CN111499871A

CN111499871A - Aromatic carboxylic acid polysiloxane ammonium salt system and preparation method thereof

Info

Publication number: CN111499871A
Application number: CN202010187483.6A
Authority: CN
Inventors: 何勇; 牛莹; 姚淼; 聂俊
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2020-03-17
Filing date: 2020-03-17
Publication date: 2020-08-07
Anticipated expiration: 2040-03-17
Also published as: CN111499871B

Abstract

The viscosity and modulus of the aliphatic carboxylic acid polysiloxane ammonium salt system can be improved by adding aliphatic mono-acid or diacid into a polysiloxane system, and generating a quadri-dipole interaction between two ion centers through electrostatic interaction to form cross-linking, or forming an electrostatic physical cross-linking network by using the diacid as a cross-linking agent. However, the aliphatic monoacid is introduced, so that the viscosity and modulus of the system are improved far less than those of the system with the diacid. The ammonium polysiloxane salt system of the aromatic carboxylic acid and the preparation method thereof are provided, wherein the aromatic carboxylic acid is introduced, the interaction between new ionic centers is increased through the pi-pi stacking effect between aromatic rings, and the attraction between adjacent chains is promoted.

Description

Aromatic carboxylic acid polysiloxane ammonium salt system and preparation method thereof

Technical Field

The method can prepare the aromatic carboxylic acid polysiloxane ammonium salt system with high viscosity and high modulus, has simple preparation process, and does not need additional cross-linking agent.

Background

The viscosity and modulus of the aliphatic carboxylic acid polysiloxane ammonium salt system can be improved by adding aliphatic mono-acid or diacid into a polysiloxane system, and generating a quadri-dipole interaction between two ion centers through electrostatic interaction to form cross-linking, or forming an electrostatic physical cross-linking network by using the diacid as a cross-linking agent. However, the aliphatic monoacid is introduced, so that the viscosity and modulus of the system are improved far less than those of the system with the diacid. The aromatic pi systems form a specific arrangement in the vertical direction due to their particular horizontal orientation, the ring plane spacing between the two pi systems is about 0.33nm to 0.38nm for the carbon backbone, and at least a portion of the pi orbitals overlap, forming a relatively weak non-covalent effect known as pi-pi stacking effect. The amino in the amino polysiloxane and the carboxyl of the acid can be subjected to common electrostatic crosslinking, and the interaction between new ion centers is increased through the pi-pi stacking effect, so that the attraction between adjacent chains is promoted, the intermolecular force is further improved, and the viscosity and the modulus of the system are further improved.

In order to achieve the purpose, the invention adopts the technical scheme that:

according to the method, an acid containing a benzene ring is mixed with amino polysiloxane, ethyl acetate is added as a solvent, and the mixture is immediately stirred uniformly by a magnetic stirrer. Heating the mixed system in a rotary evaporation bottle, controlling the reaction temperature, observing the reaction system, and continuously stirring at the reflux temperature when the reflux phenomenon appears. After the reaction is finished, placing the reaction product in a vacuum rotary evaporation device, rotating until large bubbles are generated in the system, indicating that most of the solvent is rotated out, then transferring the reaction product into a vacuum oven, drying, and finally drying by using a diaphragm vacuum pump and an oil bath.

Disclosure of Invention

The invention provides an aromatic carboxylic acid polysiloxane ammonium salt system and a preparation method thereof, wherein the reaction formula of the system has the following structural general formula I:

wherein the content of the first and second substances,

ar is an aromatic ring having 1 to 5 benzene rings

Wherein the preferred structure of the acid containing a benzene ring is

The preparation process comprises the following steps:

1) uniformly mixing an acid containing a benzene ring with an amino polysiloxane according to a molar ratio of 1: 1, wherein the amino polysiloxane comprises (2-3%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (2-3 PSi L), (4-5%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (4-5 PSi L), (6-7%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (6-7 PSi L), (9-11%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (9-11 PSi L), (20-25%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (20-25 PSi L), and high molecular weight (6-7%) 3-propyl methyl polysiloxane-dimethyl siloxane copolymer (HM)_W6-7PSi L), and the acid includes benzoic acid, naphthoic acid, anthracenecarboxylic acid, pyrenecarboxylic acid, perylenecarboxylic acid.

2) Adding ethyl acetate with the volume of 5% into the mixed system, and further uniformly mixing;

3) condensing and refluxing the mixed system in the step 2) at 80 ℃, and continuously stirring for more than 4 hours;

4) carrying out vacuum rotary evaporation on the mixed system obtained in the step 3) until no bubbles exist;

5) drying the mixed system obtained in the step 4) in a vacuum oven at 55 ℃ for 24 hours.

Drawings

FIG. 1 Anthracene formate shear rate vs. viscosity change for different aminopolysiloxanes.

FIG. 2 is a graph showing the relationship between the anthraceneformate systems of different aminopolysiloxanes and the storage modulus and loss modulus at a frequency of 1Hz and 0.1% shear strain.

Detailed Description

Example 1

1) Uniformly mixing 9-anthracenecarboxylic acid with 20-25PSi L according to a molar ratio of 1: 1;

condensing and refluxing the mixed system in the step 1) at 80 ℃, and continuously stirring for more than 4 hours;

3) carrying out vacuum rotary evaporation on the mixed system in the step 2) until no bubbles exist;

4) drying the mixed system obtained in the step 3) in a vacuum oven at 55 ℃ for 24 hours.

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 2

The specific experimental procedure was the same as in example 1, with only the following reactant contents being varied:

9-Anthraenecarboxylic acid with 9-11PSi L = 1: 1

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 3

9-Anthraenecarboxylic acid with 6-7PSi L = 1: 1

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 4

9-Anthraenecarboxylic acid with 4-5PSi L = 1: 1

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 5

9-Anthraenecarboxylic acid with 2-3PSi L = 1: 1

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 6

9-Anthraenecarboxylic acid and HM_W6-7PSiL=1：1

The viscosity is shown in FIG. 1 and the modulus is shown in FIG. 2.

Example 7

1-naphthoic acid with 4-5PSi L = 1: 1

The viscosity is shown in Table 1 and the modulus is shown in Table 2.

Example 8

benzoic acid with 4-5PSi L = 1: 1

The viscosity is shown in Table 1 and the modulus is shown in Table 2.

Example 9

1-pyrenecarboxylic acid with 4-5PSi L = 1: 1

The viscosity is shown in Table 1 and the modulus is shown in Table 2.

Example 10

3-perylenecarboxylic acid with 4-5PSi L = 1: 1

The viscosity is shown in Table 1 and the modulus is shown in Table 2.

TABLE 1 ammonium salts of aromatic carboxylic polysiloxanes formed with various acids and 4-5PSi L at shear rates of 0.1s^-1Viscosity of (2)

Examples	Example 8	Example 7	Example 4	Example 9	Example 10
						Viscosity (mPa. s)	3.4*10⁴	6.8*10⁶	7.4*10⁷	8.9*10⁸	9.3*10¹⁰

TABLE 2 modulus at frequency of 1Hz and 0.1% shear strain of ammonium salts of aromatic carboxylic polysiloxanes formed with various acids and 4-5PSi L

Examples	Example 8	Example 7	Example 4	Example 9	Example 10
						Storage modulus (Pa)	1667	4564	5457	7809	123812
Loss modulus (Pa)	2345	5908	7698	14546	346678

Claims

1. An aromatic carboxylic acid polysiloxane ammonium salt system having the following structural formula I:

wherein the content of the first and second substances,

ar is an aromatic ring, and the number of benzene rings is 1-5.

2. The process of claim 1 for the preparation of formula I comprising the steps of:

mixing acid containing benzene ring, amino polysiloxane and ethyl acetate, controlling reaction temperature at about 80 ℃, continuously stirring for more than 4h by condensation reflux, after the reaction is finished, carrying out vacuum rotary evaporation, then transferring to a vacuum oven, drying for 24h at 55 ℃, and finally drying for 6h in an oil bath at about 80 ℃ under the pressure of 0.01Mpa by using a diaphragm vacuum pump.