Biogenic liquid crystal polyarylester as well as preparation method and application thereof

Abstract

The invention discloses biogenic liquid crystal polyarylester as well as a preparation method and application thereof, and belongs to the field of high polymer materials. Monomers of the biogenic liquid crystal polyarylester are all composed of biogenic molecules, a polymer chain of the biogenic liquid crystal polyarylester is formed by connecting ester bonds, the biogenic liquid crystal polyarylester has an obvious liquid crystal structure, the density is 0.90-1.40 g / cm < 3 >, and the melt index is 10-200; the preparation method comprises the following steps: under the action of a catalyst, carrying out condensation polymerization on three monomers, namely p-acetyl naphthoic acid, p-diacetoxybenzene and HOOC-R-COOH, and removing acetic acid to obtain the biogenic liquid crystal polyarylester. The biogenic monomer is adopted, so that the method has the characteristics of cleanness, environment friendliness and the like; meanwhile, the biogenic liquid crystal polyarylester provided by the invention has the characteristics of high intrinsic heat conductivity coefficient, low dielectric constant, high temperature resistance and the like, and can be applied to packaging materials such as 5G antennas and the like.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and more specifically, relates to a biogenic liquid crystal polyarylate and a preparation method and application thereof. Background Art

[0002] Liquid crystal polyarylate generally refers to a type of polymer containing a liquid crystal structure whose molecular chain is alternately connected by ester groups and aromatic groups. It has excellent mechanical, dielectric, creep resistance, high and low temperature resistance, chemical corrosion resistance, radiation resistance, and moisture and heat resistance. It is widely used in military aerospace, armor, electronics and chemical fields.

[0003] However, the traditional liquid crystal polyarylate is difficult to be used directly as a packaging material for 5G antennas because it is difficult to have both low dielectric properties and high thermal conductivity. In addition, in the traditional preparation method of liquid crystal polyarylate, the monomers used are generally derived from fossil raw materials such as petroleum, natural gas, and coal. Therefore, in order to meet the performance requirements of 5G antenna packaging materials and overcome the problem that the traditional liquid crystal polyarylate monomers are derived from fossils, it is of great significance to prepare a liquid crystal polyarylate with excellent comprehensive performance. Summary of the invention

[0004] In view of the defects of the prior art and the need for improvement, the present invention provides a biogenic liquid crystal polyarylate and a preparation method and application thereof, aiming to solve the problem that the biogenic liquid crystal polyarylate prepared in the prior art is difficult to have both low dielectric and high thermal conductivity.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a biogenic liquid crystal polyarylate, the structural formula of the biogenic liquid crystal polyarylate is shown in formula (I):

[0006]

[0007] Wherein, in the structural formula, the value range of x is 0-200, and the value range of y is 20-500.

[0008] Furthermore, the R group in the structural formula is a combination of one or more of thiophene, furan, pyridine, indole and pyrazine.

[0009] Furthermore, the monomer HOOC-R-COOH containing the R group in the structural formula is any one of the following structures:

[0010]

[0011] Furthermore, the density of the biogenic liquid crystal polyarylate is 0.9-1.4 g / cm 3 , melt index is 10-200.

[0012] In a second aspect, the present invention provides a method for preparing a biogenic liquid crystal polyarylate, comprising the following steps:

[0013] The three monomers of p-acetylnaphthoic acid having a structure of formula (II), p-diacetoxybenzene having a structure of formula (III) and HOOC-R-COOH are subjected to polycondensation reaction to obtain a biogenic liquid crystal polyarylate;

[0014]

[0015] Furthermore, the preparation method of the biogenic liquid crystal polyarylate is specifically as follows:

[0016] (1) adding three monomers of p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH and a catalyst into a reaction container, mixing them thoroughly, and introducing an inert gas to remove oxygen in the reaction container;

[0017] (2) The reaction container is heated to 220-330° C. and reacted for 1-5 hours, and then vacuumed and continued to react for 0-3 hours to obtain biogenic liquid crystal polyarylate.

[0018] Furthermore, the catalyst is one of sodium acetate, sodium formate, zinc acetate, potassium acetate, sodium propionate, sodium benzoate, and imidazole acetate.

[0019] Furthermore, the amount of the catalyst used is 0.01%-5% of the total amount of the three monomers of p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH.

[0020] Furthermore, the inert gas is one of nitrogen, helium, argon and neon.

[0021] In a third aspect, the present invention provides an application of the biogenic liquid crystal polyarylate described in the first aspect or the biogenic liquid crystal polyarylate prepared by the preparation method described in the second aspect in 5G antenna packaging materials.

[0022] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0023] (1) The monomers of the biogenic liquid crystal polyarylate provided by the present invention are all composed of biogenic molecules, which overcomes the problem that the monomers of traditional liquid crystal polyarylates are derived from non-renewable fossil raw materials and conforms to the concept of green environmental protection and sustainable development in the world today.

[0024] (2) The polymer chain of the biogenic liquid crystal polyarylate provided by the present invention is connected by ester bonds and has a distinct liquid crystal structure, and its density is 0.90-1.40 g / cm 3, the melt index is 10-200. Compared with traditional liquid crystal polyarylate, bio-source liquid crystal polyarylate has the characteristics of high intrinsic thermal conductivity, low dielectric constant and high temperature resistance, and can be used as packaging materials for 5G antennas.

[0025] (3) The preparation method of the biogenic liquid crystal polyarylate provided by the present invention is to cause a condensation reaction between three monomers, p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH, under the action of a catalyst, and remove acetic acid to obtain the biogenic liquid crystal polyarylate. The process is simple and the preparation efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an infrared spectrum of the biogenic liquid crystal polyarylate prepared in Example 1 of the present invention.

[0027] Figure 2 This is an optical image of the liquid crystal domains of the biogenic liquid crystal polyarylate prepared in Example 2 of the present invention.

[0028] Figure 3 This is a diagram of the dielectric constant of the biogenic liquid crystal polyarylate prepared in Example 3 of the present invention.

[0029] Figure 4 This is a graph of thermal conductivity of the biogenic liquid crystal polyarylate prepared in Example 4 of the present invention.

[0030] Figure 5 This is a thermogravimetric analysis diagram of the biogenic liquid crystal polyarylate prepared in Example 5 of the present invention.

[0031] Figure 6 This is an optical image of the liquid crystal domains of the biogenic liquid crystal polyarylate prepared in Example 6 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0034] Embodiment 1:

[0035] The preparation method of the biogenic liquid crystal polyarylate of the present invention comprises the following steps:

[0036] (1) Add p-acetylnaphthoic acid monomer (1 mmol), p-diacetoxybenzene monomer (1 mmol), thiophenedicarboxylic acid (1 mmol) and catalyst sodium acetate (0.01 mmol) into a reactor, stir thoroughly until completely mixed, and introduce nitrogen to remove oxygen in the reactor.

[0037] (2) The mixture prepared in step (1) is heated to 280° C. in a reaction kettle, reacted for 1 hour, and then vacuumed and continued to react for 1 hour to obtain a biogenic liquid crystal polyarylate having a structure described by formula (I).

[0038] The yield of the biogenic liquid crystal polyarylate in this example is 77.1% and the density is 1.12 g / cm 3 , the melt index is 53; the infrared spectrum of the corresponding biogenic liquid crystal polyarylate is shown in Figure 1 , it can be seen that the characteristic vibration peaks of the ester group, phenyl group, thiophene and other functional groups of the liquid crystal polyarylate are present, proving the successful preparation of the liquid crystal polyarylate.

[0039] Embodiment 2:

[0040] The preparation method of the biogenic liquid crystal polyarylate of the present invention comprises the following steps:

[0041] (1) Add p-acetylnaphthoic acid monomer (1 mmol), p-diacetoxybenzene monomer (1 mmol), thiophenedicarboxylic acid (1 mmol) and catalyst sodium acetate (0.07 mmol) into a reactor, stir thoroughly until completely mixed, and introduce nitrogen to remove oxygen in the reactor.

[0042] (2) The mixture prepared in step (1) is heated to 280° C. in a reaction kettle and reacted for 2 hours, and then vacuumed and continued to react for 1 hour to obtain a biogenic liquid crystal polyarylate having a structure described by formula (I).

[0043] The yield of the biogenic liquid crystal polyarylate in this example is 80.1% and the density is 1.15 g / cm 3 , the melt index is 82; the corresponding optical microscope spectrum of biogenic liquid crystal polyarylate is shown in Figure 2 , it can be seen that the liquid crystal polyarylate has an obvious liquid crystal structure, proving the formation of liquid crystal domains.

[0044] Embodiment 3:

[0045] The preparation method of the biogenic liquid crystal polyarylate of the present invention comprises the following steps:

[0046] (1) Add p-acetylnaphthoic acid monomer (1 mmol), p-diacetoxybenzene monomer (1 mmol), thiophenedicarboxylic acid (1 mmol) and catalyst sodium acetate (0.0003 mmol) into a reactor, stir thoroughly until completely mixed, and introduce nitrogen to remove oxygen in the reactor.

[0047] (2) The mixture prepared in step (1) is heated to 330° C. in a reaction vessel and reacted for 2 hours to obtain a biogenic liquid crystal polyarylate having a structure described by formula (I).

[0048] The yield of the biogenic liquid crystal polyarylate in this example is 75.5% and the density is 0.97 g / cm 3 , the melt index is 190; the corresponding dielectric constant spectrum of biogenic liquid crystal polyarylate is shown in Figure 3 It can be seen that the dielectric constant of liquid crystal polyarylate is less than 3.5 in the range of 0.4-1GHz, which meets the requirements of packaging resin for 5G antennas.

[0049] Embodiment 4:

[0050] The preparation method of the biogenic liquid crystal polyarylate of the present invention comprises the following steps:

[0051] (1) Add p-acetylnaphthoic acid monomer (1 mmol), p-diacetoxybenzene monomer (1 mmol), thiophenedicarboxylic acid (1 mmol) and catalyst sodium acetate (0.01 mmol) into a reactor, stir thoroughly until completely mixed, and introduce nitrogen to remove oxygen in the reactor.

[0052] (2) The mixture prepared in step (1) was heated to 220° C. in a reaction vessel and reacted for 5 hours, and then vacuumed and continued to react for 1 hour to obtain a biogenic liquid crystal polyarylate having a structure described by formula (I).

[0053] The yield of the biogenic liquid crystal polyarylate in this example is 76.6% and the density is 1.38 g / cm 3 , the melt index is 106; analysis shows that the thermal conductivity of the corresponding biogenic liquid crystal polyarylate is Figure 4 It can be seen that the thermal conductivity of liquid crystal polyarylate is 0.272 W·m -1 ·K -1 , indicating its relatively high intrinsic thermal conductivity and good heat transfer capability.

[0054] Embodiment 5:

[0055] The preparation method of the biogenic liquid crystal polyarylate of the present invention comprises the following steps:

[0056] (1) Add 4-acetylnaphthoic acid monomer (1 mmol), 4-diacetoxybenzene monomer (1 mmol), thiophenedicarboxylic acid (1 mmol) and catalyst sodium acetate (0.15 mmol) into a reactor, stir thoroughly until completely mixed, and introduce nitrogen to remove oxygen in the reactor.

[0057] (2) The mixture prepared in step (1) is heated to 280° C. in a reaction kettle, reacted for 2 hours, and then vacuumed and continued to react for 3 hours to obtain a biogenic liquid crystal polyarylate having a structure described by formula (I).

[0058] The yield of the biogenic liquid crystal polyarylate in this example is 83.2% and the density is 1.25 g / cm 3 , the melt index is 23; for analysis, the corresponding thermogravimetric analysis of biogenic liquid crystal polyarylate can be found in Figure 5 , it can be seen that the initial degradation temperature of liquid crystal polyarylate is about 500 °C, which has high thermal stability and meets the requirements of packaging resin for 5G antennas.

[0059] Embodiment 6:

[0060] Example 6 Example 1 was repeated, except that thiophenedicarboxylic acid was replaced by pyridinedicarboxylic acid.

[0061] The yield of the biogenic liquid crystal polyarylate in this example is 85.3% and the density is 1.31 g / cm 3 , the melt index is 76; the corresponding optical microscope spectrum of biogenic liquid crystal polyarylate is shown in Figure 6 , it can be seen that the liquid crystal polyarylate has an obvious liquid crystal structure, proving the formation of liquid crystal domains.

[0062] It should be noted that in Examples 1-6, only the ratio of the three monomers of p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH is 1:1:1 for example. In the actual preparation process, after the values ​​of x and y in formula (I) are determined according to demand, the ratio of the three monomers of p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH is x:y:y.

[0063] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A biogenic liquid crystal polyarylate, characterized in that: The structural formula of the biogenic liquid crystal polyarylate is shown in formula (I): Wherein, in the structural formula, the value range of x is 0-200, and the value range of y is 20-500.

2. The biogenic liquid crystal polyarylate according to claim 1, characterized in that: In the structural formula, the R group is a combination of one or more of thiophene, furan, pyridine, indole and pyrazine.

3. A biogenic liquid crystal polyarylate according to claim 1 or 2, characterized in that: The monomer HOOC-R-COOH containing the R group in the structural formula is any of the following structures:

4. The biogenic liquid crystal polyarylate according to claim 1, characterized in that: The density of the biogenic liquid crystal polyarylate is 0.90-1.40 g / cm 3 , melt index is 10-200.

5. A method for preparing the biogenic liquid crystal polyarylate according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: subjecting three monomers, namely, p-acetylnaphthoic acid having a structure of formula (II), p-diacetoxybenzene having a structure of formula (III) and HOOC-R-COOH, to polycondensation reaction to obtain biogenic liquid crystal polyarylate; 6. The preparation method according to claim 5, characterized in that: The preparation method is specifically: (1) adding three monomers of p-acetylnaphthoic acid, p-diacetoxybenzene and HOOC-R-COOH and a catalyst into a reaction container, mixing them thoroughly, and introducing an inert gas to remove oxygen in the reaction container; (2) The reaction container is heated to 220-330° C. and reacted for 1-5 hours, and then vacuumed and continued to react for 0-3 hours to obtain biogenic liquid crystal polyarylate.

7. The preparation method according to claim 6, characterized in that: The catalyst is one of sodium acetate, sodium formate, zinc acetate, potassium acetate, sodium propionate, sodium benzoate, and imidazole acetate.

8. The preparation method according to claim 7, characterized in that: The dosage of the catalyst is 0.01% to 5% of the total amount of the three monomers of p-acetyl naphthoic acid, p-diacetoxybenzene and HOOC-R-COOH.

9. The preparation method according to claim 5, characterized in that: The inert gas is one of nitrogen, helium, argon and neon.

10. Use of the biogenic liquid crystal polyarylate described in any one of claims 1 to 4 or the biogenic liquid crystal polyarylate prepared by the preparation method described in any one of claims 5 to 9 in 5G antenna packaging materials.

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