Straw and soil block for multi-rib sandwich plate and preparation method thereof

Abstract

The application relates to the field of building materials, in particular to a straw and mud block for a dense rib sandwich plate and a preparation method thereof, wherein the straw and mud block is prepared from the following raw materials in parts by weight: clay 30-40 parts, cement 15-25 parts, desulfurization gypsum powder 10-15 parts, epoxy resin emulsion 5-10 parts, hyperbranched polyurethane acrylate emulsion 2-4 parts, hydrogen-containing polysiloxane modified allyl epoxy resin 0.5-1 part, organic amine 1-3 parts, straw fiber 10-15 parts, polycarboxylic acid water reducing agent 0.1-1 part and water 20-40 parts. The straw and mud block prepared by the application has excellent mechanical properties and heat insulation performance, and has low water absorption, and is an ideal core material for the dense rib sandwich plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, in particular to a straw and mud block for a multi-rib sandwich panel and a preparation method thereof. BACKGROUND

[0002] As a new type of building structure system, the multi-rib sandwich panel building structure can effectively reduce the amount of building materials, improve the construction speed, improve the self-insulation effect of the building, and reduce energy consumption. In application scenarios, it is widely used in various building components such as walls, roofs, partitions, etc., and is suitable for various scenes such as industrial plants, commercial buildings, residences and sports venues, showing great flexibility and applicability.

[0003] The straw and mud block is a high-performance building material made of plant straw and mud as raw materials through mold pressing, which not only has good thermal insulation performance, but also realizes resource recycling by turning waste into treasure. How to improve the mechanical properties and thermal insulation performance of the straw and mud block so that it can be used as a core material for a multi-rib sandwich panel has become a research hotspot. SUMMARY

[0004] The present application provides a straw and mud block for a multi-rib sandwich panel and a preparation method thereof.

[0005] The technical scheme adopted is as follows:

[0006] A straw and mud block for a multi-rib sandwich panel is prepared from the following raw materials in parts by weight:

[0007] 30-40 parts of clay, 15-25 parts of cement, 10-15 parts of desulfurization gypsum powder, 5-10 parts of epoxy resin emulsion, 2-4 parts of hyperbranched polyurethane acrylate emulsion, 0.5-1 part of hydrogen-containing polysiloxane modified allyl epoxy resin, 1-3 parts of organic amine, 10-15 parts of straw fiber, 0.1-1 part of polycarboxylic acid water reducer, and 20-40 parts of water.

[0008] Further, the clay is modified by a silane coupling agent.

[0009] Further, the preparation method of the clay is as follows:

[0010] The nano-clay is dispersed in an ethanol aqueous solution to obtain a dispersion liquid, the silane coupling agent is added to the ethanol aqueous solution and stirred in a water bath at 40-60℃ for 30-60min, then the dispersion liquid is added, and after 10-20h of incubation, centrifugation, collection of the precipitate, washing and drying are performed.

[0011] Further, the silane coupling agent is KH-560.

[0012] Further, the preparation method of the hyperbranched polyurethane acrylate emulsion is as follows:

[0013] Polytetrahydrofuran and dimethylol propionic acid are mixed and heated to 55-65 DEG C, 4,4'-dicyclohexyl methane diisocyanate and tin catalyst are added dropwise under stirring, after dropping, the reaction is stirred for 30-60 min, then heated to 75-85 DEG C and continue to react for 1-5 h, hydroxyethyl acrylate is added and continue to react for 1-5 h, pentaerythritol triacrylate is added and continue to react for 1-5 h, hydroxyl-terminated hyperbranched polyester is added and continue to react for 1-5 h, then cooled to 40-60 DEG C, triethylamine is added and reacted for 30-60 min, then restore room temperature, deionized water is added under strong stirring for emulsification, and the hyperbranched polyurethane acrylate emulsion is obtained.

[0014] Further, the tin catalyst is a metal organic compound formed by direct combination of tin and carbon element, and preferably is dibutyl tin dilaurate.

[0015] Further, the preparation method of the hydrogen-containing polysiloxane modified allyl epoxy resin is as follows:

[0016] Chloroplatinic acid is added into the hydrogen-containing polysiloxane, stirred and heated to 80-100 DEG C, then the allyl epoxy resin is slowly added, after adding, the reaction is kept for 5-10 h, and finally low boiling point substances are removed by distillation under reduced pressure.

[0017] Further, the mass ratio of the hydrogen-containing polysiloxane to the allyl epoxy resin is 1:0.5-1.

[0018] Further, the organic amine is a combination of triethanolamine and ethylenediamine.

[0019] The mass ratio of the triethanolamine to the ethylenediamine is 1-5:1-5.

[0020] Further, the preparation method of the straw fiber is as follows:

[0021] After the crop straw is cut into segments, it is soaked in a 5-10 wt% sodium hydroxide solution at 40-60 DEG C for 1-10 h, filtered, washed with water until neutral, and dried.

[0022] Further, the crop straw is preferably a cereal crop, and specifically can be rice straw, wheat straw, corn straw, barley straw, oat straw, sorghum straw, millet straw.

[0023] Further, the crop straw is preferably wheat straw.

[0024] The application also provides a preparation method of a straw soil block for a multi-rib sandwich panel.

[0025] The clay, cement, desulfurization gypsum powder and straw fiber are uniformly mixed in advance to obtain a solid material, the polycarboxylic acid water reducing agent is dissolved in water and then added to the solid material and stirred uniformly, then the epoxy resin emulsion, hyperbranched polyurethane acrylate emulsion and hydrogen-containing polysiloxane modified allyl epoxy resin are added and continue to stir, finally the organic amine is added and then poured into a mold for cold pressing forming, demolding after steam curing, and then placed in a light-proof and ventilated place until the corresponding age.

[0026] The beneficial effects of the present application are:

[0027] The present application provides a kind of for dense rib sandwich board straw mud block, clay as a kind of mud, main mineral component is kaolinite, illite and montmorillonite, the addition of clay can promote the hydration of cement, generate hydrated calcium silicate, hydrated calcium aluminate, garnet, amorphous gel and Ca (OH) 2 etc., these hydration products increase the density of gelling crystal network structure, so as to improve the mechanical strength of straw mud block, reduce water absorption, after modification by silane coupling agent KH-560, condensation reaction occurs between silicon hydroxyl and the hydroxyl on the surface of clay, so that epoxy group is introduced on the surface of clay, epoxy group can enter the polymer film by crosslinking reaction of chemical bond, improve the bonding strength of clay in straw mud block, so as to further improve the performance of straw mud block;

[0028] Epoxy resin emulsion and hyperbranched polyurethane acrylate emulsion can form interpenetrating polymer network, can inhibit the generation of microcracks, improve the internal pore structure, play the role of heat insulation and fixed support, and make the structure of straw mud block more dense, the contained hyperbranched polyhydroxy structure not only improves the compatibility of polyurethane acrylate emulsion and epoxy resin emulsion, but also the contained hydroxyl can promote the curing of epoxy resin emulsion, improve the crosslinking density of interpenetrating polymer network, so that it can absorb impact energy from all directions, and can play a better resistance when subjected to external impact, improve the compressive and flexural properties of straw mud block;

[0029] Hydrogen-containing polysiloxane modified allyl epoxy resin not only can participate in the crosslinking of epoxy resin emulsion and hyperbranched polyurethane acrylate emulsion to form a hydrophobic network structure, but also can form a microstructure inside the straw mud block to inhibit shrinkage and cracking, making it more compact and strong, improving the strength and durability of straw mud block, and improving the waterproof and impermeable ability;

[0030] The addition of the straw fiber divides the air bubbles in the mixing process into closed small bubbles, which can effectively prevent heat transfer, so that the thermal conductivity of the sample is reduced, the thermal insulation performance is improved, in addition, the straw fiber has large porosity, which is a low thermal conductivity material, and can also improve the thermal insulation performance, the straw fiber can increase the internal skeleton structure and reduce the shrinkage, so as to reduce the cracking tendency, the straw soil block prepared by the application has excellent mechanical properties and thermal insulation performance, and low water absorption rate, which is an ideal core material of the multi-rib sandwich panel. DETAILED DESCRIPTION

[0031] Unless otherwise specified, the specific conditions in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, and are all conventional products that can be purchased on the market. The technologies not mentioned in the application refer to the prior art, and the following examples and comparative examples are parallel tests, using the same processing steps and parameters.

[0032] Clay: self-made;

[0033] Cement: P.O 42.5 ordinary Portland cement, Hailuo;

[0034] Desulfurized gypsum powder: 200-325 mesh, purchased from Xinxiang City Babang Calcium Industry Co., Ltd.;

[0035] Epoxy resin emulsion: solid content 60%, Shengwanjia;

[0036] Hyperbranched polyurethane acrylate emulsion: self-made;

[0037] Hydrogen-containing polysiloxane modified allyl epoxy resin: self-made;

[0038] Triethanolamine: purchased from Jinan Shunwang Chemical Co., Ltd.;

[0039] Ethylene diamine: purchased from Jinan Shunwang Chemical Co., Ltd.;

[0040] Straw fiber: self-made;

[0041] Polycarboxylic acid water reducing agent: PC-412, Hengda;

[0042] Water: tap water.

[0043] Example 1:

[0044] A straw soil block for a multi-rib sandwich panel is prepared from the following raw materials in parts by weight:

[0045] Clay 35 parts, cement 20 parts, desulfurization gypsum powder 12 parts, epoxy resin emulsion 8 parts, hyperbranched polyurethane acrylate emulsion 3 parts, hydrogen-containing polysiloxane modified allyl epoxy resin 1 part, triethanolamine 1 part, ethylenediamine 1 part, straw fiber 12 parts, polycarboxylic acid water reducer 0.5 parts, water 30 parts.

[0046] The preparation method of the clay is as follows:

[0047] 100g of nanoclay was dispersed in 500ml of 75% volume fraction ethanol aqueous solution, ultrasonic oscillation treatment was performed for 30min to obtain a dispersion liquid, 200ml of silane coupling agent KH-560 was added to 500ml of 75% volume fraction ethanol aqueous solution and stirred in a 50℃ water bath for 60min, then the above dispersion liquid was slowly added within 10min, after 15h of incubation, centrifugation was performed, the precipitate was collected, washed repeatedly with anhydrous ethanol and deionized water, and then vacuum dried at 50℃ for 24h.

[0048] The preparation method of the hyperbranched polyurethane acrylate emulsion is as follows:

[0049] 40g of polytetrahydrofuran-1000 and 3.56g of bis-hydroxymethyl propionic acid were mixed, stirred and heated to 60℃, 43.81g of 4,4'-dicyclohexylmethane diisocyanate and 0.01g of dibutyltin dilaurate were added dropwise under stirring, after dropping, stirring reaction was performed for 60min, then heating to 80℃ was continued for 2.5h, 12.32g of hydroxyethyl acrylate was added and the reaction was continued for 1h, then 13.12g of pentaerythritol triacrylate was added and the reaction was continued for 4h, 4.57g of hydroxyl-terminated hyperbranched polyester H101 was added and the reaction was continued for 2h, then the temperature was lowered to 60℃, 2.36g of triethylamine was added and reacted for 30min, then the temperature was restored to room temperature, deionized water was added under strong stirring for emulsification, and a hyperbranched polyurethane acrylate emulsion with a solid content of 55% was obtained.

[0050] The preparation method of the hydrogen-containing polysiloxane modified allyl epoxy resin is as follows:

[0051] 0.5mg of chloroplatinic acid was added to 100g of hydrogen-containing polysiloxane (hydrogen content 0.15%), stirred and heated to 80-100℃, then 63g of allyl epoxy resin (DADGEBA) was slowly added, after addition, the reaction was continued for 8h, and finally low-boiling substances were removed by distillation under reduced pressure.

[0052] The preparation method of the straw fiber is as follows:

[0053] Wheat straw was cut into 5-10cm segments, soaked in a 50℃ sodium hydroxide solution with a mass concentration of 5wt% for 10h at a solid-liquid mass ratio of 1:10, filtered, washed with water until neutral, and then dried.

[0054] The preparation method of the straw soil block for the multi-rib sandwich board is as follows:

[0055] The clay, cement, desulfurization gypsum powder and straw fiber are uniformly mixed in advance to obtain solid materials, the polycarboxylic acid water reducing agent is dissolved in water and then added to the solid materials and stirred uniformly, then the epoxy resin emulsion, hyperbranched polyurethane acrylate emulsion and hydrogen-containing polysiloxane modified allyl epoxy resin are added and continue to stir for 10 min, finally the triethanolamine and ethylenediamine are added and stirred for 3 min, then poured into a mold and cold-pressed into shape under 20 MPa, naturally cooled to room temperature after steam curing at 110 DEG C for 5 h, demolded, and the obtained green body is placed in a cool and ventilated place for 7 days.

[0056] Example 2

[0057] A straw soil block for a multi-rib sandwich board is prepared from the following raw materials in parts by weight:

[0058] Clay 40 parts, cement 25 parts, desulfurization gypsum powder 15 parts, epoxy resin emulsion 10 parts, hyperbranched polyurethane acrylate emulsion 4 parts, hydrogen-containing polysiloxane modified allyl epoxy resin 1 part, triethanolamine 1 part, ethylenediamine 1 part, straw fiber 15 parts, polycarboxylic acid water reducing agent 0.5 parts, and water 30 parts.

[0059] The preparation method of the clay, hyperbranched polyurethane acrylate emulsion, hydrogen-containing polysiloxane modified allyl epoxy resin and straw fiber is the same as that in Example 1.

[0060] The preparation method of the straw soil block for the multi-rib sandwich board is as follows:

[0061] The clay, cement, desulfurization gypsum powder and straw fiber are uniformly mixed in advance to obtain solid materials, the polycarboxylic acid water reducing agent is dissolved in water and then added to the solid materials and stirred uniformly, then the epoxy resin emulsion, hyperbranched polyurethane acrylate emulsion and hydrogen-containing polysiloxane modified allyl epoxy resin are added and continue to stir for 10 min, finally the triethanolamine and ethylenediamine are added and stirred for 3 min, then poured into a mold and cold-pressed into shape under 20 MPa, naturally cooled to room temperature after steam curing at 110 DEG C for 5 h, demolded, and the obtained green body is placed in a cool and ventilated place for 7 days.

[0062] Example 3

[0063] A straw soil block for a multi-rib sandwich board is prepared from the following raw materials in parts by weight:

[0064] Clay 30 parts, cement 15 parts, desulfurization gypsum powder 10 parts, epoxy resin emulsion 5 parts, hyperbranched polyurethane acrylate emulsion 2 parts, hydrogen-containing polysiloxane modified allyl epoxy resin 0.5 parts, triethanolamine 1 part, ethylenediamine 1 part, straw fiber 10 parts, polycarboxylic acid water reducing agent 0.1 parts, and water 20 parts.

[0065] The preparation method of the clay, the hyperbranched polyurethane acrylate emulsion, the hydrogen-containing polysiloxane modified allyl epoxy resin and the straw fiber is the same as that in Example 1.

[0066] The preparation method of the straw clay block for the ribbed core sandwich panel is as follows:

[0067] The clay, the cement, the desulfurization gypsum powder and the straw fiber are uniformly mixed in advance to obtain a solid material, the polycarboxylic acid water reducing agent is dissolved in water and then added to the solid material and uniformly stirred, the epoxy resin emulsion, the hyperbranched polyurethane acrylate emulsion and the hydrogen-containing polysiloxane modified allyl epoxy resin are added and continuously stirred for 10 min, finally, the triethanolamine and the ethylenediamine are added and stirred for 3 min, and then poured into a mold and cold-pressed into a shape under 20 MPa, and then naturally cooled to room temperature after steam curing at 110 ℃ for 5 h, demolded, and then the obtained blank is placed in a cool and ventilated place for 7 days.

[0068] Comparative Example 1:

[0069] The preparation method is basically the same as that in Example 1, and the difference is that the nano clay is directly added, that is, without modification by the silane coupling agent KH-560.

[0070] Comparative Example 2:

[0071] The preparation method is basically the same as that in Example 1, and the difference is that the epoxy resin emulsion is not added.

[0072] Comparative Example 3:

[0073] The preparation method is basically the same as that in Example 1, and the difference is that the hyperbranched polyurethane acrylate emulsion is not added.

[0074] Comparative Example 4:

[0075] The preparation method is basically the same as that in Example 1, and the difference is that the commercially available water-based polyurethane modified acrylic emulsion PUA2922 (Chengzhenhao) is used instead of the self-made hyperbranched polyurethane acrylate emulsion.

[0076] Comparative Example 5:

[0077] The preparation method is basically the same as that in Example 1, and the difference is that the hydrogen-containing polysiloxane modified allyl epoxy resin is not added.

[0078] Performance test:

[0079] The straw clay blocks prepared in Examples 1-3 and Comparative Examples 1-5 of the application are used as test samples.

[0080] The mechanical property indexes are tested according to the standard JC / T 422-1991 (96) “Non-sintered ordinary clay brick”;

[0081] The thermal conductivity is tested by a DRH-300 thermal conductivity tester, and the testing method is a steady-state double heat protection plate method, and the results of the above testing are shown in Table 1 below:

[0082] Table 1:

[0083]

[0084] From Table 1 above, it can be seen that the straw soil block prepared by the application has excellent mechanical properties and heat insulation properties, and low water absorption rate;

[0085] It can be known from the comparison between Example 1 and Comparative Example 1 that after the nano clay is modified by the silane coupling agent KH-560, the various properties of the straw soil block are improved;

[0086] It can be known from the comparison between Example 1 and Comparative Examples 2-3 that the addition of the epoxy resin emulsion and the hyperbranched polyurethane acrylate emulsion can improve the mechanical properties and heat insulation properties of the straw soil block and reduce the water absorption rate;

[0087] It can be known from the comparison between Example 1 and Comparative Example 4 that compared with the commercially available water-based polyurethane modified acrylic emulsion, the hyperbranched polyurethane acrylate emulsion in the application has more obvious improvement on the various properties of the straw soil block.

[0088] It can be known from the comparison between Example 1 and Comparative Example 5 that the addition of the hydrogen-containing polysiloxane modified allyl epoxy resin can improve the mechanical properties and heat insulation properties of the straw soil block and reduce the water absorption rate.

[0089] The above examples are only used to illustrate the technical solutions of the application, but not to limit it; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A straw-mud block for use in closely ribbed sandwich panels, characterized in that, It is prepared from the following raw materials in parts by weight: 30-40 parts clay, 15-25 parts cement, 10-15 parts desulfurized gypsum powder, 5-10 parts epoxy resin emulsion, 2-4 parts hyperbranched polyurethane acrylate emulsion, 0.5-1 part hydrogen-containing polysiloxane modified allyl epoxy resin, 1-3 parts organic amine, 10-15 parts straw fiber, 0.1-1 part polycarboxylate superplasticizer, and 20-40 parts water. The preparation method of the hydrogen-containing polysiloxane-modified allyl epoxy resin is as follows: Add chloroplatinic acid to hydrogen-containing polysiloxane, stir and heat to 80-100℃, then slowly add allyl epoxy resin, keep the reaction at the temperature for 5-10 hours, and finally remove low-boiling substances by vacuum distillation. The hydrogen content of the hydrogen-containing polysiloxane is 0.15%; The mass ratio of the hydrogen-containing polysiloxane to the allyl epoxy resin is 1:0.5-1; The preparation method of hyperbranched polyurethane acrylate emulsion is as follows: Polytetrahydrofuran and dimethylolpropionic acid are mixed and heated to 55-65°C. 4,4'-dicyclohexylmethane diisocyanate and organotin catalyst are added dropwise under stirring. After the addition is complete, the mixture is stirred for 30-60 minutes. The temperature is then raised to 75-85°C and the reaction continues for 1-5 hours. Hydroxyethyl acrylate is added and the reaction continues for 1-5 hours. Pentaerythritol triacrylate is added and the reaction continues for 1-5 hours. Hydroxyl-terminated hyperbranched polyester is added and the reaction continues for 1-5 hours. The temperature is then lowered to 40-60°C, and triethylamine is added. The reaction continues for 30-60 minutes, and the mixture is restored to room temperature. Deionized water is added under vigorous stirring for emulsification to obtain the hyperbranched polyurethane acrylate emulsion.

2. The straw-mud block for densely ribbed sandwich panels as described in claim 1, characterized in that, The clay was modified with a silane coupling agent.

3. The straw-mud block for densely ribbed sandwich panels as described in claim 2, characterized in that, The method for preparing the clay is as follows: Nano-clay is dispersed in an ethanol aqueous solution to obtain a dispersion. Silane coupling agent is added to the ethanol aqueous solution and stirred in a water bath at 40-60℃ for 30-60 min. Then the dispersion is added, and the reaction is kept at this temperature for 10-20 h. After centrifugation, the precipitate is collected, washed, and dried.

4. The straw-mud block for densely ribbed sandwich panels as described in claim 3, characterized in that, The silane coupling agent is KH-560.

5. The straw-mud block for ribbed sandwich panels as described in claim 1, characterized in that, The organic amine is a combination of triethanolamine and ethylenediamine; The mass ratio of triethanolamine to ethylenediamine is 1-5:1-5.

6. The straw-mud block for ribbed sandwich panels as described in claim 1, characterized in that, The method for preparing the straw fiber is as follows: After cutting the crop straw into sections, soak it in a sodium hydroxide solution with a mass concentration of 5-10 wt% at 40-60℃ for 1-10 hours, filter, wash with water until neutral, and then dry.

7. A method for preparing straw-mud blocks for ribbed sandwich panels as described in any one of claims 1-6, characterized in that, Clay, cement, desulfurized gypsum powder, and straw fiber are premixed to obtain a solid material. Polycarboxylate superplasticizer is dissolved in water and added to the solid material and stirred evenly. Then, epoxy resin emulsion, hyperbranched polyurethane acrylate emulsion, and hydrogen-containing polysiloxane modified allyl epoxy resin are added and stirred continuously. Finally, organic amine is added and poured into a mold for cold pressing. After steam curing, the mixture is demolded and placed in a dark and ventilated place until the appropriate age is reached.

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