阅读说明：本技术 一种生物基可降解聚氨酯及其制备方法 (Bio-based degradable polyurethane and preparation method thereof ) 是由 李洪有 马荣哲 高宾 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种生物基可降解聚氨酯,包括以下重量份原料16-19份多元醇、5-8份N,N-二甲基甲酰胺、6-11份异氰酸酯和0.1-0.3份扩链剂,属于聚氨酯技术领域。通过在聚氨酯的原料中使用扩链剂,其中扩链剂采用十一烯酸做为原料,将扩链剂作为原料与多元醇反应制备出的聚氨酯含有悬挂链,由于悬挂链的存在降低了聚合物链之间的分子间的作用力,阻碍了分子链有序排列,降低了分子链的有序性,因此结晶微区减少,从而有效降低聚氨酯材料的结晶度,由于聚氨酯材料的结晶度低,微生物更容易附着和侵蚀聚氨酯材料,从而有效提高聚氨酯材料的降解效率。(The invention discloses a bio-based degradable polyurethane, which comprises the following raw materials, by weight, 16-19 parts of polyol, 5-8 parts of N, N-dimethylformamide, 6-11 parts of isocyanate and 0.1-0.3 part of chain extender, and belongs to the technical field of polyurethane. The chain extender is used in the raw materials of the polyurethane, wherein the chain extender adopts undecylenic acid as the raw material, the polyurethane prepared by reacting the chain extender as the raw material with the polyol contains a pendant chain, the intermolecular acting force between polymer chains is reduced due to the pendant chain, the ordered arrangement of the molecular chains is hindered, and the orderliness of the molecular chains is reduced, so that the crystallization micro-region is reduced, thereby effectively reducing the crystallinity of the polyurethane material.)

1. A biodegradable polyurethane characterized by: comprises the following raw materials of 16 to 19 portions of polyhydric alcohol, 5 to 8 portions of N, N-dimethylformamide, 6 to 11 portions of isocyanate and 0.1 to 0.3 portion of chain extender by weight portion;

the chain extender is prepared by the following method:

step one, adding undecylenic acid, nonanol and p-toluenesulfonic acid into a reaction kettle, stirring uniformly, adding dichloromethane, stirring for reaction, heating to 80-85 ℃, standing for reaction for 6-7.5h, standing and layering a reaction product at room temperature, extracting an upper oily product, and performing rotary evaporation treatment on the oily product to obtain an intermediate 1;

adding the intermediate 1, 3-mercapto-1, 2-propanediol and a photoinitiator into a round-bottom flask, stirring for reaction, sealing the round-bottom flask, irradiating the round-bottom flask by using an ultraviolet lamp at room temperature, and performing rotary evaporation and suction filtration on a reaction product to obtain an intermediate 2;

step three, adding the intermediate 2 and deionized water into a reaction kettle, adding potassium permanganate under the condition of temperature of 110-120 ℃, and performing reflux reaction for 3-5h to obtain an intermediate 3;

adding butanediol and succinic acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, adding a catalyst, continuously stirring for reaction, heating to 210 ℃, continuously reacting for 2-2.5 hours, heating to 220 ℃, continuously reacting for 1-2 hours, and drying the obtained product in a constant-temperature vacuum oven to obtain an intermediate 4;

and step five, adding the intermediate 3, the intermediate 4, dibutyltin oxide and hydrochloric acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring for reaction, filtering, removing filtrate, and drying in a constant-temperature vacuum oven to obtain the chain extender.

2. A biodegradable polyurethane according to claim 1, characterized in that: the polyol is formed by mixing homopolymerized polyol and caprolactone copolymerized polyol according to the mass ratio of 1: 1.

3. A biodegradable polyurethane according to claim 1, characterized in that: the isocyanate is one of toluene diisocyanate, hexamethylene diisocyanate and diphenylmethane diisocyanate.

4. The method for producing a biodegradable polyurethane according to claim 1, wherein: the method comprises the following steps:

placing polyol in a vacuum oven for drying for 5-6h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60-70 ℃, cooling to room temperature, adding isocyanate, heating to 70-80 ℃ under the protection of nitrogen, reacting for 1-1.5h, adding a chain extender, reacting for 4-6h, pouring a reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed part, placing in an oven, drying for 20-24h at the temperature of 60-65 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

Technical Field

The invention relates to the technical field of polyurethane, in particular to bio-based degradable polyurethane and a preparation method thereof.

Background

Polyurethane is a high polymer material, is a new organic high polymer material, and is widely applied to daily life such as paint and coating in furniture, refrigerators and freezers in household appliances, roof waterproof heat-insulating layers and inner and outer wall coatings in the building industry and the like.

The degradable polyurethane material has the characteristics of strong molecular designability and environmental friendliness, and can realize regulation and control of material performance, degradation mode and degradation rate, but the existing synthetic degradable polyurethane material is difficult to regulate and control the degradation rate, so that the problem to be solved at present is to provide the bio-based degradable polyurethane and the preparation method thereof.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a bio-based degradable polyurethane and a preparation method thereof, and solves the problem that the degradation rate of the existing synthetic degradable polyurethane material is difficult to regulate.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a biodegradable polyurethane comprises the following raw materials, by weight, 16-19 parts of polyol, 5-8 parts of N, N-dimethylformamide, 6-11 parts of isocyanate and 0.1-0.3 part of chain extender;

the chain extender is prepared by the following method:

step one, adding undecylenic acid, nonanol and p-toluenesulfonic acid into a reaction kettle, stirring for 30-50min under the conditions of the rotation speed of 200-;

the reaction process is as follows:

step two, adding the intermediate 1, 3-mercapto-1, 2-propanediol and photoinitiator into a round-bottom flask, stirring for 5-8min at the rotation speed of 200-300r/min at room temperature, sealing the round-bottom flask, irradiating the round-bottom flask for 5-6h by using an ultraviolet lamp at the room temperature, and then performing rotary evaporation and suction filtration on the reaction product to obtain an intermediate 2;

the reaction process is as follows:

step three, adding the intermediate 2 and deionized water into a reaction kettle, adding potassium permanganate under the condition of temperature of 110-120 ℃, and performing reflux reaction for 3-5h to obtain an intermediate 3;

the reaction process is as follows:

adding butanediol and succinic acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring at the rotation speed of 400-200 ℃ for 20-40min, adding a catalyst, continuously stirring for reaction for 1-1.5h, heating to 210 ℃, continuously reacting for 2-2.5h, heating to 220 ℃, continuously reacting for 1-2h, putting the obtained product into a constant-temperature vacuum oven, and drying for 24-26h at the temperature of 40-45 ℃ to obtain an intermediate 4;

the reaction process is as follows:

and step five, adding the intermediate 3, the intermediate 4, dibutyltin oxide and hydrochloric acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring and reacting for 1-2h under the conditions that the rotating speed is 400-140 ℃ and the temperature is 120-140 ℃, filtering, removing the filtrate, and drying in a constant-temperature vacuum oven for 10-12h to obtain the chain extender.

The reaction process is as follows:

preferably, in the first step, the molar ratio of the used undecylenic acid to the used nonanol is 1:1, the used p-toluenesulfonic acid is 5% of the total mass of the undecylenic acid and the nonanol, the used dichloromethane is 12% of the total mass of the undecylenic acid and the nonanol, and the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-acetone.

Preferably, in the second step, the molar ratio of the intermediate 1 to the 3-mercapto-1, 2-propanediol is 1:1, the amount of the photoinitiator is 1.5% of the total mass of the intermediate 1 and the 3-mercapto-1, 2-propanediol, and the wavelength of the ultraviolet lamp is 365 nm.

Preferably, in the third step, the dosage ratio of the intermediate 2, the deionized water and the potassium permanganate is 3.5g, 100mL and 5.8 g.

Preferably, in the fourth step, the molar ratio of the used butanediol to the used succinic acid is 2:1, the used amount of the catalyst is 0.1 percent of the total mass of the succinic acid, the catalyst adopts n-butyl titanate, and the air pressure in the reaction kettle is controlled to be 60-240 Pa.

Preferably, in the fifth step, the using ratio of the intermediate 3, the intermediate 4, the dibutyltin oxide and the hydrochloric acid is 3.68 g: 3.12 g: 1.55 g: 50mL, the mass fraction of hydrochloric acid is 36%.

Preferably, the polyol is a mixture of a homopolypolyol and a caprolactone copolyol according to a mass ratio of 1: 1.

Preferably, the isocyanate is one of toluene diisocyanate, hexamethylene diisocyanate and diphenylmethane diisocyanate.

Preferably, the preparation method of the biodegradable polyurethane comprises the following steps:

placing polyol in a vacuum oven for drying for 5-6h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60-70 ℃, cooling to room temperature, adding isocyanate, heating to 70-80 ℃ under the protection of nitrogen, reacting for 1-1.5h, adding a chain extender, reacting for 4-6h, pouring a reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed part, placing in an oven, drying for 20-24h at the temperature of 60-65 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

(III) advantageous effects

Compared with the prior art, the bio-based degradable polyurethane and the preparation method thereof have the following beneficial effects:

by using a chain extender in the raw material of polyurethane, wherein the chain extender adopts undecylenic acid as the raw material, undecylenic acid base diol and undecylenic acid base diol chain extender containing different pendant chain lengths are synthesized through sulfydryl-alkene reaction and esterification reaction, polyurethane prepared by taking the chain extender as a raw material to react with polyol contains pendant chains, the crystallinity of a hard section of the polyurethane is reduced along with the increase of the length of the pendant chains in the polyurethane, because the existence of the hanging chain reduces intermolecular acting force among polymer chains, hinders ordered arrangement of the molecular chains, reduces the orderliness of the molecular chains, reduces crystallization micro-regions, thereby effectively reducing the crystallinity of the polyurethane material, because the crystallinity of the polyurethane material is low, microorganisms are easier to attach and erode the polyurethane material, so that the degradation efficiency of the polyurethane material is effectively improved;

by introducing an intermediate 4 into an undecylenic acid based diol chain extender, wherein the intermediate 4 adopts butanediol and succinic acid as raw materials to prepare homopolyester, further increasing the length of the pendant chain of the undecylenic acid based diol chain extender, along with the increase of the length of the pendant chain, the melting point of the soft segment of the polyurethane is gradually reduced, the melting point of the hard segment is also gradually reduced, because the existence of the hanging chain disturbs the ordered arrangement among molecules, increases the free volume among the molecules of the polyurethane and reduces the piling of the chain, thereby playing a role in plasticizing the polyurethane, simultaneously reduces the glass transition temperature of the soft segment and the melting temperature of the hard segment, can realize convenient regulation and control of the degradation rate of the degradable polyurethane material by regulating and controlling the composition and the crystallinity of the polyurethane, thereby obtaining the polyurethane material with excellent mechanical property and degradation property and meeting different application requirements.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the chain extender is prepared by the following method:

step one, adding 3.5mL of undecylenic acid, 3.8mL of nonanol and 0.35mL of p-toluenesulfonic acid into a reaction kettle, stirring for 30min at the rotation speed of 200r/min and the temperature of 40 ℃, adding 0.86mL of dichloromethane, continuing stirring for 1h at the rotation speed of 200r/min and the temperature of 60 ℃, standing for 6h at the temperature of 80 ℃, finally standing and layering the reaction product at room temperature for 20h, extracting an upper-layer oily product, and performing rotary evaporation treatment on the oily product for 15min at the rotation speed of 600r/min and the temperature of 105 ℃ by using a vacuum rotary evaporator to obtain an intermediate 1;

step two, adding 4.8mL of intermediate 1, 5.5g of 3-mercapto-1, 2-propanediol and 0.14mL of photoinitiator into a round-bottom flask, stirring for 5min at the room temperature at the rotating speed of 200r/min, sealing the round-bottom flask, irradiating the round-bottom flask for 5h by using an ultraviolet lamp at the room temperature, and then carrying out rotary evaporation and suction filtration on a reaction product to obtain an intermediate 2;

step three, adding 3.5g of the intermediate 2 and 100mL of deionized water into a reaction kettle, adding 5.8g of potassium permanganate at the temperature of 110 ℃, and carrying out reflux reaction for 3 hours to obtain an intermediate 3;

adding 8.1mL of butanediol and 3.6mL of succinic acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring at the rotation speed of 400r/min and the temperature of 180 ℃ for 20min, adding 0.12mL of catalyst, continuously stirring for reaction for 1h, heating to 210 ℃, continuously reacting for 2h, heating to 220 ℃, continuously reacting for 1h, putting the obtained product into a constant-temperature vacuum oven, and drying for 24h at the temperature of 40 ℃ to obtain an intermediate 4;

and step five, adding 3.68g of the intermediate 3, 3.12g of the intermediate 4, 1.55g of dibutyltin oxide and 50mL of hydrochloric acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring and reacting for 1h under the conditions that the rotating speed is 400r/min and the temperature is 120 ℃, filtering, removing filtrate, and drying in a constant-temperature vacuum oven for 10h to obtain the chain extender.

Example 2:

the chain extender is prepared by the following method:

step one, adding 3.5mL of undecylenic acid, 3.8mL of nonanol and 0.35mL of p-toluenesulfonic acid into a reaction kettle, stirring for 50min at the rotation speed of 300r/min and the temperature of 45 ℃, adding 0.86mL of dichloromethane, continuing stirring for 1.5h at the rotation speed of 300r/min and the temperature of 70 ℃, standing for reaction for 7.5h at the temperature of 85 ℃, finally standing and layering the reaction product at room temperature for 20h, extracting an upper oily product, and carrying out rotary evaporation treatment on the oily product for 20min at the rotation speed of 800r/min and the temperature of 110 ℃ by using a vacuum rotary evaporator to obtain an intermediate 1;

step two, adding 4.8mL of intermediate 1, 5.5g of 3-mercapto-1, 2-propanediol and 0.14mL of photoinitiator into a round-bottom flask, stirring for 8min at the room temperature at the rotating speed of 300r/min, sealing the round-bottom flask, irradiating the round-bottom flask for 6h by using an ultraviolet lamp at the room temperature, and then carrying out rotary evaporation and suction filtration on a reaction product to obtain an intermediate 2;

step three, adding 3.5g of the intermediate 2 and 100mL of deionized water into a reaction kettle, adding 5.8g of potassium permanganate at the temperature of 120 ℃, and carrying out reflux reaction for 5 hours to obtain an intermediate 3;

adding 8.1mL of butanediol and 3.6mL of succinic acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring at the rotation speed of 600r/min and the temperature of 200 ℃ for 40min, adding 0.12mL of catalyst, continuously stirring for reaction for 1.5h, heating to 210 ℃, continuously reacting for 2.5h, heating to 220 ℃, continuously reacting for 2h, putting the obtained product into a constant-temperature vacuum oven, and drying for 26h at the temperature of 45 ℃ to obtain an intermediate 4;

and step five, adding 3.68g of the intermediate 3, 3.12g of the intermediate 4, 1.55g of dibutyltin oxide and 50mL of hydrochloric acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring and reacting for 2 hours at the rotation speed of 600r/min and the temperature of 140 ℃, filtering, removing filtrate, and drying in a constant-temperature vacuum oven for 12 hours to obtain the chain extender.

Example 3:

the chain extender is prepared by the following method:

step one, adding 3.5mL of undecylenic acid, 3.8mL of nonanol and 0.35mL of p-toluenesulfonic acid into a reaction kettle, stirring for 40min at the rotation speed of 250r/min and the temperature of 43 ℃, adding 0.86mL of dichloromethane, continuing stirring for 1.2h at the rotation speed of 250r/min and the temperature of 65 ℃, standing for reaction for 7h at the temperature of 83 ℃, finally standing and layering the reaction product at room temperature for 20h, extracting an upper oily product, and carrying out rotary evaporation treatment on the oily product for 18min at the rotation speed of 700r/min and the temperature of 108 ℃ by using a vacuum rotary evaporator to obtain an intermediate 1;

step two, adding 4.8mL of intermediate 1, 5.5g of 3-mercapto-1, 2-propanediol and 0.14mL of photoinitiator into a round-bottom flask, stirring for 6min at the room temperature at the rotation speed of 250r/min, sealing the round-bottom flask, irradiating the round-bottom flask for 5.5h by using an ultraviolet lamp at the room temperature, and then carrying out rotary evaporation and suction filtration on a reaction product to obtain an intermediate 2;

step three, adding 3.5g of the intermediate 2 and 100mL of deionized water into a reaction kettle, adding 5.8g of potassium permanganate at the temperature of 115 ℃, and carrying out reflux reaction for 4 hours to obtain an intermediate 3;

adding 8.1mL of butanediol and 3.6mL of succinic acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring at the rotation speed of 500r/min and the temperature of 190 ℃ for 30min, adding 0.12mL of catalyst, continuously stirring for reaction for 1.3h, heating to 210 ℃, continuously reacting for 2.3h, heating to 220 ℃, continuously reacting for 1.5h, putting the obtained product into a constant-temperature vacuum oven, and drying at the temperature of 43 ℃ for 25h to obtain an intermediate 4;

and step five, adding 3.68g of the intermediate 3, 3.12g of the intermediate 4, 1.55g of dibutyltin oxide and 50mL of hydrochloric acid into a reaction kettle, introducing nitrogen into the reaction kettle for protection, stirring and reacting for 1.5h under the conditions that the rotating speed is 500r/min and the temperature is 130 ℃, filtering, removing filtrate, and drying in a constant-temperature vacuum oven for 11h to obtain the chain extender.

Example 4:

this example differs from example 3 in that no intermediate 3 was introduced into intermediate 4, and the chain extender was obtained as in the other preparation methods.

Example 5:

a preparation method of biodegradable polyurethane comprises the following steps:

placing polyol in a vacuum oven for drying for 5h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60 ℃, cooling to room temperature, adding isocyanate, heating to 70 ℃ under the protection of nitrogen, reacting for 1h, adding the chain extender obtained in example 1, reacting for 4h, pouring the reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed piece, placing in the oven, drying for 20h at the temperature of 60 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

Example 6:

a preparation method of biodegradable polyurethane comprises the following steps:

placing polyol in a vacuum oven for drying for 5h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60 ℃, cooling to room temperature, adding isocyanate, heating to 70 ℃ under the protection of nitrogen, reacting for 1h, adding the chain extender obtained in example 2, reacting for 4h, pouring the reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed piece, placing into the oven, drying for 20h at the temperature of 60 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

Example 7:

a preparation method of biodegradable polyurethane comprises the following steps:

placing polyol in a vacuum oven for drying for 5h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60 ℃, cooling to room temperature, adding isocyanate, heating to 70 ℃ under the protection of nitrogen, reacting for 1h, adding the chain extender obtained in example 3, reacting for 4h, pouring the reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed piece, placing in the oven, drying for 20h at the temperature of 60 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

Example 8:

a preparation method of biodegradable polyurethane comprises the following steps:

placing polyol in a vacuum oven for drying for 5h, then adding the polyol, tetrahydrofuran and N, N-dimethylformamide into a three-neck flask, dissolving the polyol at the temperature of 60 ℃, cooling to room temperature, adding isocyanate, heating to 70 ℃ under the protection of nitrogen, reacting for 1h, adding the chain extender obtained in example 4, reacting for 4h, pouring the reaction product into a forming mold, placing for 12h at the room temperature, then taking out the formed part, placing in the oven, drying for 20h at the temperature of 60 ℃, and finally vulcanizing by using a flat vulcanizing machine to obtain the biodegradable polyurethane.

Comparative example 1:

the comparative example uses the aqueous polyurethane resin proposed in chinese patent CN 107266641B.

Comparative example 2:

the comparative example used a polyurethane board produced by Hebei Mingqi building materials Co.

Comparative experiment:

the polyurethane materials in examples 5-8 and comparative examples 1-2 were tested for degradation performance, using a set-up controlled composting degradation apparatus, the polyurethane samples were cultured in different environments, the degradation degree of the polyurethane samples was recorded, and the results of the test are reported in table 1:

TABLE 1

As can be seen from Table 1, the polyurethanes of examples 5 to 7 are significantly superior in degradability to the polyurethane of example 8, because the dangling chain length of the chain extender in the polyurethane of example 8 is short, resulting in higher crystallinity of the polyurethane material, and therefore the degradability of the polyurethane is also reduced, and the polyurethanes of examples 5 to 8 are significantly superior in degradability to the polyurethanes of comparative examples 1 to 2, because the crystallinity of the polyurethane material is effectively reduced by using the chain extender in the raw material of the polyurethane, and because the crystallinity of the polyurethane material is low, microorganisms are more likely to attach to and attack the polyurethane material, thereby effectively improving the degradation efficiency of the polyurethane material.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.