an (absolute) pressure of 20-10000 Pa. For example, the pressure may be 20Pa, 30Pa, 40Pa, 50Pa, 60Pa, 70Pa, 80Pa, 90Pa, 100Pa, 200Pa, 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 1000Pa, 2000Pa, 3000Pa, 4000Pa, 5000Pa , 6000Pa, 7000Pa, 8000Pa, 9000Pa, 10000Pa, or a range limited by any two of them. In one embodiment, the prepolymerization reaction in step (1) is performed at a lower pressure than the esterification or transesterification reaction in step (1).

In one embodiment, the prepolymerization reaction in step (1) is performed at a higher temperature than the esterification or transesterification reaction temperature in step (1). Preferably, the prepolymerization reaction is carried out at a temperature of 200°C to 260°C, preferably 230°C to 250°C. For example, the prepolymerization temperature may be 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, or other The scope limited by any two.

In one embodiment, the prepolymerization reaction in step (1) can be carried out for any suitable reaction time according to the reaction temperature and the desired molecular weight of prepolymer 1. For example, the reaction time can be 0.5h, 1h, 2h, 3h. , 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24 hours or any two of them Limited scope.

In one embodiment, Prepolymer 1 has a weight average molecular weight of 50,000-150,000, as determined according to gel permeation chromatography. For example, the weight average molecular weight may be 50000, 55000, 60000, 65000, 70000, 75000, 80000, 85000, 90000, 95000, 10000, 105000, 110000, 105000, 120000, 125000, 130000, 13500 0, 140000, 145000, 150000 , or the scope defined by any two of them.

About step (2)

In one embodiment, the second aliphatic dibasic acid is selected from: linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or any two or more thereof A mixture of species, preferably linear C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably an even number of carbon atoms (such as C2, C4, C6, C8, C10, C12, C14, C16, C18, C20) aliphatic dibasic acid, or a mixture of any two or more thereof, preferably selected from succinic acid, adipic acid, sebacic acid , oxalic acid, or a mixture of any two or more thereof, preferably succinic acid.

In one embodiment, the alkyl groups in the dialkyl ester of the second aliphatic dibasic acid may be the same or different from each other, preferably the same, and are preferably each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl. Preferably, the dialkyl ester of the second aliphatic dibasic acid is selected from dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or any two or more thereof. A variety of mixtures, preferably dimethyl succinate.

In one embodiment, the second aliphatic dibasic acid and the first aliphatic dibasic acid in step (1) may be the same or different, and are preferably the same.

In one embodiment, the aromatic dicarboxylic acid is selected from C6-C20 aromatic dicarboxylic acids, or a mixture of any two or more thereof, preferably phthalic acid, terephthalic acid, isophthalic acid Dicarboxylic acid, or a mixture of any two or more thereof, more preferably terephthalic acid.

In one embodiment, the alkyl groups in the dialkyl ester of the aromatic dibasic acid can be the same or different from each other, preferably the same, and are preferably each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl. Preferably, the dialkyl ester of the aromatic dicarboxylic acid is selected from the group consisting of dimethyl phthalate, diethyl phthalate, dimethyl terephthalate, diethyl terephthalate, meta- Dimethyl terephthalate, diethyl isophthalate, or a mixture of any two or more thereof, preferably dimethyl terephthalate, diethyl terephthalate or a combination thereof, more preferably Dimethyl phthalate.

In one embodiment, the second aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, or any two or more thereof A mixture of, preferably linear C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diol, or a mixture of any two or more thereof, preferably an even number of carbon atoms (such as C2, C4, C6 , C8, C10, C12, C14, C16, C18, C20) aliphatic diol, or a mixture of any two or more thereof; preferably, it is selected from 1,4-butanediol, 1, 6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3-propanediol or any combination thereof, more preferably 1,4-butanediol.

In one embodiment, the second aliphatic glycol and the first aliphatic glycol may be the same or different, preferably the same.

In one embodiment, relative to the total moles of the second aliphatic dibasic acid or dialkyl ester thereof and the aromatic dibasic acid or dialkyl ester thereof used in step (2), step (2) The amount of aromatic dibasic acid or its dialkyl ester used in is 1.0%-25.0% mole, for example, it can be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7% , 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4 %, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7% , 6.8%, 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9%, 8.0%, 8.1%, 8.2%, 8.3%, 8.4 %, 8.5%, 8.6%, 8.7%, 8.8%, 8.9%, 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, 9.6%, 9.7%, 9.8%, 9.9%, 10.0%, 10.1%, 10.2%, 10.3%, 10.4%, 10.5%, 10.6%, 10.7%, 10.8%, 10.9%, 11.0%, 11.1%, 11.2%, 11.3%, 11.4%, 11.5%, 11.6%, 11.7% , 11.8%, 11.9%, 12.0%, 12.1%, 12.2%, 12.3%, 12.4%, 12.5%, 12.6%, 12.7%, 12.8%, 12.9%, 13.0%, 13.1%, 13.2%, 13.3%, 13.4 %, 13.5%, 13.6%, 13.7%, 13.8%, 13.9%, 14.0%, 14.1%, 14.2%, 14.3%, 14.4%, 14.5%, 14.6%, 14.7%, 14.8%, 14.9%, 15.0%, 15.1%, 15.2%, 15.3%, 15.4%, 15.5%, 15.6%, 15.7%, 15.8%, 15.9%, 16.0%, 16.1%, 16.2%, 16.3%, 16.4%, 16.5%, 16.6%, 16.7%, 16.8%, 16.9%, 17.0%, 17.1%, 17.2%, 17.3%, 17.4%, 17.5%, 17.6%, 17.7% , 17.8%, 17.9%, 18.0%, 18.1%, 18.2%, 18.3%, 18.4%, 18.5%, 18.6%, 18.7%, 18.8%, 18.9%, 19.0%, 19.1%, 19.2%, 19.3%, 19.4 %, 19.5%, 19.6%, 19.7%, 19.8%, 19.9%, 20.0%, 20.1%, 20.2%, 20.3%, 20.4%, 20.5%, 20.6%, 20.7%, 20.8%, 20.9%, 21.0%, 21.1%, 21.2%, 21.3%, 21.4%, 21.5%, 21.6%, 21.7%, 21.8%, 21.9%, 22.0%, 22.1%, 22.2%, 22.3%, 22.4%, 22.5%, 22.6%, 22.7% , 22.8%, 22.9%, 23.0%, 23.1%, 23.2%, 23.3%, 23.4%, 23.5%, 23.6%, 23.7%, 23.8%, 23.9%, 24.0%, 24.1%, 24.2%, 24.3%, 24.4 %, 24.5%, 24.6%, 24.7%, 24.8%, 24.9%, 25.0%, or a range defined by any two of them.

In one embodiment, the molar ratio of the second aliphatic diol relative to the sum of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester is greater than 1.0, that is, There is an excess of hydroxyl groups relative to carboxyl groups.

In one embodiment, the molar ratio of the second aliphatic diol to the sum of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester is 1 to 3 :1, preferably greater than 1 to 3, preferably 1.1-2.0, preferably 1.2-1.5, for example, it can be 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2 .90, 2.95, 3.00, or a range limited by any two thereof.

In one embodiment, in step (2), the second aliphatic dibasic acid or dialkyl ester thereof is a second aliphatic dibasic acid, and the aromatic dibasic acid or dialkyl ester thereof is The ester is an aromatic dibasic acid, and the prepolymer 2 is produced by subjecting the second aliphatic dibasic acid, the aromatic dibasic acid and the second aliphatic diol to an esterification reaction and then performing a prepolymerization (polycondensation) reaction. preparation.

In one embodiment, in step (2), the second aliphatic dibasic acid or dialkyl ester thereof is a dialkyl ester of the second aliphatic dibasic acid, and the aromatic dibasic acid Or the dialkyl ester thereof is a dialkyl ester of an aromatic dibasic acid, and the prepolymer 2 is prepared by making the dialkyl ester of the second aliphatic dibasic acid, the dialkyl ester of the aromatic dibasic acid and the third It is prepared by carrying out transesterification of dialiphatic diol and then carrying out prepolymerization (polycondensation) reaction. Preferably, the alkyl group in the dialkyl ester of the second aliphatic dibasic acid is the same alkyl group as the alkyl group in the dialkyl ester of the aromatic dibasic acid.

In one embodiment, in step (2), the esterification or transesterification and prepolymerization reactions are carried out in the presence of a second catalyst.

In one embodiment, the second catalyst is selected from organic compounds, metal oxides, metal salts of elements such as zirconium, cobalt, titanium, manganese, tin, zinc, germanium, or any combination thereof, and is preferably selected from tetrabutyl acid ester. , tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctanoate, germanium oxide, cobalt acetate, zirconium oxide or any combination thereof. The second catalyst may be the same as or different from the first catalyst.

In one embodiment, the addition amount of the second catalyst is 0.01% to 1.0% of the total mass of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester, for example Can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33% , 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50 %, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83% , 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.0 %, or a range defined by any two of them.

In one embodiment, the esterification or transesterification reaction in step (2) is carried out under reduced pressure, preferably under an (absolute) pressure of 1000-100000 Pa. For example, the pressure can be 1000Pa, 2000Pa, 3000Pa, 4000Pa, 5000Pa, 6000Pa, 7000Pa, 8000Pa, 9000Pa, 10000Pa, 20000Pa, 30000Pa, 40000Pa, 50000Pa, 60000Pa, 70000Pa, 80000Pa, 90000Pa , 100000Pa, or any two of them scope limited by the person.

In one embodiment, the esterification or transesterification reaction in step (2) is carried out at any suitable temperature, for example, at a temperature of 140-230°C. For example, the reaction temperature can be 140°C, 145°C, or 150°C. ,155℃,160℃,165℃,170℃,175℃,180℃,185℃,190℃,195℃,200℃,205℃,210℃,215℃,220℃,225℃,230℃, or The scope is limited by any two of them.

In one embodiment, the esterification or transesterification reaction in step (2) can be carried out for any suitable reaction time according to the reaction temperature and the desired molecular weight of the prepolymer 2, for example, the reaction time can be 0.5-24 hours or Longer time, such as 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24 hours, or a range limited by any two of them.

In one embodiment, the prepolymerization reaction in step (2) is performed under reduced pressure, preferably under an (absolute) pressure of 20-10000 Pa. For example, the pressure may be 20Pa, 30Pa, 40Pa, 50Pa, 60Pa, 70Pa, 80Pa, 90Pa, 100Pa, 200Pa, 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 1000Pa, 2000Pa, 3000Pa, 4000Pa, 5000Pa , 6000Pa, 7000Pa, 8000Pa, 9000Pa, 10000Pa, or a range limited by any two of them. In one embodiment, the prepolymerization reaction in step (2) is performed at a lower pressure than the esterification or transesterification reaction in step (2).

In one embodiment, the prepolymerization reaction in step (2) is performed at a higher temperature than the esterification or transesterification reaction temperature in step (2). Preferably, the prepolymerization reaction is carried out at a temperature of 200°C to 260°C, preferably 230°C to 250°C. For example, the prepolymerization temperature may be 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, or other The scope limited by any two.

In one embodiment, the prepolymerization reaction in step (2) can be carried out for any suitable reaction time according to the reaction temperature and the desired molecular weight of the prepolymer 2, for example, the reaction time can be 0.5-24 hours or longer. , such as 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h , 24 hours, or a range limited by any two of them.

In one embodiment, the weight average molecular weight of prepolymer 2 is 20,000-80,000, as determined according to gel permeation chromatography. For example, the weight average molecular weight may be 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, or a range limited by any two thereof.

About step (3)

In one embodiment, the mass ratio of prepolymer 1 to prepolymer 2 in step (3) is such that, relative to the first aliphatic dibasic acid or dialkyl ester thereof used in step (1) and the The total number of moles of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester used in (2), step The amount of the aromatic dibasic acid or its dialkyl ester used in (2) is 0.45%-10.0% mole, for example, it can be 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75% ,0.80%,0.85%,0.90%,0.95%,1.00%,1.05%,1.10%,1.15%,1.20%,1.25%,1.30%,1.35%,1.40%,1.45%,1.50%,1.55%,1.60 %, 1.65%, 1.70%, 1.75%, 1.80%, 1.85%, 1.90%, 1.95%, 2.00%, 2.05%, 2.10%, 2.15%, 2.20%, 2.25%, 2.30%, 2.35%, 2.40%, 2.45%, 2.50%, 2.55%, 2.60%, 2.65%, 2.70%, 2.75%, 2.80%, 2.85%, 2.90%, 2.95%, 3.00%, 3.05%, 3.10%, 3.15%, 3.20%, 3.25% , 3.30%, 3.35%, 3.40%, 3.45%, 3.50%, 3.55%, 3.60%, 3.65%, 3.70%, 3.75%, 3.80%, 3.85%, 3.90%, 3.95%, 4.00%, 4.05%, 4.10 %, 4.15%, 4.20%, 4.25%, 4.30%, 4.35%, 4.40%, 4.45%, 4.50%, 4.55%, 4.60%, 4.65%, 4.70%, 4.75%, 4.80%, 4.85%, 4.90%, 4.95%, 5.00%, 5.05%, 5.10%, 5.15%, 5.20%, 5.25%, 5.30%, 5.35%, 5.40%, 5.45%, 5.50%, 5.55%, 5.60%, 5.65%, 5.70%, 5.75% , 5.80%, 5.85%, 5.90%, 5.95%, 6.00%, 6.05%, 6.10%, 6.15%, 6.20%, 6.25%, 6.30%, 6.35%, 6.40%, 6.45%, 6.50%, 6.55%, 6.60 %, 6.65%, 6.70%, 6.75%, 6.80%, 6.85%, 6.90%, 6.95%, 7.00%, 7.05%, 7.10%, 7.15%, 7.20%, 7.25%, 7.30%, 7.35%, 7.40%, 7.45%, 7.50%, 7.55%, 7.60%, 7.65%, 7.70%, 7.75%, 7.80%, 7.85%, 7.90%, 7.95%, 8.00%, 8.05%, 8.10%, 8.15%, 8.20%, 8.25% , 8.30%, 8.35%, 8.40%, 8.45%, 8.50%, 8.55%, 8.60%, 8.65%, 8.70%, 8.75%, 8.80%, 8.85%, 8.90%, 8.95%, 9.00%, 9.05%, 9.10 %, 9.15%, 9.20%, 9.25%, 9.30%, 9.35%, 9.40%, 9.45%, 9.50%, 9.55%, 9.60%, 9.65%, 9.70%, 9.75%, 9.80%, 9.85%, 9.90%, 9.95%, 10.00%, or a range limited by any two of them.

In one embodiment, the chain extender is selected from diisocyanates, dioxazolines, diperoxides, diepoxides, dianhydrides, or diacid chlorides. For example, the chain extender can be selected from: toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate And 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate; 2,2'-bis(2-oxazoline), bis(2-oxazoline) Zozolinyl)methane, 1,2-bis(2-oxazolinyl)ethane, 1,3-bis(2-oxazolinyl)propane, 1,4-bis(2-oxazolinyl) Butane, 1,4-bis(2-oxazolinyl)benzene, 1,2-bis(2-oxazolinyl)benzene, 1,3-bis(2-oxazolinyl)benzene; peroxide Benzoyl, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)methylcyclododecane, 4 , 4-bis(butylperoxy)n-butyl valerate, dicumyl peroxide, tert-butyl peroxybenzoate, dibutyl peroxide, α,α-bis(tert-butylperoxy) Diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane Alkane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, tert-butylcumyl peroxide; hydroquinone, diglycidyl ether, resorcinol Diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, etc. For example, the chain extender can be selected from: toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or any mixture thereof. Preferably, the chain extender is 1,6-hexamethylene diisocyanate.

In one embodiment, the added amount of the chain extender is 0.01% to 1.0% of the total mass of prepolymer 1 and prepolymer 2, for example, it can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05 %, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38% , 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55 %, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88% , 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.0%, or a range defined by any two of them.

In one embodiment, the weight average molecular weight of the copolyester prepared in step (3) can be at least 70000, for example, it can be 70000-500000, for example, 70000-230000, for example, it can be 70000, 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000, 180000, 190000, 200000, 210000, 220000, 230000, 240000, 250000, 260000, 270000, 28 0000, 290000, 300000, 310000, 320000, 330000, 340000, 350000, 360000, 370000, 380000, 390000, 400000, 410000, 420000, 430000, 440000, 450000, 460000, 470000, 480000, 490000, 500000, or a range limited by any two thereof. The weight average molecular weight is determined according to gel permeation chromatography.

In another aspect, the invention also provides polyester copolymers (block copolyesters) obtained by the process of the invention.

The inventor found that the polyester copolymer (polyester block copolymer) obtained by the method of the present invention,

- Relative to a comparative polyester (hereinafter referred to as Comparative Polyester 1) prepared from an aliphatic dicarboxylic acid or an ester derivative thereof and an aliphatic diol (not chain-extended using a chain extender),

- Compared with directly mixing aliphatic dicarboxylic acid or its ester derivatives, aromatic carboxylic acid or its ester derivatives with aliphatic diol and then reacting to prepare a prepolymer, the prepolymer is prepared without using a chain extender In the case of chain extension, the prepared comparative polyester copolymer (hereinafter referred to as comparative polyester 2) is directly connected,

-Rather than directly mixing aliphatic dicarboxylic acid or its ester derivatives, aromatic carboxylic acid or its ester derivatives with aliphatic diol and then reacting to prepare a prepolymer, the prepolymer is chain extended using a chain extender The obtained comparative polyester copolymer (hereinafter referred to as comparative polyester 3),

- compared to a comparative polyester copolymer prepared by directly connecting the prepolymers 1 and 2 obtained in steps (1) and (2) of the method of the invention without using a chain extender (hereinafter referred to as comparative polyester 4),

The mechanical properties of the product, such as impact resistance (such as notched impact strength) and/or bending resistance (such as flexural modulus), can be significantly improved to achieve mechanical properties such as impact resistance (such as notched impact strength) and bending resistance (such as bending modulus). For example, a better balance of flexural modulus).

In particular, compared to comparative polyester 4, the present invention can significantly improve the mechanical properties of the product, while improving impact resistance (such as notched impact strength) and bending resistance (such as flexural modulus), achieving mechanical properties such as impact resistance. A better balance of properties (such as notched impact strength) and bending resistance (such as flexural modulus). For directly mixing aliphatic dicarboxylic acid or its ester derivatives, aromatic carboxylic acid or its ester derivatives and aliphatic diol, and then reacting to prepare a prepolymer, the prepolymer is chain-extended using a chain extender. The resulting comparative polyester copolymer (Comparative Polyester 3) was unable to simultaneously improve the impact resistance (such as notched impact strength) relative to the comparative polyester copolymer obtained by directly connecting the polyester prepolymer (Comparative Polyester 2) ) and bending resistance (such as flexural modulus).

The inventor also found that by further

(1) Control the weight average molecular weight of prepolymer 1 to 50,000-150,000,

(2) Control the weight average molecular weight of prepolymer 2 to 20000-80000,

(3) Control the amount of the aromatic dibasic acid or dialkyl ester thereof used in step (2) so that it is relative to the amount of the second aliphatic dibasic acid or dialkyl ester thereof used in step (2) and The total mole number of aromatic dibasic acids or dialkyl esters thereof is 1.0%-25.0% mole, and/or

(4) Control the mass ratio of prepolymer 1 to prepolymer 2 in step (3) so that, relative to the first aliphatic dibasic acid or dialkyl ester thereof used in step (1) and step (2) ) used in the second aliphatic di The total number of moles of primary acid or its dialkyl ester and aromatic dibasic acid or its dialkyl ester, the amount of aromatic dibasic acid or its dialkyl ester used in step (2) is 0.45%-10.0 %mol,

The mechanical properties of the resulting product, such as impact resistance (such as notched impact strength) and/or bending resistance (such as flexural modulus), are improved more significantly, and mechanical properties such as impact resistance (such as notched impact strength) and bending resistance are achieved A better balance of properties (e.g. flexural modulus).

In particular, the inventor found that when the above conditions (1)-(4) are simultaneously satisfied,

- Compared with the comparative polyester 1, the mechanical properties of the product, especially the impact resistance (such as notched impact strength), can be significantly improved;

- the mechanical properties of the product, in particular the impact resistance (e.g. notched impact strength) and the bending resistance (e.g. flexural modulus), can be improved particularly significantly compared to the comparative polyester 2;

- Compared with the comparative polyester 3, the mechanical properties of the product, especially the bending resistance (such as flexural modulus), can be significantly improved;

- The mechanical properties of the product, in particular the impact resistance (eg notched impact strength) and the bending resistance (eg flexural modulus), can be improved particularly significantly compared to the comparative polyester 4.

Example

The following are only representative embodiments of the present invention, and all equivalent changes and modifications made in accordance with the patentable scope of the present invention shall fall within the scope of the present invention.

The weight average molecular weight was tested using an Agilent 1260Infinity II gel permeation chromatograph. The mobile phase was chloroform, the flow rate was 1ml/min, and polystyrene was used as the standard sample.

The notched impact strength was tested according to the standard ISO 179-1, and the testing instrument was the simply supported beam impact testing machine XJJD-50 of Chengde Jinjian Testing Instrument Co., Ltd.

The flexural modulus was tested according to the standard ISO 178, and the testing instrument was the universal testing machine WDS-5KN of Chengde Precision Testing Machine Co., Ltd.

Comparative example 1

Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, and then perform transesterification at 165°C and 80KPa Reaction 3h. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours. Finally, the reaction temperature remained unchanged, the reaction pressure was reduced to 200 Pa, and the melt polycondensation reaction was carried out for 4 hours to obtain polybutylene succinate P1.

Comparative example 2

Weigh 8.0Kg (54.74mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 7.1Kg (78.78mol) 1,4-butanediol and 42g tetrabutyl titanate and add In the reaction kettle, the transesterification reaction was then carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours. Finally, the reaction temperature remained unchanged, the reaction pressure was reduced to 200 Pa, and the melt polycondensation reaction was carried out for 4 hours to obtain copolyester P2.

Comparative example 3

Step (1): Weigh 8Kg (54.74mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 7.1Kg (78.78mol) 1,4-butanediol and 42g tetrakis titanate Butyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 2 hours to obtain succinic acid-butylene terephthalate prepolymer 1.

Step (2): Finally, add 25g of hexamethylene diisocyanate into the reaction kettle for chain extension to obtain copolyester P3.

Comparative example 4

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 2 hours to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 2.5Kg (27.74mol) 1,4-butanediol and 15g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 17g of tetrabutyl titanate into the reaction kettle, and perform melt polycondensation to obtain copolyester P4.

Example 1

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 2 hours to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 2.5Kg (27.74mol) 1,4-butanediol and 15g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 25g of hexamethylene diisocyanate into the reaction kettle, and perform chain extension to obtain copolyester P5.

Example 2

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 2 hours to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 0.05Kg (0.26mol) dimethyl terephthalate, 2.3Kg (25.52mol) 1,4-butanediol and 14g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 24g of hexamethylene diisocyanate into the reaction kettle, and perform chain extension to obtain copolyester P6.

Example 3

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 2 hours to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 1.18Kg (6.08mol) dimethyl terephthalate, 3.06Kg (33.95mol) 1,4-butanediol and 19g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 2 hours to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 28g of hexamethylene diisocyanate into the reaction kettle, and perform chain extension to obtain copolyester P7.

Example 4

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was carried out for 1 hour to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 2.5Kg (27.74mol) 1,4-butanediol and 15g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and precondensation polymerization was performed for 1 hour to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 25g of hexamethylene diisocyanate into the reaction kettle, and perform chain extension to obtain copolyester P8.

Example 5

Step (1): Weigh 5.3Kg (36.27mol) dimethyl succinate, 4.6Kg (51.04mol) 1,4-butanediol and 26g tetrabutyl titanate into the reaction kettle, then heat it at 165°C, The transesterification reaction was carried out at 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and a precondensation polymerization reaction was performed for 3.5 hours to obtain butylene succinate prepolymer 1;

Step (2): Weigh 2.7Kg (18.48mol) dimethyl succinate, 0.33Kg (1.70mol) dimethyl terephthalate, 2.5Kg (27.74mol) 1,4-butanediol and 15g titanate Tetrabutyl ester was added to the reaction kettle, and then the transesterification reaction was carried out at 220°C and 80KPa for 3 hours. Then the temperature was raised to 230°C, the reaction pressure was reduced to 5Kpa, and a precondensation polymerization reaction was performed for 3.5 hours to obtain succinic acid-butylene terephthalate prepolymer 2;

Step (3): Add prepolymer 1, prepolymer 2 and 25g of hexamethylene diisocyanate into the reaction kettle, and perform chain extension to obtain copolyester P9.

The properties of the prepolymer or copolyester obtained in the above examples are as follows:

As can be seen from the above table,

- Compared with Comparative Example 1, Examples 1-5 all significantly improved the impact resistance (notched impact strength) of the product;

- Compared with Comparative Example 2, Example 1 significantly improves the impact resistance (notched impact strength) and bending resistance (flexural modulus) of the product;

- Compared with Comparative Example 3, Example 1 significantly improves the bending resistance (flexural modulus) of the product;

- Compared with Comparative Example 4, Example 1 significantly improves both the impact resistance (notched impact strength) and the bending resistance (flexural modulus) of the product; and from the comparison between Comparative Example 2 and Comparative Example 3, it can be seen that when When the method of the present invention is not used, the polyester copolymer prepared by chain extending the prepolymer using a chain extender does not improve the bending resistance (flexural modulus) compared to the polyester copolymer prepared by directly connecting the prepolymer.

Therefore, the product prepared by the method of the present invention achieves better mechanical properties such as impact resistance (such as notched impact strength) and/or bending resistance (such as flexural modulus), and achieves better mechanical properties such as impact resistance (such as notched impact strength). impact strength) and/or bending resistance (e.g. flexural modulus).

Claims (10)

1. A synthesis method of biodegradable block copolyester, which includes the following steps:

   (1) Reacting a first aliphatic dibasic acid or a dialkyl ester thereof and a first aliphatic diol in the presence of a first catalyst to prepare a prepolymer as an aliphatic dibasic acid diol ester prepolymer object 1;

   Preferably, the first aliphatic dibasic acid is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably Succinic acid, adipic acid, sebacic acid, oxalic acid, or a mixture of any two or more thereof, preferably succinic acid;

   Preferably, the alkyl groups in the dialkyl ester of the first aliphatic dibasic acid are each independently selected from C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the first aliphatic dibasic acid The dialkyl ester of the acid is selected from dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or a mixture of any two or more thereof, preferably succinate. acid dimethyl ester;

   Preferably, the first aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, or a mixture of any two or more thereof; preferably Selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3-propanediol, or a mixture of any two or more thereof, more Preferably, it is 1,4-butanediol;

   Preferably, the molar ratio of the first aliphatic dihydric alcohol to the first aliphatic dibasic acid or its dialkyl ester is 1.0 to 3.0, preferably greater than 1.0 to 3.0, preferably 1.1 to 2.0, preferably 1.2 to 1.5;

   (2) Reacting a second aliphatic dibasic acid or a dialkyl ester thereof, an aromatic dibasic acid or a dialkyl ester thereof, and a second aliphatic diol in the presence of a second catalyst to prepare an aliphatic- Prepolymer 2 of aromatic dibasic acid glycol ester prepolymer;

   The second aliphatic dibasic acid is the same as or different from the first aliphatic dibasic acid;

   The second aliphatic glycol is the same as or different from the first aliphatic glycol;

   Preferably, the second aliphatic dibasic acid is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic dibasic acid, or a mixture of any two or more thereof, preferably is selected from succinic acid, adipic acid, sebacic acid, oxalic acid, or a mixture of any two or more thereof, preferably succinic acid;

   Preferably, the alkyl groups in the dialkyl ester of the second aliphatic dibasic acid are each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the second aliphatic dibasic acid The dialkyl ester of a basic acid is selected from dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl oxalate, or a mixture of any two or more thereof, preferably butanedioic acid. Dimethyl diacid;

   Preferably, the aromatic dicarboxylic acid is selected from C6-C20 aromatic dicarboxylic acids, or a mixture of any two or more thereof, preferably phthalic acid, terephthalic acid, isophthalic acid, or any of them. A mixture of two or more, more preferably terephthalic acid;

   Preferably, the alkyl groups in the dialkyl ester of the aromatic dibasic acid are each independently selected from: C1-C4 alkyl, preferably C1-C2 alkyl, preferably methyl; preferably, the aromatic dibasic acid The dialkyl ester of the basic acid is selected from the group consisting of dimethyl phthalate, diethyl phthalate, dimethyl terephthalate, diethyl terephthalate, dimethyl isophthalate, and m-isophthalate. Diethyl terephthalate, or a mixture of any two or more thereof, preferably dimethyl terephthalate, diethyl terephthalate or a combination thereof, more preferably dimethyl terephthalate;

   Preferably, the second aliphatic diol is selected from linear or branched C2-C20, preferably C2-C10, preferably C2-C8 aliphatic diols, or a mixture of any two or more thereof, preferably Specifically, it is selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, 1,3-propanediol or any combination thereof, more preferably 1,4- butylene glycol;

   Preferably, the molar ratio of the second aliphatic diol to the sum of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester is 1 to 3:1, preferably Greater than 1 to 3, preferably 1.1-2.0, preferably 1.2-1.5;

   (3) Connect prepolymer 1 and prepolymer 2 using a chain extender to obtain block copolyester.
2. The method according to claim 1, wherein the weight average molecular weight of prepolymer 1 is 50,000-150,000, which is determined by gel permeation chromatography.
3. The method according to any one of claims 1-2, wherein the weight average molecular weight of the prepolymer 2 is 20,000-80,000, which is determined by gel permeation chromatography.
4. The method according to any one of claims 1 to 3, wherein relative to the second aliphatic dibasic acid or dialkyl ester thereof and the aromatic dibasic acid or dialkyl ester thereof used in step (2) The total number of moles, the amount of aromatic dibasic acid or its dialkyl ester used in step (2) is 1.0%-25.0% mole.
5. The method according to any one of claims 1 to 4, wherein the first aliphatic dibasic acid or dialkyl ester thereof used in step (1) and the second aliphatic dibasic acid used in step (2) are The total number of moles of primary acid or its dialkyl ester and aromatic dibasic acid or its dialkyl ester, the amount of aromatic dibasic acid or its dialkyl ester used in step (2) is 0.45%-10.0 %mol.
6. The method according to any one of claims 1-5, wherein:

   In step (1),

   - the first aliphatic dibasic acid or its dialkyl ester is a first aliphatic dibasic acid, and the prepolymer 1 is esterified by esterifying the first aliphatic dibasic acid with a first aliphatic diol reaction, and then prepared by prepolymerization; or

   -The first aliphatic dibasic acid or dialkyl ester thereof is a dialkyl ester of a first aliphatic dibasic acid, and the prepolymer 1 is prepared by making the dialkyl ester of the first aliphatic dibasic acid and The first aliphatic diol is prepared by transesterification followed by prepolymerization; and

   In step (2),

   - the second aliphatic dibasic acid or dialkyl ester thereof is a second aliphatic dibasic acid, the aromatic dibasic acid or dialkyl ester thereof is an aromatic dibasic acid, and prepolymer 2 Prepared by subjecting a second aliphatic dibasic acid, an aromatic dibasic acid and a second aliphatic diol to an esterification reaction and then performing a prepolymerization reaction; or

   -The second aliphatic dibasic acid or dialkyl ester thereof is a dialkyl ester of a second aliphatic dibasic acid, and the aromatic dibasic acid or dialkyl ester thereof is an aromatic dibasic acid. dialkyl ester, and prepolymer 2 is prepared by transesterifying the dialkyl ester of the second aliphatic dibasic acid, the dialkyl ester of the aromatic dibasic acid and the second aliphatic diol, and then preforming Prepared by polymerization reaction;

   Preferably, the alkyl group in the dialkyl ester of the second aliphatic dibasic acid is the same alkyl group as the alkyl group in the dialkyl ester of the aromatic dibasic acid.
7. The method according to any one of claims 1 to 6, wherein the first catalyst is selected from organic compounds, metal oxides, metal salts or any combination thereof of zirconium, cobalt, titanium, manganese, tin, zinc, germanium and other elements, Preferably selected from the group consisting of tetrabutyl titanate, tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctanoate, germanium oxide, cobalt acetate, zirconium oxide or its random combination;

   Preferably, the amount of the first catalyst added is 0.01% to 1.0% of the mass of the first aliphatic dibasic acid or its dialkyl ester.
8. The method according to any one of claims 1 to 7, wherein the second catalyst is selected from organic compounds, metal oxides, metal salts or any combination thereof of zirconium, cobalt, titanium, manganese, tin, zinc, germanium and other elements, Preferably selected from tetrabutyl acid, tetraisopropyl titanate, titanium acetylacetonate, zinc acetate, manganese acetate, stannous oxide, tin stearate, tin isooctanoate, germanium oxide, cobalt acetate, zirconium oxide or any of them combination;

   Preferably, the addition amount of the second catalyst is 0.01% to 1.0% of the total mass of the second aliphatic dibasic acid or its dialkyl ester and the aromatic dibasic acid or its dialkyl ester.
9. The method according to any one of claims 1 to 8, wherein the chain extender is selected from diisocyanate, dioxazoline, diperoxide, diepoxide, dianhydride, or dichloride;

   Preferably, the chain extender is selected from toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4 ,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate; 2,2'-bis(2-oxazoline), bis(2-oxazoline) methyl)methane, 1,2-bis(2-oxazolinyl)ethane, 1,3-bis(2-oxazolinyl)propane, 1,4-bis(2-oxazolinyl)butane , 1,4-bis(2-oxazolinyl)benzene, 1,2-bis(2-oxazolinyl)benzene, 1,3-bis(2-oxazolinyl)benzene; benzyl peroxide Acyl, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)methylcyclododecane, 4,4 -N-butyl bis(butylperoxy)valerate, dicumyl peroxide, tert-butyl peroxybenzoate, dibutyl peroxide, α,α-bis(tert-butylperoxy)diiso Propylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3 -Alkynes, tert-butyl cumene peroxide; hydroquinone, diglycidyl ether, resorcinol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether ;

   Preferably, the chain extender is selected from toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 4 ,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or any mixture thereof;

   Preferably, the chain extender is 1,6-hexamethylene diisocyanate;

   Preferably, the added amount of the chain extender is 0.01% to 1.0% of the total mass of prepolymer 1 and prepolymer 2.
10. Block copolyester obtained by the method of any one of claims 1 to 9.