Polyester fabric / polyvinyl chloride / hollow microsphere composite material and preparation method thereof

Abstract

The invention belongs to the technical field of composite materials, particularly relates to a polyester fabric / polyvinyl chloride / hollow microsphere composite material and a preparation method thereof, and discloses the polyester fabric / polyvinyl chloride / hollow microsphere composite material. The composite material comprises a polyester fabric base layer, a polyvinyl chloride layer and hollow glass beads dispersed in the polyvinyl chloride layer, the particle size of the hollow glass beads is 50-70 [mu] m, and the volume fraction of the hollow glass beads in the polyvinyl chloride layer is 10%-30%. The invention discloses a preparation method of the composite material, and the composite material is excellent in heat insulation performance and good in market application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to a polyester fabric / polyvinyl chloride / hollow microsphere composite material and a preparation method thereof. Background Art

[0002] In recent years, global warming and the consumption of fossil fuels have received increasing attention, and thermal insulation materials are playing an increasingly important role. With the proposal of the sustainable development strategy, the call for energy conservation and environmental protection is getting louder and louder. Developing an automotive interior material with heat insulation function has important practical significance. Therefore, how to improve the heat insulation performance of polyester fabric / polyvinyl chloride composite materials is an urgent problem to be solved.

[0003] Hollow glass microspheres (HGM) are an attractive functional spherical filler for composite materials due to their isotropic, low density, good chemical stability, good moisture resistance and heat insulation properties. HGM is a micron-sized hollow glass sphere, belonging to inorganic non-metallic materials, which is processed from borosilicate raw materials and is a new type of lightweight material with wide uses and excellent properties. Its tiny spherical structure not only gives it good fluidity, better dispersibility and fluidity than flaky, needle-shaped or irregular-shaped fillers, thus enabling it to have excellent filling properties, but also endows it with the isotropic characteristic. This characteristic enables it to effectively control the shrinkage of the product in all directions during the curing process when used as a filler to fill the matrix material, making the product dimensions stable in all directions without warping. The hollow structure of HGM gives it the characteristics of low density and low thermal conductivity, making it an ideal filler for improving the heat insulation performance of composite materials.

[0004] CN101418105B discloses a hollow glass microsphere-reinforced rigid polyvinyl chloride material and a preparation method thereof. The weight ratio of each component of the material, namely polyvinyl chloride resin powder, hollow glass microspheres, coupling agent, heat stabilizer, lubricant, processing modifier, and impact modifier, is 100:1 - 50:0.1 - 10.0:0.5 - 3.0:0.2 - 5.0:0.1 - 5.0:0.1 - 10.0. Through the coupling compatibility and distribution technology, this invention makes the hollow glass microspheres be compounded with the resin and directly injection-molded, obtaining a hollow glass microsphere-reinforced rigid polyvinyl chloride material with higher impact strength, water pressure resistance and burst strength, and higher dimensional stability. However, there has been no relevant report on using HGM to improve the heat insulation performance of polyester fabric / PVC composite materials so far. Studying the application of HGM in improving polyester fabric / PVC composite materials has important significance. Summary of the Invention

[0005] To solve the above technical problems, the present invention explores the application of HGM in the research of improving the heat insulation performance of polyester fabric / PVC composites, and develops a new type of heat insulation composite material with good heat insulation performance: polyester fabric / polyvinyl chloride / hollow glass microsphere composite material.

[0006] On the one hand, the present invention discloses a polyester fabric / polyvinyl chloride / hollow glass microsphere composite material, which comprises a polyester fabric base layer, a polyvinyl chloride layer, and hollow glass microspheres dispersed in the polyvinyl chloride layer. The particle size of the hollow glass microspheres is 50μm - 70μm, and the volume fraction of the hollow glass microspheres in the polyvinyl chloride layer is 10% - 30%.

[0007] Furthermore, in the composite material, the hollow glass microspheres are dispersed in the polyvinyl chloride layer in the form of a particle size gradient distribution and / or a volume fraction gradient distribution.

[0008] On the other hand, the present invention also discloses a preparation method of the composite material, which comprises the following steps:

[0009] Step 1: Prepare a polyvinyl chloride - hollow glass microsphere mixed paste;

[0010] Step 2: Adopt a hand - lay - up process to coat the polyvinyl chloride - hollow glass microsphere mixed paste prepared in Step 1 onto the polyester fabric and spread it evenly;

[0011] Step 3: Put the polyester fabric coated with the mixed paste prepared in Step 2 into an air - drying device and heat - cure it;

[0012] Step 4: Cut and polish the composite material cured in Step 3 to obtain a polyester fabric / polyvinyl chloride - hollow glass microsphere composite material.

[0013] Furthermore, in the method, the preparation method of the polyvinyl chloride - hollow glass microsphere mixed paste comprises the following steps:

[0014] S1: Preparation of polyvinyl chloride resin mixed paste: Mix polyvinyl chloride paste resin EPVC, tributyl citrate TBC, and epoxidized soybean oil ESO, and stir at a first speed for 30 min to prepare a uniform polyvinyl chloride resin paste mixture;

[0015] S2: Weigh a certain amount of hollow glass microspheres HGM, add them to the uniformly stirred polyvinyl chloride resin paste mixture, and stir at a second speed less than the first speed for 60 min to obtain a polyvinyl chloride - hollow glass microsphere mixed paste.

[0016] Furthermore, in the method, the volume fraction of the hollow glass microspheres HGM in S2 is 10% - 30%.

[0017] Further, in the method, the volume fraction of hollow glass microspheres (HGM) in S2 is 30%.

[0018] Further, in the method, the particle size of the hollow glass microspheres (HGM) in S2 is 50 μm - 70 μm.

[0019] Further, in the method, the particle size of the hollow glass microspheres (HGM) in S2 is 70 μm.

[0020] Further, in the method, the particle size of the hollow glass microspheres (HGM) in S2 is a gradient particle size, and the gradient particle sizes are 50 μm - 70 μm / 60 μm / 50 μm - 70 μm.

[0021] Further, in the method, the volume fraction of the hollow glass microspheres (HGM) in S2 is a gradient volume fraction, and the gradient volume fractions are 10% - 30% / 20% / 10% - 30%.

[0022] Further, in the method, the mass ratio of polyvinyl chloride paste resin (EPVC), tributyl citrate (TBC), and epoxidized soybean oil (ESO) in S1 is 100:130:7.

[0023] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0024] The present invention applies HGM to the research on improving the heat insulation performance of polyester fabric / PVC composites, develops a new type of heat insulation composite material with good heat insulation performance, discloses the preparation process of the new composite material, and finds that the hand lay-up process can significantly improve the heat insulation performance of the composite material by distributing hollow microspheres in a gradient distribution form in the composite material. The measured results are as Figure 13 shown in: the heat insulation performance is the best when the gradient volume fraction of hollow glass microspheres (HGM) is 30% / 20% / 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the morphology of HGM with different particle sizes in this application.

[0026] Figure 2 It is the process flow chart of this application.

[0027] Figure 3 It is the result diagram of the influence of the volume density of the HGM volume fraction composite material in this application.

[0028] Figure 4 It is the result diagram of the influence of the HGM volume fraction on the heat insulation performance of the composite material in this application; (a) Thermal conductivity; (b) Thermal diffusivity.

[0029] Figure 5Infrared images of the composite materials containing HGM with different volume fractions in this application.

[0030] Figure 6 Curves showing the variation of the surface temperature of the composite materials containing HGM with different volume fractions in this application over time; (a) Variation curve; (b) Local enlarged view.

[0031] Figure 7 Graph showing the influence of the particle size of HGM in this application on the volume density of the composite materials.

[0032] Figure 8 Influence of the particle size of HGM in this application on the heat insulation performance of the composite materials (a) Thermal conductivity; (b) Thermal diffusivity.

[0033] Figure 9 Curves showing the variation of the surface temperature of the composite materials containing HGM with different particle sizes in this application over time; (a) Variation curve; (b) Local enlarged view.

[0034] Figure 10 Test results showing the influence of the gradient distribution of the particle size of HGM in this application on the heat insulation performance of the composite materials.

[0035] Figure 11 SEM photos of the composite materials with different gradient distributions of the particle size of HGM in this application; (a) Fabric / 60 / 60 / 60; (b) Fabric / 50 / 60 / 70; (c) Fabric / 70 / 60 / 50.

[0036] Figure 12 Schematic diagrams of heat conduction of the composite materials in this application; (a) Fabric / 60 / 60 / 60; (b) Fabric / 50 / 60 / 70; (c) Fabric / 70 / 60 / 50.

[0037] Figure 13 Influence of the gradient distribution of the volume fraction of HGM in this application on the heat insulation performance of the composite materials; (a) Thermal conductivity and thermal diffusivity; (b) Curve showing the variation of the surface temperature over time.

[0038] Figure 14 SEM photos of the composite materials with different gradient distributions of the volume fraction of HGM in this application; (a) Fabric / 30%20% / 10%; (b) Fabric / 10%20% / 30%; (c) Fabric / 20%20% / 20%. Detailed implementation manners

[0039] Next, the technical solutions of the present invention will be described in conjunction with the embodiments. However, the present invention is not limited to the following embodiments.

[0040] To enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention will be further described below in conjunction with specific embodiments and the accompanying drawings. However, the specific embodiments cited do not limit the present invention.

[0041] In the following embodiments, the experimental methods and detection methods are conventional methods unless otherwise specified; the reagents and materials can be purchased on the market unless otherwise specified.

[0042] The hollow glass microspheres were purchased from 3M Company, model VS5500.

[0043] Example 1

[0044] This example is the screening of HGM.

[0045] To prepare HGM with different particle sizes, the HGM was screened multiple times using standard sieves with different mesh numbers. The conversion between the mesh number and particle size of the standard sieve is based on the Tyler standard sieve system. Taking the 200-mesh sieve pore size of 0.074 mm as the benchmark, multiplying or dividing by the nth power of the square root of the main modulus 2 (n = 1, 2, 3...), the sieve pore sizes coarser or finer than 200 can be obtained. If 0.074 mm is multiplied or divided by the nth power of the fourth root of the secondary modulus 2 (1.1892), the sieve mesh sizes of a series of finer graduations can be obtained. The specification parameters of the sample sieves used in this example are shown in Table 1. Since HGM is a hard, hollow, thin-walled, and lightweight sphere, during the screening process of HGM, it is required that the screening process be carried out in a closed environment to avoid the difficulty of collecting the scattered HGM particles during the screening process.

[0046] Table 1 Specifications of standard sample sieves

[0047] Mesh number (mesh) 320 270 260 250 240 200 Aperture (μm) 48 53 57 63 65 75

[0048] Using the sample sieves in Table 1 to conduct a series of screenings on VS5500-type HGM, HGM with average particle sizes of 50 μm, 60 μm, and 70 μm can be obtained.

[0049] The bulk density of HGM with different particle sizes was measured using a 3H-2000PS series fully automatic surface and pore size analyzer, that is, the ratio of the mass of HGM to its true volume (the true volume of HGM refers to the volume of the HGM aggregate after removing the pore volume between the microspheres). Before the test, the airtightness was detected first. During the test, the sample tube and the filling rod were installed first, and the volume of the empty tube V1 was measured; then the sample tube was disassembled, the sample to be measured with a mass of M was loaded into the sample tube, and then the filling rod was also loaded into the sample tube, and the volume of the sample tube V2 after loading the sample was measured; after the test was completed, the true density ρ of the sample was calculated according to the formula.

[0050] ρ = M / (V1 - V2)

[0051] Each sample was tested 5 times and the average value was taken.

[0052] The HGM sieved by standard sample dividers of different models was observed by field emission scanning electron microscope, and the results are as Figure 1 shown. Figure 1 In (a), (b), and (c) are HGM with particle size of 70μm, 60μm, and 50μm respectively. It can be seen from the figure that the size of the HGM sieved by the standard sample divider is relatively uniform, indicating that the standard sample divider has a good sieving effect on the HGM and can be used for the preparation of subsequent composite materials.

[0053] To further analyze the influence of the particle size difference on the bulk density of HGM, the 3H-2000PS series full-automatic surface and pore size analyzer was used to measure its bulk density, and the results are shown in Table 2.

[0054] Table 2 Bulk density of HGM with different particle sizes

[0055] Particle size (μm) 50±2 60±2 70±5 <![CDATA[Bulk density (g / cm 3 )]]> 0.3821±0.0016 0.3811±0.0019 0.3798±0.0017

[0056] It is not difficult to find from Table 2 that the bulk density of HGM with different particle sizes fluctuates around 0.38 g / cm 3 which, compared with the density of 0.38 of the HGM (VS5500 type) raw material given by 3M Company, indicates that the influence of the particle size difference of HGM on its bulk density can be ignored.

[0057] Example 2

[0058] This example is for the preparation of polyester fabric / polyvinyl chloride-hollow microsphere composite materials.

[0059] (1) Preparation of polyvinyl chloride-hollow microsphere mixed paste

[0060] Polyvinyl chloride paste resin (EPVC), tributyl citrate (TBC) and epoxidized soybean oil (ESO) were mixed in a mass ratio of 100:130:7 and stirred at a speed of 1000 r / min for 30 min to obtain a PVC resin paste mixture.

[0061] Weigh a certain amount of HGM (type VS5500), and slowly add it to the well-stirred PVC resin paste mixture. Stir at a speed of 600 r / min for 60 min to prepare PVC-HGM mixed pastes with volume fractions of HGM being 0, 10%, 20%, and 30% respectively. Weigh HGM with average particle sizes of 50 μm, 60 μm, and 70 μm prepared in Example 1 according to the amount with a volume fraction of HGM being 30%, and then slowly add them to the well-stirred PVC resin paste mixture respectively. Stir at a speed of 600 r / min for 60 min to prepare polyvinyl chloride-hollow microsphere mixed pastes (PVC-HGM mixed pastes) with average particle sizes of 50 μm, 60 μm, and 70 μm respectively.

[0062] (2) Preparation of polyester fabric / polyvinyl chloride-hollow microsphere composite

[0063] Using polyester fabric as the reinforcing material, apply the prepared PVC-HGM mixed paste onto the polyester fabric and spread it evenly with a scraper.

[0064] Put the polyester fabric coated with the mixed paste into a drying equipment such as a blast drying oven and heat-cure it at 80 °C for 2 hours. Cut and polish the cured composite material to obtain the polyester fabric / polyvinyl chloride-hollow microsphere composite.

[0065] The process flow chart of this example is as Figure 2 shown.

[0066] Example 3

[0067] This example is an optimization test on the process of polyester fabric / polyvinyl chloride-hollow microsphere composite.

[0068] 3.1 Test on the influence of different HGM volume fractions on the properties of polyester fabric / polyvinyl chloride-hollow microsphere composite.

[0069] Adopt the method of Example 2 to prepare four kinds of polyester fabric / polyvinyl chloride-hollow microsphere composites with a thickness of 1.6 mm and volume contents of HGM (model VS5500) being 0, 10%, 20%, and 30% respectively. Used for the performance test of the composite materials prepared under the condition of HGM volume fraction.

[0070] 3.1.1 Composite density test

[0071] Use the drainage method to test the volume density of the above-prepared composite materials. The results are as Figure 3 shown. As the content of HGM in the matrix material increases, the volume density of the composite material decreases. The volume density of the composite material with a volume fraction of HGM in the matrix being 30% is 0.883 g / cm 3, compared with the volume density of 1.135 g / cm³ of the composite material with a volume fraction of HGM of 0 in the matrix 3 , it decreased by 22.2%. This indicates that the composite material with a volume fraction of HGM of 30% has better heat insulation performance.

[0072] 3.1.2 Testing the heat insulation performance of the composite material

[0073] Using a Hotdisk thermal constant analyzer, its thermal conductivity, thermal diffusivity and other indicators were tested at 20 °C, and the test results are as Figure 4 shown.

[0074] As can be seen from Figure 4 (a) in, as the volume fraction of HGM increases, the thermal conductivity of the composite material gradually decreases. The thermal conductivities of the composite materials with volume fractions of HGM in the matrix of 0, 10%, 20%, and 30% are 0.2247 W / (m·K), 0.1974 W / (m·K), 0.1802 W / (m·K), and 0.1656 W / (m·K) respectively. The composite material with a volume fraction of HGM of 30% has a 26.30% lower thermal conductivity compared to the composite material without HGM in the matrix. The decrease in the thermal conductivity of the composite material indicates an improvement in its heat insulation performance.

[0075] As can be seen from Figure 4 (b) in, as the volume fraction of HGM increases, the thermal diffusivity of the composite material gradually decreases. The thermal diffusivities of the composite materials with volume fractions of HGM in the matrix of 0, 10%, 20%, and 30% are 0.2227 mm 2 / s, 0.1866 mm 2 / s, 0.1694 mm 2 / s, 0.1523 mm 2 / s respectively. The composite material with a volume fraction of HGM of 30% has a 31.61% lower thermal diffusivity compared to the composite material without HGM in the matrix. The decrease in the thermal diffusivity of the composite material also indicates an improvement in its heat insulation performance.

[0076] In order to further analyze the influence of the volume fraction of HGM on the heat insulation performance of the composite material, an infrared thermal imager was used to photograph the surface temperature field distribution of the composite material.

[0077] Under the conditions of an ambient temperature of 23 °C and a relative humidity of 55%, the camera of the infrared thermal imager was fixed 50 cm directly above the heating table. The composite material specimen was quickly placed on the 40 °C electric heating table with tweezers. Timing started from the moment the specimen was placed on the heating table, and the change in the surface temperature distribution T of the composite material with time t was recorded. An image was collected every 6 s. The results of collecting images of composite material specimens with HGM volume fractions of 0, 10%, 20%, and 30% under the infrared thermal imaging system are as Figure 5 shown.

[0078] From Figure 5 it can be seen that from the moment the composite material specimen came into contact with the electric heating table to 6 s, the infrared images of the four composite material specimens with HGM volume fractions of 0, 10%, 20%, and 30% all changed rapidly, indicating that the temperature on the surface of the composite material specimen increased rapidly. As the contact time extended, the change in the infrared image of the composite material specimen tended to slow down, indicating that the temperature change on the surface of the composite material specimen gradually became gentle.

[0079] To more intuitively compare and analyze the influence of the HGM volume fraction on the heat insulation performance of the composite material, the temperature data represented by the Figure 5 mid-infrared images were placed in the same coordinate system, and a curve as shown in Figure 6 was made.

[0080] From Figure 6 (a) in it can be seen that within the first 6 s, the temperature on the surface of the composite material specimen increased rapidly, and after 30 s, the temperature change on the surface of the composite material specimen tended to become gentle. Figure 6 (b) in it is an enlarged view of the change in the surface temperature of the composite material specimen with time between 0 and 6 s. From it, it can be clearly seen that the slope of the temperature-time curve of the composite material specimen with an HGM volume fraction of 0 is the largest, followed by that of the composite material specimen with an HGM volume fraction of 10%, then that of the composite material specimen with an HGM volume fraction of 20%, and the smallest for the composite material specimen with an HGM volume fraction of 30%. The larger the slope of the specimen temperature-time curve, the faster the temperature of the specimen rises within the same time, which also means that the rate of heat conduction is faster, and correspondingly, the heat insulation performance is worse. It shows that the heat insulation performance of the four composite material specimens with HGM volume fractions of 0, 10%, 20%, and 30% increases in turn.

[0081] Through the test results of the volume density and heat insulation performance of the composite materials prepared with different HGM volume fractions, it was found that the composite material with an HGM volume fraction of 30% had the best performance.

[0082] 3.2 Test on the influence of different HGM particle sizes on the performance of polyester fabric / polyvinyl chloride-hollow microsphere composite materials

[0083] To further analyze the effect of the size of HGM particle size on the density of the composite material, composites with a volume fraction of 30% of HGM were prepared using HGM with average particle sizes of 50 μm, 60 μm, and 70 μm separated by sieving, and their properties were tested.

[0084] 3.2.1 Test results of the effect of HGM particle size on the bulk density of the composite material

[0085] The test results are as Figure 7 shown. As the particle size of HGM increases, the bulk density of the composite material decreases slightly, indicating that the porosity inside the composite material with a larger HGM particle size is higher than that of the composite material with a smaller HGM particle size, that is, as the particle size of HGM increases, the porosity inside the composite material also increases accordingly.

[0086] 3.2.2 Test results of the effect of HGM particle size on the heat insulation performance of the composite material

[0087] The heat insulation performance of the three groups of prepared composite materials was tested using a Hotdisk thermal constant analyzer and an infrared thermal imager respectively. The measured results are as Figure 8 and Figure 9 shown.

[0088] It can be clearly seen from Figure 8 that as the particle size of HGM increases, both the thermal conductivity and the thermal diffusivity of the composite material show a downward trend. The thermal conductivity of the composite material with an HGM particle size of 70 μm is 0.1594 W / (m·K), which is 7.27% lower than the thermal conductivity of 0.1719 W / (m·K) of the composite material with a particle size of 50 μm. The thermal diffusivity of the composite material with an HGM particle size of 70 μm is 0.1487 mm 2 / s, which is 10.64% lower than the thermal diffusivity of 0.1664 mm 2 / s of the composite material with a particle size of 50 μm. The decrease in the thermal conductivity and thermal diffusivity of the composite material indicates an improvement in the heat insulation performance of the composite material.

[0089] It can be seen from Figure 9As can be seen from Fig. (a), the composite material was placed on an electrically heated table set at a temperature of 40 °C. Within the first 6 s, the surface temperature increased rapidly. Between 6 s and 30 s, the surface temperature of the composite material increased slowly. After 30 s, the surface temperature of the composite material gradually stabilized. The surface temperatures of the composite material specimens with HGM particle sizes of 50 μm, 60 μm, and 70 μm stabilized at 42.05 °C, 41.30 °C, and 40.81 °C respectively at 54 s. If the initial temperatures of the materials are the same, after being placed on a hot table at the same temperature for the same period of time, the greater the change in surface temperature, the poorer the heat insulation performance. The initial temperatures of the three groups of composite material specimens with HGM particle sizes of 50 μm, 60 μm, and 70 μm are basically the same. After being placed on an electrically heated table at the same temperature for a certain period of time, the stable surface temperatures decrease in sequence, indicating that the changes in their surface temperatures decrease in sequence and the heat insulation performance improves in sequence. At the same time, from Figure 9 As can also be seen from Fig. (b), within 0 to 6 s, the slopes of the temperature-time curves of the three groups of composite material specimens with HGM particle sizes of 50 μm, 60 μm, and 70 μm are 1.90, 1.85, and 1.77 respectively. The slopes decrease in sequence, indicating that within the first 6 s when the three groups of composite material specimens with HGM particle sizes of 50 μm, 60 μm, and 70 μm start to contact the 40 °C electrically heated table, the temperature changes with time become slower in sequence. This result also shows that with the increase in HGM particle size, the heat insulation performance of the composite material improves.

[0090] In summary, from the analysis of data such as the thermal conductivity, thermal diffusivity of the composite material, the trend of the surface temperature of the composite material changing with time when placed on an electrically heated table for a certain period of time, and the slope of the temperature-time curve in the initial period of time, it is fully demonstrated that with the increase in HGM particle size, the heat insulation performance of the composite material improves.

[0091] 3.3 Test on the Influence of HGM Particle Size Gradient Distribution on the Heat Insulation Performance of Composite Materials

[0092] In order to further explore the influence of HGM particle size gradient distribution on the heat insulation performance of composite materials, three forms of HGM particle size gradient distributions were designed, namely 60 / 60 / 60, 50 / 60 / 70, and 70 / 60 / 50. Three groups of composite materials, Fabric / 60 / 60 / 60, Fabric / 50 / 60 / 70, and Fabric / 70 / 60 / 50, were prepared by the hand lay-up method. The heat insulation performance of the composite materials was tested using a Hotdisk thermal constants analyzer and an infrared thermal imager, and the measured results are as Figure 10 shown.

[0093] Figure 10(a) shows the influence of the HGM particle size gradient distribution on the thermal conductivity and thermal diffusivity of the composite material. Among the three groups of composite materials with different HGM particle size gradient distributions, the thermal conductivity and thermal diffusivity of the composite material Fabric / 70 / 60 / 50 are 0.1487 W / (m·K) and 0.1231 mm 2 / s respectively, which are the lowest among the three groups of composite materials with different HGM particle size distributions, indicating that the composite material with the HGM particle size gradient distribution in the form of 70 / 60 / 50 has the best heat insulation performance. The thermal conductivities and thermal diffusivities of the two groups of composite materials with the HGM particle size gradient distributions of 60 / 60 / 60 and 50 / 60 / 70 are not very different, indicating that the heat insulation performances of the composite materials Fabric / 60 / 60 / 60 and Fabric / 50 / 60 / 70 are similar. Among the three composite materials with different HGM particle size gradient distributions, the composite material Fabric / 70 / 60 / 50 with the best heat insulation performance has a 10.15% and 20.42% reduction in thermal conductivity and thermal diffusivity respectively compared to the composite material Fabric / 50 / 60 / 70 with the worst heat insulation performance. It can be seen that the HGM particle size gradient distribution has a significant influence on the heat insulation performance of the composite material.

[0094] Figure 10 (b) shows the influence of the HGM particle size distribution on the relationship between the surface temperature and time of the composite material. Figure 10 As can be seen from (b), among the three groups of composite materials with different HGM particle size gradient distributions, the trend of the surface temperature of the material changing with time is basically the same. Starting from the moment when the composite material comes into contact with the electric heating table, the surface temperature of the material rises at a relatively fast speed, and then the speed gradually becomes flat until it stabilizes at a certain temperature.

[0095] Among the three groups of composite materials with different HGM particle size distributions, the temperature change of the surface of the composite material Fabric / 70 / 60 / 50 with time is the slowest, and the temperature at which it stabilizes is the lowest, indicating that it has the best heat insulation performance. The temperature changes of the surfaces of the composite materials Fabric / 50 / 60 / 70 and Fabric / 60 / 60 / 60 with time are basically the same, and the temperatures at which they stabilize are also very close, indicating that the heat insulation performances of the composite materials Fabric / 50 / 60 / 70 and Fabric / 60 / 60 / 60 are basically the same, and the heat insulation performances of both composite materials are inferior to that of the composite material Fabric / 70 / 60 / 50.

[0096] For the three groups of composite materials with different HGM particle size distributions, the components, thickness, and volume density in the materials are the same, but the heat insulation performances are significantly different, which is mainly attributed to their different internal structures. Figure 11Among them, (a), (b), and (c) are respectively the microscopic photos of the cross-sectional structures of three groups of composite materials with HGM particle size distributions of Fabric / 60 / 60 / 60, Fabric / 50 / 60 / 70, and Fabric / 70 / 60 / 50. From Figure 11 it can be seen that for the three groups of composite materials with different HGM particle size distributions prepared by the hand lay-up method, the cross-section has a clear gradient distribution.

[0097] The heat conduction of three groups of composite materials with HGM particle size distributions of Fabric / 60 / 60 / 60, Fabric / 50 / 60 / 70, and Fabric / 70 / 60 / 50 can be analyzed through Figure 12 the following. Figure 11 Among them, (a), (b), and (c) are respectively the schematic diagrams of heat conduction of composite materials with HGM particle size distributions of Fabric / 60 / 60 / 60, Fabric / 50 / 60 / 70, and Fabric / 70 / 60 / 50. The temperature difference is the largest at the part where the material surface contacts the outside world, and the trend of heat transfer is the strongest. During the process of heat from the outside transferring into the material, the temperature difference becomes smaller and smaller, and the trend of heat transfer becomes weaker and weaker. Figure 12 For the composite material Fabric / 60 / 60 / 60 in , the heat insulation ability remains unchanged as the heat transfer trend weakens. Figure 12 For the composite material Fabric / 50 / 60 / 70 in (b) of , the heat insulation ability weakens as the heat transfer trend weakens. Figure 12 For the composite material Fabric / 70 / 60 / 50 in (c) of , the heat insulation ability strengthens as the heat transfer trend weakens, indicating that the composite material Fabric / 70 / 60 / 50 exhibits significantly better heat insulation performance than the composite materials Fabric / 60 / 60 / 60 and Fabric / 50 / 60 / 70.

[0098] 3.4 Test on the Influence of the Gradient Distribution of HGM Volume Fraction on the Heat Insulation Performance of Composite Materials

[0099] In order to explore the influence of the gradient distribution of HGM volume fraction on the heat insulation performance of composite materials, three forms of gradient distributions of HGM volume fraction, namely 20% / 20% / 20%, 10% / 20% / 30%, and 30% / 20% / 10%, were designed, and the composite materials Fabric / 20% / 20% / 20%, Fabric / 10% / 20% / 30%, and Fabric / 30% / 20% / 10% were prepared by the hand lay-up method. The heat insulation performance of the composite materials was tested through a Hotdisk thermal constant analyzer and an infrared thermal imager, and the measured results are as Figure 13 shown.

[0100] Figure 13 (a) shows the influence of the HGM volume fraction gradient distribution on the thermal conductivity and thermal diffusivity of the composite material. Among the three groups of composite materials with different HGM volume fraction gradient distributions, the thermal conductivity and thermal diffusivity of the composite material with an average volume fraction distribution Fabric / 20% / 20% / 20% are 0.1802 W / (m·K) and 0.1694 mm 2 / s respectively. For the two composite materials with a volume fraction gradient distribution, Fabric / 10% / 20% / 30% and Fabric / 30% / 20% / 10%, both the thermal conductivity and thermal diffusivity show a downward trend. Among them, the composite material Fabric / 30% / 20% / 10% shows a relatively large decrease, with the thermal conductivity and thermal diffusivity decreasing by 12.04% and 20.60% respectively. The test results of the thermal conductivity and thermal diffusivity indicate that the HGM volume fraction gradient distribution significantly improves the heat insulation performance of the composite material.

[0101] Figure 13 (b) shows the influence of the HGM volume fraction distribution on the relationship between the surface temperature and time of the composite material. Through Figure 13 (b), it can be seen that among the three groups of composite materials with different HGM volume fraction gradient distributions, for the composite material with a volume fraction gradient distribution Fabric / 30% / 20% / 10%, the temperature on the surface changes the slowest with time and the temperature tending to be stable is the lowest, indicating that its heat insulation performance is the best. For the composite material with an average volume fraction distribution Fabric / 20% / 20% / 20%, the temperature on the surface changes the fastest with time and the temperature tending to be stable is the highest, indicating that its heat insulation performance is the worst. For the composite material with a volume fraction gradient distribution Fabric / 30% / 20% / 10%, the change in surface temperature with time is in the middle. From the analysis of the relationship between the surface temperature and time of the composite material, it can be known that the HGM volume fraction gradient distribution can improve the heat insulation performance of the composite material, and the composite material with the distribution form of Fabric / 30% / 20% / 10% has the best heat insulation performance.

[0102] For the three groups of composite materials with different distribution forms of the HGM volume fraction, under the conditions of the same thickness and the same volume density, the reason for the obvious difference in heat insulation performance lies in their different internal structures. Figure 14 These are the microscopic photos of the cross-sectional structures of the three groups of composite materials with HGM volume fraction gradient distributions of 20% / 20% / 20%, 10% / 20% / 30%, and 30% / 20% / 10% respectively. Figure 14 In (a) and

[0103] (b) are the cross-sectional views of the composites with HGM volume gradient distributions of Fabric / 30% / 20% / 10% and Fabric / 10% / 20% / 30%, respectively. It can be seen that in the part with an HGM volume fraction of 30%, due to the relatively large aggregation degree of hollow glass microspheres, a certain amount of pores appear between the HGMs. The cross-section of the Fabric / 20% / 20% / 20% composite with a uniform distribution of HGM volume fraction is as shown in Figure 14 (c). The HGMs are evenly distributed and relatively dispersed, and there are fewer pores between the HGMs. The presence of pores inside the composite can greatly improve its heat insulation ability. Therefore, the heat insulation performance of the composite with a gradient distribution of HGM volume fraction is better than that of the composite with a uniform distribution of HGM volume fraction. And the composite with the distribution form of Fabric / 30% / 20% / 10% has the best heat insulation performance.

[0104] As described above, the basic principles, main features and advantages of the present invention are preferably described. The above embodiments and the description are only for describing the preferred embodiments of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the present invention.

Claims

1. A polyester fabric / polyvinyl chloride / hollow microsphere composite material, characterized in that: The invention comprises a polyester fabric base layer, a polyvinyl chloride layer and hollow glass microbeads dispersed in the polyvinyl chloride layer. The particle size of the hollow glass microbeads is 50-70 μm, and the volume fraction of the hollow glass microbeads in the polyvinyl chloride layer is 10%-30%.

2. The composite material according to claim 1, characterized in that The hollow glass microspheres are dispersed in the polyvinyl chloride layer in the form of a particle size gradient distribution and / or a volume fraction gradient distribution.

3. A method for preparing the composite material according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1, preparing polyvinyl chloride-hollow microsphere mixed paste; Step 2: using a hand lay-up process to apply the polyvinyl chloride-hollow microbead mixed paste prepared in step 1 onto the polyester fabric and spread it evenly; Step 3, placing the polyester fabric coated with the mixed paste obtained in step 2 into an air drying device for heating and curing; Step 4: cutting and polishing the composite material cured in step 3 to obtain a polyester fabric / polyvinyl chloride-hollow microsphere composite material.

4. The preparation method according to claim 3, characterized in that: The preparation method of the polyvinyl chloride-hollow microsphere mixed paste comprises the following steps: S1. Preparation of polyvinyl chloride resin mixed paste: polyvinyl chloride paste resin EPVC, tributyl citrate TBC and epoxy soybean oil ESO are mixed in a mass ratio of 100:130:7, and stirred at a first speed for 30 minutes to prepare a uniform polyvinyl chloride resin paste mixture; S2. Weigh a certain amount of hollow glass microspheres HGM, add it to the uniformly stirred polyvinyl chloride resin paste mixture, and stir for 60 minutes at a second speed lower than the first speed to obtain a polyvinyl chloride-hollow microsphere mixed paste.

5. The preparation method according to claim 4, characterized in that: The volume fraction of the hollow glass microspheres HGM in the S2 is 10%-30%.

6. The preparation method according to claim 4, characterized in that: The volume fraction of the hollow glass microspheres HGM in the S2 is 30%.

7. The preparation method according to claim 4, characterized in that: The particle size of the hollow glass microspheres HGM in S2 is 50 μm-70 μm.

8. The preparation method according to claim 4, characterized in that: The particle size of the hollow glass microspheres HGM in S2 is 70 μm.

9. The preparation method according to claim 4, characterized in that: The particle size of the hollow glass microspheres HGM in S2 is a gradient particle size, and the gradient particle sizes are 50 μm-70 μm / 60 μm / 50 μm-70 μm respectively.

10. The preparation method according to claim 4, characterized in that: The volume fraction of the hollow glass microspheres HGM in the S2 is a gradient volume fraction, and the gradient volume fraction is 10%-30% / 20% / 10%-30%.

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