CN114874469B - Method for rapid preparation of flexible deployable dark fiber composites based on two-stage and photothermal synergistic technology and its application - Google Patents

Abstract

The invention discloses a method for rapidly preparing a flexibly deployable dark fiber composite material based on two-stage and photothermal synergy technology and its application. The method includes the following steps: step 1, configuring a resin system; step 2, combining step 1 The prepared resin system is coated on the carbon fiber to make it completely infiltrated, covered with PET film, and transferred to a place protected from light for the first stage curing at room temperature; At room temperature, photothermal co-curing was performed to obtain a flexible and deployable dark fiber composite material. The method utilizes the first-stage room temperature thermal curing and the second-stage photothermal synergistic curing to prepare the dark fiber composite material, which can realize the rapid curing problem of the dark fiber composite material with the transition of flexibility and rigidity, wherein the first-stage room temperature thermal curing product can be Flexible folding and unfolding, second-stage photothermal co-curing is used to broaden the application prospects of photocuring in the field of dark fiber composites.

Description

Rapid preparation of flexible and unfoldable dark fiber composites based on two-stage and photothermal synergistic technology Methods of compounding materials and their applications

technical field

The invention relates to a preparation method of a dark fiber composite material, in particular to a method for rapidly preparing a flexibly deployable dark fiber composite material based on two-stage and photothermal synergy technology and its application.

Background technique

The flexible unfolded structure has great application prospects in the fields of automobile, aerospace and other fields due to its light weight and high strength. In order to solve the problem of resin flow during the folding process of flexible composite materials, two-stage curing technology is introduced; In order to achieve the purpose of rapid curing, free radical photocuring is often used in the second stage. The UV light source generally only exists on one side. Due to the blocking of UV by the resin layer or the dark fiber layer, light curing often only cures a thin layer of light-colored resin system and light-transmitting fiber composite materials, and the dark fiber composite material that can be flexibly folded and unfolded There are still some difficulties in material production.

SUMMARY OF THE INVENTION

In order to solve the problems of resin flow and dark fiber composite material curing during the folding and unfolding process of the composite material, the present invention provides a method for rapidly preparing a flexible and unfolding dark fiber composite material based on two-stage and photothermal synergy technology and its application. The method utilizes the first-stage room temperature thermal curing and the second-stage photothermal synergistic curing to prepare the dark fiber composite material, which can realize the rapid curing problem of the dark fiber composite material with the transition of flexibility and rigidity, wherein the first-stage room temperature thermal curing product can be Flexible folding and unfolding, second-stage photothermal co-curing is used to broaden the application prospects of photocuring in the field of dark fiber composites.

The purpose of this invention is to realize through the following technical solutions:

A method for rapidly preparing a flexibly deployable dark fiber composite material based on two-stage and photothermal synergy technology, comprising the following steps:

Step 1. Configure the resin system:

(1) Ultrasonic for 10-40 min after mixing the diluent and the second-stage thermal initiator;

(2) After complete dissolution, add acrylate and second-stage photoinitiator, stir by hand until the mixture is uniform, and put it into a vacuum drying box to remove air bubbles;

(3) Add mercaptan, mix well and remove air bubbles again;

(4) Drop into the first-stage catalyst to activate the click reaction, and the resin system is now prepared;

The resin formula is composed of the following components in parts by mass: 30-70 parts of acrylate, 30-70 parts of diluent, 1-5 parts of second-stage photoinitiator, and 1-5 parts of second-stage thermal initiator , 5~20 parts of mercaptan, 0.01~1 part of first stage catalyst;

The acrylate is one or more of methyl methacrylate, urethane acrylate and other acrylates, for example: one or more of CN9010NS, CN966NS and CN996NS;

The diluent is an acrylate diluent, for example: one or more of trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipentaerythritol pentaacrylate;

The second-stage photoinitiator is a free radical or cationic photoinitiator, such as: phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1 -Phenyl-1-propanone 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinebenzylphenyl)butanone, 2,4,6-trimethylbenzoyl-diphenyl One or more of phosphine oxides;

The second-stage thermal initiator is a peroxide-based or azo-based radical initiator;

The thiol is one or both of tetrakis (3-mercaptopropionate) pentaerythritol ester and trimethylolpropane tris (3-mercaptopropionate);

The first-stage catalyst is a basic catalyst;

Step 2, the first stage room temperature thermal curing

Coat the resin system prepared in step 1 on the carbon fiber to make it completely infiltrated, cover it with PET film, and transfer it to a dark place for the first stage curing at room temperature, and the curing time is 2~24h;

Step 3, second stage photothermal co-curing

The first-stage room temperature thermally cured intermediate product was placed at room temperature, and irradiated with a 365nm light intensity of 10-300mW/cm ² UV light source for 10-600s to perform photothermal synergistic curing to obtain a flexible and unfoldable dark fiber composite material, The weight of the resin system in the composite material is 40-80%.

In the above method, in the first stage, room temperature thermal curing is performed, and the product can be folded and unfolded flexibly, and it takes up a very small volume; , The composite material prepared by this method has the characteristics of light weight, high strength and rapid prototyping, and has a very broad application prospect in the rapid production of individual combat antennas.

Compared with the prior art, the present invention has the following advantages:

1. For the purpose of saving energy consumption, the present invention firstly adopts two-stage curing technology to cure a part of the resin to keep the resin layer stable during the folding and unfolding process of the composite material, and the product can be stored for a long time at this time. In the second stage, only one side of the dark fiber composite material needs to be irradiated with a specific wavelength of UV for a short time, and the resin layer on both sides of the dark fiber composite material can be cured, and the cured composite material has good mechanical properties.

2. Acrylate is one of the most commonly used resin matrices, which can rapidly cure free radicals and release a large amount of heat in a very short period of time. In the experimental process, this part of the heat energy is often insufficiently utilized. The present invention utilizes the light curing process. The thermal energy generated in the resin formula triggers the decomposition of the thermal initiator in the resin formula, and the resin system is thermally cured, thereby generating more heat, generating cycles, and realizing photothermal synergistic curing. The resin layer on both sides of the material is cured, and as the thickness of the resin layer increases, the greater the heat generated during the curing process, the more obvious the photothermal synergy effect.

3. Since the degree of free radical polymerization reaction is uncontrollable, in order to achieve partial curing, the present invention introduces thiol into the resin system, and uses the click reaction between thiol and C=C to control the degree of reaction of the resin system, which can be controlled by controlling the amount of thiol. The first-stage product exists in a state of being in a state of flexible folding and unfolding.

Description of drawings

Fig. 1 is the DSC curve of resin system;

Fig. 2 is the temperature change of resin system reaction process;

Figure 3 shows the flexible folding and unfolding performance;

Figure 4 is a schematic diagram of the structure of the composite material;

Figure 5 is an example of the application of flexible deployable dark fiber composite materials in individual combat antennas.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be included in the present invention. within the scope of protection.

Example 1:

The present embodiment provides a method for rapidly preparing a flexibly deployable dark fiber composite material based on two-stage and photothermal synergy technology and its application. The experimental process of the method is as follows:

1. Use scissors to cut the carbon fiber into a shape of 15*18 cm in length and width, and weigh the carbon fiber for later use.

2. First mix the diluent and the second-stage thermal initiator, then ultrasonicate for 30 min. After complete dissolution, add the acrylate and the second-stage photoinitiator, stir by hand until the mixture is uniform, put it in a vacuum drying box to remove air bubbles, and then add Thiol, after mixing evenly, remove air bubbles again, and finally drop the first-stage catalyst to activate the click reaction. At this point, the formulation of the resin system is completed. The resin formulation is composed of the following components in parts by mass: 60 parts of acrylate, 40 parts of diluent parts, 2 parts of the second-stage photoinitiator, 3 parts of the second-stage thermal initiator, 20 parts of mercaptans, and 0.05 parts of the first-stage catalyst. Among them, the acrylate is CN9010NS and CN996NS mixed resin, the mass ratio of the two is 1:1; the diluent is trimethylolpropane triacrylate; the second stage photoinitiator is 2-hydroxy-2-methyl-1- Phenyl-1-acetone; the second-stage thermal initiator is benzoyl peroxide; the thiol is tetrakis (3-mercaptopropionic acid) pentaerythritol; the first-stage catalyst is 1-methylimidazole.

3. Coat the prepared resin system on the carbon fiber to make it completely infiltrated, use external force to press the composite material, control the weight of the resin system used, keep the glue content in the composite material at 70%, cover it with PET film, and transfer it into The first stage of curing is carried out at room temperature in the dark place, and the curing time is controlled to be more than 12h.

4. The intermediate product of the first stage is placed at room temperature, and is irradiated with a 365 nm light intensity of 150 mW/cm ² UV light source for 180 s to perform photothermal synergistic curing.

5. Experimental results:

(1) The resin system can be divided into two stages of reaction and the interval between the two reactions is obvious. The DSC curve of the resin system is shown in Figure 1.

(2) The temperature of the second-stage photothermal synergistic curing process of the intermediate product reaches the decomposition temperature of the thermal initiator, and the temperature change of the resin system reaction process is shown in Figure 2.

(3) After the first stage of room temperature thermal curing, the product can achieve 180° flexible folding and unfolding, and the flexible folding and unfolding performance is shown in Figure 3.

(4) Comparison of the curing degree of the front and back sides of the composite materials prepared by the photocuring system and the photothermal synergistic system

The schematic diagram of the composite structure is shown in Figure 4, and the C=C conversion rates of different resin systems are shown in Table 1.

Table 1 C=C conversion ratio of different resin systems

resin system Upper layer C=C conversion rate (%) Lower C=C conversion rate (%) light curing system 84.12 47.95 Photothermal synergy system 92.43 73.84

(5) The final product has good mechanical properties, and the tensile properties of the composite are shown in Table 2.

Table 2 Tensile properties of composites

6. Application example (Figure 5)

The carbon fiber composite material was prepared by using the resin formula of this example, and the composite material was bonded after curing for 5 hours in the first stage to make an individual combat antenna, which was placed at room temperature and cured for 7 hours to complete the first stage of curing. , At this time, the individual combat antenna can be folded flexibly, taking up small space, light weight and high strength. It can be unfolded when used, and can be quickly formed by UV irradiation, with short production time and strong practicability.

Example 2:

The difference between this example and Example 1 is that the resin formulation is composed of the following components in parts by mass: 70 parts of acrylate, 30 parts of diluent, 2 parts of second-stage photoinitiator, and second-stage thermal initiator 2 parts of the agent, 20 parts of mercaptan, and 0.1 part of the first stage catalyst. Among them, the acrylate is CN9010NS resin; the diluent is trimethylolpropane triacrylate; the second stage photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone; the second stage thermal initiation The agent is azobisisobutyronitrile; the thiol is tetrakis (3-mercaptopropionic acid) pentaerythritol; the first stage catalyst is 1-methylimidazole.

Example 3:

The difference between this example and Example 1 is that the resin formulation is composed of the following components in parts by mass: 60 parts of acrylate, 40 parts of diluent, 2 parts of second-stage photoinitiator, and second-stage thermal initiator 2 parts of the agent, 20 parts of mercaptan, and 0.1 part of the first stage catalyst. Among them, the acrylate is CN9010NS and CN966NS resin, and the mass ratio of the two is 1:1; the diluent is trimethylolpropane triacrylate; the second stage photoinitiator is 2-hydroxy-2-methyl-1-benzene The second stage thermal initiator is azobisisobutyronitrile; the thiol is tetrakis (3-mercaptopropionic acid) pentaerythritol ester; the first stage catalyst is triethylamine.

Claims (10)

1. A method for rapidly preparing a soft deployable dark fiber composite material based on two-stage and photo-thermal synergistic technology is characterized by comprising the following steps:

step one, preparing a resin system:

(1) Mixing a diluent and a second-stage thermal initiator, and performing ultrasonic treatment for 10 to 40 min;

(2) After complete dissolution, adding acrylate and a second-stage photoinitiator, manually stirring until the mixture is uniformly mixed, and putting the mixture into a vacuum drying oven to remove bubbles;

(3) Adding mercaptan, and removing bubbles after uniformly mixing;

(4) And (2) dropwise adding a first-stage catalyst to activate click reaction, so that the preparation of a resin system is completed, wherein the resin formula comprises the following components in parts by mass: 30-70 parts of acrylate, 30-70 parts of diluent, 1-5 parts of second-stage photoinitiator, 1-5 parts of second-stage thermal initiator, 5-20 parts of mercaptan and 0.01-1 part of first-stage catalyst;

step two, first stage room temperature thermal curing

Coating the resin system prepared in the step one on carbon fibers to enable the carbon fibers to be completely soaked, covering the carbon fibers with a PET film, and transferring the carbon fibers to a dark place to perform first-stage curing at room temperature;

step three and second stage photo-thermal co-curing

And (3) placing the room-temperature thermosetting intermediate product in the first stage at room temperature, and carrying out photo-thermal co-curing to obtain the soft deployable dark fiber composite material.

2. The method for rapidly preparing the soft deployable dark fiber composite based on two-stage and photothermal synergistic technique according to claim 1, characterized in that the acrylate is one or more of methyl methacrylate, urethane acrylate and other acrylates.

3. The method for rapidly preparing a soft developable dark fiber composite based on two-stage and photothermal synergistic technique according to claim 1 characterized in that the diluent is an acrylate diluent.

4. The method for rapidly preparing a soft developable dark fiber composite based on two-stage and photothermal synergistic technique according to claim 1 characterized in that the second stage photoinitiator is a radical or cationic photoinitiator.

5. The method for rapidly preparing the soft developable dark fiber composite based on two-stage and photothermal synergistic technique according to claim 1 characterized in that the second-stage thermal initiator is a peroxide-based or azo-based radical initiator.

6. The method for rapidly preparing the soft deployable dark fiber composite based on the two-stage and photothermal synergistic technique according to claim 1, characterized in that the thiol is one or two of pentaerythritol tetrakis (3-mercaptopropionate) and trimethylolpropane tris (3-mercaptopropionate).

7. The method for rapidly preparing a soft developable dark fiber composite based on two-stage and photothermal synergistic technique according to claim 1 characterized in that the first stage catalyst is an alkaline catalyst.

8. The method for rapidly preparing the soft deployable dark fiber composite material based on the two-stage and photothermal synergistic technology according to claim 1, wherein the curing time of the first stage is 2 to 24h, and the photothermal synergistic curing conditions are as follows: the illumination intensity is 10 to 30 under 365nm0 mW/cm ² And (5) irradiating by using a UV light source for 10 to 600s.

9. The method for rapidly preparing the flexibly deployable dark fiber composite material based on the two-stage and photothermal synergistic technology according to claim 1, wherein the weight of the resin system in the flexibly deployable dark fiber composite material is 40 to 80%.

10. Use of a flexibly deployable dark-colored fibrous composite prepared by the method of any one of claims 1 to 9 in an individual combat antenna.

Images