A macromolecular titanate coupling agent and a method for preparing the same

Abstract

The application provides a macromolecular titanate coupling agent and a preparation method thereof, which is obtained by using an ester exchange polycondensation method on small molecule titanate coupling agent and dihydric alcohol monomers, and is polymerized in a gradient heating mode under a nitrogen atmosphere, and synthesis steps are as follows: under a nitrogen atmosphere, the small molecule titanate coupling agent and the dihydric alcohol monomers are added into a three-necked flask, the three-necked flask is heated through an oil bath, first, the heating temperature is increased from room temperature to 60-120 DEG C, and is kept for 3-5 hours, then the heating is continuously increased to 140-160 DEG C, and is reacted for 3-5 hours, then the heating is continuously increased to 175-180 DEG C, and is reacted for 1-3 hours. The macromolecular titanate coupling agent is obtained by using the ester exchange polycondensation method on the small molecule titanate coupling agent and the dihydric alcohol monomers, the coupling agent can avoid the problem that the alkoxyl in the structure of the titanate coupling agent is easy to contact with water vapor in the air and hydrolyze due to the characteristics of large molecular weight and linear / branched structure, and the macromolecular coupling agent structure still contains characteristic functional groups, so that the functionality of the coupling agent can be reserved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer chemistry science and technology, in particular, relates to a macromolecular titanate coupling agent and a preparation method thereof. BACKGROUND

[0002] Coupling agent is an important chemical additive, the biggest structural feature of which is that the molecule contains two groups with different chemical properties, one is a group that is easy to react with the surface of inorganic matter, and the other is a group that is easy to react with synthetic resin or other polymers or connect with them in the form of hydrogen bond. Therefore, coupling agent is called "molecular bridge", which is used to improve the interface action between inorganic matter and organic matter, thereby greatly improving the performance of the composite material, such as physical performance, electrical performance, thermal performance, optical performance, etc. Coupling agents are various, and the most widely used at present are silane coupling agent and titanate coupling agent, which are widely used in fiber reinforced resin-based composite materials, rubber, paint, adhesive and other fields.

[0003] Silane coupling agent was first developed by Union Carbide Corporation and Dow Corning Corporation in the 1940s as a glass fiber surface treatment agent to improve the mechanical properties of glass fiber composites. After that, silane coupling agents with different chemical structures have been widely developed and applied, and have become an indispensable additive in the fields of chemical industry and materials. Titanate coupling agent was developed by Kenrich Petrochemicals Corporation in 1975, and then titanate coupling agents with different chemical structures were developed and applied. At present, the existing titanate coupling agents can be divided into four categories according to their chemical structure: single alkoxy fatty acid type, phosphate type, chelate type and ligand type. The chemical structure of the titanate coupling agent is as follows:

[0004] (RO)m—Ti—(OX-R’-Y)n

[0005] In the formula, 1≤m≤4; m+n≤6

[0006] In the general structure of the titanate coupling agent, RO- is a short carbon chain alkyl group that can be hydrolyzed; -OX is a functional group such as carboxyl, alkoxy, sulfonic acid group, phosphoric acid group, which can endow the titanate coupling agent with special functionality; R' is a long carbon chain alkyl group, which can be entangled with organic polymers; Y can be hydroxyl, amino, epoxy and double bond, which can be chemically reacted with organic polymers and combined together. Compared with silane coupling agent, the application range of titanate coupling agent is wider, and the role of titanate coupling agent is not limited to improving the strength of the composite material, but also can endow the composite material with certain flexibility. However, the existing titanate coupling agent is mainly small molecule, which is extremely sensitive to moisture in the air and will be quickly hydrolyzed and lose its efficacy when used in a humid environment. SUMMARY

[0007] Therefore, the present application aims to provide a macromolecular titanate coupling agent and a preparation method thereof to solve the problem that the small molecule titanate coupling agent is easy to decompose in the prior art.

[0008] To achieve the above-mentioned purposes, the technical scheme of the present application is as follows:

[0009] A macromolecular titanate coupling agent is obtained by using an ester exchange polycondensation method on a small molecule titanate coupling agent and a dihydric alcohol monomer, and is polymerized in a gradient heating manner under a nitrogen atmosphere.

[0010] The present application obtains a macromolecular titanate coupling agent with linear or branched structure by using an ester exchange polycondensation method on a small molecule titanate coupling agent and a dihydric alcohol monomer. Due to the characteristics of large molecular weight and linear / branched structure, the coupling agent can avoid the problem that the alkoxyl group in the structure of the titanate coupling agent is easy to contact with water vapor in the air and hydrolyze. Moreover, the macromolecular coupling agent structure still contains characteristic functional groups, which can retain the functionality of the coupling agent.

[0011] Further, the weight average molecular weight of the macromolecular titanate coupling agent should be greater than or equal to 2000 g / mol.

[0012] Further, the small molecule titanate coupling agent is one of tetrabutyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetra-tert-butyl titanate, triisostearyl titanate, and isopropyl tri(dioctyl pyrophosphoryl) titanate.

[0013] Further, the dihydric alcohol monomer is one of 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, N-methyl diethanolamine, diethylene glycol, and neopentyl glycol.

[0014] Further, when the small molecule titanate coupling agent is tetrabutyl titanate and the dihydric alcohol monomer is diethylene glycol, the structural formula of the synthesized macromolecular titanate coupling agent is as formula (I):

[0015]

[0016]

[0017] The structure makes the macromolecular titanate coupling agent have excellent hydrolysis stability, and the structure is applied in the modification of the interface of a composite material.

[0018] Further, the weight average molecular weight of the macromolecular titanate coupling agent synthesized by the tetrabutyl titanate and diethylene glycol is 8500 g / mol.

[0019] Further, the hydrolysis time of the macromolecular titanate coupling agent is greater than that of the small molecule titanate coupling agent.

[0020] A preparation method of the macromolecular titanate coupling agent as described above, comprising a synthesis step: under a nitrogen atmosphere, a small molecule titanate coupling agent and a dihydric alcohol monomer are added to a three-necked flask, the three-necked flask is heated by an oil bath, the heating temperature is increased from room temperature to 60-120 DEG C, and the temperature is kept for 3-5 h, then the heating is continued to 140-160 DEG C, the reaction is carried out for 3-5 h, then the heating is continued to 170-180 DEG C, and the reaction is carried out for 1-3 h.

[0021] Further, the molar ratio of the small molecule titanate coupling agent to the dihydric alcohol monomer is 1:1-3.

[0022] The present application can prepare alkoxyl or hydroxyl terminated polymers by different monomer ratios, and can play a better effect when applied.

[0023] Further, when the small molecule titanate coupling agent is weighed, the weighing process is as fast as possible, and the weighing is completed within 60 s.

[0024] Compared with the prior art, the macromolecular titanate coupling agent and the preparation method thereof have the following advantages:

[0025] 1) The macromolecular titanate coupling agent is obtained by using the ester exchange polycondensation method of the small molecule titanate coupling agent and the dihydric alcohol monomer, and has a linear or branched structure. Due to the large molecular weight and the linear / branched structure, the problem of hydrolysis of the alkoxyl group in the structure of the titanate coupling agent due to contact with water vapor in the air can be avoided, and the characteristic functional group is still contained in the structure of the macromolecular coupling agent, so that the functionality of the coupling agent can be retained.

[0026] 2) In the preparation of the macromolecular titanate coupling agent, the molecular structure of the macromolecular titanate coupling agent is controlled by adjusting the molar ratio of the monomers with different structures and the two kinds of monomers, and the macromolecular coupling agent with different reaction degrees (i.e. different molecular weights) is obtained by controlling the reaction temperature and the reaction time. The synthesized macromolecular titanate coupling agent is not easy to hydrolyze, and has more excellent modification effect in the fields of fiber reinforced resin matrix composite, rubber, paint, adhesive and the like.

[0027] 3) The macromolecular titanate coupling agent is synthesized by using gradient heating and controlling the heating rate. At the beginning of the polymerization reaction, the reaction rate is slow, and the heating rate is also fast at this time. With the progress of the polymerization reaction of the multi-functional group system, the polymerization rate is significantly improved, and the linear and branched macromolecules begin to covalently bond, and crosslinking occurs. At this time, a slower heating rate is required, otherwise gelation is easy to occur. Gradient heating can make the reaction more stable, and is not easy to directly produce local overheating, and prevents gelation.

[0028] 4) The present application has the characteristics of rich raw material source, simple synthesis steps, and easy mass production. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The schematic diagram of synthesizing the macromolecular titanate coupling agent by using tetrabutyl titanate and diethylene glycol as raw materials in Example 1 of the present application;

[0030] Figure 2 The infrared spectrum of synthesizing the macromolecular titanate coupling agent by using tetrabutyl titanate and diethylene glycol as raw materials in Example 1 of the present application;

[0031] Figure 3 The molecular weight of synthesizing the macromolecular titanate coupling agent by using tetrabutyl titanate and diethylene glycol as raw materials in Example 1 of the present application is measured by gel permeation chromatography (GPC). DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0033] Example 1

[0034] (1) Prepare the experimental apparatuses such as three-necked flasks and condensers in advance;

[0035] (2) Weigh 272.3 g of tetrabutyl titanate and 271.7 g of diethylene glycol into a three-necked flask, and the weighing process is as fast as possible, which is completed within 60 s to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0036] (3) Set up the experimental apparatuses so that the reaction is carried out in a nitrogen atmosphere, and raise the oil bath from room temperature to 60℃, and keep the temperature at this temperature for 3 hours; then raise the temperature to 140℃ in steps, and react at this temperature for another 3 hours;

[0037] (4) Then slowly raise the temperature to the highest temperature of 180℃ and react for 1 hour, and after the viscosity of the product is increased and the color is deepened, collect the distillate, stop heating, and end the reaction.

[0038] Example 2

[0039] (1) Prepare the experimental apparatuses such as three-necked flasks and condensers in advance;

[0040] (2) Weigh 227.4 g of tetrabutyl titanate and 230.7 g of 1,4-butanediol into a three-necked flask, and the weighing process is as fast as possible, which is completed within 60 s to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0041] (3) Set up the experimental device, and make the reaction in nitrogen atmosphere. Increase the oil bath temperature from room temperature to 90°C, and keep the temperature for 3 hours. Then increase the temperature to 160°C, and keep the temperature for another 3 hours;

[0042] (4) Then slowly increase the temperature to the highest temperature 180°C, and keep the temperature for 2 hours. After the viscosity of the product increases and the color deepens, collect the distillate, stop heating, and end the reaction.

[0043] Example 3

[0044] (1) Prepare the experimental devices such as three-necked flasks and condensers in advance;

[0045] (2) Put 272.3 g of tetra-tert-butyl titanate and 304.9 g of N-methyl diethanolamine into a three-necked flask. The weighing process is completed within 60 seconds to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0046] (3) Set up the experimental device, and make the reaction in nitrogen atmosphere. Increase the oil bath temperature from room temperature to 80°C, and keep the temperature for 4 hours. Then increase the temperature to 160°C, and keep the temperature for another 3 hours;

[0047] (4) Then slowly increase the temperature to the highest temperature 180°C, and keep the temperature for 2 hours. After the viscosity of the product increases and the color deepens, collect the distillate, stop heating, and end the reaction.

[0048] Example 4

[0049] (1) Prepare the experimental devices such as three-necked flasks and condensers in advance;

[0050] (2) Put 557.1 g of triisostearyl titanate and 271.7 g of diethylene glycol into a three-necked flask. The weighing process is completed within 60 seconds to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0051] (3) Set up the experimental device, and make the reaction in nitrogen atmosphere. Increase the oil bath temperature from room temperature to 100°C, and keep the temperature for 5 hours. Then increase the temperature to 160°C, and keep the temperature for another 5 hours;

[0052] (4) Then slowly increase the temperature to the highest temperature 180°C, and keep the temperature for 3 hours. After the viscosity of the product increases and the color deepens, collect the distillate, stop heating, and end the reaction.

[0053] Example 5

[0054] (1) Prepare the experimental devices such as three-necked flasks and condensers in advance;

[0055] (2) Take 209.8 g of isopropyl tris (dioctyl phosphityl) titanate and 304.9 g of N-methyl diethanolamine into a three-necked flask, and try to weigh as quickly as possible, and complete the weighing within 60 s to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0056] (3) Set up the experimental device, and make the reaction proceed in a nitrogen atmosphere. Increase the oil bath from room temperature to 100°C, and keep the temperature at this value for 4 hours. Then increase the temperature stepwise to 160°C, and keep the temperature at this value for another 4 hours;

[0057] (4) Then slowly increase the temperature to the highest temperature of 180°C, and react for 3 hours. After the viscosity of the product increases and the color deepens, and distillate is collected, stop heating and end the reaction.

[0058] Example 6

[0059] (1) Prepare the experimental devices such as a three-necked flask and a condenser tube in advance;

[0060] (2) Take 227.4 g of tetrapropyl titanate and 194.8 g of 1,3-propanediol into a three-necked flask, and try to weigh as quickly as possible, and complete the weighing within 60 s to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0061] (3) Set up the experimental device, and make the reaction proceed in a nitrogen atmosphere. Increase the oil bath from room temperature to 80°C, and keep the temperature at this value for 3 hours. Then increase the temperature stepwise to 150°C, and keep the temperature at this value for another 5 hours;

[0062] (4) Then slowly increase the temperature to the highest temperature of 170°C, and react for 1 hour. After the viscosity of the product increases and the color deepens, and distillate is collected, stop heating and end the reaction.

[0063] Example 7

[0064] (1) Prepare the experimental devices such as a three-necked flask and a condenser tube in advance;

[0065] (2) Take 272.3 g of tetrabutyl titanate and 230.7 g of 1,4-butanediol into a three-necked flask, and try to weigh as quickly as possible, and complete the weighing within 60 s to reduce the hydrolysis of the coupling agent by moisture in the environment;

[0066] (3) Set up the experimental device, and make the reaction proceed in a nitrogen atmosphere. Increase the oil bath from room temperature to 120°C, and keep the temperature at this value for 3 hours. Then increase the temperature stepwise to 160°C, and keep the temperature at this value for another 4 hours;

[0067] (4) Then slowly increase the temperature to the highest temperature of 180°C, and react for 2 hours. After the viscosity of the product increases and the color deepens, and distillate is collected, stop heating and end the reaction.

[0068] Comparative Example 1

[0069] Commercially available tetrabutyl titanate coupling agent.

[0070] Comparative Example 2

[0071] The differences between the present comparative example and Example 1 are as follows, and are as follows:

[0072] (3) Set up the experimental device to make the reaction in a nitrogen atmosphere, and raise the oil bath temperature to 140°C, and react for 5 hours at this temperature;

[0073] (4) Then slowly raise the temperature to the maximum temperature of 180°C and react for 1 hour, and after the viscosity of the product increases and the color deepens, collect the distillate, stop heating and end the reaction.

[0074] Performance test

[0075] Examples 1-7, i.e. Comparative Examples 1-2, were subjected to hydrolysis stability testing, and the test results are shown in Table 1 below:

[0076] Table 1

[0077]

[0078]

[0079] As can be seen from the results in Table 1, the macromolecular titanate coupling agent of the present application has excellent hydrolysis stability, which is significantly stronger than that of commercially available titanate coupling agents. Therefore, in the present application, the macromolecular coupling agent obtained by reacting a small molecule coupling agent with a dihydric alcohol significantly improves the stability of the coupling agent in water.

[0080] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application should be defined by the scope defined in the claims.

Claims

1. A macromolecular titanate coupling agent, characterized by, The macromolecular titanate coupling agent is prepared by using the ester exchange polycondensation method of a small molecule titanate coupling agent and a dihydric alcohol monomer, and the polymerization is carried out in a nitrogen atmosphere in a gradient heating mode; the weight average molecular weight of the macromolecular titanate coupling agent should be greater than or equal to 2000 g / mol; the small molecule titanate coupling agent is one of tetrabutyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetra-tert-butyl titanate, triisostearyl titanate, and isopropyl tri(dioctyl pyrophosphoryl) titanate; the dihydric alcohol monomer is one of 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, N-methyl diethanolamine, diethylene glycol, and neopentyl glycol; the preparation method of the macromolecular titanate coupling agent comprises a synthesis step: in a nitrogen atmosphere, the small molecule titanate coupling agent and the dihydric alcohol monomer are added to a three-necked flask, the three-necked flask is heated by an oil bath, first, the heating temperature is increased from room temperature to 60-120℃, and the temperature is kept for 3-5 h, then the heating is continued to 140-160℃, the reaction is carried out for 3-5 h, then the heating is continued to 170-180℃, and the reaction is carried out for 1-3 h.

2. The macromolecular titanate coupling agent according to claim 1, characterized in that, When the small molecule titanate coupling agent is tetrabutyl titanate, and the dihydric alcohol monomer is diethylene glycol, the structural formula of the synthesized macromolecular titanate coupling agent is as formula (I): Formula (I).

3. The macromolecular titanate coupling agent according to claim 2, characterized in that, The weight average molecular weight of the macromolecular titanate coupling agent synthesized by the tetrabutyl titanate and the diethylene glycol is 8500 g / mol.

4. The macromolecular titanate coupling agent according to claim 1, characterized in that, The hydrolysis time of the macromolecular titanate coupling agent is greater than the hydrolysis time of the small molecule titanate coupling agent.

5. The macromolecular titanate coupling agent according to claim 1, wherein The molar ratio of the small molecule titanate coupling agent to the dihydric alcohol monomer is 1:1-3.

6. The macromolecular titanate coupling agent according to claim 1, wherein When the small molecule titanate coupling agent is weighed, the weighing process is as fast as possible, and the weighing is completed within 60 s.

Images