阅读说明：本技术 一种生态聚酯多元醇及其制备方法 (Ecological polyester polyol and preparation method thereof ) 是由 王元有 于 2021-01-05 设计创作，主要内容包括：本案涉及一种生态聚酯多元醇及其制备方法,所述生态聚酯多元醇是以天然多元酸和天然多元醇为反应原料,通过梯次升温以及控制氮气流量进行酯化反应制得的。本发明使用的原材料均可由自然界中提取、原料来源广泛、价格低廉、可以再生；制备出的聚酯多元醇能够用于制备聚氨酯树脂,随后制成合成革,其湿法贝斯厚度和剥离强度性能优异；经济价值高、易于操作。(The scheme relates to ecological polyester polyol and a preparation method thereof, wherein the ecological polyester polyol is prepared by taking natural polybasic acid and natural polyol as reaction raw materials and performing esterification reaction through gradient heating and nitrogen flow control. The raw materials used by the invention can be extracted from nature, have wide sources and low price and can be regenerated; the prepared polyester polyol can be used for preparing polyurethane resin and then preparing synthetic leather, and the wet method bass thickness and the peel strength performance of the synthetic leather are excellent; high economic value and easy operation.)

1. The ecological polyester polyol is characterized in that natural polybasic acid and natural polyhydric alcohol are used as reaction raw materials, and esterification and ester exchange reaction are carried out by heating in steps and controlling nitrogen flow.

2. The ecological polyester polyol of claim 1, wherein the natural polyacid is one or more of lactic acid, saccharinic acid, oleic acid, palmitic acid, linolenic acid, and arachidic acid.

3. The ecological polyester polyol according to claim 1, wherein the natural polyol is one or more of xylitol, sorbitol, betulin and castor oil.

4. A method for preparing the ecological polyester polyol according to any one of claims 1 to 3, comprising the steps of:

1) putting natural polybasic acid and natural polyalcohol into a reaction kettle, and setting N in the reaction kettle₂Dehydrating at flow rate and temperature;

2) when the temperature at the top of the tower drops, the temperature is slowly increased, then the catalyst is added, and the N is increased₂Carrying out ester exchange reaction on the flow;

3) and (3) measuring the acid value and the hydroxyl value in the system by infrared, when the acid value in the system is lower than 0.3g/KOH and the hydroxyl value is within the range of 24-28 g/KOH, cooling the reaction kettle, and then packaging to obtain the ecological polyester polyol.

5. The method for preparing ecological polyester polyol according to claim 4, wherein the mass ratio of the polyol to the polyacid is 1-1.6: 1.

6. The method for preparing ecological polyester polyol according to claim 4, wherein the dehydration condition in the step 1) is to set N₂The flow rate is 3-4L/min, and the temperature is 130-.

7. The method for preparing ecological polyester polyol as claimed in claim 4, wherein the transesterification reaction condition in the step 2) is raising the temperature to 200-235 ℃, and setting N₂The flow rate is 10L/min.

8. The method for preparing the ecological polyester polyol according to claim 4, wherein the catalyst is tetraisopropyl titanate.

Technical Field

The invention relates to the field of polyester polyol synthesis, in particular to ecological polyester polyol and a preparation method thereof.

Background

Petrochemical resources such as crude oil and natural gas play an important role in the worldwide chemical industry, but are consumed all day after all due to the non-renewable defect. Practitioners of the chemical industry have been seeking renewable natural materials that can replace petrochemicals. But the renewable natural raw materials capable of replacing petrochemicals must have two characteristics of low price and wide raw material source or lose the economic significance.

The preparation of renewable polyester polyols using natural raw materials has become a research hotspot in the polyurethane industry in recent years. For example, triglyceride extracted from animal fat or vegetable oil can be hydrolyzed to prepare glycerol, and the glycerol can be used as a chain extender and an anti-blocking/viscosity-reducing auxiliary agent in polyurethane resin and also can be used as an initiator for producing polyether polyol, and plays an extremely important role in the field of polyurethane. Meanwhile, the biodiesel which is popular in recent years can also be prepared by the conversion of glycerol.

The raw materials of polyester polyol used in the polyurethane industry at present are all from the nonrenewable petrochemical industry, and the preparation of the polyester polyol by using renewable natural raw materials is relatively less.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to prepare the polyester polyol by utilizing natural polybasic acid and natural polyol through esterification and ester exchange and condensation polymerization, and the polyester polyol is applied to the field of polyurethane elastomers, thereby being beneficial to promoting the development of ecological environment-friendly materials in the polyurethane industry.

In order to achieve the purpose, the invention provides the following technical scheme:

an ecological polyester polyol is prepared from natural polybasic acid and natural polyol through esterification reaction by heating in steps and controlling nitrogen flow.

Further, the natural polybasic acid is one or more of lactic acid, saccharinic acid, oleic acid, palmitic acid, linolenic acid and arachidic acid.

Further, the natural polyol is one or more of xylitol, sorbitol, betulin and castor oil.

The invention further provides a preparation method of the ecological polyester polyol, which comprises the following steps:

1) putting natural polybasic acid and natural polyalcohol into a reaction kettle, and setting N in the reaction kettle₂Dehydrating at flow rate and temperature;

2) when the temperature at the top of the tower drops, the temperature is slowly increased, then the catalyst is added, and the N is increased₂Carrying out ester exchange reaction on the flow;

3) and (3) measuring the acid value and the hydroxyl value in the system by infrared, when the acid value in the system is lower than 0.3g/KOH and the hydroxyl value is within the range of 24-28 g/KOH, cooling the reaction kettle, and then packaging to obtain the ecological polyester polyol.

Further, the mass ratio of the polyhydric alcohol to the polybasic acid is 1-1.6: 1.

Further, theThe dehydration conditions in step 1) are set to N₂The flow rate is 3-4L/min, and the temperature is 130-.

Further, the transesterification reaction condition in the step 2) is to heat up to 200 ℃ and 235 ℃, and N is set₂The flow rate is 10L/min.

Further, the catalyst is tetraisopropyl titanate.

The invention has the beneficial effects that: compared with the prior art, the invention adopts the natural polybasic acid compound and the natural polybasic alcohol compound as the raw materials, and has the characteristics of excellent physical properties, low price and wide raw material source; the introduction of the compound is that the compound contains a plurality of hydroxyl groups, and the compound can generate condensation polymerization reaction to produce macromolecular polyester polyol; meanwhile, the polymer also contains other reaction functional groups, which can promote the generation of chain growth reaction, thereby being beneficial to forming macromolecular polymers.

According to N in the invention₂The flow rate can adjust the dehydration speed in the reaction system. According to the invention, a vacuumizing mode is not selected, so that part of polyhydric alcohol and polybasic acid can be effectively prevented from being taken away by water, the reaction efficiency is improved on one hand, and the COD content in the removed water is reduced on the other hand. Reaction earlier stage N₂Is a small flow, this stage N₂The function of the polyester polyol is mainly to prevent the polyester polyol from being oxidized by contacting with oxygen; increase of N in the late stage of reaction₂Flow rate, this stage N₂The effect of (b) is mainly to carry out the small amount of water generated by the transesterification reaction.

The raw materials used by the invention can be extracted from nature, have wide sources and low price and can be regenerated; the prepared polyester polyol can be used for preparing polyurethane resin and then preparing synthetic leather, and the wet method bass thickness and the peel strength performance of the synthetic leather are excellent; high economic value and easy operation.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. 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.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example (b): a preparation method of ecological polyester polyol comprises the following steps:

1) putting natural polybasic acid and natural polyalcohol into a reaction kettle, and setting N in the reaction kettle₂The flow rate is 4L/min, and the temperature is raised to 140 ℃ for dehydration;

2) when the temperature at the top of the tower drops, the temperature is slowly raised to 220 ℃, then catalyst tetraisopropyl titanate (TIPT) is added, and N is increased₂Carrying out ester exchange reaction when the flow is 10L/min;

3) and (3) measuring the acid value and the hydroxyl value in the system by infrared, when the acid value in the system is lower than 0.3g/KOH and the hydroxyl value is within the range of 24-28 g/KOH, cooling the reaction kettle, and then packaging to obtain the ecological polyester polyol.

Example 1: the total weight of the lactic acid is 200g, the saccharic acid is 200g, the oleic acid is 100g, the xylitol is 300g and the sorbitol is 300g, and the total weight is 1100 g.

Example 2: the total weight of 200g of palmitic acid, 200g of linolenic acid, 100g of arachidic acid, 300g of castor oil and 300g of xylitol is 1100 g.

Example 3: the total weight of the composition is 1100g of linolenic acid 200g, lactic acid 100g, oleic acid 200g, sorbitol 300g and betulin 300 g.

Example 4: the total weight of the extract is 1100g of saccharic acid 200g, palmitic acid 200g, oleic acid 100g, betulin 300g and xylitol 300 g.

Comparative example 1: commercially available polycaprolactone polyols.

Comparative example 2: a commercially available polycarbonate diol.

And (3) performance verification: polyurethane formulations were prepared by preparing polyurethane resins from the polyester polyols prepared in examples 1 to 4 above and the polyester polyols of comparative examples 1 and 2, and then preparing synthetic leather to test the base thickness and peel strength thereof as follows:

317g of the polyester polyol prepared in the above example is weighed into a reaction bottle, heated to 120 ℃ and dehydrated under negative pressure, and then 286g of DMF solvent, 0.02g of Butylated Hydroxytoluene (BHT) and 0.003g of phosphoric acid are added into the reaction bottle to be fully and uniformly stirred. Then 19.5g of diphenylmethane diisocyanate (MDI) (R is 0.98) is added, and the temperature is raised to 70-80 ℃ for reaction for 1.5 h. And (3) adding 21g of chain extender Ethylene Glycol (EG) after the prepolymerization is finished, adding 85g of MDI (R is 1) after uniformly stirring, properly diluting the resin by using a solvent during the reaction tackifying period, and supplementing a small amount of MDI in the reaction process to promote the reaction. When the reaction is finished, 3g of methanol is used for terminating the reaction, the solid content of the obtained adhesive is controlled to be 30%, and the viscosity is 20-26 ten thousand (cps/DEG C).

100g of the synthesized resin is weighed under the same condition, 30g of wood powder, 1g of black paste and 50g of DMF (dimethyl formamide) solvent are added into the resin, and the mixture is uniformly dispersed at high speed and then is subjected to vacuum defoaming for later use. Soaking leather base cloth in 25% DMF water solution, taking out the leather base cloth after 30min, pressing and spreading the leather base cloth on the surface of a glass plate, pouring a little prepared slurry on the surface of the glass plate for blade coating after the leather base cloth is fully cooled, then fully solidifying the leather base cloth in constant-temperature water bath for 10min, taking out the leather base cloth, washing with water and drying to obtain the wet-process bass. The thickness and peel strength of the wet-process bes prepared in the above examples were comprehensively evaluated, and the results of the experiments are shown in table 1.

TABLE 1

	Bass thickness/mm	Peel strength/N
			Example 1	1.08	47.49
Example 2	1.08	65.73
			Example 3	1.06	49.15
Example 4	1.07	46.09
			Comparative example 1	1.08	46.54
Comparative example 2	1.07	51.23

Through the above examples and the research on the proportion, it can be seen that table 1 specifically shows that the preparation method of the novel ecological polyester polyol material is really feasible, the utilization of renewable raw materials in the polyurethane industry can be realized, and the bass thickness and the peel strength of the prepared synthetic leather are excellent. The table shows that the performance of each aspect in the embodiment 2 is better, the invention is feasible, provides a powerful reference for the application of renewable resources to polyurethane materials, and has stronger economic benefit and environmental benefit.

While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.