CN113773641A - Polyamide composite material and preparation method and application thereof - Google Patents

Abstract

The invention provides a polyamide composite material which comprises the following components in parts by weight: 80-100 parts of short-carbon-chain polyamide; 0.1-6 parts of amide oligomer; in the repeating unit of the short carbon chain polyamide, the number of carbon atoms on the main chain is less than or equal to 6. According to the invention, by adding a small amount of amide oligomer, the injection molding property of the polyamide composite material can be obviously improved, the problems of mucous membrane, crown and the like in the production link can be improved, the production efficiency can be improved, and other properties such as mechanical properties and the like of the polyamide composite material can not be obviously reduced.

Description

Polyamide composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a polyamide composite material and a preparation method and application thereof.

Background

Nylon products have been invented since the last century and are widely used in the electronics, electrical, automotive and spinning industries. However, when the nylon is used as engineering plastic to be applied to injection molding products, the nylon faces the problems of slow crystallization rate, long molding period, ejection deformation of products, mucous membrane and the like, which seriously affects the production efficiency of nylon in the injection molding process.

The prior art mainly solves the defect of poor injection molding performance by the following 3 methods: 1) at present, ultrafine talcum powder is usually used as a crystallization nucleating agent of a nylon material, but the inorganic filler has low efficiency as the nucleating agent, more parts by weight need to be added to achieve a relatively ideal rapid crystallization rate, the mechanical property is greatly damaged when the inorganic filler is added in a large amount, and particularly, the notch impact property is often attenuated by 50%. 2) Some commercial products use stearate substances as nucleating agents of materials, but the nucleating efficiency is very low, and the products with higher requirements cannot be met. 3) At present, some novel nano-filler technologies can accelerate the crystallization rate of nylon, but the existing technologies are still immature, and the price is very high, so that the commercialization requirement cannot be met.

Disclosure of Invention

The invention aims to provide a polyamide composite material with good processing performance, and a preparation method and application thereof.

The invention is realized by the following technical scheme:

the polyamide composite material comprises the following components in parts by weight:

80-100 parts of short-carbon-chain polyamide;

0.1-6 parts of amide oligomer;

the number average molecular weight of the amide oligomer is in the range of 100-680;

in the repeating unit of the short carbon chain polyamide, the number of carbon atoms on the main chain is less than or equal to 6.

Preferably, 0.6-3 parts of amide oligomer; more preferably, the amide oligomer is 1-2 parts by weight.

Preferably, the amide oligomer has a number average molecular weight in the range of 160-340.

The short carbon chain polyamide is selected from at least one of PA6, PA66 and PA 56; preferably, the short carbon chain polyamide is selected from PA 66.

The amide oligomer is at least one selected from polyethylene glycol diamide, polybutylene glycol diamide, polyhexamethylene glycol diamide, polybutylene glycol diamide, polyhexamethylene glycol diamide, polytetramethylene glycol diamide and polytetramethylene glycol diamide.

The amide oligomer may be a commercially available product or a self-made product. In order to more accurately show the technical scheme of the invention, the self-made products are adopted in the examples and the comparative examples, and the preparation method comprises the following steps:

adding reaction raw materials (diamine and diacid) into a pressure kettle which is provided with a magnetic coupling stirring device, a condensing tube, a gas phase port, a feeding port and a pressure explosion-proof port according to the proportion in the table; adding a blocking agent, sodium hypophosphite (catalyst) and deionized water; the amount of the end-capping reagent substance is 2.5 percent of the total amount of the diamine and the diacid, the weight of the sodium hypophosphite is 0.1 percent of the weight of the other materials except the deionized water, and the weight of the deionized water is 30 percent of the total material weight; vacuumizing, filling high-purity nitrogen as protective gas, heating to 220 ℃ within 2 hours under stirring, stirring the reaction mixture at 220 ℃ for 1 hour, and then raising the temperature of reactants to 230 ℃ under stirring; the reaction was continued at a constant temperature of 230 ℃ and a constant pressure of 2.2 MPa for 2 hours, the pressure was kept constant by removing the water formed, the discharge was effected after the reaction was completed, and the prepolymer was vacuum-dried at 80 ℃ for 24 hours to give an amide oligomer.

Unless otherwise specified, the number average molecular weight test method of the present invention is: using a Waters company e-Alliance GPC system gel permeation chromatograph, 2.5mg of the analyte was dissolved in 4mL of hexafluoroisopropanol solvent (containing 0.005N sodium trifluoroacetate), and then filtered with a 0.45 μm standard filter. The filtrate was tested for number average molecular weight (Mn).

Preferably, the amide oligomer is selected from at least one of polyoxamide ethylenediamine and polysuccinimide; more preferably, the amide oligomer is selected from the group consisting of polyoxamide ethylenediamine.

The molecular weight range of the short-carbon-chain polyamide is not particularly limited, and the technical purpose of the invention can be realized when the number average molecular weight range of the short-carbon-chain polyamide is within 5000-50000; preferably, the number average molecular weight of the short carbon chain polyamide is 10000-16000.

Whether a certain amount of the auxiliary agent is added or not can be selected according to the actual situation: 0-2 parts of auxiliary agent is also included according to the parts by weight; the auxiliary agent is at least one of an antioxidant and a lubricant.

The antioxidant can be used in 0-1 part, and can be one or more of monophenol and bisphenol, phosphite ester, sulfur-containing, amine, and semi-hindered phenol, such as commonly used hindered phenol N, N' -hexamethylene bis (3, 5-di-tert-butyl-4-hydroxy hydrocinnamamide);

the lubricant can be used in an amount of 0-1 part, and can be any one or more of ethylene bis stearamide, dimethyl silicon oil, stearamide, stearic acid, butyl stearate, ester wax and saponified wax, such as aluminum stearate which is a common lubricant;

the preparation method of the polyamide composite material comprises the following steps: according to the proportion, the short-carbon-chain polyamide and the amide oligomer are uniformly mixed, and are extruded and granulated through a double-screw extruder, wherein the length-diameter ratio of a screw of the double-screw extruder is 40-48: 1, the temperature of a screw barrel is 200-275 ℃, and the rotating speed of the screw is 250-500 rpm, so that the polyamide composite material is obtained.

The invention relates to application of a polyamide composite material for manufacturing electronic and electric parts.

The invention has the following beneficial effects:

the invention utilizes the good compatibility of the short carbon chain polyamide and the polyamide resin, and can play a role of heterogeneous nucleation, thereby accelerating the crystallization rate of the polyamide resin;

firstly, the defects of mucous membrane, top projection and the like in the injection molding production link can be obviously improved, and secondly, the molding period can be improved. It has further been found that due to the good compatibility between the short carbon chain polyamide and the amide oligomer, there is less impact on other properties of the polyamide composite material, in particular on the mechanical properties.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

The raw materials used in the invention are as follows:

PA 6-A: number average molecular weight 6580, designation PA 6M 2000, Xinhui Meida;

PA 6-B: number average molecular weight of 11080, trademark PA6 HY-2500A, and sun chemical fiber;

PA 6-C: number average molecular weight 15620, trademark PA6 HY-2800A, and YANG CHENG CHEMICAL FIBRE;

PA 6-D: number average molecular weight 48520, designation PA6 HL40H, basf;

PA 66: number average molecular weight 20730, designation PA66 EPR27, mare;

PA 10T: brand number VICNYL 600P, golden hair science and technology;

PA 1010: designation RILSAN TMFO, arkema;

PA 1012: the trade name HIPROLON 400NN, arkema.

The following amide oligomers were prepared by the following method: adding reaction raw materials (diamine and diacid) into a pressure kettle which is provided with a magnetic coupling stirring device, a condensing tube, a gas phase port, a feeding port and a pressure explosion-proof port according to the proportion in the table; adding a blocking agent, sodium hypophosphite (catalyst) and deionized water; the amount of the end-capping reagent substance is 2.5 percent of the total amount of the diamine and the diacid, the weight of the sodium hypophosphite is 0.1 percent of the weight of the other materials except the deionized water, and the weight of the deionized water is 30 percent of the total material weight; vacuumizing, filling high-purity nitrogen as protective gas, heating to 220 ℃ within 2 hours under stirring, stirring the reaction mixture at 220 ℃ for 1 hour, and then raising the temperature of reactants to 230 ℃ under stirring; the reaction was continued at a constant temperature of 230 ℃ and a constant pressure of 2.2 MPa for 2 hours, the pressure was kept constant by removing the water formed, the discharge was effected after completion of the reaction, and the prepolymer was dried under vacuum at 80 ℃ for 24 hours to give an amide oligomer

Polyoxamide ethylenediamine a: the number average molecular weight is 100, and the product is prepared by self;

polyoxamide ethylenediamine B: number average molecular weight 160, self-made;

polyoxamide ethylenediamine C: the number average molecular weight is 340, self-made;

polyoxamide ethylenediamine D: number average molecular weight 680, self-made;

oxalylethylenediamine: is sold on the market;

polyoxamide ethylenediamine E: the number average molecular weight is 800, self-made;

poly (hexamethylene succinamide): number average molecular weight 320, self-made;

polytetramethyleneadipamide: the number average molecular weight is 300, and the method is self-made;

polybutylene succinamide: the number average molecular weight is 250, and the method is self-made;

antioxidant: IRGANOX 1098, basf;

lubricant: stearyl stearate, LOXIOL G32, german konin;

examples and comparative examples preparation methods of polyamide composite materials: according to the proportion, the short-carbon-chain polyamide and the amide oligomer are uniformly mixed, and are extruded and granulated by a double-screw extruder, wherein the length-diameter ratio of a screw of the double-screw extruder is 44:1, the temperature of a screw cylinder is 60, 260, 240, 220, 210, 220 and 240 ℃, and the rotating speed of the screw is 350rpm, so that the polyamide composite material is obtained.

The test method comprises the following steps:

(1) and (3) formability test: the actual minimum cooling time and the minimum molding period are adopted to set under the condition of not influencing demoulding and the top convex deformation of the product. The injection molding temperature is 275-270-265 ℃, and the mold temperature is 75 ℃; and observing whether the appearance of the injection molding part has the defects of mucous membrane, top projection and the like, and evaluating the defect grade according to the obvious or number of the defects of the mucous membrane, the top projection and the like. The defect grade is 0-5 grade, 0 grade is that no mucous membrane or crown defect is observed, and the higher the grade of 1-5 grade is, the more obvious the mucous membrane and crown are, the more the quantity is.

(2) Tensile strength: the test was carried out according to ISO 527-2012 test standard, using a tensile rate of 50mm/min at ambient temperature.

Table 1: component contents (parts by weight) of polyamide composite materials of examples 1 to 6 and comparative examples 1 to 3 and test results

	Example 1	Example 2	Example 3	Example 4	Example 5	Comparative example 1	Comparative example 2	Comparative example 3
									PA6-A	100
PA6-B		100
									PA6-C			100
PA6-D				100
									PA66					100
PA10T						100
									PA1010							100
PA1012								100
									Polyoxoethylenediamine A	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6
Antioxidant agent	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
									Lubricant agent	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4
Injection cooling time(s)	8.7	9.5	10.1	10.8	5.3	13.9	19.4	21.5
									Injection molding cycle(s)	20.3	20.8	21.9	22.1	17.2	26.2	30.1	32.7
Appearance of the article, grade	2	1	0	2	1	4	5	5
									Tensile strength, MPa	73.7	76.7	77.1	76.1	84.5	79.4	64.8	61.5

As can be seen from examples 1-4, the number average molecular weight of the short carbon chain polyamide is preferably 10000-16000, and the appearance of the molded article is the best.

From comparative examples 1 to 3, it is clear that the addition of amide oligomers to long carbon chain polyamides PA1010, PA1012 or semi-aromatic polyamide PA10T is not technically effective.

Table 2: component contents (parts by weight) of polyamide composite materials of examples 6 to 11 and comparative examples 4 to 5 and test results

	Example 6	Example 7	Example 8	Example 9	Example 10	Example 11	Comparative example 4	Comparative example 5
									PA6-B	100	100	100	100	100	100	100	100
Polyoxoethylenediamine B	0.6
									Polyoxoethylenediamine C		0.6
Polyoxoethylenediamine D			0.6
									Poly (hexamethylene succinamide)				0.6
Polytetramethylene adipamide					0.6
									Polybutylene succinamide						0.6
Ethanedioyl ethylenediamine							0.6
									Polyoxoethylenediamine E								0.6
Antioxidant agent	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
									Lubricant agent	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4
Injection cooling time(s)	9.3	9.4	8.2	8.0	7.4	8.2	17.3	15.2
									Injection molding cycle(s)	20.4	20.6	21	20.5	19.3	20.5	28	26.4
Appearance of the article, grade	0	0	2	1	2	2	5	4
									Tensile strength, MPa	77.8	77.5	74.1	74.8	73.5	74.4	72.7	73.6

From example 2/6-8, it is found that the preferred number average molecular weight range of the amide oligomer is 160-340, the molding cycle is shorter, and the mechanical properties are higher.

As can be seen from example 7/9/10/11, the amide oligomer is preferably polyoxoethylenediamine at a similar number average molecular weight, giving a better appearance and higher tensile strength.

Comparative example 4/5 shows that the object of the present invention is not achieved by adding an oxalylethylenediamine monomer and polyoxylethylenediamine having an excessively high number average molecular weight.

Table 3: component contents (parts by weight) of polyamide composite materials of examples 12 to 17 and comparative examples 6 to 7 and test results

	Example 12	Example 13	Example 14	Example 15	Example 16	Example 17	Comparative example 6	Comparative example 7
									PA6-B	100	100	100	100	100	100	100	100
Polyoxoethylenediamine A	0.1	1	2	3	6	1.5		8
									Antioxidant agent	0.2	0.2	0.2	0.2	0.2		0.2	0.2
Lubricant agent	0.4	0.4	0.4	0.4	0.4		0.4	0.4
									Injection cooling time(s)	9.5	9.1	8.4	7.5	6.8	8.5	23.5	6.5
Injection molding cycle(s)	21.1	20.4	20.2	18.8	18.7	20.8	34.2	16.8
									Appearance of the article, grade	3	1	1	2	3	1	4	5
Tensile strength, MPa	77.2	76.4	75.8	75.1	74.1	76.2	77.2	67.6

From examples 2/12 to 16, it is apparent that the amount of the amide oligomer is preferably 0.6 to 3 parts, more preferably 1 to 2 parts.

As is clear from the whole examples and comparative examples 6 to 7, the addition of a proper amount of the amide oligomer can improve the molding appearance and molding cycle of the polyamide composite material, while having little influence on the mechanical properties.

It will be appreciated by those of ordinary skill in the art that the examples provided herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited examples and embodiments. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims (10)

1. The polyamide composite material is characterized by comprising the following components in parts by weight:

80-100 parts of short-carbon-chain polyamide;

0.1-6 parts of amide oligomer;

the number average molecular weight of the amide oligomer is in the range of 100-680;

in the repeating unit of the short carbon chain polyamide, the number of carbon atoms on the main chain is less than or equal to 6.

2. Polyamide composite material according to claim 1, characterized in that the amide oligomer is present in an amount of 0.6 to 3 parts by weight; more preferably, the amide oligomer is 1-2 parts.

3. The polyamide composite material as claimed in claim 1, wherein the amide oligomer has a number average molecular weight in the range of 160-340.

4. The polyamide composite material as claimed in claim 1, wherein the short carbon chain polyamide is selected from at least one of PA6, PA66, PA 56; preferably, the short carbon chain polyamide is selected from PA 66.

5. The polyamide composite of claim 1 wherein the amide oligomer is at least one member selected from the group consisting of polyethyleneoxalamide, polybutyleneoxalamide, polyhexamethyleneoxalamide, polytetramethylenesuccinamide, polybutylenesuccinamide, polyhexamethylenesuccinamide, polyhexamethyleneadipamide, and polytetramethyleneadipamide.

6. The polyamide composite material of claim 5, wherein the amide oligomer is at least one selected from the group consisting of polyethylene glycol diamine, and polyhexamethylene succinamide; more preferably, the amide oligomer is selected from the group consisting of polyoxamide ethylenediamine.

7. The polyamide composite material as claimed in claim 1, wherein the number average molecular weight of the short carbon chain polyamide is in the range of 5000-50000; preferably, the number average molecular weight of the short carbon chain polyamide is 10000-16000.

8. The polyamide composite material according to claim 1, further comprising 0 to 2 parts by weight of an auxiliary; the auxiliary agent is at least one of an antioxidant and a lubricant.

9. Process for the preparation of a polyamide composite material according to any one of claims 1 to 8, characterized in that it comprises the following steps: according to the proportion, the short-carbon-chain polyamide and the amide oligomer are uniformly mixed, and are extruded and granulated through a double-screw extruder, wherein the length-diameter ratio of a screw of the double-screw extruder is 40-48: 1, the temperature of a screw barrel is 200-275 ℃, and the rotating speed of the screw is 250-500 rpm, so that the polyamide composite material is obtained.

10. Use of the polyamide composite material according to any one of claims 1 to 8 for the manufacture of components for electronic and electrical appliances.