CN101891881B - Biodegradable high-polymer additive, preparation method and application thereof - Google Patents

Abstract

The invention discloses a biodegradable polymer additive with a branched structure, a preparation method and application thereof. The branched polymer provided by the present invention is to combine polycaprolactone (PCL), L-polylactic acid (PLLA), or D-polylactic acid ( PDLA) and polyglycidol were prepared as grafted polymers with controllable structure. Each block of the main chain of the graft polymer and the length of the graft chain can be regulated by changing the feed ratio of monomers. The grafted polymer not only has a good compatibilizing effect on the polylactic acid/polycaprolactone blend system, but also can reduce the melt viscosity and improve the processing performance of the blend.

Description

Biodegradable polymer additive and its preparation method and application

technical field

The invention relates to the technical field of polymer materials, in particular to a biodegradable polymer additive with a branched structure and a compatibilization modification function, and a preparation method and application thereof.

Background technique

Polylactic acid (PLA) is a biodegradable synthetic polymer material with excellent biocompatibility. PLA, a biodegradable aliphatic polyester, is usually obtained from some renewable natural plants through chemical synthesis. Under the action of microorganisms, water, acid and alkali, PLA is finally degraded into carbon dioxide and water, and its degradation products can participate in human metabolism. Due to its excellent biocompatibility, polylactic acid has been approved by the US Food and Drug Administration (FDA), and can be used as medical surgical sutures, injection capsules, microspheres and implants. In addition, PLA has good mechanical properties and is easy to process and shape. However, PLA is hard and has poor toughness, lack of flexibility and elasticity, poor impact resistance, low heat distortion temperature, and easy to bend and deform. The shortcomings of these properties of polylactic acid greatly limit its practical application fields.

As one of the important ways of polymer modification, blending is not only simple and easy to implement, but also low in cost, and the blending system can often synthesize the properties of each component, thus better meeting the requirements of various aspects. Polycaprolactone (PCL)/PLA blend system is one of the common PLA blend systems. First of all, PCL has a longer -CH2- segment and better flexibility, so mixing it into PLA can improve the brittleness of PLA; secondly, the introduction of segments with different properties will destroy the order of molecular chains in polylactic acid. It affects its crystallization properties, which will also partially reduce the brittleness of PLA materials, but the compatibility of the PCL/PLA blend system is not good, so that the improvement of the mechanical properties of the blend materials is not obvious enough. If a small amount of corresponding graft copolymers are added to the PCL/PLA blend system to disperse them on the incompatible homopolymer interface, the interfacial tension can be reduced, the phase separation phenomenon can be improved, and the blend material can be improved. mechanical properties. In addition, because the graft copolymer has a branched structure, it can reduce the viscosity of the melt and improve the processing performance of the blend system. This kind of graft copolymer, which can not only play the role of compatibilization, but also reduce the melt viscosity, has a potential application prospect in the PCL/PLA blend system. But there are no relevant research reports and patents at present.

Contents of the invention

The purpose of the present invention is to provide a biodegradable polymer additive and its preparation method and application.

The biodegradable additive with branched structure provided by the present invention is shown in formula VI;

(Formula VI)

In formula VI, when A is a polylactic acid repeating unit, B is a polycaprolactone repeating unit or a polylactic acid repeating unit; when A is a polycaprolactone repeating unit, B is a polylactic acid repeating unit; the polycaprolactone repeating The units are obtained by ring-opening polymerization of cyclic ester monomers; the cyclic ester monomers are lactide or lactone cyclic monomers; x, y and z are all 1-7000.

The number average molecular weight of the copolymer is 2,000-100,000, and the molecular weight distribution is less than 2.

The method for preparing the above-mentioned biodegradable polymer additive with branched structure provided by the present invention comprises the following steps:

1) Preparation of a macroinitiator containing side hydroxyl groups:

Using ethoxy ethyl glycidyl ether (EEGE) shown in formula V and cyclic ester monomers as raw materials, under the initiation of potassium alkoxide, anionic sequential ring-opening polymerization is carried out in an organic solvent to obtain the protected The block copolymer of group, after removing the side hydroxyl protecting group in the block copolymer containing side hydroxyl protecting group again, obtain the block copolymer containing side hydroxyl;

2) Preparation of polymers with branched structures:

In the presence of a catalyst, using the block copolymer containing side hydroxyl groups obtained in the step 1) as an initiator, the ring-opening polymerization reaction of the cyclic ester monomer is carried out to obtain a biodegradable additive with a branched structure.

In step 1) of the method, the cyclic ester monomer is a lactide or lactone cyclic monomer; wherein, the lactide cyclic monomer is selected from the group consisting of L-lactide (LLA) shown in formula I, Any one of dextrolactide (DLA) shown in formula II and racemic lactide (D, LLA) shown in formula III;

(Formula I: LLA) (Formula II: DLA) (Formula III: D, LLA)

(Formula IV: CL)

(Formula V: EEGE)

The lactone cyclic monomer is caprolactone (CL) shown in formula IV;

The potassium alkoxide is selected from any one of potassium tert-butoxide, potassium tert-pentoxide and potassium hexoxide;

The molar ratio of the ethoxy ethyl glycidyl ether, cyclic ester monomer and potassium alcoholate is 1:1:0.01-1:1000:10, preferably 1:1:0.1-1:100:1;

The temperature of the anionic sequential ring-opening polymerization reaction is 0-80°C, preferably 20-60°C; the reaction time is 16-168h, preferably 24-72h;

The anionic sequential ring-opening polymerization is carried out in an organic solvent; the organic solvent is selected from at least one of toluene, tetrahydrofuran and chloroform;

The mass percentage concentration of the ethoxy ethyl glycidyl ether in the organic solvent is 1%-95%;

The method for removing the side hydroxyl protecting group in the block copolymer containing the side hydroxyl protecting group is as follows: remove the block copolymer containing the side hydroxyl protecting group under the condition of pH value 2-7 Side hydroxyl protecting groups in segment copolymers;

In step 2), the cyclic ester monomer is a lactide or lactone cyclic monomer, wherein the lactide cyclic monomer is selected from the group consisting of L-lactide shown in Formula I, D-lactide shown in Formula II Any one of lactide and racemic lactide shown in formula III; the lactone cyclic monomer is caprolactone (CL) shown in formula IV; the catalyst is selected from potassium hydroxide, octanoic acid Any one of stannous and potassium tert-butoxide. The catalyst is selected from any one of metal hydroxides, metal carboxylates, metal alcoholates and metal alkyls.

The molar ratio of the catalyst, the block copolymer containing side hydroxyl groups obtained in step 1) and the cyclic ester monomer is 0.001:1:1-1:1:1000, preferably 0.01:1:1-1:1 :500;

The temperature of the ring-opening polymerization reaction is 40-200°C, preferably 80-160°C; the reaction time is 12-168h, preferably 48-144h.

The ring-opening polymerization reaction is carried out in an organic solvent; the organic solvent is selected from at least one of toluene, tetrahydrofuran and chloroform;

The mass percent concentration of the cyclic ester monomer in the organic solvent is 1%-80%.

In addition, the application of the biodegradable additive with branched structure provided by the present invention in the modification of polylactic acid and polycaprolactone also belongs to the protection scope of the present invention.

The present invention has the following advantages:

(1) The branched copolymer prepared by the ring-opening polymerization method has a good compatibilizing effect on the polylactic acid/polycaprolactone blend system, and can reduce the melt viscosity, effectively improving the polylactic acid/polycaprolactone blend system. The compatibility of the two components of the mixed system can be improved, and the mechanical properties of the composite material can be improved.

(2) Additives suitable for different polylactic acid/polycaprolactone blend systems can be obtained by adjusting the structure, molecular weight and ratio of the cyclic ester monomer and the macroinitiator during the preparation of the branched copolymer .

(3) The polylactic acid/polycaprolactone blend system is still a biodegradable material, and adding it as an additive to the composite material will not affect the biodegradability of the composite material.

(4) Due to the existence of the branched structure, the graft copolymer can improve the processing performance of the polylactic acid/polycaprolactone blend system.

Description of drawings

Fig. 1 is the ¹ H NMR spectrum of PCL-b-PG-g-PLLA prepared by the method of the present invention.

Fig. 2 is the ¹ H NMR spectrum of PLLA-b-PG-g-PCL prepared by the method of the present invention.

Fig. 3 is the ¹ H NMR spectrum of PDLA-b-PG-g-PLLA prepared by the method of the present invention.

Fig. 4 is the ¹ H NMR spectrum of PLLA-b-PG-g-PDLA prepared by the method of the present invention.

Figure 5a is a scanning electron micrograph of a common polylactic acid/polycaprolactone blend system, and Figure 5b is a scanning electron micrograph of the additive-modified polylactic acid/polycaprolactone blend system prepared in Example 1.

Fig. 6 is the GPC spectrogram of the polymer prepared in Example 1.

Detailed ways

The present invention will be further described below through the examples, but the present invention is not limited to the following examples.

The specific steps and conditions for preparing the biodegradable additive with branched structure provided by the invention are as follows:

1) preparation of macromolecular initiator containing side hydroxyl

Dissolve the protective group-containing glycidyl alcohol in tetrahydrofuran in a dry reaction vessel, heat to 30-70°C, and the reaction time is less than 72h. Until the reaction is complete, under the protection of argon, the cyclic ester mono Add the tetrahydrofuran solution of the solid body into the reaction system, react at 0-70°C for <24h, remove the organic solvent, and obtain a block copolymer containing a hydroxyl protecting group. Then, dissolve the block copolymer in a mixed solvent of organic solvent/water, and react under acidic conditions at 0-50°C for <48h to remove the ethyl ethoxy group from the side chain of the copolymer, A macromolecular initiator containing side hydroxyl groups is obtained.

2) Preparation of additives with branched structure

Under the condition of argon protection, the macroinitiator and cyclic ester monomer prepared in the above step 1) were added into a dry reaction vessel, stannous octoate (SnOct ₂ ) was used as a catalyst, and toluene was used as a solvent. Reaction at 180°C for <200h, after the monomer reaction is complete, the organic solvent is removed to obtain the product.

Dissolve the branched polymer prepared in the above step 2) as a compatibilizer or additive together with the polylactic acid and/or polycaprolactone used for blending in an organic solvent, and cast a film after completely dissolving, and wait for the organic solvent to volatilize Get the composition when complete. The preferred parts by weight of each component are: polylactic acid: 48-99, polycaprolactone: 1-50, branched polymer: 0.5-30.

The polymer film is used for processing and molding, or the branched polymer, polylactic acid and polycaprolactone prepared in the above step (2) can be directly added to the processing equipment for processing and molding to obtain the desired product. All kinds of processing and molding are applicable, such as injection molding (injection), blow molding (blow molding), extrusion molding, vacuum molding, compressed air molding or spinning molding and other processing molding methods.

Utilize the polylactic acid modified by the branched polymer additive provided by the invention, its performance test is as follows:

The branched polymer-modified polylactic acid prepared above was melted on a vacuum laminator at 180° C. to form a dumbbell-shaped sample with a thickness of 0.5 mm and an initial length of 1 cm. The splines were quenched under liquid nitrogen, and the phase separation improvement of the spline section was observed with a scanning electron microscope (SEM). The analysis and test results of branched polymer modified polylactic acid are shown in the accompanying drawings.

The obtained biodegradable additive prepared by the present invention is a copolymer with a branched structure, which is polycaprolactone (PCL), left-handed polylactic acid (PLLA) or right-handed polylactic acid (PDLA) and polyglycidyl alcohol (PG) The graft copolymers, referred to as PCL-b-PG-g-PLLA (copolymer A), PLLA-b-PG-g-PCL (copolymer B), PDLA-b-PG-g-PLLA (copolymer C) and PLLA-b-PG-g-PDLA (copolymer D). Prepare PLLA-b-PG first during polymerization, then graft caprolactone (CL) or dextrolactide (DLA) onto the polymer chain to obtain copolymer B or D; prepare first during polymerization PCL-b-PG, then grafting L-lactide (LLA) onto the polymer chain to obtain copolymer A; during polymerization, first prepare PDLA-b-PG, and then grafting L-lactide (LLA) branched onto the polymer chain to obtain copolymer C.

Embodiment 1, preparation PCL-b-PG-g-PLLA

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, add 0.5mL potassium tert-butoxide tetrahydrofuran solution (1mol/L) and 3mL tetrahydrofuran at the same time, react at 60°C for 24h; At room temperature, 5 mL of caprolactone monomer tetrahydrofuran solution (0.333 g/mL) was slowly added dropwise to the reaction vessel, and reacted for 4 h at 40 ° C; the reaction mixture was poured into ether to precipitate and wash, and after drying, poly(ε -caprolactone-b-ethoxyethyl glycidyl ether) (PCL-b-PEEGE). Dissolve 3g of poly(ε-caprolactone-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid into the polymer solution, react at room temperature for 16h, then add calcium hydroxide, The molar ratio of hydroxyl/oxalic acid/calcium hydroxide in the polymer is 1/0.5/1. After reacting for 1 hour at room temperature, the precipitate in the solution is removed by centrifugation, and then the polymer solution is poured into ether for precipitation. After drying, the product is ready It is poly(ε-caprolactone-b-glycidyl alcohol) (PCL-b-PG).

Add 0.2g of poly(ε-caprolactone-b-glycidyl alcohol) into the dry reactor, dissolve it with 20mL of toluene, then add 1g of L-lactide and 0.67mmol of stannous octoate in toluene solution, at 100 Reaction at ℃ for 96h. The reaction was stopped, and the reaction mixture was poured into diethyl ether to precipitate and dry to obtain a white solid which was poly(ε-caprolactone-b-glycidyl alcohol-gL-lactic acid) (PCL-b-PG-g-PLLA). The ¹ H NMR spectrum of the branched polymer in deuterated chloroform (CDCl ₃ ) is shown in Fig. 1 , which shows that the structure of the compound is correct. Figure 6 is the GPC spectra of PCL-b-PG and PCL-b-PG-g-PLLA. It can be seen that Mn=11900, Mw/Mn=1.36 of PCL-b-PG; Mn=28800, Mw/Mn=1.59 of PCL-b-PG-g-PLLA.

Embodiment 2, preparation PCL-b-PG-g-PLLA

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, add 6.8uL potassium tert-butoxide tetrahydrofuran solution (1mol/L) and 1mL tetrahydrofuran at the same time, and react at 20°C for 168h; under the protection of argon At room temperature, slowly drop 0.75mL caprolactone monomer tetrahydrofuran solution (0.5g/mL) into the reaction vessel, and react at 0°C for 6h; pour the reaction mixture into diethyl ether for precipitation and washing, and obtain poly( ε-caprolactone-b-ethoxyethyl glycidyl ether) (PCL-b-PEEGE). Dissolve 1g of poly(ε-caprolactone-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid into the polymer solution, react at room temperature for 16h, then add calcium hydroxide, The molar ratio of hydroxyl/oxalic acid/calcium hydroxide in the polymer is 1/0.5/1. After reacting for 1 hour at room temperature, the precipitate in the solution is removed by centrifugation, and then the polymer solution is poured into ether for precipitation. After drying, the product is ready It is poly(ε-caprolactone-b-glycidyl alcohol) (PCL-b-PG).

Add 0.2g poly(ε-caprolactone-b-glycidyl alcohol) into the dry reactor, dissolve it with 20mL toluene, then add 0.11g L-lactide and 0.75mmol stannous octoate toluene solution, in Reaction at 40°C for 12h. The reaction was stopped, and the reaction mixture was poured into diethyl ether to precipitate and dry to obtain a white solid which was poly(ε-caprolactone-b-glycidyl alcohol-g-L-lactic acid) (PCL-b-PG-g-PLLA). GPC: Mn=140700, Mw/Mn=1.58 for PCL-b-PG; Mn=310800, Mw/Mn=2 for PCL-b-PG-g-PLLA.

Embodiment 3, preparation PLLA-b-PG-g-PCL

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, and at the same time add 0.5ml of potassium tert-butoxide in tetrahydrofuran (1mol/L) and 3mL of tetrahydrofuran, and react at 60°C for 24h; under the protection of argon At room temperature, 5g of L-lactide monomer tetrahydrofuran solution (0.333g/mL) was slowly added dropwise to the reaction vessel, and reacted at 40°C for 6h; the reaction mixture was poured into diethyl ether to precipitate and wash, and after drying, poly( L-lactic acid-b-ethoxyethyl glycidyl ether) (PLLA-b-PEEGE). Dissolve 3g of poly(L-lactic acid-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid to the polymer solution, react at room temperature for 16h, add calcium hydroxide, the polymer The molar ratio of hydroxyl/oxalic acid/calcium hydroxide is 1/0.5/1. After reacting for 1 hour at room temperature, centrifuge to remove the precipitate in the solution, then pour the polymer solution into ether to precipitate, and the product after drying is poly (L-lactic acid-b-glycidyl alcohol) (PLLA-b-PG).

Add 0.2g poly(L-lactic acid-b-glycidyl alcohol) into a dry reactor, dissolve it with 20mL toluene, then add 1g caprolactone and 0.67mmol stannous octoate toluene solution, and react at 100°C 96h. The reaction was stopped, and the reaction mixture solution was poured into diethyl ether for precipitation and drying to obtain a white solid which was poly(L-lactic acid-b-glycidyl alcohol-g-caprolactone) (PCL-b-PG-g-PLLA). The ¹ H NMR spectrum ( ¹ HNMR) of the branched polymer in deuterated chloroform (CDCl ₃ ) is shown in Figure 2, which shows that the structure of the compound is correct. GPC: Mn=21000, Mw/Mn=1.45 for PLLA-b-PG; Mn=31800, Mw/Mn=1.72 for PLLA-b-PG-g-PCL.

Embodiment 4, preparation PLLA-b-PG-g-PCL

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, add 10ml of potassium tert-butoxide in tetrahydrofuran (1mol/L) and 3mL of tetrahydrofuran, and react at 80°C for 16h; under the protection of argon, Slowly add 6.85g of L-lactide monomer tetrahydrofuran solution (0.333g/mL) dropwise into the reaction vessel at room temperature, and react at 40°C for 6h; pour the reaction mixture into diethyl ether for precipitation and washing, and obtain poly( L-lactic acid-b-ethoxyethyl glycidyl ether) (PLLA-b-PEEGE). Dissolve 3g of poly(L-lactic acid-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid to the polymer solution, react at room temperature for 16h, add calcium hydroxide, the polymer The molar ratio of hydroxyl/oxalic acid/calcium hydroxide is 1/0.5/1. After reacting for 1 hour at room temperature, centrifuge to remove the precipitate in the solution, then pour the polymer solution into ether to precipitate, and the product after drying is poly (L-lactic acid-b-glycidyl alcohol) (PLLA-b-PG).

Add 0.2g of poly(L-lactic acid-b-glycidyl alcohol) into a dry reactor, dissolve it with 20mL of toluene, then add 28.5g of caprolactone and 0.25umol of stannous octoate toluene solution, at 200°C Reaction 168h. The reaction was stopped, and the reaction mixture solution was poured into diethyl ether for precipitation and drying to obtain a white solid which was poly(L-lactic acid-b-glycidyl alcohol-g-caprolactone) (PCL-b-PG-g-PLLA). GPC: Mn=3000, Mw/Mn=1.35 of PLLA-b-PG; Mn=311800, Mw/Mn=1.72 of PLLA-b-PG-g-PCL.

Embodiment 5, preparation PDLA-b-PG-g-PLLA

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, and at the same time add 0.5ml of potassium tert-butoxide in tetrahydrofuran (1mol/L) and 3mL of tetrahydrofuran, and react at 60°C for 24h; under the protection of argon At room temperature, 5g of D-lactide monomer tetrahydrofuran solution (0.333g/mL) was slowly added dropwise to the reaction vessel, and reacted at 40°C for 6h; (D-Lactic acid-b-ethoxyethyl glycidyl ether) (PDLA-b-PEEGE). Dissolve 3g of poly(D-lactic acid-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid to the polymer solution, react at room temperature for 16h, add calcium hydroxide, the polymer The molar ratio of hydroxyl/oxalic acid/calcium hydroxide is 1/0.5/1. After reacting for 1 hour at room temperature, centrifuge to remove the precipitate in the solution, then pour the polymer solution into ether to precipitate, and the product after drying is poly (D-Lactic acid-b-glycidyl alcohol)(PDLA-b-PG).

Add 0.2g of poly(D-lactic acid-b-glycidyl alcohol) into the dry reactor, dissolve it with 20mL of toluene, then add 1g of L-lactide and 0.67mmol of stannous octoate toluene solution, at 100°C Reaction 96h. The reaction was stopped, and the reaction mixture solution was poured into diethyl ether to precipitate and dry to obtain a white solid which was poly(D-lactic acid-b-glycidyl alcohol-gL-lactic acid) (PDLA-b-PG-g-PLLA). The ¹ H NMR spectrum ( ¹ HNMR) of the branched polymer in deuterated chloroform (CDCl ₃ ) is shown in FIG. 3 , which shows that the structure of the compound is correct. GPC: Mn=24500, Mw/Mn=1.36 of PDLA-b-PG; Mn=38100, Mw/Mn=1.63 of PDLA-b-PG-g-PLLA.

Embodiment 6, preparation PLLA-b-PG-g-PDLA

Add 1g of ethoxyethyl glycidyl ether into a dry reaction vessel, and at the same time add 0.5ml of potassium tert-butoxide in tetrahydrofuran (1mol/L) and 3mL of tetrahydrofuran, and react at 60°C for 24h; under the protection of argon At room temperature, 5g of L-lactide monomer tetrahydrofuran solution (0.333g/mL) was slowly added dropwise to the reaction vessel, and reacted at 40°C for 6h; the reaction mixture was poured into diethyl ether to precipitate and wash, and after drying, poly( L-lactic acid-b-ethoxyethyl glycidyl ether) (PLLA-b-PEEGE). Dissolve 3g of poly(L-lactic acid-b-ethoxyethyl glycidyl ether) in 15ml of acetone, then add the aqueous solution of oxalic acid to the polymer solution, react at room temperature for 16h, add calcium hydroxide, the polymer The molar ratio of hydroxyl/oxalic acid/calcium hydroxide is 1/0.5/1. After reacting for 1 hour at room temperature, centrifuge to remove the precipitate in the solution, then pour the polymer solution into ether to precipitate, and the product after drying is poly (L-lactic acid-b-glycidyl alcohol) (PLLA-b-PG).

Add 0.2g of poly(L-lactic acid-b-glycidyl alcohol) into the dry reactor, dissolve it with 20mL of toluene, then add 1g of D-lactide and 0.67mmol of stannous octoate in toluene solution, at 100°C Under reaction 96h. The reaction was stopped, and the reaction mixture solution was poured into diethyl ether to precipitate and dry to obtain a white solid which was poly(L-lactic acid-b-glycidyl alcohol-gD-lactic acid) (PLLA-b-PG-g-PDLA). The ¹ H NMR spectrum ( ¹ HNMR) of the branched polymer in deuterated chloroform (CDCl ₃ ) is shown in FIG. 4 , which shows that the structure of the compound is correct. GPC: Mn=28500, Mw/Mn=1.26 of PLLA-b-PG; Mn=68100, Mw/Mn=1.52 of PLLA-b-PG-g-PDLA.

Embodiment 7, utilizing branched structure additive to modify polylactic acid

Dissolve 0.05 g of PLLA-b-PG-g-PCL, 0.8 g of PLLA and 0.2 g of PCL prepared in Example 2 in 20 m of dichloromethane, and cast the film after the dissolution is sufficient. The dried polymer film was melted on a vacuum laminator at 180° C. to form a dumbbell-shaped sample with a thickness of 0.5 mm and an initial length of 1 cm. The spline was quenched under liquid nitrogen, and the phase separation improvement of the spline section was observed with a scanning electron microscope (SEM)

In Fig. 5 (a) is a scanning electron micrograph of a common polylactic acid/polycaprolactone blend system, (b) is modified by an additive with a branched structure prepared in Example 1 of the present invention. Scanning electron micrographs of the caprolactone blend system. It can be seen that adding the additive with a branched structure prepared by the method of the present invention can obviously change the phase separation phenomenon of the polylactic acid/polycaprolactone blend system.

Claims (3)

1. the biodegradable additive that has branched structure shown in the formula VI;

(formula VI)

Among the described formula VI, when A was the poly(lactic acid) repeating unit, B was polycaprolactone repeating unit or poly(lactic acid) repeating unit; When A was the polycaprolactone repeating unit, B was the poly(lactic acid) repeating unit;

Described polycaprolactone repeating unit is obtained by the ring-opening polymerization of lactone cyclic monomer;

Described poly(lactic acid) repeating unit is obtained by the ring-opening polymerization of lactides cyclic monomer;

The preparation method who has the biodegradable additive of branched structure shown in the formula VI is following 1)-6) arbitrary shown in:

1) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5mL1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5mL 0.333g/mL caprolactone monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 4h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (6-caprolactone-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(6-caprolactone-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(6-caprolactone-b-R-GLYCIDOL);

0.2g poly-(6-caprolactone-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g levorotatory lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(6-caprolactone-b-R-GLYCIDOL-g-L-lactic acid); The Mn=11900 of PCL-b-PG, Mw/Mn=1.36; The Mn=28800 of PCL-b-PG-g-PLLA, Mw/Mn=1.59;

2) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 1mL tetrahydrofuran (THF) of 6.8uL1mol/L potassium tert.-butoxide, 20 ℃ of lower reaction 168h; Under the argon shield condition, the tetrahydrofuran solution with 0.75mL 0.5g/mL caprolactone monomer under the room temperature slowly is added drop-wise in the reaction vessel, 0 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (6-caprolactone-b-ethoxyethyl group glycidyl ether) after the drying; 1g poly-(6-caprolactone-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(6-caprolactone-b-R-GLYCIDOL); 0.2g poly-(6-caprolactone-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 0.11g levorotatory lactide and 0.75mmol, at 40 ℃ of lower reaction 12h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(6-caprolactone-b-R-GLYCIDOL-g-L-lactic acid); The Mn=140700 of PCL-b-PG, Mw/Mn=1.58; The Mn=310800 of PCL-b-PG-g-PLLA, Mw/Mn=2;

3) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL); 0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g caprolactone and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-caprolactone); The Mn=21000 of PLLA-b-PG, Mw/Mn=1.45; The Mn=31800 of PLLA-b-PG-g-PCL, Mw/Mn=1.72;

4) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 10ml1mol/L potassium tert.-butoxide, 80 ℃ of lower reaction 16h; Under the argon shield condition, the tetrahydrofuran solution with 6.85g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL); 0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 28.5g caprolactone and 0.25umol, at 200 ℃ of lower reaction 168h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-caprolactone); The Mn=3000 of PLLA-b-PG, Mw/Mn=1.35; The Mn=311800 of PLLA-b-PG-g-PCL, Mw/Mn=1.72;

5) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL dextrorotation lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (D-ALPHA-Hydroxypropionic acid-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(D-ALPHA-Hydroxypropionic acid-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL); 0.2g poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g levorotatory lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL-g-L-lactic acid); The Mn=24500 of PDLA-b-PG, Mw/Mn=1.36; The Mn=38100 of PDLA-b-PG-g-PLLA, Mw/Mn=1.63;

6) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL);

0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g dextrorotation rac-Lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-D-lactic acid); The Mn=28500 of PLLA-b-PG, Mw/Mn=1.26; The Mn=68100 of PLLA-b-PG-g-PDLA, Mw/Mn=1.52.

2. one kind prepares the described method with biodegradable additive of branched structure of claim 1, is following 1)-6) arbitrary shown in:

1) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5mL1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5mL 0.333g/mL caprolactone monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 4h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (6-caprolactone-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(6-caprolactone-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(6-caprolactone-b-R-GLYCIDOL);

0.2g poly-(6-caprolactone-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g levorotatory lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(6-caprolactone-b-R-GLYCIDOL-g-L-lactic acid); The Mn=11900 of PCL-b-PG, Mw/Mn=1.36; The Mn=28800 of PCL-b-PG-g-PLLA, Mw/Mn=1.59;

2) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 1mL tetrahydrofuran (THF) of 6.8uL1mol/L potassium tert.-butoxide, 20 ℃ of lower reaction 168h; Under the argon shield condition, the tetrahydrofuran solution with 0.75mL 0.5g/mL caprolactone monomer under the room temperature slowly is added drop-wise in the reaction vessel, 0 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (6-caprolactone-b-ethoxyethyl group glycidyl ether) after the drying; 1g poly-(6-caprolactone-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(6-caprolactone-b-R-GLYCIDOL);

0.2g poly-(6-caprolactone-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 0.11g levorotatory lactide and 0.75mmol, at 40 ℃ of lower reaction 12h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(6-caprolactone-b-R-GLYCIDOL-g-L-lactic acid); The Mn=140700 of PCL-b-PG, Mw/Mn=1.58; The Mn=310800 of PCL-b-PG-g-PLLA, Mw/Mn=2;

3) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL);

0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g caprolactone and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-caprolactone); The Mn=21000 of PLLA-b-PG, Mw/Mn=1.45; The Mn=31800 of PLLA-b-PG-g-PCL, Mw/Mn=1.72;

4) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 10ml1mol/L potassium tert.-butoxide, 80 ℃ of lower reaction 16h; Under the argon shield condition, the tetrahydrofuran solution with 6.85g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL);

0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 28.5g caprolactone and 0.25umol, at 200 ℃ of lower reaction 168h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-caprolactone); The Mn=3000 of PLLA-b-PG, Mw/Mn=1.35; The Mn=311800 of PLLA-b-PG-g-PCL, Mw/Mn=1.72;

5) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL dextrorotation lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (D-ALPHA-Hydroxypropionic acid-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(D-ALPHA-Hydroxypropionic acid-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL);

0.2g poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g levorotatory lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(D-ALPHA-Hydroxypropionic acid-b-R-GLYCIDOL-g-L-lactic acid); The Mn=24500 of PDLA-b-PG, Mw/Mn=1.36; The Mn=38100 of PDLA-b-PG-g-PLLA, Mw/Mn=1.63;

6) 1g ethoxyethyl group glycidyl ether is joined in the dry reaction vessel, add simultaneously tetrahydrofuran solution and the 3mL tetrahydrofuran (THF) of 0.5ml1mol/L potassium tert.-butoxide, 60 ℃ of lower reaction 24h; Under the argon shield condition, the tetrahydrofuran solution with 5g 0.333g/mL levorotatory lactide monomer under the room temperature slowly is added drop-wise in the reaction vessel, 40 ℃ of lower reaction 6h; Reaction mixture is poured into washing of precipitate in the ether, is gathered (Pfansteihl-b-ethoxyethyl group glycidyl ether) after the drying; 3g poly-(Pfansteihl-b-ethoxyethyl group glycidyl ether) is dissolved in the 15ml acetone, the aqueous solution with oxalic acid joins in the polymers soln again, after reacting 16h under the room temperature, add calcium hydroxide, the mol ratio of hydroxyl/oxalic acid in the polymkeric substance/calcium hydroxide is 1/0.5/1, under the room temperature reaction 1h after, the centrifugal throw out of removing in the solution, polymers soln is poured in the ether again and precipitates, dried product exhibited is poly-(Pfansteihl-b-R-GLYCIDOL);

0.2g poly-(Pfansteihl-b-R-GLYCIDOL) is joined in the dry reactor, with the dissolving of 20mL toluene, add again the stannous octoate toluene solution of 1g dextrorotation rac-Lactide and 0.67mmol, at 100 ℃ of lower reaction 96h; Stopped reaction, reaction mixture are poured into precipitation drying in the ether, obtain white solid and are poly-(Pfansteihl-b-R-GLYCIDOL-g-D-lactic acid); The Mn=28500 of PLLA-b-PG, Mw/Mn=1.26; The Mn=68100 of PLLA-b-PG-g-PDLA, Mw/Mn=1.52.

3. the described application of biodegradable additive in poly(lactic acid) and the modification of polycaprolactone co-mixing system with branched structure of claim 1.

Images