Solid composite material and preparation method thereof

Abstract

The present invention relates to a solid composite material comprising: a first polymer, preferably a solid having a porous structure; a second polymer, preferably different from the first polymer; a first additive, preferably selected from perovskite; and optionally a second additive; wherein the solid composite material is prepared by the following steps of: mixing monomers of the first polymer with the second polymer, the first additive and optionally the second additive, and then curing the monomers through polymerization reaction to generate the first polymer, whereby the second polymer, the first additive, and optionally the second additive are dispersed in the porous structure of the first polymer.

Description

TECHNICAL FIELD

[0001] The present invention relates to a solid composite material, and a method for preparing a polymer composite material. In particular, the solid composite material is a polymer solid composite material. BACKGROUND

[0002] Most of the commercially available polymer composite materials in the market contain harmful substances and non-renewable polymers, resulting in a large amount of waste. These conventional composite material formulations are heavily dependent on virgin polymers, significantly increasing the global polymer pollution problem. In addition, the manufacturing process involves the use of various toxic chemicals and solvents, further compromising the viability of production. Furthermore, these unsustainable manufacturing methods generate long-term toxic waste and lack biodegradability.

[0003] Therefore, the present invention studies a new polymer composite material containing recycled polymers, creating a sustainable alternative for commercial applications, promoting environmental sustainability. The polymer composite material developed in the present invention can be configured to include functional additives or fillers that can provide different functions, making the polymer composite material useful for a wide range of applications, including automotive, construction, and sound insulation. Alternatively, the present invention provides an alternative solution for public use. SUMMARY

[0004] A first aspect of the present invention relates to a solid composite material comprising:

[0005] - a first polymer, preferably a solid having a porous structure;

[0006] - a second polymer, preferably different from the first polymer;

[0007] - a first additive, preferably selected from a perovskite; and

[0008] - optionally a second additive;

[0009] wherein the solid composite material is prepared by mixing monomers of the first polymer with the second polymer, the first additive and optionally the second additive, and then curing the monomers by polymerization to form the first polymer, whereby the second polymer, the first additive and optionally the second additive are dispersed in the porous structure of the first polymer.

[0010] In some embodiments, the first polymer is selected from polyvinyl acetate, low density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam, polyol, polyester, polyacrylate, polyurethane, polysulfide, or a combination thereof. Preferably, the concentration of the first polymer in the solid composite material varies from 1% w / w to 25% w / w.

[0011] In some embodiments, the second polymer is selected from polystyrene, polyurethane, polyethylene terephthalate, polyol, polyester, polyacrylate, polyurethane, polysulfide, polyvinyl acetate, low density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam, or a combination thereof. Preferably, the concentration of the second polymer in the solid composite material varies from 30% w / w to 70% w / w. More preferably, the second polymer is a recycled material.

[0012] In some embodiments, the first additive is selected from lead perovskite crystals, lead-free perovskite crystals, lead-free double perovskite crystals, or a combination thereof. Advantageously, the first additive is characterized by a high Goldschmidt tolerance factor. More advantageously, the diameter of the crystals is in the range of 5 to 500 nm.

[0013] In some embodiments, the lead-free perovskite crystals are selected from tin halide perovskite (CH3NH3)SnI3, bismuth halide perovskite (CH3NH3)3Bi2I9, antimony halide perovskite (CH3NH3)3Sb2I9, silver bismuth iodide AgBiI4, or a combination thereof.

[0014] In some embodiments, the lead-free double perovskite crystals are selected from Cs3Bi2Br9, Cs2AgInCl6, Cs2AgBiBr6, Cs2AgBiI6, Cs2AgSbBr6, Cs2AgSbI6, or a combination thereof.

[0015] In some embodiments, the first additive is Cs2AgInBiCl6, Cs3Bi2Cl6, or a combination thereof.

[0016] In some embodiments, the concentration of the first additive in the solid composite material varies from 0.01% w / w to 40% w / w, preferably from 0.01% w / w to 25% w / w, more preferably from 0.05% w / w to 40% w / w, most preferably from 0.05% w / w to 25% w / w.

[0017] In some embodiments, the second additive is selected from carbon nanotubes, carbon quantum dots, graphene, silica nanoparticles, metal nanoparticles comprising silver, gold, copper or a combination thereof, clay nanoparticles comprising montmorillonite, halloysite or a combination thereof, metal oxide nanoparticles comprising titanium dioxide, zinc oxide, aluminum oxide or a combination thereof, cellulose nanofibers or a combination thereof. Advantageously, the second additive is further cellulose, chitosan, alginate, starch, dextran, or a combination thereof. More advantageously, the second additive is biodegradable. Preferably, the average size of the second additive is in the range of 5 to 500 nm, preferably less than 10 nm. More preferably, the concentration of the second additive in the solid composite material is from 0.02 wt% to 1 wt%.

[0018] In some embodiments, the solid composite material further comprises:

[0019] - a foaming agent selected from water, carbon dioxide, hydrocarbons comprising propane, butane, pentane, or a combination thereof, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFC), azodicarbonamide (ADA), sodium bicarbonate, citric acid, sodium carbonate, ammonium bicarbonate, or a combination thereof; and / or

[0020] - a third additive comprising: a surfactant, a stabilizer, a plasticizer, a crosslinking agent, or a combination thereof.

[0021] In some embodiments, the concentration of the foaming agent in the solid composite material is 1% w / w to 15% w / w.

[0022] In some embodiments, the concentration of the third additive in the solid composite material is 1% w / w to 30% w / w.

[0023] In some embodiments, the surfactant is selected from cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), oleic acid, dimethyldioctadecylammonium bromide (DDAB), polyethylene glycol and their corresponding block copolymers.

[0024] In some embodiments, the stabilizer is selected from oleic acid, oleylamine, Tween 20, cetyltrimethylammonium bromide (CTAB), or a combination thereof.

[0025] In some embodiments, the plasticizer is selected from glycerol, ethyl acetate, sorbitol, ethylene glycol, xylitol and diethylene glycol, or a combination thereof.

[0026] In some embodiments, the cross-linking agent is selected from isocyanates including toluene diisocyanate, p-xylylene diamine, gelatin, collagen, agarose, agar, or a combination thereof.

[0027] A second aspect of the present application relates to the preparation of the composite material of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Some embodiments of the present application will be explained below with reference to the drawings, in which:

[0029] Figure 1 Foams of different shapes and sizes prepared from the first polymer of the present application are shown;

[0030] Figure 2a and Figure 2b SEM image of Cs2AgInBiCl6;

[0031] Figure 3a and Figure 3b TEM image of Cs3Bi2Cl6;

[0032] Figure 4a and Figure 4b SEM image of cellulose nanoparticles and SEM image of cellulose nanoparticles in combination with the composite material prepared according to the present application;

[0033] Figure 5a and Figure 5b TEM image of alginate nanoparticles;

[0034] Figure 6a and Figure 6b TEM image of chitosan nanoparticles;

[0035] Figure 7a and Figure 7b TEM image of dextran nanoparticles;

[0036] Figure 8a SEM image of the foam gel in which different additives are dispersed;

[0037] Figure 8b SEM image showing the pore distribution of the foam gel;

[0038] Figure 9a and Figure 9b Contact angle of the foam gel showing the characteristic of hydrophobicity;

[0039] Figure 10The results of the acoustic test ASTM E 2611-17 at 26°C and 65% humidity are shown; and

[0040] Figure 11a and Figure 11b SEM images of the composites with different additives dispersed are shown. DETAILED DESCRIPTION

[0041] The present application will now be described by way of example, with reference to the accompanying drawings. The objects, features and advantages of the present disclosure will be apparent from the following description of the exemplary embodiments. It will be understood by those skilled in the art that the following description is illustrative only of exemplary embodiments and does not intend to limit the broader aspects of the present disclosure, which are embodied in the exemplary constructions.

[0042] It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present application shall have their ordinary meanings as understood by those skilled in the art to which the present application pertains. The use of "first", "second" and similar expressions in the embodiments of the present application does not denote any order, quantity or importance, but is merely used to distinguish different components.

[0043] Unless otherwise specified, all chemicals described in the present application are commercially available and used directly without special treatment, and can contain impurities (such as residual solvents or by-products). Unless otherwise specified, the percentages in the present application refer to weight percentages. For the convenience of explaining the present application, the chemicals used in the specification are only examples. It should be understood that it has no any limiting effect on the present application.

[0044] Firstly, a first aspect of the present application (i.e. a composite material) will be described as follows, which comprises:

[0045] - a first polymer, preferably prepared in situ;

[0046] - a second polymer;

[0047] - a first additive (alternatively a first filler), preferably selected from perovskite crystals; and

[0048] - a second additive (alternatively a second filler).

[0049] Preferably, the composite material is solid. More preferably, the first polymer is solid and has a porous structure.

[0050] For the first polymer applicable in the present application, it is preferred to use a hydrophilic polymer, a hydrophobic polymer, or a combination of these polymers. Long-chain polymers and cross-linked polymers are also preferred.

[0051] Most preferably, a polymeric foam glue is used. Examples of the first polymer can be selected from polyethylene vinyl acetate, low density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam, or a combination thereof.

[0052] In some embodiments, polyols, polyesters, polyacrylates, polyurethanes and polysulfides are also suitable for the first polymer.

[0053] Advantageously, the concentration of the first polymer in the composite material ranges from 1% w / w to 25% w / w.

[0054] For illustration purposes only, below is shown how to prepare a polyurethane. However, the person skilled in the art should not interpret the below as a limitation to the present invention, in particular to the first polymer suitable for use in the present invention.

[0055] In some embodiments, the polyurethane is prepared by polymerizing methylene diphenyl diisocyanate (PMI). It is a diisocyanate compound commonly used in the production of polyurethane foams and resins. PMI is known for its high reactivity and is often used to manufacture rigid polyurethane foams for insulation purposes.

[0056] In some embodiments, the polyurethane is prepared by methylene diphenyl diisocyanate (MDI). MDI is another diisocyanate compound used in the production of polyurethane polymers. MDI is mainly used to manufacture flexible polyurethane foams (such as foams in furniture, mattresses and car seats).

[0057] Figure 1 Different shapes and sizes of foams prepared from the first polymer of the present invention are shown;

[0058] For the second polymer suitable for use in the present invention, both hydrophilic and hydrophobic polymers are preferred. Long chain polymers and cross-linked polymers are also preferred.

[0059] The concentration of the second polymer in the composite material preferably ranges from 30% w / w to 75% w / w. Advantageously, the concentration of the second polymer in the composite material ranges from 50% w / w to 70% w / w. More advantageously, the concentration of the second polymer in the composite material is at least 30% w / w.

[0060] Advantageously, the second polymer can be a recycled polymer obtained from post-consumer waste, such as plastic bottles, containers, packaging materials, or combinations thereof. For example, the second polymer can be a recycled polystyrene, polyurethane, polyethylene terephthalate, polyol, polyester, polyacrylate, polyurethane, polythiol, or combinations thereof.

[0061] More advantageously, the second polymer can be a recycled polymer selected from the group consisting of polyethylene vinyl acetate, low-density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam, or combinations thereof.

[0062] The formulation for making the composite material of the present invention is economically viable because it utilizes recycled polymers and reduces the demand for virgin materials. Reusing waste polymers helps combat climate change, global warming, and worldwide pollution because it reduces the amount of waste sent to landfills and the demand for new materials.

[0063] Experimental studies show that the concentration of the second polymer has an effect on the foam density and cell size of the composite material of the present invention. Experimental studies show that the lower the concentration of the second polymer, the better the foam density and the better the cell size distribution.

[0064] For the first additive applicable in the present invention, the concentration of the first additive is preferably in the range from 0.01% w / w to 40% w / w, preferably from 0.01% w / w to 25% w / w, more preferably from 0.05% w / w to 40% w / w, and most preferably from 0.05% w / w to 25% w / w. It should be understood that any number within these numerical ranges can be the end point of another numerical range. It can be of different shapes (such as spheroidal, cubic, and hexagonal), preferably having a lattice structure with a higher number of defects. In some embodiments, perovskite crystals (especially perovskite nanocrystals) are preferred. Nanocrystals with Goldschmidt tolerance factor in the range from 0.8 to 1 are preferred. In some embodiments, perovskite crystals that support fluorescence through radiative or non-radiative pathways are preferred. The diameter size of the crystals is preferably in the range between 5 to 500 nm. Examples of perovskite crystals are selected from the group consisting of lead perovskite crystals, lead-free perovskite crystals, lead-free double perovskite crystals, or combinations thereof.

[0065] The lead-free perovskite crystals are selected from the group consisting of tin halide perovskite (CH3NH3)SnI3, bismuth halide perovskite (CH3NH3)3Bi2I9, antimony halide perovskite (CH3NH3)3Sb2I9, silver bismuth iodide AgBiI4, or combinations thereof.

[0066] The lead-free double perovskite crystals are selected from Cs3Bi2Br9, Cs2AgInCl6, Cs2AgBiBr6, Cs2AgBiI6, Cs2AgSbBr6, Cs2AgSbI6, or a combination thereof.

[0067] In some embodiments, Cs2AgInBiCl6, which is one of the lead-free double perovskite nanocrystals, can be used. Figure 2a and Figure 2b SEM images of Cs2AgInBiCl6are shown.

[0068] In some embodiments, Cs3Bi2Cl6, which is one of the lead-free perovskite nanocrystals, can be used. As shown in Figure 3a and Figure 3b Cs3Bi2Cl6nanocrystals with a size less than 20 nm.

[0069] Preferably, the crystals and / or nanocrystals are synthesized at room temperature, which reduces energy consumption and cost, and have high atom economy, and provide a sustainable alternative to the existing fillers used in industry. In this context, "high atom economy" refers to a measure of the efficiency of a chemical reaction in making use of starting materials when preparing perovskite materials. "High atom economy" indicates a high yield of product, indicating that the starting precursors are significantly converted into the desired perovskite product with a yield of up to 70% of the initial precursor concentration. Furthermore, their high atom economy ensures efficient use of raw materials, thus becoming a sustainable alternative to traditional nanofillers used in industry.

[0070] The crystals, especially nanocrystals, are synthesized at room temperature, and have high atom economy, and provide a sustainable alternative to the existing nanofillers used in industry.

[0071] Preparation of lead-free perovskite nanocrystals under ambient conditions at room temperature

[0072] The desired precursors, such as cesium chloride, bismuth chloride, and methylammonium chloride, are dissolved in a suitable solvent, such as dimethylformamide or dimethyl sulfoxide, at a concentration of 0.1-1 M. The precursor solution is mixed with a coordinating solvent, such as oleic acid, and a surfactant, such as oleylamine or oleic acid, at a molar ratio of 3:1:1. The mixture is vigorously stirred at 500-1000 rpm for 2-3 hours. The reaction mixture is cooled to room temperature, and a non-polar solvent, such as hexane, is added to precipitate the perovskite nanocrystals. The resulting suspension is centrifuged at 10,000-15,000 rpm for 15-20 minutes to collect the nanocrystals. The collected nanocrystals are washed several times with a non-polar solvent to remove any residual solvent or impurities. The nanocrystals are dried at room temperature or under vacuum to obtain a dry powder. As shown in Figure 3a and Figure 3b The size of the Cs3Bi2Cl6nanocrystals is less than 20 nm.

[0073] For the second additive applicable in the present application, it can be carbon nanotubes, carbon quantum dots, graphene, silica nanoparticles, metal nanoparticles including silver, gold, copper or combinations thereof, clay nanoparticles including montmorillonite, halloysite or combinations thereof, metal oxide nanoparticles including titanium dioxide, zinc oxide, aluminum oxide or combinations thereof, cellulose nanofiber, or combinations thereof.

[0074] It can also be biodegradable materials including cellulose, chitosan, alginate, starch, dextran, or combinations thereof. The biodegradable materials are selected based on their high surface area, compatibility with polymers, biodegradability, and combinations thereof. The particles synthesized from the biodegradable materials can advantageously have an average size ranging between 5 to 500 nm. The concentration of these nanoparticles in the composite material can range from 0.02 wt% to 1 wt%.

[0075] In some embodiments, biomolecules with large groups such as those present in alginate structures (G and M blocks) are also preferred.

[0076] In some embodiments, the concentration of the second additive preferably ranges from 0.01 M to 4 M.

[0077] In some embodiments, the second additive comprises quantum dots with a size less than 10 nm as nanofillers to optimize performance.

[0078] The use of biodegradable fillers further contributes to sustainability as it reduces the environmental impact of the composite formulation.

[0079] Preparation of cellulose nanoparticles from cellulose acetate

[0080] Cellulose acetate was dissolved in an acetone / water mixture (9:1) at a concentration of 2-5% (w / w). The solution was homogenized using a high-speed homogenizer for 10-15 minutes. While continuously stirring, the homogenized solution was added to a large volume of deionized water. The resulting suspension was centrifuged at 10,000-15,000 rpm for 15-20 minutes to collect the cellulose nanoparticles. The collected nanoparticles were washed several times with deionized water to remove any residual solvent or impurities. The nanoparticles were dried at room temperature or under vacuum to obtain a dry powder. Figure 4a and Figure 4b SEM images of cellulose nanoparticles are shown.

[0081] Preparation of alginate nanoparticles from sodium alginate

[0082] Sodium alginate is dissolved in deionized water at a concentration of 0.5-2% (w / w). The required amount of cross-linking agent (such as calcium chloride) is added to the alginate solution under continuous stirring. The mixture is homogenized using a high-speed homogenizer for 10-15 minutes. The homogenized mixture is added drop-wise to a large volume of deionized water while continuously stirring. The resulting suspension is centrifuged at 10,000-15,000 rpm for 15-20 minutes to collect the alginate nanoparticles. The collected nanoparticles are washed several times with deionized water to remove any residual cross-linking agent or impurities. The nanoparticles are dried at room temperature or under vacuum to obtain a dry powder. Figure 5a and Figure 5b A TEM image of alginate nanoparticles is shown.

[0083] Preparation of chitosan nanoparticles under ambient conditions at room temperature

[0084] Chitosan is dissolved in acetic acid or other suitable solvent at a concentration of 0.5-2% (w / w). The required amount of cross-linking agent (sodium tripolyphosphate) is added to the chitosan solution under continuous stirring. The mixture is homogenized using a high-speed homogenizer for 10-15 minutes. The homogenized mixture is added drop-wise to a large volume of deionized water while continuously stirring. The resulting suspension is centrifuged at 10,000-15,000 rpm for 15-20 minutes to collect the chitosan nanoparticles. The collected nanoparticles are washed several times with deionized water to remove any residual cross-linking agent or impurities. The nanoparticles are dried at room temperature or under vacuum to obtain a dry powder. Figure 6a and Figure 6b A TEM image of chitosan nanoparticles is shown.

[0085] Preparation of dextran nanoparticles under ambient conditions at room temperature

[0086] Dextran is dissolved in deionized water at a concentration of 0.5-2% (w / w). The required amount of cross-linking agent (glutaraldehyde) is added to the dextran solution under continuous stirring. The mixture is homogenized using a high-speed homogenizer for 10-15 minutes. The homogenized mixture is added drop-wise to a large volume of deionized water while continuously stirring. The resulting suspension is centrifuged at 10,000-15,000 rpm for 15-20 minutes to collect the dextran nanoparticles. The collected nanoparticles are washed several times with deionized water to remove any residual cross-linking agent or impurities. The nanoparticles are dried at room temperature or under vacuum to obtain a dry powder. Figure 7a and Figure 7b A TEM image of dextran nanoparticles is shown.

[0087] In some embodiments, the composite material of the present application comprises:

[0088] - a first polymer, preferably prepared in situ;

[0089] - a second polymer;

[0090] - a first additive (alternatively a first filler), preferably selected from perovskite crystals;

[0091] - a second additive (alternatively a second filler); and

[0092] - a foaming agent.

[0093] For the foaming agent, it can be water, carbon dioxide, hydrocarbons comprising propane, butane, pentane, or combinations thereof, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), azodicarbonamide (ADA), sodium bicarbonate, citric acid, sodium carbonate, ammonium bicarbonate, or combinations thereof. Advantageously, one / more of water, carbon dioxide, or combinations thereof is used. The concentration range in the composite material is preferably from 1% w / w to 15% w / w.

[0094] In some embodiments, the composite material of the present application comprises:

[0095] - a first polymer, preferably prepared in situ;

[0096] - a second polymer;

[0097] - a first additive (alternatively a first filler), preferably selected from perovskite crystals;

[0098] - a second additive (alternatively a second filler);

[0099] - a foaming agent; and

[0100] - a third additive (alternatively a second filler).

[0101] For the third additive, it can be a surfactant, a stabilizer, a plasticizer, a crosslinker, or combinations thereof. The third additive optimizes the formation process of the composite material, improves the material properties, and ensures stability and durability. Specific examples of the third additive can be toluene, isopropyl alcohol, hexane, chloroform, ethanol; the stabilizer comprises oleic acid, oleylamine, Tween 20, cetyltrimethylammonium bromide (CTAB), or combinations thereof; the surfactant comprises cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), oleic acid, dimethyldioctadecylammonium bromide (DDAB), polyethylene glycol, their corresponding block copolymers, or combinations thereof; the plasticizer comprises glycerol, ethyl acetate, sorbitol, ethylene glycol, xylitol, and diethylene glycol, or combinations thereof; the crosslinker comprises isocyanate, such as toluene diisocyanate, p-phenylenediamine, gelatin, collagen, agarose, agar, or combinations thereof. The range concentration in the composite material is preferably from 1% w / w to 30% w / w.

[0102] In particular, the surfactant can be composed of at least one chemical from the following group: cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), oleic acid, dimethyldioctadecylammonium bromide (DDAB), polyethylene glycol, and their corresponding block copolymers.

[0103] Figure 8a SEM images of the foamed glue with additives dispersed.

[0104] Figure 8b SEM images showing the pore distribution of the foamed glue.

[0105] Figure 9a and Figure 9b The contact angles of the foamed glue with hydrophobicity characteristics are shown. These figures show that the contact angles of the final foamed glue exceed 120°, demonstrating that these foamed glues are highly hydrophobic in nature.

[0106] The composite materials of the present invention can be used in a wide range of commercial applications, including automotive, construction, and acoustics.

[0107] In automotive applications, the composite materials can be used to improve the acoustic comfort of vehicles and reduce the propagation of engine noise.

[0108] In construction applications, the composite materials can be used to improve the acoustic performance of walls, ceilings, and floors. The composite materials of the present invention can be used as building materials, with applications including, but not limited to, facade panels, partition walls, thermal insulation, soundproof walls, and doors in buildings.

[0109] In acoustic applications, the composite materials can be used to reduce noise pollution in buildings, vehicles, and industrial facilities. The composite materials of the present invention exhibit excellent sound absorption performance due to their high surface area and porous structure. The embedded fillers, especially nanofillers, also enhance the acoustic performance of the composite materials by increasing sound scattering and damping effects.

[0110] Due to the presence of additives, such as biodegradable additives, the composite materials of the present invention can be configured to advantageously utilize recycled plastics in functional soundproof panels with better acoustic performance. The present invention provides a sustainable approach to change the sustainability features of a building complex and protect users from the harmful effects of noise pollution. For densely populated places like Hong Kong, China, such solutions can help create a huge positive social impact and alleviate health problems.

[0111] The Sound Transmission Class (STC) values were measured using the ASTM E 2611-17 acoustic test setup, with a frequency range between 100 and 5000 Hz, and a maximum transmission loss of up to 59.1 dB.

[0112] Figure 10Results of acoustic test ASTM E 2611-17 performed at 26°C and 65% humidity are shown, where the x-axis is the frequency (Hz) and the y-axis is the sound transmission loss (dB). The test was performed following the guidelines of ASTM E 2611-17. Figure 10 It is shown that the STL loss is at maximum when the frequency is about 2000 Hz.

[0113] The resulting acoustic panels have high STC values, making them effective in reducing noise levels in residential buildings, offices and large construction projects. The panels are easily integrated into existing structures and can be customized to fit any size or shape. The use of recycled plastic as a base material, preferably, reduces the overall precursor cost, making the panels more affordable and accessible to a wider audience.

[0114] Due to the presence of the additives, the surface area of the composite is increased, the fundamental interaction at the molecular level (interaction of the sound waves at the molecular level with the different polymers and additives present therein) is increased by 100 times and allows maximum conversion of the applied sound waves. The presence of high concentrations of additives (preferably nanoparticles) in the composite has several significant effects on sound transmission. First, each nanoparticle acts as an active site due to its nanoscale size, resulting in a rapid increase in the number of active surface areas. This increased surface area enables greater interaction between the nanoparticles and the applied sound waves, thereby converting the sound energy into other forms. In addition, the nanoparticles help to scatter the sound waves in all directions. When the sound waves encounter these nanoparticles, they scatter, resulting in a decrease in their overall energy. This scattering phenomenon occurs in all directions, further contributing to the reduction of the energy of the incident sound waves. Therefore, these interactions between the nanoparticles and the sound waves result in a rapid dissipation of the overall energy of the applied sound waves. The conversion of sound energy into other forms, combined with the scattering of the sound waves, accelerates the dissipation process. Because the energy of the sound waves is effectively dissipated and attenuated within the system, this ultimately leads to an improvement in sound transmission loss. In addition, due to the foamy nature of the polymer (such as polyurethane), the remaining sound waves and energy are easily dissipated in the polymer base. Therefore, the composite material disclosed in the present invention makes a positive contribution to sound deadening, absorption, conversion, and dissipation, and thus the overall efficiency of the panel is superior to the prior art in the same field.

[0115] In the composite material of the present invention, the first additive has a robust energy absorption capacity without destroying its crystal lattice, phase, and morphology.

[0116] The first and second additives improve the STC values of the polyurethane foam glue and the structural properties of the composite material, thereby extending their overall lifespan. The nanofillers are derived from sustainable sources and are non-toxic, making them an environmentally friendly solution.

[0117] The density of the composite material is between 50-200 kg / m3 The composite forces the sound waves to dissipate into different forms of energy (such as heat) and into the embedded additives, allowing the sound waves to scatter in all directions to reduce the energy of the incoming waves. The nanofillers can capture the energy of the sound waves without destroying their lattice structure and functional properties.

[0118] Further, the present invention provides a solution to the pressing problem of waste management. By using recycled polymers (such as polystyrene and polyethylene terephthalate) as the primary material, this method effectively reduces the generation of waste and helps to reduce pollution. The fillers (especially nanofillers) used in the present invention are preferably derived from sustainable sources and are biodegradable, making them environmentally friendly. The present invention presents a sustainable solution that not only addresses noise pollution but also contributes to the overall well-being of the environment. Thus, the resulting products are more environmentally friendly while having robust acoustic properties, making them green and sustainable alternatives in the construction field.

[0119] The present invention presents an environmentally sustainable and cost-effective method for manufacturing soundproof panels with superior STC values. By using recycled polymers as the base material and incorporating fillers (preferably nanofillers, more preferably biodegradable fillers and / or nanofillers), the STC values of the composite and the structural performance of the panel are simultaneously improved, thereby extending their overall lifespan. The present invention not only addresses the growing problem of waste management but also promotes environmental well-being.

[0120] For example, the following provides a method of preparing a composite material comprising: polyurethane foam glue as a first polymer; recycled polystyrene and recycled polyethylene terephthalate as a second polymer; Cs2AgInBiCl6 as a first additive; dextran as a second additive; isothiocyanate solution as a crosslinking agent. The mixing step in the example can be carried out in a high shear mixer. It should be understood that this example is for illustration only and should not be construed as any limitation on the present invention.

[0121] The method comprises the following steps:

[0122] Step 1: Preparation of recycled materials

[0123] This processing step involves reducing the recycled materials into smaller particles. The recycled polystyrene and polyethylene terephthalate are processed to achieve the desired particle size and shape.

[0124] Step 2: Mixing recycled materials with polyurethane foam glue precursors

[0125] The processed recycled polystyrene and polyethylene terephthalate particles are mixed with the polyurethane foam glue precursor. The foam glue precursor is typically composed of a polyol solution and isocyanate.

[0126] Step 3: Addition of first and second additives

[0127] The first and second additives are added separately to the mixture prepared in Step 2. These additives have the property of converting acoustic energy into heat energy, which is dissipated through all the pores present in the foam glue structure of the composite material to be prepared.

[0128] Step 4: Intensive mixing

[0129] The mixture of polyol solution, melted recycled polymers, and nanofillers is mixed intensively. A stirring speed of 600-1000 rpm is used to ensure a thorough blending and uniform distribution of all ingredients.

[0130] Step 5: Addition of isocyanate solution

[0131] After complete homogeneous mixing in Step 4, the isocyanate solution is added to the mixture. This solution acts as a cross-linking agent for the polyurethane foam glue formation.

[0132] Step 6: Formation of polyurethane foam glue

[0133] After the addition of the isocyanate solution, the mixture is continuously stirred. Due to the reaction between the polyol and the isocyanate, the polyurethane foam glue starts to form immediately within 30 seconds. The foam glue is left to cool at room temperature until it is completely dry.

[0134] The resulting polyurethane foam glue composite material exhibits a low density, a high porosity, and a high surface area of the foam glue structure.

[0135] Figure 11a and 11b SEM images of the composite material with different additives dispersed are shown.

[0136] Although the processing parameters for all possible materials suitable for the present application are not exhaustively described in the specification, it should be understood that those processing parameters known for all possible materials are also within the scope of the present disclosure.

[0137] Experimental studies have shown that the concentration of the second polymer has an effect on the foam glue density and pore size of the present composite material. Experimental studies have shown that the lower the concentration of the second polymer, the better the foam glue density and the better the pore size distribution, resulting in better acoustic absorption performance. In contrast, a higher concentration of the second polymer results in a rigid foam glue structure, thereby destroying the pore size. The first additive provides better structural and mechanical properties. The second additive provides better acoustic properties due to its elasticity at the molecular level.

[0138] The present invention provides a sustainable and high performance foam glue formulation that addresses the demand for environmentally friendly materials across various industries. The use of recycled polymers and biodegradable nanofillers reduces the environmental impact of the foam glue formulation while also contributing to the fight against climate change, global warming, and worldwide pollution. The foam glue formulation is also cost-effective and can be used in a wide range of commercial applications, making it a promising innovation for the future.

[0139] The above description of the embodiments is merely intended to help understand the method and core idea of the present invention. For those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. Various modifications to the embodiments are apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention should not be limited to the embodiments shown in the present document, but should conform to the widest scope consistent with the principles and novel features disclosed in the present document and its equivalents.

Claims

1. A solid composite material comprising: - a first polymer which is a solid having a porous structure; - a second polymer which is different from the first polymer; - a first additive selected from a perovskite; and - optionally a second additive; wherein the solid composite material is prepared by mixing monomers of the first polymer with the second polymer, the first additive and optionally the second additive, and then curing the monomers by polymerization to form the first polymer, whereby the second polymer, the first additive and optionally the second additive are dispersed in the porous structure of the first polymer.

2. The solid composite material as claimed in claim 1, wherein the first polymer is selected from polyethylene vinyl acetate, low density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam, polyol, polyester, polyacrylate, polyurethane, polysulfide or a combination thereof.

3. The solid composite material as claimed in claim 1 or 2, wherein the concentration of the first polymer in the solid composite material varies from 1% w / w to 25% w / w.

4. The solid composite material as claimed in claim 1, wherein the second polymer is selected from polystyrene, polyurethane, polyethylene terephthalate, polyol, polyester, polyacrylate, polyurethane, polysulfide, polyethylene vinyl acetate, low density polyethylene foam, nitrile rubber foam, polychloroprene foam, polyimide foam, polypropylene foam, polystyrene foam, polyurethane foam, polyurea foam, polyethylene foam, polyvinyl chloride foam, polyisocyanurate foam, silicone foam, microcellular foam or a combination thereof.

5. The solid composite material as claimed in claim 4, wherein the concentration of the second polymer in the solid composite material varies from 30% w / w to 70% w / w.

6. The solid composite material as claimed in claim 4 or 5, wherein the second polymer is a recycled material.

7. The solid composite material as claimed in claim 1, wherein the first additive is selected from a lead perovskite crystal, a lead-free perovskite crystal, a lead-free double perovskite crystal, or a combination thereof.

8. The solid composite material as claimed in claim 7, wherein the first additive is characterized by a high Goldschmidt tolerance factor.

9. The solid composite material as claimed in any one of claims 7-8, wherein the diameter of the crystal is in the range of 5 to 500 nm.

10. The solid composite material as claimed in claim 7, wherein the lead-free perovskite crystal is selected from a tin halide perovskite (CH3NH3)SnI3, a bismuth halide perovskite (CH3NH3)3Bi2I9, an antimony halide perovskite (CH3NH3)3Sb2I9, silver bismuth iodide AgBiI4, or a combination thereof.

11. The solid composite material as described in claim 7, wherein the lead-free double perovskite crystal is selected from Cs3Bi2Br9, Cs2AgInCl6, Cs2AgBiBr6, Cs2AgBiI6, Cs2AgSbBr6, Cs2AgSbI6, or combinations thereof.

12. The solid composite material as described in claim 7, wherein the first additive is Cs2AgInBiCl6, Cs3Bi2Cl6, or a combination thereof.

13. The solid composite material as described in claim 8, 10, 11 or 12, wherein the concentration of the first additive in the solid composite material varies from 0.01% w / w to 40% w / w.

14. The solid composite material as described in claim 8, 10, 11 or 12, wherein the concentration of the first additive in the solid composite material varies from 0.01% w / w to 25% w / w.

15. The solid composite material as described in claim 8, 10, 11 or 12, wherein the concentration of the first additive in the solid composite material varies from 0.05% w / w to 40% w / w.

16. The solid composite material as described in claim 8, 10, 11 or 12, wherein the concentration of the first additive in the solid composite material varies from 0.05% w / w to 25% w / w.

17. The solid composite material of claim 1, wherein the second additive is selected from carbon nanotubes, carbon quantum dots, graphene, silica nanoparticles, metal nanoparticles including silver, gold, copper or combinations thereof, clay nanoparticles including montmorillonite, halloysite or combinations thereof, metal oxide nanoparticles including titanium dioxide, zinc oxide, aluminum oxide or combinations thereof, cellulose nanofibers or combinations thereof.

18. The solid composite material of claim 17, wherein the second additive is further selected from cellulose, chitosan, alginate, starch, dextran, or combinations thereof.

19. The solid composite material of claim 18, wherein the second additive is biodegradable.

20. The solid composite material of claim 18, wherein the average size of the second additive is in the range of 5 to 500 nm.

21. The solid composite material of claim 18, wherein the average size of the second additive is less than 10 nm.

22. The solid composite material according to any one of claims 19-21, wherein the concentration of the second additive in the solid composite material is from 0.02 wt% to 1 wt%.

23. The solid composite material as described in claim 1, wherein the solid composite material further comprises: - A foaming agent selected from water, carbon dioxide, hydrocarbons including propane, butane, pentane, or combinations thereof, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), azodicarbonamide (ADA), sodium bicarbonate, citric acid, sodium carbonate, ammonium bicarbonate, or combinations thereof; and / or - The third additive includes: surfactants, stabilizers, plasticizers, crosslinking agents, or combinations thereof.

24. The solid composite as claimed in claim 23, wherein the concentration of the foaming agent in the solid composite is 1% w / w to 15% w / w.

25. The solid composite as claimed in claim 24, wherein the concentration of the third additive in the solid composite is 1% w / w to 30% w / w.

26. The solid composite as claimed in claim 25, wherein the surfactant is selected from cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), oleic acid, dimethyldioctadecylammonium bromide (DDAB), polyethylene glycol, and their corresponding block copolymers.

27. The solid composite as claimed in claim 25, wherein the stabilizer is selected from oleic acid, oleylamine, Tween 20, cetyltrimethylammonium bromide (CTAB), or a combination thereof.

28. The solid composite as claimed in claim 25, wherein the plasticizer is selected from glycerol, ethyl acetate, sorbitol, ethylene glycol, xylitol, and diethylene glycol, or a combination thereof.

29. The solid composite as claimed in claim 25, wherein the crosslinking agent is selected from isocyanates including toluene diisocyanate, p-xylylenediamine, gelatin, collagen, agarose, agar, or a combination thereof.

30. A method of preparing the solid composite as claimed in any one of claims 1-29.

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