A crack-resistant, sound-insulating, and heat-insulating low-carbon mortar and its preparation method and application

Abstract

The present application relates to a kind of crack-resistant sound-insulating and heat-insulating low-carbon mortar and its preparation method and application, the mortar includes the following raw materials: cement, gypsum, lime, magnesium oxide, modified VAE, modified polystyrene particles, defoamer, water-retaining agent, early strength agent, water-reducing agent and water, wherein the modified VAE is obtained by copolymerization of VAE emulsion with 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene, and the modified polystyrene particles are obtained by initiating graft polymerization reaction of methyl methacrylate, α-methylstyrene and maleic anhydride with polystyrene particles. The crack-resistant sound-insulating and heat-insulating low-carbon mortar of the present application can not only significantly improve the sound insulation and heat preservation performance of the building, but also improve the comprehensive performance of the mortar, and can be widely used in the fields of internal and external wall insulation, sound insulation engineering of the building, etc., which is of great significance for achieving the goal of green building.

Description

Technical Field

[0001] The present application belongs to the technical field of building materials, and relates to a crack-resistant, sound-insulating, and thermal-insulating low-carbon mortar, and a preparation method and application thereof, and specifically relates to a sound-insulating and thermal-insulating low-carbon mortar with low water absorption, high thermal insulation and sound-insulating performance, good durability under extreme conditions, and crack-resistant performance, and a preparation method and application thereof. Background Art

[0002] Green and energy-saving buildings have become an important trend in the global construction industry. They not only help reduce energy consumption and carbon emissions throughout the life cycle of buildings, but also improve the quality of living and working environments. During the entire life cycle of a building, energy consumption in the operation phase accounts for approximately 46.6% of the total energy consumption, including the energy required for daily operations such as heating, cooling, lighting, and ventilation. Energy loss in building envelope structures such as exterior walls, roofs, doors, windows, and floor slabs is one of the main reasons for this high energy consumption. Among them, the energy loss of the exterior wall accounts for about 35%, so exterior wall insulation has become one of the key measures to reduce energy loss.

[0003] The insulation materials for building exterior walls are mainly divided into inorganic insulation materials and organic insulation materials. The advantages of inorganic insulation materials are good flame retardant properties (Grade A), which are suitable for places with high fire protection requirements; the disadvantages are high energy consumption in the production process, strong water absorption, large volume, and relatively high thermal conductivity. Commonly used inorganic insulation materials include glass wool, rock wool, expanded perlite, foamed concrete, insulation mortar, etc. The advantages of organic insulation materials are light weight, easy processing and installation, and low thermal conductivity; the disadvantages are poor durability, easy aging and deformation, low flame retardant grade (highest B1 grade), and difficult to recycle and reuse. Commonly used organic insulation materials are polyurethane foam (PUF), extruded polystyrene board (XPS), molded polystyrene board (EPS), phenolic foam, etc.

[0004] Traditional mortar is mainly made of cement, sand and water mixed in a certain proportion, and is used in construction processes such as masonry and plastering. In recent years, with the advancement of science and technology, a variety of functional mortars have emerged. They add special functional ingredients such as lightweight aggregates, thermal insulation materials, waterproofing agents, etc. on the basis of traditional mortars to enhance the specific properties of mortars. Among them, lightweight mortar reduces the weight of mortar by adding lightweight aggregates (such as expanded perlite, ceramsite, etc.) and provides a certain thermal insulation effect. Thermal insulation mortar is specially used for exterior wall insulation systems and usually contains thermal insulation materials (such as polystyrene particles, etc.), which can effectively reduce heat loss through the wall. Sound insulation mortar adds sound insulation materials (such as rubber particles, cork powder, etc.) to improve the sound insulation performance of mortar. Waterproof mortar enhances the waterproof ability of mortar by adding waterproofing agents, and is suitable for humid environments such as basements and bathrooms. Fireproof mortar adds flame retardants to improve the fire resistance of mortar and is suitable for areas with high fire protection requirements.

[0005] In order to prepare a multifunctional mortar with sound insulation, heat preservation and low carbon, it is usually necessary to mix thermal insulation materials such as polystyrene particles and sound insulation materials such as rubber particles. After mixing, the following problems exist:

[0006] (1) Due to the compatibility problem between organic materials and inorganic materials, the two cannot be mixed evenly, resulting in poor sound insulation and thermal insulation performance;

[0007] (2) The organic and inorganic materials used have a certain degree of water absorption. As a result, after the mortar is cured, it has strong water absorption, and the service life of the sound insulation wall formed is short.

[0008] (3) It cannot withstand environments under extreme conditions and has poor durability.

[0009] (4) The crack resistance is poor, and cracks are likely to appear after the mortar solidifies. Summary of the invention

[0010] The purpose of this application is to provide a crack-resistant sound-insulating and heat-insulating low-carbon mortar and its preparation method and application, so as to solve the problems of poor sound insulation and heat insulation performance, durability and crack resistance of the above-mentioned mortar. The crack-resistant sound-insulating and heat-insulating low-carbon mortar of this application can not only significantly improve the sound insulation and heat insulation performance of the building through a carefully designed formula and modification process, but also improve the comprehensive performance of the mortar, such as reducing water absorption, improving crack resistance and enhancing durability, making it an ideal green building material.

[0011] The present application provides a crack-resistant, sound-insulating, and heat-insulating low-carbon mortar, which includes the following raw materials in parts by weight:

[0012] 30~50 parts of cement

[0013] 5~10 parts of gypsum

[0014] 1~5 parts lime

[0015] 1~5 parts of magnesium oxide

[0016] Modified VAE 5~15 parts

[0017] Modified polystyrene particles 20~30 parts

[0018] Defoaming agent 0.5~1.0 part

[0019] Water-retaining agent 0.05~0.1 parts

[0020] Early strength agent 0.05~0.1 part

[0021] 1~2 parts of water reducing agent

[0022] 10-15 parts water;

[0023] The modified VAE is obtained by copolymerization of VAE emulsion with 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene, wherein the mass ratio of VAE emulsion to 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene is (10-12): (1-1.5): 1:1;

[0024] The modified polystyrene particles are obtained by initiating graft polymerization reaction between methyl methacrylate, α-methylstyrene and maleic anhydride and polystyrene particles. The mass ratio of methyl methacrylate, α-methylstyrene, maleic anhydride and polystyrene particles is (1-3): (2-4): 1: (10-15).

[0025] At present, mortar is mainly made of cement, sand and water mixed in a certain proportion. In order to increase the functionality of mortar, some inorganic or organic substances are often added to mortar. However, due to the poor compatibility of the added substances with the mortar itself, the organic and inorganic substances added cannot be evenly distributed in the mortar, resulting in the inability to improve the comprehensive performance of the mortar. The present application starts from the formula combination and proportion, and rationally designs a variety of raw materials to obtain a mortar with excellent comprehensive performance, thereby realizing the multifunctionality of the mortar. The mortar raw materials in the present application include cement, gypsum, lime, magnesium oxide, modified VAE, modified polystyrene particles, defoamer, water retaining agent, early strength agent and water reducing agent, wherein cement is the main cementitious material, and cement is hardened after mixing with water to form the basic structure of mortar. The fineness of cement helps to improve the density and strength of mortar. Gypsum, as an auxiliary cementitious material, can improve the hardening speed and early strength of mortar. The average particle size of gypsum is large, which helps to improve the fluidity of mortar. Lime can increase the plasticity and adhesion of mortar and improve its durability. The average particle size of lime is small, which helps to improve the density of mortar. Magnesium oxide is a lightweight filling material that can improve the thermal insulation and crack resistance of mortar. The average particle size of magnesium oxide is fine, which helps to improve the density of mortar. VAE emulsion, that is, ethylene-vinyl acetate copolymer emulsion, is a high-performance water-based emulsion that is often used as an adhesive to enhance the flexibility and bonding strength of mortar. VAE emulsion copolymerizes with 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene to improve the weather resistance and chemical corrosion resistance of mortar. Polystyrene particles, as a lightweight thermal insulation material, can reduce the overall density of mortar and provide good thermal insulation performance. After graft polymerization, the surface hydrophilicity of the particles is improved, which improves the compatibility with other components in the mortar. Defoamers (silicones, polyethers, mineral oils) are used to eliminate bubbles generated during the mixing process of mortar and improve the density and flatness of mortar. Water-retaining agents (cellulose ethers, starch ethers) can control the evaporation rate of water inside the mortar, helping to maintain the humidity of the mortar, thereby improving its construction performance and performance after hardening. Early strength agents (sulfates, chlorides, organics) can accelerate the hardening process of the mortar and increase its early strength. Water-reducing agents (sodium methylene dimethyl dinaphthalene sulfonate polymers, aliphatic hydroxy sulfonates, polycarboxylates) can reduce the amount of water required in the mortar while maintaining or improving the working properties of the mortar.

[0026] Each mortar raw material in the present application has its specific function, which can improve the overall strength of the mortar and the compatibility between the raw materials, and make the mortar have certain thermal insulation and sound insulation properties. However, in order to further improve the durability and crack resistance of the mortar and reduce the water absorption of the mortar, further research is needed on the addition ratio of each raw material, the modification method of VAE emulsion, and the modification method of polystyrene particles.

[0027] In some embodiments of the present application, the ratio of the weight of cement to the total weight of gypsum, lime and magnesium oxide is (2~4):1, the average particle size of cement is 10~15μm, the average particle size of gypsum is 30~50μm, the average particle size of lime is 1~5μm, and the average particle size of magnesium oxide is 80~100μm.

[0028] The present application has limitations on the weight ratio and average particle size of cement, gypsum, lime and magnesium oxide, which can further improve the thermal insulation performance, sound insulation performance, crack resistance and durability under extreme conditions of the mortar and reduce water absorption.

[0029] The reasonable ratio of cement to gypsum, lime and magnesium oxide in this application helps to form a more compact mortar structure, thereby improving its sound insulation performance. The large average particle size of gypsum and lime helps to improve the fluidity of the mortar, making it easier for the mortar to fill the gaps, further improving the sound insulation effect. If the ratio of cement to auxiliary materials is not appropriate, the mortar may be too loose or porous, thereby reducing the sound insulation performance.

[0030] In the present application, the reasonable proportion of cement, gypsum, lime and magnesium oxide can form a mortar with good thermal insulation performance. The average particle size of magnesium oxide is relatively fine, which helps to improve the density of the mortar, thereby reducing the conduction of heat and improving the thermal insulation effect. If the cement content is too high, the density of the mortar may increase, thereby reducing the thermal insulation performance; conversely, if the proportion of auxiliary materials is too high, the strength of the mortar may decrease.

[0031] The reasonable proportion and average particle size distribution in this application help to form a dense mortar structure, reduce the porosity of the mortar, and thus reduce water absorption. The fine average particle size of cement helps to improve the density of the mortar. If the average particle size distribution is unreasonable or the proportion is unbalanced, it may cause the mortar structure to become loose and increase water absorption.

[0032] The reasonable ratio of cement and auxiliary materials in this application can improve the flexibility of the mortar and reduce cracks caused by shrinkage. The larger average particle size of gypsum and lime helps to improve the plasticity of the mortar and improve its crack resistance. If the cement content is too high, the mortar may become too hard and brittle and prone to cracks; if the proportion of auxiliary materials is too high, it may affect the bonding performance of the mortar.

[0033] The appropriate proportion and average particle size distribution of this application can improve the durability of the mortar, so that it can still maintain good performance in extreme environments. The reasonable use of lime and magnesium oxide helps to improve the freeze-thaw resistance of the mortar. If the proportion is not appropriate, it may cause the mortar to deteriorate under high or low temperature conditions, such as strength loss, cracking and other problems.

[0034] This application can effectively improve the sound insulation performance, thermal insulation performance, reduce water absorption, improve crack resistance and enhance durability in extreme environments of sound insulation and thermal insulation low-carbon mortar by accurately controlling the ratio of cement and auxiliary materials and the average particle size distribution. On the contrary, if the ratio and average particle size are not within the above range, it may lead to a decrease in mortar performance, such as poor sound insulation, reduced thermal insulation performance, increased water absorption, weakened crack resistance and reduced durability. Therefore, strict compliance with the ratio and average particle size requirements in the above technical solution is crucial for the preparation of high-quality crack-resistant sound insulation and thermal insulation low-carbon mortar.

[0035] In some embodiments of the present application, the mass ratio of modified VAE to cement is 1:(4-8), and the viscosity of the VAE emulsion is 100-700 cps.

[0036] This application has limitations on the ratio between cement and modified VAE and the viscosity of VAE, which can further improve the thermal insulation performance, sound insulation performance, crack resistance and durability under extreme conditions of the mortar and reduce water absorption.

[0037] The appropriate ratio of the modified VAE and cement in this application can improve the flexibility of the mortar, help absorb sound wave vibrations, and thus improve the sound insulation performance. The addition of modified VAE can improve the plasticity of the mortar, making it less likely to break when subjected to sound wave impact. If the ratio of modified VAE is too low, it may not effectively improve the flexibility of the mortar, thereby reducing the sound insulation effect; if the ratio is too high, it may cause the mechanical strength of the mortar to decrease, affecting its overall performance.

[0038] The modified VAE of the present application has good bonding properties, can improve the bonding strength between the components of the mortar, and help to form a more compact mortar structure, thereby improving the thermal insulation performance. The modified VAE in an appropriate proportion can also help to reduce the thermal conductivity of the mortar. If the proportion of the modified VAE is too low, it may not be enough to form an effective bonding network, affecting the thermal insulation performance of the mortar; if the proportion is too high, it may cause the mortar to become too soft, reducing its thermal insulation effect.

[0039] The modified VAE in this application has good sealing performance, which can reduce the micropores in the mortar, thereby reducing the water absorption rate. The appropriate VAE emulsion viscosity helps to form a dense mortar structure. If the proportion of modified VAE is too low, it may not be able to effectively seal the micropores in the mortar and increase the water absorption rate; if the proportion is too high, it may affect the air permeability of the mortar and increase the risk of water absorption.

[0040] The appropriate proportion of the modified VAE in this application can improve the flexibility and elastic modulus of the mortar, and help reduce cracks caused by shrinkage. The appropriate viscosity helps the mortar maintain good plasticity during the hardening process and reduce the risk of cracking. If the proportion of the modified VAE is too low, it may not effectively improve the flexibility of the mortar, thereby increasing the possibility of cracking; if the proportion is too high, it may cause the mortar to become too soft, affecting its structural integrity.

[0041] The modified VAE in this application can improve the weather resistance and chemical corrosion resistance of the mortar, so that it can still maintain good performance in extreme environments. Appropriate viscosity helps the mortar form a more stable structure during the hardening process and improves its durability. If the proportion of modified VAE is too low, it may not provide sufficient protection and reduce the durability of the mortar; if the proportion is too high, it may affect the hardening process of the mortar and cause performance degradation.

[0042] This application can effectively improve the sound insulation performance, thermal insulation performance, reduce water absorption, improve crack resistance and enhance durability in extreme environments of the sound insulation and thermal insulation low-carbon mortar by accurately controlling the mass ratio of modified VAE to cement and the viscosity of the VAE emulsion. On the contrary, if the ratio and viscosity are not within the above range, it may lead to a decrease in mortar performance, such as poor sound insulation, reduced thermal insulation performance, increased water absorption, weakened crack resistance and reduced durability. Therefore, strict compliance with the ratio and viscosity requirements in the above technical solution is crucial for the preparation of high-quality crack-resistant sound insulation and thermal insulation low-carbon mortar.

[0043] In some embodiments of the present application, the mass ratio of the modified polystyrene particles to cement is 1:(1-2), and the tensile modulus of the polystyrene particles is 1600-1800 MPa.

[0044] The present application has limitations on the ratio between cement and modified polystyrene particles and the tensile modulus of the polystyrene particles, which can further improve the thermal insulation performance, sound insulation performance, crack resistance and durability under extreme conditions of the mortar and reduce water absorption.

[0045] When the mass ratio of the modified polystyrene particles to cement in the present application is 1: (1-2), it can ensure that the mortar contains sufficient lightweight thermal insulation materials, which helps to improve the thermal insulation performance. When the tensile modulus of the polystyrene particles is 1600-1800 MPa, it can ensure that the particles have good mechanical properties and help to form a stable mortar structure. If the ratio of the modified polystyrene particles is too low, it may not provide sufficient thermal insulation performance; if the ratio is too high, it may affect the strength and stability of the mortar.

[0046] The addition of the modified polystyrene particles of the present application can reduce the overall density of the mortar, reduce the resistance of sound waves during propagation, and help improve the sound insulation effect. If the proportion of the modified polystyrene particles is too high, the mortar may become too loose and reduce the sound insulation performance; if the proportion is too low, the sound insulation effect may not be significantly improved.

[0047] The modified polystyrene particles of the present application have a low water absorption rate, which can reduce water penetration in the mortar and help reduce the water absorption rate. If the proportion of the modified polystyrene particles is too low, it may not be able to effectively reduce the water absorption rate of the mortar; if the proportion is too high, it may increase the porosity inside the mortar, which in turn increases the risk of water absorption.

[0048] The addition of the modified polystyrene particles of the present application can improve the flexibility and crack resistance of the mortar and reduce cracks caused by shrinkage. If the proportion of the modified polystyrene particles is too high, the mortar may become too soft and affect its structural integrity; if the proportion is too low, the crack resistance of the mortar may not be effectively improved.

[0049] The modified polystyrene particles of the present application have good weather resistance and chemical corrosion resistance, which helps to improve the durability of the mortar in extreme environments. If the proportion of the modified polystyrene particles is too high or too low, it may affect the durability of the mortar and reduce its performance under harsh conditions.

[0050] This application can effectively improve the thermal insulation performance, sound insulation performance, reduce water absorption, improve crack resistance and enhance durability in extreme environments of sound insulation and heat preservation low-carbon mortar by accurately controlling the mass ratio of modified polystyrene particles to cement and the tensile modulus of polystyrene particles. On the contrary, if the ratio and tensile modulus are not within the above range, it may lead to a decrease in mortar performance, such as poor thermal insulation effect, reduced sound insulation performance, increased water absorption, weakened crack resistance and reduced durability. Therefore, strict compliance with the ratio and tensile modulus requirements in the above technical solution is crucial for the preparation of high-quality crack-resistant sound insulation and heat preservation low-carbon mortar.

[0051] In some embodiments of the present application, the defoaming agent is at least one of a silicone defoaming agent, a polyether defoaming agent, and a mineral oil defoaming agent.

[0052] In some embodiments of the present application, the organosilicon defoaming agent is purchased from Shaoxing Zhenggang Chemical Co., Ltd. with the brand name SAG471.

[0053] In some embodiments of the present application, the polyether defoamer is purchased from Shanghai Yingshan New Materials Co., Ltd. with the brand name DF-04.

[0054] In some embodiments of the present application, the mineral oil defoamer is purchased from Mingling Company of Germany with the brand number P803.

[0055] In some embodiments of the present application, the water retaining agent is at least one of cellulose ether and starch ether.

[0056] In some embodiments of the present application, the cellulose ether is purchased from Tiansheng Company with the brand name HEMC4W.

[0057] In some embodiments of the present application, starch ether is purchased from Nanjing Fancheng Biochemical Co., Ltd., CAS: 9063-38-1.

[0058] In some embodiments of the present application, the early strength agent is at least one of sulfates, chlorides, and organics.

[0059] In some embodiments of the present application, sulfates are purchased from Shanghai Yingshan New Materials Co., Ltd. with the brand name AC-01.

[0060] In some embodiments of the present application, the chloride is calcium chloride, which is purchased from Guangzhou Dongge Chemical Company.

[0061] In some embodiments of the present application, the organic substance is calcium formate, which is purchased from Guangzhou Jiantubao Company.

[0062] In some embodiments of the present application, the water reducing agent is at least one of sodium methylene dimethyl dinaphthalene sulfonate polymer, aliphatic hydroxy sulfonate, and polycarboxylate.

[0063] In some embodiments of the present application, the sodium methylene dimethyl dinaphthalene sulfonate polymer is purchased from Zhejiang Longsheng Company with the brand name FDN-05.

[0064] In some embodiments of the present application, the aliphatic hydroxy sulfonate is purchased from Qingdao Dingchang New Materials Co., Ltd.

[0065] In some embodiments of the present application, the polycarboxylate is purchased from Shanghai Yingshan New Materials Co., Ltd. with the brand name PC400.

[0066] The present application provides a method for preparing crack-resistant, sound-insulating and heat-insulating low-carbon mortar, the preparation method comprising the following steps:

[0067] (1) Preparation of modified VAE

[0068] Mix polyvinyl alcohol, 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene at 50-90°C for 2-6 hours to obtain a mixed solution; the amount of polyvinyl alcohol added is 1-5% of the mass of 4-tert-butyl benzoic acid vinyl ester;

[0069] Add VAE emulsion and ammonium persulfate to the mixed solution for copolymerization reaction to obtain modified VAE, wherein the amount of ammonium persulfate added is 0.1-1% of the mass of 4-tert-butyl benzoic acid vinyl ester;

[0070] (2) Preparation of modified polystyrene particles

[0071] The polystyrene particles are heated to a molten state at 100-120° C., and then methyl methacrylate, α-methylstyrene, maleic anhydride and polyvinyl alcohol are added, and the amount of polyvinyl alcohol added is 1-5% of the mass of the polystyrene particles. After uniform mixing, potassium persulfate is added, and the amount of potassium persulfate added is 0.1-1% of the mass of the polystyrene particles. A graft polymerization reaction is initiated at 60-80° C. After reacting for 5-8 hours, the particles are cooled to room temperature, washed, dried, and pelletized to obtain modified polystyrene particles, and the average particle size of the modified polystyrene particles is 1-3 mm.

[0072] (3) Preparation of mortar

[0073] Cement, gypsum, lime, magnesium oxide, modified VAE, modified polystyrene particles, defoamer, water retaining agent, early strength agent and water reducing agent are weighed in proportion and stirred to obtain a mixture, water is added to the mixture, and stirring is continued until the mixture is uniform to obtain a crack-resistant, sound-insulating and heat-insulating low-carbon mortar.

[0074] The polyvinyl alcohol used in this application as an emulsifier was purchased from Yunnan Yunwei Group Co., Ltd., CAS: 9002-89-5.

[0075] In this application, 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene are specifically used to modify the VAE emulsion. 4-tert-butyl benzoic acid vinyl ester has good weather resistance. By copolymerizing with the VAE emulsion, the weather resistance of the modified VAE emulsion can be improved, so that the mortar shows better stability and durability under extreme climatic conditions. 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene can also improve the chemical corrosion resistance of the modified VAE emulsion, which helps the mortar to remain stable when in contact with acidic and alkaline substances. The modified VAE emulsion can also improve the flexibility of the mortar and help resist cracking caused by temperature changes or structural stress. The modified VAE emulsion can also improve the bonding strength between the components of the mortar, which helps to form a more compact structure. The modified VAE emulsion helps to form a denser mortar structure, thereby reducing water absorption.

[0076] This application uses 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene to modify VAE emulsion, which can significantly improve the sound insulation and thermal insulation performance of mortar, reduce water absorption, improve crack resistance and enhance durability in extreme environments. The modified VAE emulsion improves the physical and chemical properties of mortar, making it more suitable for use in the field of green energy-saving buildings, especially for construction projects that require good thermal insulation and sound insulation performance. This mortar has great application potential.

[0077] In this application, three monomers, methyl methacrylate (MMA), α-methylstyrene (α-MS), and maleic anhydride, are used to modify polystyrene particles. The modified polystyrene particles can reduce the overall density of the mortar, reduce the resistance during sound wave propagation, and help improve the sound insulation effect. The addition of MMA, α-MS, and maleic anhydride can improve the surface hydrophilicity of the particles and improve the compatibility with other components in the mortar, thereby improving the overall performance of the mortar. The modified polystyrene particles have good thermal insulation properties and can reduce heat transfer through the wall. MMA, α-MS, and maleic anhydride can improve the surface stability of polystyrene particles, help to form a more stable mortar structure, and thus improve the thermal insulation effect. The water absorption rate of the modified polystyrene particles themselves is low. The addition of MMA, α-MS, and maleic anhydride can further improve the surface hydrophilicity of the particles, help to reduce the water penetration in the mortar, and thus reduce the water absorption rate. The addition of modified polystyrene particles can improve the flexibility and crack resistance of the mortar and reduce cracks caused by shrinkage. MMA, α-MS and maleic anhydride can improve the surface adhesion of particles, which helps to improve the crack resistance of mortar. Modified polystyrene particles have good weather resistance and chemical corrosion resistance, which helps to improve the durability of mortar in extreme environments. The addition of MMA, α-MS and maleic anhydride can improve the surface stability and chemical resistance of polystyrene particles, further enhancing the durability of mortar.

[0078] If only one monomer is used for modification in this application, the surface properties of the polystyrene particles may not be fully improved, which may affect its compatibility with other components in the mortar and reduce the overall sound insulation performance of the mortar. The modification of a single monomer may not be able to fully improve the surface stability of the polystyrene particles, affect its dispersibility and stability in the mortar, and thus may reduce the thermal insulation effect. The modification of only one monomer may not be able to effectively improve the surface hydrophilicity of the polystyrene particles, and may not be able to significantly reduce the water absorption rate of the mortar. The modification of a single monomer may not be able to fully improve the surface adhesion of the polystyrene particles, which may affect its distribution in the mortar and reduce the crack resistance of the mortar. The modification of only one monomer may not be able to fully improve the weather resistance and chemical corrosion resistance of the polystyrene particles, and may reduce the durability of the mortar in extreme environments.

[0079] The present application uses three monomers, MMA, α-MS and maleic anhydride, to modify polystyrene particles, which can comprehensively improve the surface properties of polystyrene particles, thereby improving the sound insulation and thermal insulation performance of the mortar, reducing water absorption, improving crack resistance and enhancing durability in extreme environments. In contrast, if only one monomer is used for modification, the modification effect may be limited and the overall performance of the mortar may be affected. Therefore, using three monomers for modification is a more effective strategy.

[0080] The present application provides an application of a crack-resistant, sound-insulating, and heat-insulating low-carbon mortar, and an application of the crack-resistant, sound-insulating, and heat-insulating low-carbon mortar in building materials.

[0081] The application of crack-resistant, sound-insulating and heat-insulating low-carbon mortar in building materials in this application is not limited to exterior wall insulation systems, but also includes interior wall partitions, roof insulation layers, ground insulation layers, sound insulation walls, etc.

[0082] Compared with the prior art, the present application at least achieves the following technical effects:

[0083] The present application relates to a crack-resistant, sound-insulating, and heat-insulating low-carbon mortar, which can achieve at least the following technical effects:

[0084] (1) The cement, gypsum, lime and magnesium oxide in the crack-resistant sound-insulating and heat-insulating low-carbon mortar formula of the present application are used as the base material, the modified VAE (ethylene-vinyl acetate copolymer emulsion) is used as the adhesive, which increases the flexibility and bonding strength of the mortar, and the modified polystyrene particles are used as the lightweight thermal insulation material, which reduces the overall density of the mortar and provides good thermal insulation performance and improves the crack resistance. Auxiliary additives such as defoamers, water-retaining agents, early strength agents and water-reducing agents improve the working performance of the mortar and the physical properties after hardening.

[0085] (2) The present application improves the weather resistance and chemical corrosion resistance of VAE by copolymerizing VAE emulsion with 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene. The addition of modified VAE improves the flexibility of the mortar, helps to reduce cracks caused by temperature changes or structural stress, and improves the weather resistance and chemical corrosion resistance of the mortar, enabling it to maintain its performance in a wider range of environments.

[0086] (3) In the present application, methyl methacrylate, α-methylstyrene and maleic anhydride are grafted onto polystyrene particles to improve the surface hydrophilicity of the particles and their compatibility with other components. The addition of modified polystyrene particles reduces the density of the mortar, thereby reducing the resistance to sound wave propagation, which helps to improve the sound insulation effect. The modified polystyrene particles have good thermal insulation properties and reduce heat transfer through the wall.

[0087] (4) The modified VAE and modified polystyrene particles of the present application both have a low water absorption rate, which helps to improve the moisture-proof performance of the entire mortar system. The addition of a water-retaining agent also helps to control the evaporation rate of water inside the mortar, further reducing the water absorption rate.

[0088] (5) The reasonable proportion of base materials such as cement and gypsum in the present application also helps to improve the sound insulation performance of the mortar. The presence of inorganic materials such as cement and gypsum also ensures the structural stability and durability of the mortar.

[0089] (6) The addition of ingredients such as gypsum and lime in this application enhances the freeze-thaw resistance of the mortar, making it more suitable for use in cold regions. DETAILED DESCRIPTION

[0090] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below. However, it should be understood that the description here is only used to explain the present application and is not used to limit the scope of the present application.

[0091] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application, and the terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The reagents and instruments used herein are all commercially available, and the characterization means involved can refer to the relevant descriptions in the prior art, which will not be repeated herein.

[0092] Example 1

[0093] The crack-resistant, sound-insulating and heat-insulating low-carbon mortar includes the following raw materials in parts by weight:

[0094] 40 parts of cement;

[0095] 8 parts of gypsum;

[0096] 2 parts lime;

[0097] 2 parts of magnesium oxide;

[0098] Modified VAE 10 parts;

[0099] 20 parts of modified polystyrene particles;

[0100] 0.6 parts of defoaming agent; the defoaming agent is a silicone defoaming agent purchased from Shaoxing Zhenggang Chemical Co., Ltd., brand SAG471;

[0101] 0.06 parts of water retaining agent; the water retaining agent is cellulose ether purchased from Tiansheng Company, brand HEMC4W;

[0102] 0.06 parts of early strength agent; the early strength agent is calcium chloride, purchased from Guangzhou Dongge Chemical Company;

[0103] 1 part of water reducing agent; the water reducing agent is polycarboxylate, purchased from Shanghai Yingshan New Materials Co., Ltd., brand PC400;

[0104] 12 parts water.

[0105] The modified VAE is obtained by copolymerization of VAE emulsion with 4-tert-butylbenzoic acid vinyl ester (CAS: 15484-80-7, purchased from Shanghai Koraman Reagent Co., Ltd.), methyl acrylate (purchased from Zhiheng Zhiyuan Chemical, CAS 96-33-3) and styrene (purchased from Jinan Century Tongda Chemical Co., Ltd., CAS100-42-5), wherein the mass ratio of VAE emulsion to 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene is 10:1.5:1:1; the viscosity of the VAE emulsion is 100~700cps, purchased from Celanese (China) Investment Co., Ltd., and the brand is Eco VAE ® 1602 emulsion.

[0106] The preparation method of modified VAE is as follows:

[0107] Polyvinyl alcohol, 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene were mixed at 80°C for 4 hours to obtain a mixed solution; the amount of polyvinyl alcohol added was 2% of the mass of 4-tert-butyl benzoic acid vinyl ester; VAE emulsion and ammonium persulfate were added to the mixed solution for copolymerization at 80°C for 3 hours to obtain modified VAE, and the amount of ammonium persulfate added was 0.5% of the mass of 4-tert-butyl benzoic acid vinyl ester. Polyvinyl alcohol was used as an emulsifier and was purchased from Yunnan Yunwei Group Co., Ltd., CAS: 9002-89-5.

[0108] The modified polystyrene particles are obtained by initiating graft polymerization reaction between methyl methacrylate, α-methylstyrene, maleic anhydride and polystyrene particles, and the mass ratio of methyl methacrylate, α-methylstyrene and polystyrene particles is 2:3:1:12. The tensile modulus of the polystyrene particles is 1700MPa, and they are purchased from ENI, Italy, with the brand name SRL 550.

[0109] The preparation method of modified polystyrene particles is as follows:

[0110] The polystyrene particles were heated to a molten state at 120°C, and then methyl methacrylate (CAS: 80-62-6, purchased from Shandong Jinyueyuan New Materials Co., Ltd.), α-methylstyrene (CAS: 98-83-9, purchased from Hubei Chengfeng Chemical Co., Ltd.), maleic anhydride (CAS: 108-31-6, purchased from Jinan Century Tongda Chemical Co., Ltd.) and polyvinyl alcohol (purchased from Yunnan Yunwei Group Co., Ltd., CAS: 9002-89-5) were added, and the amount of polyvinyl alcohol added was 3% of the mass of the polystyrene particles. After uniform mixing, potassium persulfate was added, and the amount of potassium persulfate added was 0.3% of the mass of the polystyrene particles. A graft polymerization reaction was initiated at 70°C. After reacting for 6 hours, the mixture was cooled to room temperature, washed, dried, and pelletized to obtain modified polystyrene particles. The average particle size of the modified polystyrene particles was 2 mm.

[0111] The average particle size of cement is 12 μm, the average particle size of gypsum is 40 μm, the average particle size of lime is 3 μm, and the average particle size of magnesium oxide is 85 μm.

[0112] A method for preparing crack-resistant, sound-insulating and heat-insulating low-carbon mortar, the preparation method comprising the following steps:

[0113] Cement, gypsum, lime, magnesium oxide, modified VAE, modified polystyrene particles, defoamer, water retaining agent, early strength agent and water reducing agent are weighed in proportion and stirred to obtain a mixture, water is added to the mixture, and stirring is continued until the mixture is uniform to obtain a crack-resistant, sound-insulating and heat-insulating low-carbon mortar.

[0114] Example 2

[0115] The difference from Example 1 is that the formula of the mortar is different.

[0116] The crack-resistant, sound-insulating and heat-insulating low-carbon mortar of this embodiment includes the following raw materials in parts by weight:

[0117] 30 parts cement

[0118] 10 parts of gypsum

[0119] 2 parts lime

[0120] 3 parts magnesium oxide

[0121] Modified VAE 6 parts

[0122] 30 parts of modified polystyrene particles

[0123] 0.5 parts of defoamer

[0124] Water-retaining agent 0.05 parts

[0125] 0.05 parts of early strength agent

[0126] 1 part water reducing agent

[0127] 10 parts water.

[0128] The mass ratio of VAE emulsion to 4-tert-butyl vinyl benzoate, methyl acrylate and styrene is 11:1:1:1.

[0129] The mass ratio of methyl methacrylate, α-methylstyrene, maleic anhydride and polyphenylene particles is 1:2:1:10.

[0130] Example 3

[0131] The difference from Example 1 is that the formula of the mortar is different.

[0132] The crack-resistant, sound-insulating and heat-insulating low-carbon mortar of this embodiment includes the following raw materials in parts by weight:

[0133] 50 parts cement

[0134] 10 parts of gypsum

[0135] 4 parts lime

[0136] 4 parts of magnesium oxide

[0137] Modified VAE 10 parts

[0138] Modified polystyrene particles 27.78 parts

[0139] Defoaming agent 0.5~1.0 part

[0140] Water-retaining agent 0.05~0.1 parts

[0141] Early strength agent 0.05~0.1 part

[0142] 1~2 parts of water reducing agent

[0143] 10~15 parts of water.

[0144] The mass ratio of VAE emulsion to 4-tert-butyl vinyl benzoate, methyl acrylate and styrene is 12:1.4:1:1.

[0145] The mass ratio of methyl methacrylate, α-methylstyrene, maleic anhydride and polyphenylene particles is 3:4:1:15.

[0146] Comparative Example 1

[0147] The difference from Example 1 is that the VAE emulsion is not modified and is directly used in the preparation process of the mortar.

[0148] Comparative Example 2

[0149] The difference from Example 1 is that the parameters of the VAE emulsion are different. The viscosity of the VAE emulsion is 3200-4400 cps and it is purchased from Zhicheng New Materials Sales and Operation Department, Linzi District, Shandong Province, with a brand number of DA102.

[0150] Comparative Example 3

[0151] The difference from Example 1 is that the mass ratio of VAE emulsion to 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene is 20:1:1:1.

[0152] Comparative Example 4

[0153] The difference from Example 1 is that the polystyrene particles are not modified and are directly used in the preparation process of the mortar.

[0154] Comparative Example 5

[0155] The difference from Example 1 is that methyl methacrylate is used as a monomer to modify the polyphenylene particles, and the α-methylstyrene and maleic anhydride in Example 1 are replaced by methyl methacrylate of equal mass.

[0156] Comparative Example 6

[0157] The difference from Example 1 is that the VAE emulsion is modified by using 4-tert-butyl vinyl benzoate as a monomer, and the methyl acrylate and styrene in Example 1 are replaced by 4-tert-butyl vinyl benzoate of equal mass.

[0158] Comparative Example 7

[0159] The difference from Example 1 is that the polystyrene particles are replaced with polystyrene particles with a low tensile modulus. The polystyrene particles used in this comparative example are purchased from ENI, Italy, with a brand number of RR 740E and a tensile modulus of 1350 MPa.

[0160] Comparative Example 8

[0161] The difference from Example 1 is that the average particle size of cement is 30 μm, the average particle size of gypsum is 100 μm, the average particle size of lime is 10 μm, and the average particle size of magnesium oxide is 200 μm.

[0162] Comparative Example 9

[0163] The difference from Example 1 is that the ratio of the weight of cement to the total weight of gypsum, lime and magnesium oxide is 10:1.

[0164] Comparative Example 10

[0165] The difference from Example 1 is that the weight portion of cement is 100 parts.

[0166] The ratio of the weight of cement to the total weight of gypsum, lime and magnesium oxide is 8.33:1.

[0167] The mass ratio of modified VAE to cement is 1:10.

[0168] The mass ratio of modified polystyrene particles to cement is 1:5.

[0169] Performance Testing

[0170] The thermal insulation performance of crack-resistant sound insulation low-carbon mortar was tested according to standard JG / T266-201, the impact sound insulation performance of crack-resistant sound insulation low-carbon mortar was tested according to standard GB / T 19889.6-2005, and the 28d compressive strength, 28d tensile bond strength, impermeability, water absorption and shrinkage of crack-resistant sound insulation low-carbon mortar were tested according to standard JC / T984-2011. The test results are shown in Tables 1, 2 and 3.

[0171]

[0172]

[0173]

[0174] It can be seen from the above performance test results that the sound insulation and thermal insulation low-salt mortar prepared in Examples 1-3 not only has excellent sound insulation and thermal insulation properties, but also has excellent mechanical strength and crack resistance, and has low water absorption. Under extreme conditions, its performance can still remain basically unchanged, and the comprehensive performance is excellent, especially the comprehensive performance of Example 1 is the most outstanding. This is mainly because modified VAE and modified polystyrene particles are used in the mortar. In addition, the average particle size and raw material ratio are limited, so that the mortar raw material formula design is reasonable, thereby improving the comprehensive performance of the mortar.

[0175] The comparative examples are obviously inferior to the embodiments in the corresponding performance tests because they do not adopt the necessary technical solutions. In comparative example 1, the modified VAE is replaced with pure VAE emulsion, and it can be seen that the comprehensive effect of the mortar prepared by it is reduced, proving that the modified VAE has an important influence on the improvement of comprehensive performance. The viscosity of the VAE emulsion in comparative example 2 is increased, resulting in a decrease in the various properties of the mortar prepared by it, indicating that the type and parameters of the VAE emulsion have a very important influence on the comprehensive performance of the mortar. In comparative example 3, the ratio between the VAE emulsion and the modifier 4-tert-butylbenzoic acid vinyl ester is changed, resulting in a decrease in the various properties of the mortar prepared by it, indicating that the mass ratio of the VAE emulsion to the 4-tert-butylbenzoic acid vinyl ester in this application is very important for the improvement of the comprehensive performance of the mortar. In comparative example 4, the modified polystyrene particles in this application are replaced with pure polystyrene particles, and the sound insulation and thermal insulation properties, mechanical properties and impermeability of the prepared mortar are significantly reduced, indicating that the modification of the polystyrene particles plays an important role in improving the performance of the mortar. Comparative Example 5 uses only one monomer in the present application to modify the polystyrene particles. From the test results, it is found that the comprehensive performance of the mortar using the polystyrene particles modified with one monomer is reduced compared with the embodiment, indicating that the three monomers used in the present application to modify the polystyrene particles at the same time have a synergistic effect, which can improve the performance of the mortar in all aspects, proving the necessity of using three monomers to modify the polystyrene particles at the same time. Comparative Example 6 uses only one monomer to modify the VAE emulsion, and the comprehensive performance of the mortar decreases, indicating the importance of modifying the VAE emulsion with three monomers at the same time. Comparative Example 7 replaces the polystyrene particles with high tensile modulus in the present application with polystyrene particles with low tensile modulus, and the comprehensive performance of the mortar decreases, indicating that the performance parameters of the polystyrene particles have an impact on the performance of the mortar. Comparative Examples 8 and Comparative Examples 9 respectively change the average particle size and ratio of cement, gypsum, lime and magnesium oxide, resulting in a decrease in the comprehensive performance of the mortar, such as sound insulation and thermal insulation performance, impermeability and mechanical strength, proving that the average particle size and ratio of the four substances have an important influence on the performance of the mortar. Comparative Example 10 increases the weight of cement in the formula, which leads to a change in the ratio between hydraulic inorganic gel cement and air-hardening inorganic gel (gypsum, lime and magnesium oxide), which exceeds the limit of this application. It also affects the ratio between cement and modified VAE and modified polystyrene particles, which also exceeds the limit of this application, resulting in a decrease in various properties of the prepared mortar to varying degrees, indicating that the amount of cement added and the ratio between cement and other substances have a very important influence on the comprehensive performance of the mortar. The above experimental results further prove the importance of the technical solution defined in this application for its technical effect.

[0176] The applicant declares that this application uses the above-mentioned embodiments to illustrate a crack-resistant, sound-insulating, heat-insulating low-carbon mortar and its preparation method and application, but this application is not limited to the above-mentioned embodiments, that is, it does not mean that this application must rely on the above-mentioned embodiments to be implemented. The technicians in the relevant technical field should understand that any improvement to this application, the equivalent replacement of the raw materials of the product of this application, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of this application.

[0177] The preferred embodiments of the present application are described in detail above; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0178] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

Claims

1. A crack-resistant, sound-insulating, and heat-insulating low-carbon mortar. Features: The crack-resistant, sound-insulating and heat-insulating low-carbon mortar includes the following raw materials in parts by weight: 30~50 parts of cement 5~10 parts of gypsum 1~5 parts lime 1~5 parts of magnesium oxide Modified VAE 5~15 parts Modified polystyrene particles 20~30 parts Defoaming agent 0.5~1.0 part Water-retaining agent 0.05~0.1 parts Early strength agent 0.05~0.1 part 1~2 parts of water reducing agent 10-15 parts water; The modified VAE is obtained by copolymerization of VAE emulsion with 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene, wherein the mass ratio of VAE emulsion to 4-tert-butylbenzoic acid vinyl ester, methyl acrylate and styrene is (10-12): (1-1.5): 1:1; The modified polystyrene particles are obtained by initiating graft polymerization reaction between methyl methacrylate, α-methylstyrene and maleic anhydride and polystyrene particles. The mass ratio of methyl methacrylate, α-methylstyrene, maleic anhydride and polystyrene particles is (1-3): (2-4): 1: (10-15).

2. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The ratio of the weight of cement to the total weight of gypsum, lime and magnesium oxide is (2~4):1, the average particle size of cement is 10~15μm, the average particle size of gypsum is 30~50μm, the average particle size of lime is 1~5μm, and the average particle size of magnesium oxide is 80~100μm.

3. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The mass ratio of modified VAE and cement is 1:(4~8), and the viscosity of VAE emulsion is 100~700cps.

4. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The mass ratio of modified polystyrene particles to cement is 1:(1~2), and the tensile modulus of polystyrene particles is 1600~1800MPa.

5. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The defoaming agent is at least one of a silicone defoaming agent, a polyether defoaming agent, and a mineral oil defoaming agent.

6. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The water retaining agent is at least one of cellulose ether and starch ether.

7. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The early strengthening agent is at least one of sulfates, chlorides and organic substances.

8. The crack-resistant, sound-insulating and heat-insulating low-carbon mortar according to claim 1, Features: The water reducing agent is at least one of sodium methylene dimethyl dinaphthalene sulfonate polymer, aliphatic hydroxy sulfonate, and polycarboxylate.

9. A method for preparing a crack-resistant, sound-insulating, and heat-insulating low-carbon mortar according to any one of claims 1 to 8, Features: The following steps are involved: (1) Preparation of modified VAE Mix polyvinyl alcohol, 4-tert-butyl benzoic acid vinyl ester, methyl acrylate and styrene at 50-90°C for 2-6 hours to obtain a mixed solution; the amount of polyvinyl alcohol added is 1-5% of the mass of 4-tert-butyl benzoic acid vinyl ester; Add VAE emulsion and ammonium persulfate to the mixed solution for copolymerization reaction to obtain modified VAE, wherein the amount of ammonium persulfate added is 0.1-1% of the mass of 4-tert-butyl benzoic acid vinyl ester; (2) Preparation of modified polystyrene particles The polystyrene particles are heated to a molten state at 100-120° C., and then methyl methacrylate, α-methylstyrene, maleic anhydride and polyvinyl alcohol are added, and the amount of polyvinyl alcohol added is 1-5% of the mass of the polystyrene particles. After uniform mixing, potassium persulfate is added, and the amount of potassium persulfate added is 0.1-1% of the mass of the polystyrene particles. A graft polymerization reaction is initiated at 60-80° C. After reacting for 5-8 hours, the particles are cooled to room temperature, washed, dried, and pelletized to obtain modified polystyrene particles, and the average particle size of the modified polystyrene particles is 1-3 mm. (3) Preparation of mortar Cement, gypsum, lime, magnesium oxide, modified VAE, modified polystyrene particles, defoamer, water retaining agent, early strength agent and water reducing agent are weighed in proportion and stirred to obtain a mixture, water is added to the mixture, and stirring is continued until the mixture is uniform to obtain a crack-resistant, sound-insulating and heat-insulating low-carbon mortar.

10. Application of the anti-crack, sound-insulating and heat-insulating low-carbon mortar according to any one of claims 1 to 8, Features: Anti-crack, sound-insulating and heat-insulating low-carbon mortar is used in building materials.

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