CN105085820B - The synthesis and application of acid amide type polyethers sodium sulfonate macromolecular for mould gypsum enhancing - Google Patents

Abstract

The invention discloses a formula, synthesis and application of an amide polyether sodium sulfonate macromolecule. Adding a small amount of the product into β gypsum can replace the traditionally used α and β mixed gypsum to make a gypsum mold; in order to ensure that the gypsum mold absorbs water While meeting the efficiency requirements, it can also increase the strength of the mold plaster, thereby reducing the cost of gypsum raw materials and increasing the number of times the plaster mold is used. References: [1] GB/T1640‑1992, Test methods for physical properties of gypsum powder for ceramic molds. 1993.

Description

Synthesis and Application of Amide Polyether Sulfonate Sodium Macromolecule for Mold Gypsum Reinforcement

【Technical field】

The invention relates to the synthesis and application of an amide polyether sodium sulfonate macromolecule used for mold gypsum reinforcement, and belongs to the field of material technology.

【Background technique】

Gypsum is widely used in ceramics and other industries due to its advantages such as abundant raw materials, low production cost, environmental protection, and good plasticity. However, when preparing gypsum molds, the actual water consumption is far greater than the theoretical hydration water demand, resulting in the fatal weakness of low strength, easy damage, poor quality, and short service life of gypsum molds. With the gradual development of the ceramic industry in the direction of mechanized and automated production, the domestic demand for plaster molds is increasing, and the quality requirements are also higher. Compared with the method of mixing high-priced and high-quality α-hemihydrate gypsum and cheap and inferior β-hemihydrate gypsum (generally around 40:60 weight ratio) to improve the strength of mold gypsum, the method of adding additives To improve the strength of mold gypsum, it has more advantages in price and performance.

At present, although there are many polycarboxylate macromolecular additives used in mold gypsum, many studies on gypsum polycarboxylate macromolecules basically copy the theory of concrete systems. Since the strength and water absorption of gypsum molds are actually a pair of contradictions, and the water-to-plaster ratio used in β-hemihydrate gypsum is very high, the effect of traditional additives for water reduction and enhancement in gypsum is not good, and may even reduce the strength of gypsum , especially under the premise of maintaining the strength, the water absorption of the mold will be greatly reduced; and most of the polycarboxylic acid macromolecules contain carboxylic acid groups in their molecular structures, resulting in serious retarding effects. In the case of high water paste ratio The mechanical strength of gypsum is often adversely affected under the influence. On the other hand, just because the strength and water absorption of the gypsum mold are actually a pair of contradictions, and the water-to-paste ratio used in β-hemihydrate gypsum is very high, so the monomer formula of the macromolecular additive includes the type of monomer and the composition of each monomer. The choice of ratio is particularly important, and a reasonable and appropriate balance needs to be sought, otherwise one will lose sight of the other.

In view of this, the amide type polyether sodium sulfonate macromolecule involved in the present invention does not introduce carboxylic acid groups in its molecular structure, thereby eliminating the bad influence caused by retardation on the mechanical properties of mold gypsum; The coagulation sulfonic acid group and the appropriate hydrophilic polyether group are beneficial to improve the water absorption and mechanical strength of the mold plaster. Adding a small amount of the amide polyether sodium sulfonate macromolecule to β gypsum can replace the traditionally used α and β mixed gypsum, reducing the cost of gypsum raw materials; at the same time, because the water absorption rate of the gypsum mold is guaranteed, the strength of the gypsum mold is increased. Improvement can increase the number of times it is used, so the production cost of products such as ceramics that use plaster molds is also reduced.

【Content of invention】

[Technical problem to be solved]

The purpose of the present invention is to provide a kind of synthetic monomer formulation, synthesis process and application of the amide type polyether sodium sulfonate macromolecule that is used for mold gypsum reinforcement, so that by adding a small amount of this product in cheap and inferior β gypsum It can replace the traditionally used α and β mixed gypsum to make plaster molds; while ensuring the water absorption requirements of gypsum molds, it can also increase the strength of mold gypsum even at high water-to-plaster ratios, thereby reducing the cost of gypsum raw materials and improving the quality of gypsum molds. usage times. The raw materials used in the method are easy to obtain, the process is simple, the operation is convenient, and the method is environmentally friendly.

[Technical solutions]

The present invention is achieved through the following technical solutions: the amide type polyether sodium sulfonate macromolecule can be prepared by the following method: using sodium methacryl sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene ether, N - Methylolacrylamide is the monomer, and the monomer molar ratio is (2-10): (4-10): (5-20), and ammonium persulfate is used as the initiator, and the process is carried out at 70-90°C After 5-8 hours of free radical reaction in the water phase, the reaction can be completed; under high reaction temperature, low initiator addition and short reaction time can be selected, and technicians in the field can choose by themselves through limited experiments according to their own conditions; After liquid cooling, use 30% NaOH to neutralize to pH 7.0-7.2. Its structure is shown in the figure below; the amount of initiator is 0.4%-0.7%, preferably 0.5%. Then a certain amount of above-mentioned amide polyether sodium sulfonate macromolecule is added into the required water of casting mold with 0.05%-0.15% (preferably 0.1%-0.15%) of gypsum mass to be mixed with solution, and the water demand is based on water paste ratio (recommended use 0.60-0.75, those skilled in the art can determine by themselves according to the technical characteristics of the follow-up mud) and calculate. Add this solution to the mold plaster within 2-3 minutes under slow stirring, and then place it for 1-3 minutes to make a plaster mold test piece. After final setting, remove the mold, store it at room temperature for 8 hours, and cure it at 45°C for 40-48 hours. (to a moisture content of 15%-20%) for mud molding, and the number of molds can be tested at the same time (limited to the deformation of the mold edge not exceeding 2mm); the molding time of the mud blank of the mold is 10-15 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen. Those skilled in the art can adjust the billet forming time according to the characteristics of the mud used. At the same time, the additives PC-1, PC-2, PC-3 and blank samples containing carboxylic acid groups were used for comparison.

Refer to GBT1640-1992, Test Method ¹ for Physical Properties of Gypsum Powder for Ceramic Molds for strength determination of gypsum specimens. Water absorption is measured as follows: weigh the remaining half of the gypsum specimen after the flexural strength is measured (M ₁ ), Then immerse in water (the water surface is about 2cm higher than the upper end of the gypsum test piece), place it for 10 minutes (the technical staff in the field can adjust it according to the actual billet making time), take it out, wipe off the excess water on the surface of the test piece with a wet rag, and weigh it. Weight (M ₂ ) and calculate water absorption. Calculated as follows:

Amide polyether sodium sulfonate macromolecules described in the present invention can be obtained by the following technical methods: using sodium methyl propylene sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene ether, N-methylol acrylamide as The monomer, using ammonium persulfate as the initiator, undergoes free radical reaction in the water phase at 70-90°C for 5-8 hours, and then the reaction can be completed. After cooling, it can be neutralized with 30% NaOH to a pH of 7.0-7.2, and its structure is shown in the following formula. Wherein sodium methacryl sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene ether, N-methylol acrylamide three monomer molar ratios are (2-10): (4-10): (5-20 ), the initiator consumption is 0.4%-0.7%, and the solid content of the product after synthesis is about 40%.

The molecular structural formulas of the traditional polycarboxylic acid additives PC-1, PC-2, and PC-3 are shown in the following formulas respectively. Because of the carboxylic acid group in its molecular structure, it will form a complex carboxylate calcium salt with Ca ²⁺ during the hydration process of gypsum, which prevents the combination of SO ₄ ^2- and Ca ²⁺ in the solution to form a dihydrate, resulting in The setting time of the mold gypsum is prolonged, and the retarding effect is serious, which has an adverse effect on the mechanical strength of the gypsum. However, the macromolecule of amide polyether sodium sulfonate involved in the present invention does not introduce carboxylic acid groups in the molecular structure, thereby eliminating the adverse effect on the mechanical properties of plaster molds caused by retardation; The sulfonic acid group and the hydrophilic polyether group are beneficial to the water absorption and mechanical strength of the plaster mold.

[beneficial effect]

The invention can replace traditionally used α and β mixed gypsum to make plaster molds by adding a small amount of products to cheap and inferior β gypsum; while ensuring the water absorption requirements of gypsum molds, even under high water-to-plaster ratio, it can Improve the strength of mold gypsum, thereby reducing the cost of gypsum raw materials, and increasing the number of times the gypsum mold is used, reducing gypsum waste and reducing the production cost of ceramics and other products using gypsum molds. The raw materials used in the method are easy to obtain, the process is simple, the one-pot synthesis is convenient to operate, and the method is environmentally friendly.

【Detailed ways】

The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any way, and any transformation or replacement based on the teaching of the present invention belongs to the protection scope of the present invention.

Embodiment one

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide in a molar ratio of 2:6:10, were prepared in At 80°C, the water-phase free radical reaction was carried out for 7h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.7%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example one

Compared with the blank sample, β-hemihydrate gypsum is slowly and evenly added to the water demand calculated according to the water-to-paste ratio of 0.7 within 2 minutes, and then left for 1 minute to make a gypsum mold test piece, and the mold is removed after final setting. Store at room temperature for 8 hours, and use it for mud molding after 48 hours of curing at 45°C. The number of times the mold can be used can be tested at the same time (limited to the deformation of the mold edge not exceeding 2mm); the mud blanking time of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared with the blank sample gypsum specimen (flexural strength is 6.36MPa, compressive strength is 15.31MPa, water absorption is 32.85), the gypsum specimen (flexural strength 6.62MPa, compressive strength 15.60MPa, water absorption 32.51), its flexural strength increased by 4%, compressive strength increased by 1.89%, and water absorption decreased by 1.03%. The ceramic tableware mold made of the modified gypsum can be used for 300-320 times from the original 130-150 times.

Embodiment two

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 2:8:15 were prepared in At 80°C, the free radical reaction in water phase was carried out for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.6%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example two

Using ammonium persulfate as the initiator, the four monomers of sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, N-methylol acrylamide, and maleic anhydride have a molar ratio of 5:8 : 20: 20, carry out the free radical reaction in water phase at 80°C for 8h and end. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-1 macromolecule. Wherein, the initiator consumption is 0.6%.

Add the PC-1 macromolecule synthesized above to the water demand calculated according to the water-to-gypsum ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and slowly and evenly add β-hemihydrate gypsum to this solution within 2 minutes. Put it in the solution for another 1 minute before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours. No more than 2mm); the molding time of the mud material for the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared with the gypsum specimen mixed with additive PC-1 (the flexural strength is 5.08MPa, the compressive strength is 12.23MPa, and the water absorption rate is 34.10), the gypsum specimen mixed with amide polyether sodium sulfonate macromolecule piece (bending strength 6.78MPa, compressive strength 15.94MPa, water absorption 31.29), its bending strength increased by 33.46%, compressive strength increased by 30.33%, and water absorption decreased by 8.24%. The ceramic tableware mold made of the modified gypsum can be used for 340-360 times from the original 80-100 times.

Embodiment Three

Using ammonium persulfate as an initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 2:10:20 were used in The free radical reaction in water phase was carried out at 90°C for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.4%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after 45 hours of curing at 45°C, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example three

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene ether, and maleic anhydride in a molar ratio of 5:8:20, were carried out at 90°C. The free radical reaction in the aqueous phase was completed in 8 hours. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-2 macromolecule. Wherein, the initiator consumption is 0.4%.

Add the PC-2 macromolecule synthesized above to the water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and slowly and evenly add β-hemihydrate gypsum to this solution within 2 minutes. Put it in the solution for another 1 minute before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 45 hours. No more than 2mm); the molding time of the mud material for the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared to the gypsum specimen mixed with the additive PC-2 (the flexural strength is 5.62MPa, the compressive strength is 12.71MPa, and the water absorption rate is 33.61), the gypsum specimen mixed with the amide polyether sodium sulfonate macromolecule piece (bending strength 6.75MPa, compressive strength 15.19MPa, water absorption 32.73), its bending strength increased by 20.10%, compressive strength increased by 19.51%, and water absorption decreased by 2.62%. The ceramic tableware mold made of the modified gypsum can be used for 330-350 times from the original 100-120 times.

Embodiment four

Using ammonium persulfate as an initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 5:6:15 were used in The free radical reaction in water phase was carried out at 70°C for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.7%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 2 minutes before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours, and test the number of molds at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example four

Using ammonium persulfate as the initiator, the three monomers of sodium methacrylsulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and acrylic acid in a molar ratio of 5:8:20 were carried out at 70°C in the aqueous phase The free radical reaction was finished in 8h. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-3 macromolecule. Wherein, the initiator consumption is 0.7%.

Add the PC-3 macromolecule synthesized above to the water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and slowly and evenly add β-hemihydrate gypsum to the mixture within 2 minutes. In the solution, place it for another 2 minutes before making a plaster mold test piece, remove the mold after final setting, store it at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours. No more than 2mm); the molding time of the mud material for the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared to the gypsum specimen mixed with additive PC-3 (the flexural strength is 5.39MPa, the compressive strength is 12.56MPa, and the water absorption rate is 33.79), the gypsum specimen mixed with amide polyether sodium sulfonate macromolecule piece (the flexural strength is 7.09MPa, the compressive strength is 16.54MPa, and the water absorption rate is 32.89), the flexural strength increases by 31.54%, the compressive strength increases by 31.68%, and the water absorption rate decreases by 2.66%. The ceramic tableware mold made of the modified gypsum can be used for 355-370 times from the original 90-100 times.

Embodiment five

Using ammonium persulfate as an initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 5:8:20 were used in At 80°C, the free radical reaction in water phase was carried out for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.6%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after 45 hours of curing at 45°C, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example five

Compared with the blank, β-hemihydrate gypsum is slowly and evenly added to the water demand calculated according to the water-to-paste ratio of 0.7 within 2 minutes, and then placed for 1 minute to make a gypsum mold test piece. Store at 45°C for 8 hours, and then use it for mud molding after 48 hours of curing at 45°C. The number of molds can be tested at the same time (limited to the deformation of the mold edge not exceeding 2mm); the molding time of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared with the blank sample gypsum specimen (flexural strength is 6.36MPa, compressive strength is 15.31MPa, water absorption is 32.85), the gypsum specimen (flexural strength 7.25MPa, compressive strength 17.19MPa, water absorption 32.74), its flexural strength increased by 14%, compressive strength increased by 12.45%, and water absorption decreased by 0.33%. The ceramic tableware mold made of the modified gypsum can be used for 365-380 times from the original 130-150 times.

Embodiment six

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 5:10:10 were prepared in The water phase free radical reaction was carried out at 90°C for 7h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.5%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after 48 hours at 45°C, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example six

Compared with the blank, β-hemihydrate gypsum is slowly and evenly added to the water demand calculated according to the water-to-paste ratio of 0.7 within 2 minutes, and then placed for 1 minute to make a gypsum mold test piece. Store at 45°C for 8 hours, and then use it for mud molding after 48 hours of curing at 45°C. The number of molds can be tested at the same time (limited to the deformation of the mold edge not exceeding 2mm); the molding time of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared with the blank sample gypsum specimen (flexural strength is 6.36MPa, compressive strength is 15.31MPa, water absorption is 32.85), the gypsum specimen (flexural strength 7.13MPa, compressive strength 17.28MPa, water absorption 32.18), its flexural strength increased by 12.10%, compressive strength increased by 12.86%, and water absorption decreased by 2.04%. The ceramic tableware mold made of the modified gypsum can be used for 360-375 times from the original 130-150 times.

Embodiment seven

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 10:6:20, were prepared in The free radical reaction in water phase was carried out at 70°C for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.6%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 40 hours, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 12 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example seven

Using ammonium persulfate as the initiator, the four monomers of sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, N-methylol acrylamide, and maleic anhydride have a molar ratio of 5:8 : 20: 20, carry out the free radical reaction in water phase at 70°C for 8h to end. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-1 macromolecule. Wherein, the initiator consumption is 0.6%.

Add the PC-1 macromolecule synthesized above to the water demand calculated according to the water-to-gypsum ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and slowly and evenly add β-hemihydrate gypsum to this solution within 2 minutes. Put it in the solution for another 1 minute before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours. No more than 2mm); the molding time of the mud material for the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared with the gypsum specimen mixed with additive PC-1 (the flexural strength is 4.87MPa, the compressive strength is 12.32MPa, and the water absorption rate is 33.91), the gypsum specimen mixed with amide polyether sodium sulfonate macromolecule piece (bending strength 6.89MPa, compressive strength 16.48MPa, water absorption 32.08), its flexural strength increased by 41.47%, compressive strength increased by 33.76%, and water absorption decreased by 5.39%. The ceramic tableware mold made of the modified gypsum can be used for 345-360 times from the original 80-100 times.

Embodiment Eight

Using ammonium persulfate as an initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 10:8:10 were used in At 90°C, the free radical reaction in water phase was carried out for 6h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.7%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 2 minutes before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours, and test the number of molds at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example eight

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene ether, and maleic anhydride in a molar ratio of 5:8:20, were carried out at 90°C. The free radical reaction in the aqueous phase ended in 6h. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-2 macromolecule. Wherein, the initiator consumption is 0.7%.

Add the PC-2 macromolecule synthesized above to the water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and slowly and evenly add β-hemihydrate gypsum to this solution within 2 minutes. Put it in the solution for another 1 minute before making a plaster mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours. No more than 2mm); the molding time of the mud material for the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared to the gypsum specimen mixed with the additive PC-2 (the flexural strength is 5.62MPa, the compressive strength is 12.71MPa, and the water absorption rate is 33.61), the gypsum specimen mixed with the amide polyether sodium sulfonate macromolecule pieces (the flexural strength is 7.12MPa, the compressive strength is 16.87MPa, and the water absorption rate is 31.98), the flexural strength has increased by 26.70%, the compressive strength has increased by 32.73%, and the water absorption rate has decreased by 4.85%. The ceramic tableware mold made of the modified gypsum can be used for 355-370 times from the original 100-120 times.

Embodiment nine

Using ammonium persulfate as the initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 10:10:15 were prepared in At 70°C, the water phase free radical reaction was carried out for 7h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.7%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store it at room temperature for 8 hours, and use it for mud molding after 42 hours of curing at 45°C, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example nine

Using ammonium persulfate as the initiator, the three monomers of sodium methacrylsulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and acrylic acid in a molar ratio of 5:8:20 were carried out at 70°C in the aqueous phase The free radical reaction ended in 7h. After the product is cooled, neutralize it with 30% NaOH to pH 7 to obtain the PC-3 macromolecule. Wherein, the initiator consumption is 0.7%.

The PC-3 macromolecule synthesized in Comparative Example 4 is added to the required water requirement calculated by the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is slowly mixed within 2 minutes. Add it evenly into this solution, and let it stand for 1 minute before making a plaster mold test piece. After final setting, remove the mold, store it at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours. You can test the number of times the mold is used (with The deformation of the edge of the mold shall not exceed 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

The comparison results show that, compared to the gypsum specimen mixed with additive PC-3 (the flexural strength is 5.39MPa, the compressive strength is 12.56MPa, and the water absorption rate is 33.79), the gypsum specimen mixed with amide polyether sodium sulfonate macromolecule pieces (the flexural strength is 7.02MPa, the compressive strength is 16.92MPa, and the water absorption rate is 32.23), the flexural strength has increased by 30.24%, the compressive strength has increased by 34.39%, and the water absorption rate has decreased by 4.62%. The ceramic tableware mold made of the modified gypsum can be used for 355-370 times from the original 90-100 times.

Embodiment ten

Using ammonium persulfate as an initiator, three monomers, sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide, in a molar ratio of 5:8:20 were used in At 80°C, the free radical reaction in water phase was carried out for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.6%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store it at room temperature for 8 hours, and use it for mud molding after 42 hours of curing at 45°C, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Comparative example ten

Using ammonium persulfate as the initiator, the three monomers of sodium methacryl sulfonate, methylalkenyl polyoxyethylene polyoxypropylene ether, and N-methylol acrylamide in a molar ratio of 2:4:5 were prepared in At 80°C, the free radical reaction in water phase was carried out for 8h to end. After the product is cooled, it is neutralized with NaOH with a mass fraction of 30% until the pH is 7, and the amide polyether sodium sulfonate macromolecule of the present invention can be obtained. Wherein, the initiator consumption is 0.6%.

The amide type polyether sodium sulfonate macromolecule synthesized above is added to the required water demand calculated according to the water-to-paste ratio of 0.7 with 0.15% of the gypsum mass to prepare a solution, and the β-hemihydrate gypsum is mixed within 2 minutes. Slowly and evenly add to this solution, and then stand for 1min before making a gypsum mold test piece, remove the mold after final setting, store at room temperature for 8 hours, and use it for mud molding after curing at 45°C for 48 hours, and test the number of times the mold is used at the same time ( The deformation of the edge of the mold is limited to no more than 2mm); the molding time of the mud blank of the mold is 10 minutes. For the determination of strength and water absorption performance data, the mold is dried to constant weight to measure the strength and water absorption performance of the gypsum specimen.

Contrast result shows, with respect to the gypsum test piece of comparative example (flexural strength is 6.26MPa, compressive strength 15.19MPa, water absorption rate 33.04), the gypsum test piece of embodiment (flexural strength is 7.25MPa, compressive strength 16.53 MPa, water absorption rate 32.74), its flexural strength increased by 15.81%, compressive strength increased by 8.82%, and water absorption rate decreased by 0.91%. The ceramic tableware mold made of the modified gypsum can be used for 365-380 times from the original 300-320 times.

Claims (2)

1. the synthetic method of the acid amide type polyethers sodium sulfonate macromolecular for mould gypsum enhancing, it is characterized in that：The amide Type polyethers sodium sulfonate macromolecular is prepared by the following method：With methylpropene sodium sulfonate, methyl alkenyl polyoxyethylene polyoxypropylene Ether, N hydroxymethyl acrylamide are monomer, and monomer mole ratio is (2-10): (4-10): (5-20), and are to draw with ammonium persulfate Agent is sent out, after carrying out water phase radical reaction 5-8h at 70-90 DEG C, reaction was completed；It is with mass fraction after reaction solution cooling It is 7.0-7.2 that 30% NaOH solution, which is neutralized to pH, and structure is shown below；Wherein initiator amount is 0.4%-0.7%,

2. the acid amide type polyethers sodium sulfonate macromolecular that synthetic method as described in claim 1 is prepared is in mould gypsum Using, it is characterized in that：Under the water paste ratio of 0.60-0.75, by the acid amide type of the 0.05%-0.15% in terms of β gypsum qualities Polyethers sodium sulfonate macromolecular is added in β gypsum and makes gypsum mold to substitute α, β mixed gypsum that tradition uses, can drop The cost of low gypsum raw material；While ensureing that mould gypsum water absorption rate requires, mould gypsum intensity can be also improved, and then improve The access times of gypsum mold.