阅读说明：本技术 生物质粒子复合聚氨酯弹性体及其制备方法 (Biomass particle composite polyurethane elastomer and preparation method thereof ) 是由 李再峰 辛晨 李子健 罗明艳 于 2019-12-03 设计创作，主要内容包括：本发明提出一种生物质粒子复合聚氨酯弹性体及其制备方法,属于聚氨酯材料领域,能够解决乌贼墨在聚合体系中不易分散,影响其在聚氨酯弹性体中应用的问题。该技术方案包括以下步骤：将乌贼墨粒子溶解后在聚合物多元醇中预分散,通过与异氰酸酯反应制备得到黑色素杂化的预聚体,将黑色素杂化的预聚体与扩链剂反应制备出聚氨酯弹性体,通过对其后硫化,得到生物质粒子复合的聚氨酯弹性体。制备得到的生物质粒子复合的聚氨酯弹性体具有普通聚氨酯弹性体不具备的高强度、高导热、耐热氧老化等特性,且随着乌贼墨粒子含量的增加,该聚氨酯弹性体的抗张强度和导热能力逐渐增加,且使其抗热氧老化能力得到大大改善。(The invention provides a biomass particle composite polyurethane elastomer and a preparation method thereof, belongs to the field of polyurethane materials, and can solve the problem that sepia is not easy to disperse in a polymerization system and the application of sepia in the polyurethane elastomer is influenced. The technical scheme comprises the following steps: dissolving sepia particles, pre-dispersing in polymer polyol, reacting with isocyanate to obtain melanin hybrid prepolymer, reacting the melanin hybrid prepolymer with a chain extender to prepare a polyurethane elastomer, and vulcanizing to obtain the biomass particle composite polyurethane elastomer. The prepared biomass particle composite polyurethane elastomer has the characteristics of high strength, high heat conductivity, thermal-oxidative aging resistance and the like which are not possessed by common polyurethane elastomers, and with the increase of the content of sepia particles, the tensile strength and the heat conductivity of the polyurethane elastomer are gradually increased, and the thermal-oxidative aging resistance of the polyurethane elastomer is greatly improved.)

1. The preparation method of the biomass particle composite polyurethane elastomer is characterized in that sepia particles are dissolved and then pre-dispersed in polymer polyol, a melanin hybrid prepolymer is prepared by reacting with isocyanate, the melanin hybrid prepolymer is reacted with a chain extender to prepare the polyurethane elastomer, and the polyurethane elastomer is vulcanized to obtain the biomass particle composite polyurethane elastomer.

2. The preparation method according to claim 1, wherein the pre-dispersing of the dissolved sepia particles in the polymer polyol comprises:

vacuum drying protease-treated cuttlefish ink at 60-80 deg.C for 12-36h, grinding, and sieving with 300-400 mesh sieve to obtain cuttlefish ink particles;

dissolving the sieved cuttlefish ink particles in DMF, mixing with polymer polyol, performing ultrasonic treatment for 3-4h under stirring at 250r/min for 150-.

3. The preparation method according to claim 2, wherein the mass ratio of the sepia particles to the DMF is 1 (8-12), and the mass ratio of the sepia particles to the polymer polyol is 1-10%.

4. The production method according to any one of claims 1 to 3, wherein the polymer polyol is one of a hydroxyl-terminated nitrile polymer polyol, a polypropylene oxide ether glycol, a polytetrahydrofuran ether glycol, a polyester polyol, a polycarbonate polyol, and a hydroxyl-containing vegetable oil; the diisocyanate is one of TDI, MDI, IPDI, HDI, PPDI and NDI.

5. The preparation method of claim 1, wherein the preparation of the melanin hybridization prepolymer specifically comprises:

adding the pre-dispersed sepia particle dispersion liquid into a reaction container, stirring in vacuum at the temperature of 100-110 ℃ for 1-2h to remove trace water in polymer polyol, then cooling to 50-60 ℃, adding diisocyanate, heating to 60-70 ℃, reacting for 1-2h, then cooling to 50 ℃, and removing bubbles in vacuum for 0.5-1h to obtain the melanin hybridized prepolymer.

6. The preparation method according to claim 5, wherein the mass concentration of the sepia particles in the prepolymer is 1% -10%, preferably 1% -2%; the mass content of-NCO group in the prepolymer is 3.5-10.0%, preferably 6%.

7. The method according to claim 1, wherein the step of obtaining the biomass particle-polyurethane composite elastomer comprises:

transferring the synthesized prepolymer into a reaction container, adding a chain extender at one time, stirring vigorously, injecting into a mold preheated at 110 ℃ and 100-;

and (3) vulcanizing the vulcanized elastomer at the temperature of 100-110 ℃ for 10-12h, and then placing the vulcanized elastomer at room temperature for 60-72h to obtain the biomass particle composite polyurethane elastomer.

8. The method of claim 7, wherein the chain extender is one of DMTDA, DETDA, MOCA, 1, 4-butanediol, and 1, 3-propanediol.

9. The method according to claim 7, wherein the ratio of the chain extension coefficient of the amine group or the hydroxyl group of the chain extender to the chain extension coefficient of the NCO functional group in the prepolymer is 0.9 to 1.1, and preferably the chain extension coefficient is 1.0.

10. The biomass particle composite polyurethane elastomer produced by the production method according to any one of claims 1 to 9.

Technical Field

The invention belongs to the field of polyurethane materials, and particularly relates to a preparation method of a biomass particle composite polyurethane elastomer.

Background

In the field of nano-composite of polyurethane elastomers, common inorganic reinforcing additives comprise inorganic nano-particles such as layered silicate particles, carbon nano-tubes, graphene and silicon dioxide, and the polar functional groups such as hydroxyl and carboxyl on the surfaces of the nano-particles and the polar functional groups of polyurethane molecules have stronger physicochemical action so as to show stronger reinforcing and toughening action. However, these reinforcing additives are often required to be added with an anti-aging agent, and although the common anti-aging agent can resist thermal oxidation aging performance of the polyurethane elastomer, the physical performance of the polyurethane elastomer is reduced, so that the action effect of the inorganic reinforcing additive is limited.

The cuttlefish is known as one of four marine products in China, and has abundant cuttlefish resources in the east sea and Bohai sea in China. Researches indicate that the sepia melanin has a magical composite effect on the polyurethane elastomer, so that the tensile strength and the toughness of the polyurethane elastomer can be greatly improved, and the aging resistance of the polyurethane can be improved.

Chinese invention patent CN108264862A discloses a preparation method of a melanin stabilizer and a weather-resistant silane modified polyurethane sealant, which separates and purifies melanin by a water washing method and an enzymolysis method, improves the dispersion performance of the melanin by using the combination of the melanin and a hindered amine organic compound, further improves the capability of eliminating ultraviolet rays and obviously improves the ultraviolet aging resistance of the sealant. However, since a large amount of polypeptides and proteins are adhered among sepia particles, the sepia particles are not easily dispersed in a polymerization system, and thus the wide application of the sepia particles in polyurethane elastomers is influenced.

Disclosure of Invention

The invention provides a biomass particle composite polyurethane elastomer and a preparation method thereof aiming at the technical problems, and the polyurethane elastomer with excellent mechanical property, thermal-oxidative aging resistance and high heat conductivity is prepared by the method.

The invention discloses a preparation method of a biomass particle composite polyurethane elastomer, which comprises the steps of dissolving sepia particles, pre-dispersing in polymer polyol, reacting with isocyanate to obtain a melanin hybrid prepolymer, reacting the melanin hybrid prepolymer with a chain extender to prepare the polyurethane elastomer, and vulcanizing to obtain the biomass particle composite polyurethane elastomer.

Preferably, the pre-dispersing of the cuttlefish ink particles in the polymer polyol after dissolution specifically comprises:

vacuum drying protease-treated cuttlefish ink at 60-80 deg.C for 12-36h, grinding, and sieving with 300-400 mesh sieve to obtain cuttlefish ink particles;

dissolving the sieved cuttlefish ink particles in DMF, mixing with polymer polyol, performing ultrasonic treatment for 3-4h under stirring at 250r/min for 150-.

Preferably, the mass ratio of the sepia particles to the DMF is 1 (8-12), and the mass ratio of the sepia particles to the polymer polyol is 1-10%.

Preferably, the polymer polyol is one of hydroxyl-terminated butyronitrile polymer polyol, polypropylene oxide ether glycol, polytetrahydrofuran ether glycol, polyester polyol, polycarbonate polyol and vegetable oil containing hydroxyl; the diisocyanate is one of TDI (toluene diisocyanate), MDI (diphenylmethane diisocyanate), IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate), PPDI (p-phenylene diisocyanate) and NDI (1, 5-naphthalene diisocyanate).

Preferably, the preparation of the melanin hybridization prepolymer specifically comprises the following steps: adding the pre-dispersed sepia particle dispersion liquid into a reaction container, stirring in vacuum at the temperature of 100-110 ℃ for 1-2h to remove trace water in polymer polyol, then cooling to 50-60 ℃, adding diisocyanate, heating to 60-70 ℃, reacting for 1-2h, then cooling to 50 ℃, and removing bubbles in vacuum for 0.5-1h to obtain the melanin hybridized prepolymer.

Preferably, the mass concentration of the cuttlefish ink particles in the prepolymer is 1% -10%, preferably 1% -2%; the mass content of-NCO group in the prepolymer is 3.5-10.0%, preferably 6%.

Preferably, the step of obtaining the biomass particle composite polyurethane elastomer specifically comprises:

transferring the synthesized prepolymer into a reaction container, adding a chain extender at one time, stirring vigorously, injecting into a mold preheated at 110 ℃ and 100-;

and (3) vulcanizing the vulcanized elastomer at the temperature of 100-110 ℃ for 10-12h, and then placing the vulcanized elastomer at room temperature for 60-72h to obtain the biomass particle composite polyurethane elastomer.

Preferably, the chain extender is one of DMTDA (dimethylthiotoluenediamine), DETDA (diethyltoluenediamine), MOCA (3,3 '-dichloro-4, 4' -diaminodiphenylmethane), 1, 4-butanediol, and 1, 3-propanediol.

Preferably, the ratio of the chain extension coefficient of the amine group or the hydroxyl group of the chain extender to the chain extension coefficient of the NCO functional group in the prepolymer is 0.9-1.1, and the preferable chain extension coefficient is 1.0.

The invention also provides the biomass particle composite polyurethane elastomer prepared by the preparation method according to any one of the technical schemes.

Compared with the prior art, the invention has the advantages and positive effects that:

1. according to the invention, sepia is used for synthesizing the polyurethane elastomer, and the surfaces of sepia pigment particles contain a large amount of organic oxygen-containing functional groups, so that the method is beneficial to increasing the microphase separation degree in polyurethane, and endows the polyurethane elastomer with excellent mechanical properties, better thermal-oxidative aging resistance and excellent heat conduction capacity.

2. The invention adopts an ultrasonic-assisted mixing technology, dissolves cuttlefish ink, then carries out ultrasonic pre-dispersion in polymer polyol, then reacts with diisocyanate to generate a prepolymer, and then carries out chain extension curing reaction with a chain extender to prepare the nano-micro black element compound modified novel polyurethane elastomer.

3. The special molecular structure of the sepia pigment improves the aging resistance of polyurethane, improves the physical and mechanical properties of polyurethane elastomer, and overcomes the defect that the physical properties of polyurethane can be reduced while the thermal oxidation aging resistance of the polyurethane elastomer can be improved by the traditional anti-aging agent.

4. In the food processing process, the cuttlefish ink is usually discarded as waste, and has higher yield and extremely low price.

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.

The embodiment of the invention provides a preparation method of a biomass particle composite polyurethane elastomer, which comprises the steps of dissolving sepia particles, pre-dispersing in polymer polyol, reacting with isocyanate to prepare a melanin-hybridized prepolymer, reacting the melanin-hybridized prepolymer with a chain extender to prepare the polyurethane elastomer, and vulcanizing the polyurethane elastomer to obtain the biomass particle composite polyurethane elastomer.

In the above embodiment, the sepia is used for synthesizing the polyurethane elastomer, wherein the surface of the sepia particle contains a large amount of organic oxygen-containing functional groups, the dispersibility of the sepia particle in the product is improved by improving the adding mode of the sepia, the micro-phase separation degree in polyurethane is increased, and the polyurethane elastomer can be endowed with excellent mechanical properties, better thermal-oxidative aging resistance and excellent heat conductivity by combining with the post-vulcanization step. Cuttlefish ink particle

In an alternative embodiment, the pre-dispersing of the sepia particles in the polymer polyol after dissolution specifically comprises:

vacuum drying protease-treated cuttlefish ink at 60-80 deg.C for 12-36h, grinding, and sieving with 300-400 mesh sieve to obtain cuttlefish ink particles;

dissolving the sieved cuttlefish ink particles in DMF, mixing with polymer polyol, performing ultrasonic treatment for 3-4h under stirring at 250r/min for 150-.

In the above examples, the method comprises treating cuttlefish ink with subtilisin to break the binding polypeptide and protein between cuttlefish ink particles, thereby obtaining highly dispersible cuttlefish ink particles; and further, the dispersibility of the cuttlefish ink particles is improved by dissolving in the solvent and then mixing with the ultrasonic waves, so that the performance of the product in the subsequent steps is ensured. It is understood that, regarding the above parameters of the rotation speed, temperature and time, the skilled person can adjust the above ranges according to the actual situation, for example, in the step of obtaining the sepia particles, the temperature can be 65, 70, 75 ℃ or any point value in the above ranges, and the time can be 15, 18, 20, 24, 26, 30, 32h or any point value in the above ranges; in the latter step, the rotation speed may be 160, 180, 200, 220r/min, the temperature may be 72, 75, 76, 78 ℃ or any value within the above range, and the time may be 45, 50, 55h or any value within the above range.

In a preferred embodiment, the mass ratio of the sepia particles to the DMF is 1 (8-12), and the mass ratio of the sepia particles to the polymer polyol is 1-10%. The DMF solvent used in this example is a strongly polar solvent, and can dissolve sepia particles into smaller particles, thereby being easily dispersed in the polymer polyol. The mass ratio of the sepia particles to DMF was 1:8, which was the minimum amount of sepia particles that could be dissolved, and the sepia particles were difficult to disperse even with a small amount of solvent. It will be appreciated that more solvent than 1:12 may be used to ensure adequate dispersion.

In a preferred embodiment, the polymer polyol is one of a hydroxyl-terminated butyronitrile polymer polyol, a polypropylene oxide ether glycol, a polytetrahydrofuran ether glycol, a polyester polyol, a polycarbonate polyol, and a hydroxyl-containing vegetable oil. In a further preferred embodiment, the polymer polyol is a hydroxyl-terminated nitrile polymer polyol, with which the resulting polyurethane elastomer has optimum properties, preferably a relative molecular mass of 1000. It is understood that the hydroxyl-terminated nitrile polymer polyol is a high viscosity polymer polyol with molecular weight higher than 1000, and the viscosity of the system is too high to facilitate the processing of high quality polyurethane elastomers; the molecular weight is lower than 1000, the mechanical property of the prepared polyurethane elastomer is lower, and the research base shows that when the molecular weight is 1000, the polymer polyol shows the best comprehensive property. Of course, this embodiment is not limited to hydroxyl terminated nitrile polymer polyols, but may be other possible examples.

In an optional embodiment, the preparation of the pigment hybridization prepolymer specifically comprises: adding the pre-dispersed sepia particle dispersion liquid into a reaction container, stirring for 1-2h under vacuum at the temperature of 100-110 ℃, then cooling to 50-60 ℃, adding diisocyanate, heating to 60-70 ℃, reacting for 1-2h, then cooling to 50 ℃, and removing bubbles in vacuum for 2-3h to obtain the pigment hybrid prepolymer.

In the above examples, the mixing, complete reaction, complete defoaming, and desired product formation were achieved within the temperature and time ranges described. It will be appreciated that the parameters may be suitably adjusted within the ranges described, for example, the temperature of the vacuum agitation may also be 102 ℃, 104 ℃, 106 ℃ or 108 ℃ and the time may be 1.2h, 1.4h, 1.6h or 1.8 h; the reaction temperature can also be 62 ℃, 64 ℃, 66 ℃ or 68 ℃, and the time can be 1.2h, 1.4h, 1.6h or 1.8 h; the vacuum degassing and bubble removing time can be 2.2h, 2.4h, 2.6h or 2.8 h.

In an optional embodiment, the mass concentration of the sepia particles in the prepolymer is 1% -10%; the mass content of-NCO group in the prepolymer is 3.5-10.0%, preferably 6%. It can be understood that, with the increase of the content of the sepia ink, the tensile strength and the thermal conductivity of the prepolymer are both significantly increased, but due to the characteristic of easy agglomeration, the thermal-oxidative aging resistance is gradually reduced, so that the expected product effect can be obtained only by adjusting the mass concentration of the sepia ink within the above range. In addition, the mass content of-NCO group in the prepolymer needs to be regulated and controlled within the above range, mainly because the viscosity of the prepolymer is too high when the mass content is lower than 3.5 percent, and the high-quality polyurethane elastomer is difficult to be manually manufactured; and when the content is higher than 10%, the hardness of the polyurethane elastomer processed by the prepolymer method is too high, and the mechanical property, the elasticity and the toughness are poor.

In an alternative embodiment, the diisocyanate is one of TDI (toluene diisocyanate), MDI (diphenylmethane diisocyanate), IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate), PPDI (p-phenylene diisocyanate), and NDI (1, 5-naphthalene diisocyanate). It can be understood that TDI in the compound is liquid at normal temperature, has moderate activity, is beneficial to reaction and process control, and is very ideal diisocyanate; the other compounds can achieve the effects, but MDI, PPDI and NDI are crystals at room temperature, and need to be heated and melted before use, so that the reaction cost is increased, and the production process is complicated; IPDI and HDI are low in activity, and the ideal effect can be approached by adding a catalyst when the catalyst is used.

In an alternative embodiment, the step of obtaining the biomass particle composite polyurethane elastomer specifically includes: transferring the synthesized prepolymer into a reaction container, adding a chain extender at one time, stirring vigorously, injecting into a mold preheated at 110 ℃ and 100-; and (3) vulcanizing the vulcanized elastomer at the temperature of 100-110 ℃ for 10-14h, and then drying for 1-7 days in a dark place to obtain the biomass particle composite polyurethane elastomer. It will be appreciated that in this example, the reaction is complete over the temperature and time ranges described to give the desired product, and the skilled person can suitably adjust the parameters within the ranges described as required.

In an alternative embodiment, the chain extender is one of DMTDA (dimethylthiotoluenediamine), DETDA (diethyltoluenediamine), MOCA (3,3 '-dichloro-4, 4' -diaminodiphenylmethane), 1, 4-butanediol, and 1, 3-propanediol. The chain extenders listed in the above examples are commonly used diamine or diol small molecule chain extenders. Among them, DMTDA (dimethylthiotoluenediamine) is preferred because of its moderate activity, easy control of chemical reaction process, high mechanical properties, and being a non-carcinogenic chain extender; the other chain extenders can be selected by the technicians in the field, but MOCA is crystal and needs to be melted at high temperature before use, and the carcinogenicity is reported in literature data; 1, 4-butanediol and 1, 3-propanediol have low activity and relatively low mechanical property, so the effect is inferior to that of DMTDA.

In an alternative embodiment, the ratio of the chain extension coefficient of the amine group or the hydroxyl group of the chain extender to the chain extension coefficient of the NCO functional group in the prepolymer is 0.9-1.1, and the chain extension coefficient is preferably 1.0. The ratio of the coefficients is set within the above range, and it is considered that a high-performance polyurethane elastomer can be produced mainly within this range. When the chain extension coefficient ratio is less than 0.9, the elongation at break is small; when the tensile strength is more than 1.1, the elongation at break is larger, the toughness is better, and the tensile strength is lower. Only when the chain extension coefficient is within the above ratio range, and preferably 1.0, the molecular weight of the resulting polyurethane elastomer is maximized, and the overall properties are the best.

In order to more clearly and specifically describe the biomass particle composite polyurethane elastomer and the preparation method thereof provided in the embodiments of the present invention, the following description will be made with reference to specific examples.