CN103113551B - Preparation method of rosin-based shape-memory polyurethane - Google Patents

Abstract

The invention discloses a preparation method of rosin-based shape-memory polyurethane, which comprises: synthesizing polyol, diisocyanate, and rosin-based chain extender under the action of a catalyst by a one-step method or a two-step method to obtain rosin-based shape-memory polyurethane; The chain agent is a compound of formula I structure or formula II structure. In the present invention, the preparation method of rosin-based shape-memory polyurethane is simple to prepare, easy to implement, strong in operability, and easy for large-scale industrial production. At the same time, the prepared rosin-based shape-memory polyurethane has excellent recovery and is very suitable as a shape-memory material that exhibits excellent shape memory properties.

Description

A kind of preparation method of rosin base shape memory polyurethane

technical field

The invention relates to the field of polyurethane shape-memory polymer materials, in particular to a preparation method of rosin-based shape-memory polyurethane.

Background technique

Shape memory materials are a class of stimuli-responsive smart materials. The so-called shape memory means that the material can be restored under external stimuli (such as light, heat, electricity, magnetism, pH, etc.) to the properties of the initial shape.

In the 1960s, people first discovered the shape memory function of Ni-Ti alloy, and then shape memory materials attracted worldwide attention. In the 1980s, Ota.SLl and others found that the obtained material had a very good thermal recovery shape memory effect through the method of radiation cross-linked polyethylene, becoming the world's first shape memory polymer (SMP, Shape Memory Polymer) material ( Ota. S. The heat shrinkage properties of polyethylene [J]. Radiate Physics Chemistry, 1981, (18): 81). Compared with shape memory alloy (SMA, Shape Memory Alloy), SMP has the advantages of large deformation, easy shaping, wide temperature range of shape memory, light weight and low price, etc. It can be widely used in medical equipment, sports, textiles, clothing, Since the 1980s, the research on SMP has aroused widespread interest in academia and industry.

SMP can be thermoplastic or thermoset. Thermoplastic shape memory polymers have large deformation, simple processing methods, and can be processed into products of various complex shapes, but compared with thermosetting ones, their resilience performance is very poor. The elongation at break of thermoplastic shape memory polymers can reach more than 1000%, but the maximum rebound deformation is currently only about 400%. Therefore, it is of great significance to study thermoplastic shape memory polymers with high recovery properties.

At present, most of the synthesis of macromolecular materials are synthesized by using petroleum as raw material chemicals, such as the epoxy resin-based shape memory polymer disclosed in the Chinese patent application number 200710031342.X, and the Chinese patent application number 200610043121.X The polyurethane shape-memory polymer material disclosed in the patent, the Chinese patent application number 200810203251.4 disclosed the shell-type liquid crystal polymer type shape-memory polymer material, etc. However, fossil resources such as oil are non-renewable resources, and the simultaneous use of fossil resources has caused environmental problems such as the greenhouse effect. In consideration of saving resources and protecting the environment, it has become a research hotspot to use natural renewable resources such as biomass resources as raw materials to synthesize bio-based polymer materials. Bio-based polymer materials have dual effects of protecting the environment and saving resources. The United States, Japan, the European Union and other countries have passed bills and standards to promote the development of bio-based materials. Therefore, using renewable biological resources as raw materials, the research and development of high-performance materials conform to the development trend of the times and meet the national strategic needs, and have important application value and good development prospects.

But so far, there has been no report on the synthesis of thermoplastic shape memory polymers with high recovery performance using biomass resources as raw materials.

Contents of the invention

The invention provides a method for preparing rosin-based shape-memory polyurethane. The method is simple to prepare, easy to implement, strong in operability, and easy for large-scale industrial production. At the same time, the prepared rosin-based shape-memory polyurethane has excellent recovery and is very Suitable as shape memory materials.

A preparation method of rosin-based shape-memory polyurethane, comprising the following steps:

Polyol, diisocyanate and rosin-based chain extender are synthesized by one-step or two-step method under the action of catalyst to obtain rosin-based shape memory polyurethane;

The rosin chain extender is a compound of formula I structure or formula II structure;

Wherein, R ₁ is selected from an aromatic segment or an aliphatic segment of C ₁ to C ₁₄ ; R ₂ is selected from an aromatic segment or an aliphatic segment of C ₁ to C ₁₄ ; R ₁ and R ₂ are the same or different . More preferably, R ₁ is selected from a benzene ring segment or a C ₁ -C ₄ aliphatic segment; R ₂ is selected from a benzene ring segment or a C ₁ -C ₄ aliphatic segment; R ₁ and R ₂ are the same or different.

Preferably, the one-step method includes: reacting polyol, diisocyanate, rosin chain extender and catalyst together under the protection of protective gas at 50°C-150°C for 3h-5h, and discharging after the reaction to obtain rosin-based Shape memory polyurethane.

The two-step method includes: first reacting polyol, diisocyanate and catalyst under the protection of protective gas at 50°C to 100°C for 1h to 3h to obtain a prepolymer, and then adding a rosin-based chain extender to carry out the chain extension reaction After 3h to 5h, the material is discharged after the reaction to obtain rosin-based shape-memory polyurethane.

Preferably, the molar ratio of the polyol, diisocyanate and rosin-based chain extender is 1:1.1-5:0.1-4, which is beneficial to obtain highly resilient rosin-based shape memory polyurethane. Further preferably, the molar amount of the diisocyanate is equal to the sum of the molar amounts of the polyol and the rosin-based chain extender, which is beneficial to obtain high molecular weight polyurethane. More preferably, the molar ratio of the polyol, diisocyanate, and rosin-based chain extender is 1:3-5:2-4, so that highly resilient rosin-based shape-memory polyurethane can be obtained.

The catalyst can be added in a small amount known to those skilled in the art. Preferably, the molar ratio of the catalyst to the polyol is 0.001-0.01:1 to ensure a good catalytic effect.

Preferably, the polyol is one or both of polyester polyol and polyether polyol. Among them, the number average molecular weight of polyester polyol and polyether polyol is 500-20000. More preferably, the number average molecular weight of polyester polyol and polyether polyol is 500-6000. Further preferably, the polyol is one or more of polytetrahydrofuran ether diol, polybutylene succinate diol, polyethylene glycol, and polycaprolactone diol.

Preferably, the diisocyanate is one or more of aliphatic diisocyanate, aromatic diisocyanate and alicyclic diisocyanate. Further preferably, the diisocyanate is diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), dicyclohexyl diisocyanate One or two or more of isocyanates (HMDI).

Preferably, the catalyst is one or two or more of organotin-based polyurethane synthesis catalysts, titanate-based polyurethane synthesis catalysts, and organic bismuth-based polyurethane synthesis catalysts. Further preferably, the catalyst is stannous octoate, dibutyltin dilaurate or tetrabutyl titanate.

As preferably, in one-step or two-step synthesis, add an organic solvent to adjust the viscosity, and the organic solvent used to adjust the viscosity is a good solvent for polyurethane, such as acetone, butanone, ethyl acetate, N,N-dimethylformamide, One or more of N,N-dimethylacetamide, toluene, etc., that is, the organic solvent is acetone, butanone, ethyl acetate, N,N-dimethylformamide, N,N - One or more of dimethylacetamide and toluene. Preferably, the amount of the organic solvent added is 20% to 50% of the total mass of the polyol, diisocyanate, rosin-based chain extender and catalyst.

Nitrogen or inert gas can be selected as the protective gas to provide an inert reaction environment.

In the rosin-based shape-memory polyurethane prepared by the preparation method, the polyol forms a soft segment, and the urethane segment formed by the reaction of diisocyanate and rosin chain extender forms a hard segment.

The rosin-based chain extender of the present invention uses rosin as the basic structure. In formula I, chain extension is introduced by introducing R ₁ and R ₂ , and in formula II, chain extension is introduced by introducing R ₂ . The rosin-based chain extender is a rosin-based diol, which is beneficial to react with other compounds to generate high-performance polymer materials.

The preparation method of the rosin-based chain extender is simple in preparation, easy in implementation, strong in operability, and easy in industrialized production.

The preparation method of described rosin-based chain extender comprises the following steps:

Reaction of rosin diacid with formula III or formula IV and dihydric alcohol HO-R ₂ -OH to prepare rosin-based chain extender with formula I or formula II;

Wherein, R ₁ in formula III has the same meaning as R 1 in formula I, and R ₂ in dihydric alcohol HO-R ₂ -OH has the same meaning as _{R 2} in formula I and formula II.

Rosin diacid with the structure of formula III can be obtained by reacting maleic anhydride-modified rosin with a compound containing both amino and carboxyl groups. For the specific preparation process, please refer to the Chinese patent application with application number 201010225279.5.

The rosin diacid of the formula IV structure can be obtained by acrylic acid modified rosin, also known as acrylic acid modified rosin, the specific preparation process can refer to the existing literature (Preparation of Acrylic Modified Rosin Ind. , 11(2), pp200–202). Acrylic acid-modified rosin can adopt commercially available products, such as domestic products produced by Guangdong Jiangmen Foli Co., Ltd. and Guangzhou Lvjin Resin Co., Ltd. .

Diol HO-R ₂ -OH, R ₂ is selected from aromatic chain segment or C ₁ ~C ₁₄ aliphatic chain segment, that is, diol is one or both of aromatic diol and aliphatic diol More than one species; commercially available products can be selected.

The reaction between the rosin diacid with the structure of formula III or formula IV and dihydric alcohol HO-R ₂ -OH can specifically adopt esterification method, transesterification method or acyl chloride-alcoholysis method.

The esterification method includes: under the protection of a protective gas, the rosin diacid with the structure of formula III or formula IV reacts with the glycol HO-R ₂ -OH under the action of an esterification catalyst at 100°C to 200°C for 5h ~10h, after the reaction is completed, the rosin-based chain extender with the structure of formula I or formula II is obtained by purification.

Excessive dibasic alcohol HO-R ₂ -OH can increase the conversion rate of rosin diacid with formula III or formula IV structure. As a preference, the abietic diacid with dibasic alcohol HO-R The molar ratio of ₂ -OH is 1:2-10, which can convert more abietic diacids of formula III or IV into rosin-based chain extenders of formula I or II.

The transesterification method includes: first reacting rosin diacid with the structure of formula III or formula IV with methanol at 45°C to 75°C for 3h to 8h to obtain methyl abietate, and then reacting methyl abietate with dibasic alcohol HO- R ₂ -OH is subjected to a transesterification reaction at 100° C. to 200° C. for 3 hours to 5 hours under the action of a transesterification catalyst, and after the reaction is completed, the rosin-based chain extender with the structure of formula I or formula II is purified.

In order to improve the conversion rate, both methanol and diol HO-R ₂ -OH are in excess, as a preference, the three rosin diacids, methanol, and dibasic alcohol HO-R ₂ -OH of the formula III or formula IV The molar ratio is 1:2-10:2-10, which can increase the conversion rate of the rosin diacid with the structure of formula III or formula IV, and can convert more rosin-based chain extenders with the structure of formula I or formula II.

The acyl chloride-alcoholysis method comprises: first carry out the absin diacid with the structure of the formula III or IV and the acyl chloride reagent under the action of the acyl chloride catalyst at -15°C to 100°C for 3h to 5h, and the reaction ends Afterwards, distill under reduced pressure (to remove excess acyl chloride reagent) to obtain rosin dichloride, and then react rosin dichloride with dihydric alcohol HO-R ₂ -OH at 20°C-100°C for 3h-5h under the action of an acid-binding agent. , to obtain a rosin-based chain extender with a structure of formula I or formula II.

In order to improve the conversion rate, both the acid chloride reagent and the diol HO-R ₂ -OH are in excess, as a preference, the abietic diacid with the structure of formula III or formula IV, the acid chloride reagent, the diol HO-R ₂ - The molar ratio of the three OH is 1:10~40:2~10, which can increase the conversion rate of the abietic diacid with the structure of formula III or formula IV, and can convert more rosin-based chain extensions with the structure of formula I or formula II agent.

The esterification catalyst and the transesterification catalyst can be one or more of inorganic acid catalysts such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, etc., or solid acid catalysts. The addition amount of the esterification catalyst and the transesterification catalyst may be a small amount known to those skilled in the art. The added amount of the catalyst (referring to the molar amount) is 0.01%-0.4% of the molar amount (ie the amount of substance) of the abietic diacid with the structure of formula III or formula IV.

The acyl chloride reagent is thionyl chloride, phosphorus pentachloride, phosphorus trichloride or oxalyl chloride, and the acyl chloride catalyst is one of N,N-dimethylformamide, imidazole derivatives, triethylamine, pyridine, etc. or several, the addition amount of the acid chloride catalyst (referring to the molar amount) is 0.01% to 6% of the molar amount (ie the amount of substance) of the abietic diacid with the structure of formula III or formula IV. The acid-binding agent is one or more of inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, barium hydroxide, and lithium hydroxide, or organic weak bases such as pyridine and triethylamine, that is, the above-mentioned The acid binding agent is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, barium hydroxide, lithium hydroxide, pyridine, triethylamine, and the molar addition amount of the acid binding agent is formula III or formula 2 to 3 times the molar amount (that is, the amount of substance) of the rosin diacid with structure IV.

The rosin-based chain extender of the present invention is a rosin-based diol, which can react with other compounds to synthesize a high-performance polymer material, such as a rosin-based shape-memory polyurethane, and the rosin-based shape-memory polyurethane has a high Responsiveness.

Compared with the prior art, the present invention has the following advantages:

In the present invention, the raw material for synthesizing the rosin-based chain extender is rosin, and rosin is an important natural renewable resource in my country. Our country produces 500,000 to 600,000 tons of rosin per year, and is the country with the largest rosin production in the world. It has the world's rosin price. decision-making power. Rosin is cheap, and the prepared rosin-based shape-memory polyurethane product has high added value. Rosin is a renewable resource, and the utilization of renewable resources is of great significance to saving oil resources and protecting the environment. In addition, the preparation method of the rosin-based chain extender of the present invention is simple in preparation, easy in implementation, strong in operability, and easy in large-scale industrial production.

In the present invention, the preparation method of rosin-based shape-memory polyurethane is simple to prepare, easy to implement, strong in operability, and easy for large-scale industrial production. At the same time, the prepared rosin-based shape-memory polyurethane has excellent recovery and is very suitable as a shape-memory Material. In the hard segment of rosin-based shape memory polyurethane, the diisocyanate reacts with the rosin-based chain extender to form a carbamate bond, and there is a very strong hydrogen bond between them, and rosin has a very large hydrogen phenanthrene ring structure, which is not easy to occur deformation, thus acting as a stable physical cross-linking point throughout the system. After deformation, the physical cross-linking points are not easy to be destroyed, and the recovery performance is excellent. In the present invention, the T _g or T _m of the soft segment formed by polyol is the deformation temperature, and the transition temperature of the obtained shape memory polyurethane can be adjusted by adjusting the composition of the soft segment according to actual needs. The polyurethane is processed into a certain shape when it is higher than the deformation temperature, and then cooled to a temperature lower than the deformation temperature to set the shape; when the temperature is higher than the deformation temperature again, the polyurethane material can quickly return to the original shape, showing the performance of shape memory .

Description of drawings

Fig. 1 is the NMR spectrum of the rosin-based chain extender of formula I structure prepared in embodiment 1;

Fig. 2 is the NMR spectrum of the rosin-based chain extender of the formula II structure prepared in Example 2;

Fig. 3 is the infrared spectrogram of the rosin-based chain extender of formula I structure prepared in embodiment 1;

Fig. 4 is the infrared spectrogram of the rosin-based shape-memory polyurethane prepared in Example 7.

Detailed ways

The examples given are to better illustrate the content of the present invention, but the content of the present invention is not limited to the examples given. It is clear to those skilled in the art that without departing from the spirit or essential characteristics of the present invention , Proper modifications can be made to the ratio of raw materials, selection of raw materials, operating conditions, synthesis process, material structure, etc. Therefore, the embodiments disclosed in the examples are illustrative in all respects, not restrictive.

The embodiment is divided into two parts: the first part, the synthesis of rosin-based chain extender; the second part, the preparation of rosin-based shape memory polyurethane.

Synthesis of the first part rosin-based chain extender

Example 1

Rosin diacid (formula III, R ₁ is a benzene ring segment) 51.926g, ethylene glycol (HO-R ₂ -OH, R ₂ is a C ₂ aliphatic segment) 12.4g, sulfuric acid 0.04g, under nitrogen protection React at 150°C for 5 hours, wash with 0.1mol NaOH aqueous solution after the reaction, remove excess ethylene glycol and possibly unreacted rosin diacid to obtain a crude product, wash the crude product with methanol, and dry in vacuo to obtain an abietyl group with the structure of formula I Chain extender (i.e. ethylene glycol rosin dioate).

The H NMR spectrum of the rosin-based chain extender with the structure of formula I prepared in Example 1 is shown in Figure 1, the solvent is deuterated chloroform, and the internal standard is tetramethylsilane. δ=5.5ppm is the hydrogen on the double bond on the rosin skeleton (shown at position a on the figure), and its integral area is 1, which can prove the existence of the rosin skeleton. The four groups of peaks at δ=3.8ppm, δ=3.9ppm, δ=4.2ppm, and δ=4.5ppm have an integrated area of 2, each representing the four methylenes shown in b, c, d, and e on the figure Hydrogen atoms on the base. The two groups of peaks at δ=7.3ppm and δ=8.1ppm represent the four hydrogen atoms shown in h, i, f, and g on the figure. The obtained H NMR spectrum is completely consistent with the structure, which can prove the successful preparation of the rosin-based chain extender with the structure of formula I.

The infrared spectrogram of the rosin-based chain extender of the formula I structure prepared in Example 1 is shown in Figure 3, 1778cm ^-1 is the stretching vibration absorption peak of the C=O bond on the imide ring, and 3456cm ^-1 is the peak of —OH The stretching vibration absorption peak, 1708cm ^-1 is the stretching vibration absorption peak of the C=O bond on the ester bond, which can further prove that the prepared rosin-based chain extender has the structure of formula I.

Example 2

Rosin diacid (formula IV) 37.4g, ethylene glycol (HO-R ₂ -OH, R ₂ is an aliphatic segment of C ₂ ) 12.4g, p-toluenesulfonic acid 0.04g, reacted at 150℃ for 5h under nitrogen protection, After the reaction, wash with 0.1mol NaOH aqueous solution to remove excess ethylene glycol and possibly unreacted rosin diacid to obtain a crude product, then wash the crude product with ethanol, and dry in vacuo to obtain a rosin-based chain extender of formula II structure (ie, rosin diacid glycol ester diol).

Among them, _R2 is

The H NMR spectrum of the rosin-based chain extender with the structure of formula II prepared in Example 2 is shown in Figure 2, the solvent is deuterated chloroform, and the internal standard is tetramethylsilane. δ=5.5ppm is the hydrogen on the double bond on the rosin skeleton (shown at position a on the figure), and its integral area is 1, which can prove the existence of the rosin skeleton. δ=3.8ppm-3.9ppm, two groups of peaks at δ=4.2ppm-4.5ppm, the integral area is 4, each represents the total of 4 methylene shown in b, c, d, e on the figure 8 hydrogen atoms, combined with the infrared spectrum can prove the successful preparation of the rosin-based chain extender with the structure of formula II.

Example 3

Rosin diacid (formula III, R ₁ is methylene) 45.73g, methanol 6.4g, phosphoric acid 0.036g, react at 45°C for 5h, distill off excess methanol under reduced pressure to obtain rosin diacid dimethyl. Then add 36g of 1,3-propanediol (HO-R ₂ -OH, R ₂ is a C ₃ aliphatic segment), and react at 150°C, during which methanol is distilled off, and the reaction ends after 5 hours. After the reaction, wash with water to wash off excess 1,3-propanediol to obtain a crude product, then wash with methanol, and dry in vacuum to obtain a rosin-based chain extender with the structure of formula I (ie propylene glycol rosindialate). It can be proved that the prepared rosin-based chain extender has the structure of formula I by proton nuclear magnetic spectrum and infrared spectrum.

Example 4

Rosin diacid (formula IV) 37.4g, methanol 9.6g, p-toluenesulfonic acid 0.036g, react at 65°C for 4h, distill off excess methanol under reduced pressure to obtain rosin diacid dimethyl ester. Then add 36g of 1,4-butanediol (HO-R ₂ -OH, R ₂ is a C ₄ aliphatic segment), and react at 120°C, during which methanol is distilled off, and the reaction ends after 5 hours. After the reaction, wash with water to wash off excess 1,4-butanediol to obtain a crude product, then wash with methanol, and dry in vacuum to obtain a rosin-based chain extender with a structure of formula II (ie, ethylene glycol rosindialate). It can be proved that the prepared rosin-based chain extender has the structure of formula II by proton nuclear magnetic spectrum and infrared spectrum.

Among them, _R2 is

Example 5

Rosin diacid (formula III, R ₁ is meta-phenyl) 51.926g, thionyl chloride 150mL, catalyst N,N-dimethylformamide 0.3g, react at 25°C for 5h, and distill under reduced pressure after the reaction Remove excess thionyl chloride to obtain rosin diacid dichloride. Then add 24.8g of ethylene glycol (HO- _R2 -OH, _R2 is an aliphatic segment of _C2 ), 16g of acid-binding agent pyridine, and 50mL of acetone, react at 35°C for 5h, evaporate the solvent after the reaction, and wash with water Remove excess ethylene glycol, pyridine and generated by-products such as pyridine hydrochloride to obtain a crude product. The crude product is washed with ethanol and dried to obtain a rosin-based chain extender with the structure of formula I. It can be proved that the prepared rosin-based chain extender has the structure of formula I by proton nuclear magnetic spectrum and infrared spectrum.

Example 6

Rosin diacid (IV) 37.4g, oxalyl chloride 150mL, catalyst pyridine 0.5g, react at -15°C for 3h, after the reaction was completed, excess oxalyl chloride was distilled off under reduced pressure to obtain rosin diacid diachloride. Then add 24.8g of ethylene glycol (HO- _R2 -OH, _R2 is an aliphatic segment of _C2 ), 21g of acid-binding agent triethylamine, 50mL of toluene, react at 80°C for 5h, evaporate the solvent after the reaction , washed with water to remove excess ethylene glycol, triethylamine and by-products such as triethylamine salts generated to obtain a crude product. The crude product is washed with ethanol, and dried to obtain a rosin-based chain extender with a structure of formula II (ie, ethylene glycol rosin dioate). It can be proved that the prepared rosin-based chain extender has the structure of formula II by proton nuclear magnetic spectrum and infrared spectrum.

Among them, _R2 is

The second part preparation of rosin-based shape memory polyurethane

Example 7

After mixing polytetrahydrofuran ether diol (number average molecular weight 2000), diphenylmethane diisocyanate (MDI), rosin-based chain extender obtained in Example 1, and stannous octoate in a molar ratio of 1:3:2:0.005, Add it into the reactor, react at 75°C for 3 hours, add anhydrous acetone (the amount added is 30% of the total mass of polytetrahydrofuran ether glycol, diphenylmethane diisocyanate, rosin-based chain extender and stannous octoate) to adjust viscosity. After the reaction is finished, the acetone is removed by vacuum drying to obtain the rosin-based shape-memory polyurethane.

The infrared spectrogram of the rosin-based shape memory polyurethane prepared in Example 7 is shown in Figure 4, wherein 1772 cm ^-1 is the C=O stretching vibration absorption peak on the imide group on the rosin-based chain extender, which proves that the rosin-based chain extender The chain agent was successfully introduced into the main chain of polyurethane; 3323cm ^-1 and 1530cm ^-1 were the stretching vibration absorption peaks of NH and bending vibration absorption peaks of amide II respectively; 1720cm ^-1 was the stretching vibration absorption peak of C=O; the above three The group characteristic peak is the characteristic absorption peak of the urethane bond in polyurethane, which can prove the successful preparation of rosin-based shape memory polyurethane.

The recovery rate of the obtained rosin-based shape memory polyurethane is 90% under 500% deformation, and the recovery deformation is 450%. The test method is as follows: ① On a universal material testing machine, stretch at a tensile rate of 50mm/min to the corresponding deformation, and then cool the sample with liquid nitrogen to fix the deformation. ②Remove the sample from the universal testing machine and place it at room temperature (25°C) for 3 minutes to recover, and test the recovery rate of deformation. The following examples are all tested according to this method.

Example 8

Mix polybutylene succinate diol (number-average molecular weight 1000), isophorone diisocyanate (IPDI), and dibutyltin dilaurate at a molar ratio of 1:5:0.001 and add them to the reactor. React at 65°C for 3h to obtain a prepolymer. Then heat up to 100°C, add the rosin-based chain extender obtained in Example 2 (the molar amount of the rosin-based chain extender is 4 times the molar amount of polybutylene succinate diol), react for 5 hours, and the reaction process Add anhydrous toluene (the amount added is 40% of the total mass of polybutylene succinate diol, isophorone diisocyanate, rosin-based chain extender and dibutyltin dilaurate) to adjust the viscosity. After the reaction is finished, the solvent is removed by vacuum drying to obtain the rosin-based shape-memory polyurethane. The obtained rosin-based shape memory polyurethane has a recovery rate of 96% under 800% deformation, and a recovery deformation of 768%.

Example 9

After mixing polyethylene glycol (number average molecular weight 2000), hexamethylene diisocyanate (HDI), rosin-based chain extender obtained in Example 3, and stannous octoate in a molar ratio of 1:3:2:0.005, add Into the reactor, react at 80°C for 3 hours, add anhydrous butanone in the middle (addition amount is 20% of the total mass of polyethylene glycol, hexamethylene diisocyanate, rosin-based chain extender and stannous octoate) to adjust the viscosity . After the reaction, the methyl ethyl ketone is removed by vacuum drying to obtain the rosin-based shape-memory polyurethane. The recovery rate of the obtained rosin-based shape memory polyurethane is 95% under 400% deformation, and the recovery deformation is 380%.

Example 10

Mix polytetrahydrofuran ether diol (number average molecular weight 500), toluene diisocyanate (TDI), rosin-based chain extender obtained in Example 4, and stannous octoate in a molar ratio of 1:3:2:0.005, and then add it to the reactor , react at 75°C for 3 hours, and add anhydrous acetone (the amount added is 50% of the total mass of polytetrahydrofuran ether glycol, toluene diisocyanate, rosin-based chain extender and stannous octoate) to adjust the viscosity. After the reaction is finished, the acetone is removed by vacuum drying to obtain the rosin-based shape-memory polyurethane. The obtained rosin-based shape-memory polyurethane has a recovery rate of 93% under 300% deformation, and a recovery deformation of 279%.

Example 11

Mix polycaprolactone diol (number average molecular weight 6000), dicyclohexyl diisocyanate (HMDI), and tetrabutyl titanate in a molar ratio of 1:4:0.001, then add them to the reactor, and react at 65°C 3h, the prepolymer was obtained. Then heat up to 100°C, add the rosin-based chain extender obtained in Example 5 (the molar amount of the rosin-based chain extender is 3 times the molar amount of polycaprolactone diol), react for 5 hours, add anhydrous Toluene (the amount added is 35% of the total mass of polycaprolactone diol, dicyclohexyl diisocyanate, rosin-based chain extender and tetrabutyl titanate) is used to adjust the viscosity. After the reaction is finished, the solvent is removed by vacuum drying to obtain the rosin-based shape-memory polyurethane. The recovery rate of the obtained rosin-based shape memory polyurethane is 91% under 1000% deformation, and the recovery deformation is 910%.

Claims (7)

1. a preparation method of rosin-based shape-memory polyurethane, is characterized in that, comprises the following steps: Polyol, diisocyanate and rosin-based chain extender are synthesized by one-step or two-step method under the action of catalyst to obtain rosin-based shape memory polyurethane; The molar amount of the diisocyanate is equal to the sum of the molar amounts of the polyol and the rosin-based chain extender, and the molar ratio of the polyol, diisocyanate, and rosin-based chain extender is 1:3 to 5:2 ~4; The rosin-based chain extender is a compound of formula I or formula II; Wherein, R ₁ is selected from an aromatic segment or an aliphatic segment of C ₁ to C ₁₄ ; R ₂ is selected from an aromatic segment or an aliphatic segment of C ₁ to C ₁₄ ; R ₁ and R ₂ are the same or different . 2. the preparation method of rosin-based shape-memory polyurethane according to claim 1, is characterized in that, described one-step method comprises: Polyhydric alcohol, diisocyanate, rosin chain extender and catalyzer are together under the protection of protective gas in React at 50°C-150°C for 3h-5h, and discharge after the reaction to obtain rosin-based shape-memory polyurethane. 3. The preparation method of rosin-based shape-memory polyurethane according to claim 1, characterized in that, the two-step method comprises: polyol, diisocyanate and catalyst are first heated at 50°C to 100°C under the protection of protective gas. The reaction is carried out for 1 hour to 3 hours to obtain a prepolymer, and then a rosin-based chain extender is added to carry out a chain extension reaction for 3 hours to 5 hours. After the reaction is completed, the material is discharged to obtain a rosin-based shape-memory polyurethane. 4. The method for preparing rosin-based shape memory polyurethane according to claim 1, 2 or 3, characterized in that the molar ratio of the catalyst to the polyol is 0.001-0.01:1. 5. according to the preparation method of the described rosin base shape memory polyurethane of claim 1,2 or 3, it is characterized in that, described polyol is one or both in polyester polyol, polyether polyol, wherein , the number average molecular weight of polyester polyol and polyether polyol is 500-20000; The diisocyanate is one or more of aliphatic diisocyanate, aromatic diisocyanate and alicyclic diisocyanate; The catalyst is one or more of the catalysts for organic tin polyurethane synthesis, titanate polyurethane synthesis and organic bismuth polyurethane synthesis. 6. The preparation method of rosin-based shape-memory polyurethane according to claim 1, characterized in that, in the one-step or two-step synthesis, an organic solvent is added to adjust the viscosity, and the organic solvent used to adjust the viscosity is a good solvent for polyurethane. 7. the preparation method of rosin-based shape-memory polyurethane according to claim 6 is characterized in that, described organic solvent is acetone, butanone, ethyl acetate, N,N-dimethylformamide, N,N - One or more of dimethylacetamide and toluene.