A resin material for water quality testing

Abstract

The invention discloses a resin material for water quality testing. The resin material comprises 60-99.9% by weight of a cross-linked carboxylic acid resin and 0.1-10% by weight of an alkali-resistant binder. A double-bond silane coupling agent and a double-bond and hydroxyl-containing monomer are subjected to free radical polymerization initiated by an initiator, and then a cross-linking reaction is carried out with polyisocyanate to obtain highly cross-linked polymer microspheres. The highly cross-linked polymer microspheres are connected to polyacrylic acid via N=C=O of the polyisocyanate to obtain a cross-linked carboxylic acid resin containing carboxyl groups on the surface. The cross-linked carboxylic acid resin and the alkali-resistant binder are formed into a hollow columnar structure, which facilitates full contact between a water sample and the resin material and can also guide the water sample, so that the water flow from the outside to the inside of the resin material has a low and uniform pressure drop, thereby improving the accuracy and efficiency of alkalinity testing of the water sample.

Description

Technical Field

[0001] The invention belongs to the technical field of water quality detection, and in particular relates to a resin material for water quality detection. Background Art

[0002] A survey by the World Health Organization shows that in developing countries, 8% of diseases are caused by drinking unsafe and unhygienic water. The quality of drinking water greatly affects people's health and quality of life. Therefore, water quality measurement is essential for domestic water use.

[0003] In the existing technology, chemical analysis and instrumental analysis are generally used to detect the alkalinity of water quality. These methods usually require professional analytical and testing technicians and must be carried out in a laboratory with certain equipment, instruments, utensils and chemical reagents. The measurement process is cumbersome and time-consuming, has high requirements for users, and is prone to various operational errors, resulting in large errors in the alkalinity test results of water quality and failing to meet the technical requirements for water alkalinity measurement.

[0004] Weakly acidic resins react with alkaline substances in water, causing a change in the water's electrical conductivity. This change in conductivity is then used to detect the water's alkalinity. However, conventional weakly acidic resins are granular and spherical, making them difficult to package and pack evenly. They often have gaps, preventing the alkaline substances in the water sample from fully contacting the resin material. Consequently, the accuracy and efficiency of water sample alkalinity testing are low. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a resin material for water quality testing. A double-bond silane coupling agent and a double-bond and hydroxyl-containing monomer undergo free radical polymerization initiated by an initiator, and then undergo a cross-linking reaction with polyisocyanate to obtain highly cross-linked polymer microspheres. The highly cross-linked polymer microspheres are connected to polyacrylic acid via N=C=O of the polyisocyanate to obtain a cross-linked carboxylic acid resin containing carboxyl groups on the surface. The cross-linked carboxylic acid resin and an alkali-resistant binder are formed into a hollow columnar structure, which facilitates full contact between a water sample and the resin material. At the same time, the structure can guide the water sample, so that the water flow pattern of the resin material from the outside to the inside has low pressure drop and is uniform, thereby improving the accuracy and efficiency of alkalinity testing of the water sample.

[0006] The object of the present invention is to provide a resin material for water quality detection, wherein the resin material for water quality detection comprises 60-99.9% by weight of a cross-linked carboxylic acid resin and 0.1-10% by weight of an alkali-resistant binder.

[0007] Preferably, the cross-linked carboxylic acid resin is in granular or powdery form, the granular form has a particle size of 0.5-5 mm, and the powder form has a particle size of 100-1000 mesh.

[0008] Preferably, the alkali-resistant binder is one or more of polyethylene, polypropylene, polybutadiene, methyl cellulose, polyethylene oxide, hydroxypropyl methyl cellulose, polyvinyl alcohol, and polytetrafluoroethylene; the alkali-resistant binder selected in this solution has a large molecular weight, good compatibility with the prepared cross-linked carboxylic acid resin, and strong bonding strength.

[0009] Furthermore, the preparation of the acidic resin comprises the following steps:

[0010] S1. Under nitrogen, the stabilizer and solvent were mixed, a double bond-containing silane coupling agent, a double bond-containing and hydroxyl monomer, a crosslinking agent, a first initiator were added, stirred, and heated to obtain a crosslinked copolymer microsphere mixture and set aside;

[0011] S2. Mix the acrylic monomer and the second initiator, heat and stir to react, add the cross-linked copolymer microsphere mixture obtained in step S1, continue the reaction, and post-treat to obtain a cross-linked carboxylic acid resin.

[0012] Furthermore, in step S1, the stabilizer is one or both of polyvinyl alcohol and polyvinyl pyrrolidone.

[0013] Furthermore, in step S1, the heating temperature is 40-70°C; the heating temperature is selected based on the decomposition temperature of the initiator.

[0014] Furthermore, in step S1, the solvent is a mixture of water and an alcohol solvent.

[0015] Furthermore, in step S1, the double bond-containing silane coupling agent is one of silane coupling agent KH-570, (4-vinylphenyl)trimethoxysilane, silane coupling agent A171, silane coupling agent A151, silane coupling agent A172, and (4-vinylphenyl)triethoxysilane; the double bond-containing silane coupling agent selected in this scheme has high reactivity with monomers containing double bonds and hydroxyl groups, and the polymer molecular chain obtained by polymerization contains Si-O bonds, so that the obtained polymer has high strength and is not easy to dissociate.

[0016] Furthermore, in step S1, the monomer containing double bonds and hydroxyl groups is one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-methyl-2-propene-1-ol, hydroxypropyl acrylate, hydroxypropyl methacrylate, allyl lactate, hydroxypolyethylene glycol methacrylate, and methoxypolypropylene glycol methacrylate; the double bonds of the monomer containing double bonds and hydroxyl groups used in this scheme have high reactivity, and the copolymer molecular chain obtained by polymerization contains more hydroxyl active reactive groups, which can subsequently undergo a cross-linking reaction with a polyisocyanate curing agent.

[0017] Furthermore, in step S1, the cross-linking agent is polyisocyanate; the N=C=O of the polyisocyanate can react with the hydroxyl group to play a cross-linking role.

[0018] Furthermore, in step S1, the first initiator is at least one of azobisisobutyronitrile and azobisisoheptanonitrile; the initiator used in this solution has a low decomposition temperature and high activity, so that the polymerization reaction can be carried out at a lower temperature.

[0019] Furthermore, in step S2, the mass ratio of the stabilizer to the double bond-containing silane coupling agent, the double bond- and hydroxyl-containing monomer, the crosslinking agent, and the first initiator is 1:20-40:20-40:10-20:0.4-4.

[0020] Furthermore, in step S2, the heating temperature is 80-90°C; the heating temperature is selected based on the decomposition temperature of the initiator.

[0021] Furthermore, in step S2, the post-treatment is washing with water / alcohol solvent, grinding, and screening; the continuous washing with water / alcohol solvent is to wash away the remaining unreacted acrylic monomer, reduce the presence of residual acrylic monomer in the system, reduce the dissolution rate of the resin material in the water sample, and improve the accuracy of alkalinity detection.

[0022] Furthermore, in step S2, the second initiator is at least one of benzoyl peroxide and tert-butyl benzoyl peroxide; the initiator used in this scheme has a high decomposition temperature and relatively low activity, so that the reaction proceeds smoothly.

[0023] Furthermore, in step S2, the acrylic monomer is one or more of acrylic acid, methacrylic acid, 2-(trifluoromethyl)acrylic acid, cinnamic acid, maleic acid, and itaconic acid; the monomer selected in this scheme contains a large number of carboxyl groups and has a high boiling point, and is stable at a heating temperature of 80-90°C.

[0024] Furthermore, in step S2, the mass ratio of the cross-linked copolymer microsphere mixture, the acrylic monomer, and the second initiator is 1:30-50:0.3-2.5.

[0025] Another object of the present invention is a method for preparing a resin material for water quality testing, comprising the following steps:

[0026] The cross-linked carboxylic acid resin is ground into powder, mixed evenly with an alkali-resistant binder, a thickener and an auxiliary agent, and the mixture is extruded to form a columnar resin material.

[0027] Furthermore, the thickener is one or both of carboxymethyl cellulose and polyacrylamide. The thickener selected in this solution has a large molecular weight, good compatibility with the cross-linked carboxylic acid resin and the alkali-resistant binder, and good thickening effect.

[0028] Furthermore, the auxiliary agent is one or more of phosphate ester, fatty amide, and sodium dodecylbenzenesulfonate.

[0029] Furthermore, the weight content of the thickener is 0-15%.

[0030] Furthermore, the weight content of the auxiliary agent is 0-15%.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention uses an initiator to initiate free radical polymerization of a double-bond silane coupling agent and a double-bond and hydroxyl-containing monomer, and the hydroxyl groups on the molecular chain of the obtained copolymer undergo a cross-linking reaction with polyisocyanate to obtain highly cross-linked polymer microspheres. The highly cross-linked polymer microspheres are connected to polyacrylic acid via the N=C=O of the polyisocyanate to obtain a cross-linked carboxylic acid resin containing carboxyl groups on the surface. The cross-linked carboxylic acid resin has a high degree of cross-linking, is not easily dissolved in water, and has high stability.

[0033] (2) The present invention adds an alkali-resistant binder to the cross-linked carboxylic acid resin. The polarity of the alkali-resistant binder and the cross-linked carboxylic acid resin is similar, and the two have good compatibility. In addition, due to the movement and mutual diffusion of the chain segments of the two, there is also van der Waals attraction and hydrogen bonding force between the alkali-resistant binder and the cross-linked carboxylic acid resin. The two adsorb on each other, thereby enhancing the bonding force between the two, making the prepared columnar resin material less likely to dissolve in water, and further improving the stability of the prepared columnar resin material in water.

[0034] (3) The resin material prepared by the present invention utilizes an alkali-resistant binder to form a hollow columnar structure, which is conducive to full contact between the water sample and the resin material. At the same time, it can play a guiding role on the water sample, so that the water flow from the outside to the inside of the resin material has a low pressure drop and is uniform, thereby improving the accuracy and efficiency of the water sample alkalinity test. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A linear relationship fitting diagram was constructed for the resin material prepared in Example 4, which correlates the change in conductivity of the water sample with the alkalinity value.

[0036] Figure 2 A linear relationship fitting diagram was constructed for the resin material prepared in Example 5, which correlates the change in conductivity of the water sample with the alkalinity value.

[0037] Figure 3A linear relationship fitting diagram was constructed for the resin material prepared in Example 6, which correlates the change in conductivity of the water sample with the alkalinity value.

[0038] Figure 4 Construct a linear relationship fitting graph for Rohm and Haas Amberlite IRC76 regarding the correlation between the change in conductivity and alkalinity of water samples. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0040] Example 1

[0041] S1. Under nitrogen protection, polyvinyl alcohol (1g), 5mL water, and 40mL ethanol were mixed, and silane coupling agent KH570 (20g), hydroxyethyl methacrylate (20g), crosslinking agent PAPI (10g), and azobisisobutyronitrile (0.4g) were added. Stir and heat at 60°C for 1 hour to obtain a crosslinked copolymer microsphere mixture, which was set aside.

[0042] S2. Methacrylic acid (30 g) and benzoyl peroxide (0.3 g) were mixed, heated and stirred at 70°C, and the cross-linked copolymer microsphere mixture (1 g) obtained in step S1 was added and the reaction was continued for 1 hour. The mixture was washed with water / alcohol solvent, ground, and sieved to obtain a cross-linked carboxylic acid resin.

[0043] Example 2

[0044] S1. Under nitrogen protection, polyvinyl alcohol (1 g), 5 mL of water, and 40 mL of ethanol were mixed, and (4-vinylphenyl)trimethoxysilane (30 g), 2-methyl-2-propen-1-ol (30 g), a crosslinker PAPI (15 g), and azobisisoheptanenitrile (2 g) were added. The mixture was stirred and heated at 60°C for 1 hour to obtain a crosslinked copolymer microsphere mixture, which was set aside.

[0045] S2. Mix 2-(trifluoromethyl)acrylic acid (40 g) and benzoyl peroxide (1.5 g), heat and stir at 70°C to react, add the cross-linked copolymer microsphere mixture (1 g) prepared in step S1, continue the reaction for 1 hour, wash with water / alcohol solvent, grind, and sieve to obtain a cross-linked carboxylic acid resin.

[0046] Example 3

[0047] S1. Under nitrogen, polyvinyl pyrrolidone (1 g), 5 mL of water, and 40 mL of propanol were mixed, and silane coupling agent A172 (40 g), hydroxypolyethylene glycol methacrylate (40 g), crosslinker PAPI (20 g), and azobisisobutyronitrile (0.4 g) were added. The mixture was stirred and heated at 70°C for 1 hour to obtain a crosslinked copolymer microsphere mixture, which was set aside.

[0048] S2. Acrylic acid (50 g) and tert-butyl benzoyl peroxide (2.5 g) were mixed, heated and stirred at 90°C, and the cross-linked copolymer microsphere mixture (1 g) obtained in step S1 was added and the reaction was continued for 1 hour. The mixture was washed with water / alcohol solvent, ground, and sieved to obtain a cross-linked carboxylic acid resin.

[0049] Example 4

[0050] 60 g of the cross-linked carboxylic acid resin prepared in Example 1 was ground into powder, and uniformly mixed with 10 g of methyl cellulose, 15 g of carboxymethyl cellulose, and 15 g of phosphate ester. The mixture was extruded to obtain a columnar resin material for water quality testing.

[0051] Example 5

[0052] 80 g of the cross-linked carboxylic acid resin prepared in Example 2 was ground into powder, and uniformly mixed with 5 g of polyvinyl alcohol, 10 g of polyacrylamide, and 5 g of fatty amide. The mixture was extruded to obtain a columnar resin material for water quality testing.

[0053] Example 6

[0054] 99.9 g of the cross-linked carboxylic acid resin prepared in Example 3 was ground into powder, and mixed evenly with 0.1 g of polyethylene oxide. The mixture was extruded to obtain a columnar resin material for water quality testing.

[0055] Performance testing:

[0056] The resin material for water quality testing and Rohm and Haas Amberlite IRC76 prepared in Examples 4-6 were pre-treated as follows before use: a certain mass of the resin material for water quality testing and Rohm and Haas Amberlite IRC76 prepared in Examples 4-6 were respectively soaked in deionized water to remove the extracts from the resin material for water quality testing and Rohm and Haas Amberlite IRC76 prepared in Examples 4-6, and the soaking and stirring were continued. After about 12 hours, the resin material for water quality testing and Rohm and Haas Amberlite IRC76 prepared in Examples 4-6 were respectively removed, and the acidic resin was washed with a large amount of deionized water and dried for later use.

[0057] The resin materials for water quality testing prepared in Examples 4-6 were soaked in pure water and tap water for 24 hours, and the changes in conductivity were observed. The test results are shown in Table 1.

[0058] Table 1. Test results of the changes in the conductivity of water samples by the resin materials prepared in Examples 4-6.

[0059] Example Changes in conductivity of soaked pure water Changes in conductivity of soaked tap water Example 1 ＜10％ 39.3％ Example 2 ＜10％ 35.6％ Example 3 ＜10％ 39.1％

[0060] As can be seen from Table 1, when the resin materials for water quality testing prepared in Examples 4-6 of the present invention are soaked in pure water, the conductivity of the pure water changes by less than 10%, indicating that the resin materials for water quality testing prepared in Examples 4-6 of the present invention hardly contribute to the conductivity of the water body. When the resin materials for water quality testing prepared in Examples 4-6 of the present invention are soaked in tap water, the conductivity of the tap water changes significantly, indicating that the resin materials for water quality testing prepared in Examples 4-6 of the present invention can fully react with the water sample, causing a significant change in the conductivity of the water sample, and are suitable for detecting the alkalinity of the water sample.

[0061] Water sample alkalinity test:

[0062] S1. Using water samples with gradient alkalinity values ​​(as shown in Table 2) as gradient standards, the conductivity of each gradient standard was measured;

[0063] S2. Each gradient standard was mixed with the resin material for water quality testing prepared in Examples 4-6 or a commercially available acidic resin (Rohm and Haas Amberlite IRC76);

[0064] S3. Test the conductivity values ​​of each gradient standard;

[0065] S4. For the same standard, the conductivity value measured for the first time is T1, and the conductivity value measured for the second time is T2. The conductivity change values ​​(i.e., T1-T2) before and after the reaction of each gradient standard with the resin material for water quality testing prepared in Examples 4-6 or the commercially available acidic resin are collated. The mass of water used in this test is 80 g, the drained resin material for water quality testing prepared in Examples 4-6 is 15 g, and the drained Rohm and Haas Amberlite IRC76 is 20 g. The conductivity change value is the horizontal axis, and the alkalinity value of the water sample is the vertical axis. A linear relationship curve is fitted, as shown in FIG. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 shown.

[0066] Table 2. Data involved in establishing a linear relationship for the resin material for water quality testing prepared in Example 4.

[0067] Standards Initial alkalinity (mg / L) T1 / μs T1-T2 / μs Theoretical conductivity drop value / μs Relative error Tap water in place A 42 116.7 31.5 29.8 5.7％ Tap water at site B 125 476.8 178.4 180.7 1.3％ C tap water 97 324.1 136.8 129.8 5.4％ D tap water 204 701.5 312.8 324.4 3.6％ E tap water 158 598.5 229.8 240.7 4.5％ F tap water 172 646.3 269.5 266.2 1.2％ G tap water 276 823.8 471.2 455.3 3.5％ H tap water 71 219.4 88.7 82.5 7.5％ I local tap water 231 956.2 364.1 373.5 2.5％

[0068] From Table 2 and Figure 1 It can be found that when the resin material for water quality testing prepared in Example 4 is used to detect the alkalinity of water samples, the change value of the water sample conductivity has a strong linear relationship with the alkalinity of the water sample, indicating that the resin material for water quality testing prepared in Example 4 of the present invention can be used for testing the alkalinity of water samples. When used for testing the alkalinity of water samples, the relative error is below 7.5%.

[0069] Table 3. Data involved in establishing a linear relationship for the resin material for water quality testing prepared in Example 5.

[0070] Standards Initial alkalinity (mg / L) T1 / μs T1-T2 / μs Theoretical conductivity drop value / μs Relative error Tap water in place A 42 116.7 30.1 28.1 7.1％ Tap water at site B 125 476.8 175.8 180.2 2.4％ C tap water 97 324.1 130.5 128.9 1.2％ D tap water 204 701.5 327.5 325.0 0.8％ E tap water 158 598.5 239.5 240.7 0.5％ F tap water 172 646.3 261.7 266.3 1.7％ G tap water 276 823.8 469.3 457.0 2.3％ H tap water 71 219.4 87.2 81.2 7.4％ I local tap water 231 956.2 360.3 374.5 3.8％

[0071] From Table 3 and Figure 2 It can be found that when the resin material for water quality testing prepared in Example 5 is used to detect the alkalinity of water samples, the change value of the water sample conductivity has a strong linear relationship with the alkalinity of the water sample, indicating that the resin material for water quality testing prepared in Example 5 of the present invention can be used for testing the alkalinity of water samples with a relative error of less than 7.4%.

[0072] Table 4. Data involved in establishing a linear relationship for the resin material for water quality testing prepared in Example 6.

[0073] Standards Initial alkalinity (mg / L) T1 / μs T1-T2 / μs Theoretical conductivity drop value / μs Relative error Tap water in place A 42 116.7 31.2 29.4 6.1％ Tap water at site B 125 476.8 180.7 183.3 1.4％ C tap water 97 324.1 125.6 131.4 4.4％ D tap water 204 701.5 322.3 329.7 2.2％ E tap water 158 598.5 246.5 244.5 0.8％ F tap water 172 646.3 280.2 270.4 3.6％ G tap water 276 823.8 475.9 463.2 1.6％ H tap water 71 219.4 90.3 83.2 8.5％ I local tap water 231 956.2 362.1 379.8 4.7％

[0074] From Table 4 and Figure 3 It can be found that when the resin material for water quality testing prepared in Example 6 is used to detect the alkalinity of water samples, the change value of the water sample conductivity has a strong linear relationship with the alkalinity of the water sample, indicating that the resin material for water quality testing prepared in Example 6 of the present invention can be used for testing the alkalinity of water samples with a relative error of less than 8.5%.

[0075] Table 5. Data involved in constructing the linear relationship for Rohm and Haas Amberlite IRC76.

[0076] Standards Initial alkalinity (mg / L) T1 / μs T1-T2 / μs Theoretical conductivity drop value / μs Relative error Tap water in place A 42 116.7 57.6 43.5 32.4％ Tap water at site B 125 476.8 165.8 182.6 9.2％ C tap water 97 324.1 147.2 135.6 8.6％ D tap water 204 701.5 304.6 315.0 3.3％ E tap water 158 598.5 229.7 237.9 3.4％ F tap water 172 646.3 275.3 261.4 5.3％ G tap water 276 823.8 429.1 436.7 1.7％ H tap water 71 219.4 80.4 92.1 12.7％ I local tap water 231 956.2 374.3 360.2 3.9％

[0077] From Table 5 and Figure 4 It can be found that when Rohm and Haas Amberlite IRC76 is used to detect the alkalinity of water samples, the linear relationship between the change in conductivity of the water samples and the alkalinity of the water samples is weak, indicating that the error of Rohm and Haas Amberlite IRC76 when used to test the alkalinity of water samples is large, and the relative error can reach 32.4%.

[0078] In summary, the resin materials for water quality testing prepared in Examples 4-6 of the present invention have smaller relative errors when used for alkalinity testing of water samples than conventional weakly acidic resins (such as Rohm and Haas Amberlite IRC76).

[0079] Water sample alkalinity test:

[0080] The resin material for water quality detection prepared by using Examples 4-6 of the present invention and Rohm and Haas Amberlite IRC76 and the attached Figure 1-4 The alkalinity of the water sample is tested according to the linear relationship shown in the figure. The specific operation is as follows:

[0081] S1. Before testing the water sample, the conductivity of the test water was measured using a conductivity meter and recorded as C1. The resin materials for water quality testing prepared in Examples 4-6 and Rohm and Haas Amberlite IRC76 were then mixed with the test water and stirred for approximately 1.5 hours. The mass of the test water was 80 g, the drained resin materials for water quality testing prepared in Examples 4-6 were 15 g each, and the drained Rohm and Haas Amberlite IRC76 was 20 g. The conductivity of the water after stirring for 1.5 hours was measured and recorded as C2.

[0082] S2. Calculate the conductivity change value (i.e., C1-C2) before and after the water sample reacts with the resin material for water quality testing prepared in Examples 4-6 and Rohm and Haas Amberlite IRC76, and bring the calculated conductivity change values ​​into the attached Figure 1-4 The linear relationship is shown in Table 6.

[0083] Table 6. Application of attachments Figure 1-4 The linear relationship shown is used to calculate the alkalinity value of the water sample.

[0084]

[0085]

[0086] As can be seen from Table 6, when the weak acid substrates prepared in Examples 1-3 of the present invention are used to test the alkalinity of water samples, the relative errors of the measured alkalinity of the water samples are all less than 10%, while when commercially available acidic resins (such as Rohm and Haas Amberlite IRC76) are used to test the alkalinity of water samples, the relative errors of the measured alkalinity of the water samples are all greater than 10%.

[0087] In summary, when the weak acid substrates prepared in Examples 1-3 of the present invention are used for alkalinity testing of water samples, the relative error is small and the accuracy is high compared to commercially available acidic resins (such as Rohm and Haas Amberlite IRC76).

[0088] Comparison of water sample alkalinity test time:

[0089] The resin materials for water quality testing prepared in Examples 4-6 and Rohm and Haas Amberlite IRC76 were added to water samples respectively to react with the alkaline substances in the water samples, and the changes in conductivity over different time periods were observed. The specific operations are as follows:

[0090] Before the water sample test, the conductivity of the test water was measured using a conductivity meter, and the conductivity value T1 was recorded. The resin material for water quality testing prepared in Examples 4-6 was mixed with the test water and stirred for 0.5-1.5 hours, and Rohm and Haas Amberlite IRC76 was mixed with the test water and stirred for 0.5-2 hours. The conductivity values ​​T2 were recorded respectively. The conductivity change (T1-T2) before and after the reaction of the water sample with the resin material for water quality testing prepared in Examples 4-6 or Rohm and Haas Amberlite IRC76 was calculated. The mass of the test water was 80 g, the drained resin material for water quality testing prepared in Examples 4-6 was 15 g, and the drained Rohm and Haas Amberlite IRC76 was 20 g. The results are shown in Table 6.

[0091] Table 7. Changes in conductivity of water samples tested using the resin material prepared in the present invention and Rohm and Haas Amberlite IRC76.

[0092]

[0093]

[0094] As can be seen from Table 7, when the resin materials for water quality testing prepared in Examples 4-6 of the present invention are added to a water sample, the conductivity value no longer changes after 1 hour, indicating that the resin materials for water quality testing prepared in Examples 4-6 have completely reacted with the alkaline substances in the water sample after 1 hour. In contrast, the conductivity value of the commercially available weakly acidic resin (e.g., Rohm and Haas Amberlite IRC76) no longer changes after 1.5 hours, indicating that the commercially available weakly acidic resin (e.g., Rohm and Haas Amberlite IRC76) has completely reacted with the alkaline substances in the water sample after 1.5 hours. Therefore, compared with the commercially available weakly acidic resin (e.g., Rohm and Haas Amberlite IRC76), the resin materials for water quality testing prepared in Examples 4-6 of the present invention react faster with the alkaline substances in the water sample, and the time required for alkalinity testing of water samples is shorter, thereby reducing the reading time of the alkalinity test.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Ordinary technicians in the relevant field should understand that after reading the description of this application, they can still modify or replace the specific implementation methods of the present invention with equivalents, but these modifications or changes do not depart from the scope of protection of the pending claims of the present application.

Claims

1. A resin material for water quality testing, characterized in that: The resin material for water quality testing comprises 60-99.9% by weight of a cross-linked carboxylic acid resin and 0.1-10% by weight of an alkali-resistant binder; The preparation of the cross-linked carboxylic acid resin comprises the following steps: S1. Under nitrogen, the stabilizer and solvent were mixed, a double bond-containing silane coupling agent, a double bond-containing and hydroxyl monomer, a crosslinking agent and a first initiator were added, stirred, and heated to obtain a crosslinked copolymer microsphere mixture and set aside; S2. The acrylic monomer and the second initiator are mixed, the reaction is heated with stirring, the cross-linked copolymer microsphere mixture obtained in step S1 is added, the reaction is continued, and post-processing is performed to obtain a cross-linked carboxylic acid resin; The cross-linking agent is polyisocyanate.

2. The resin material for water quality testing according to claim 1, characterized in that: The cross-linked carboxylic acid resin is in granular or powdery form. The particle size of the granular resin is 0.5-5 mm, and the particle size of the powder resin is 100-1000 mesh.

3. The resin material for water quality testing according to claim 1, characterized in that: The alkali-resistant binder is one or more of polyethylene, polypropylene, polybutadiene, methyl cellulose, polyethylene oxide, hydroxypropyl methyl cellulose, polyvinyl alcohol, and polytetrafluoroethylene.

4. The resin material for water quality testing according to claim 1, characterized in that: In step S1, the stabilizer is one or both of polyvinyl alcohol and polyvinyl pyrrolidone; The solvent is a mixture of water and an alcohol solvent; The double bond-containing silane coupling agent is one of silane coupling agent KH-570, (4-vinylphenyl)trimethoxysilane, silane coupling agent A171, silane coupling agent A151, silane coupling agent A172, and (4-vinylphenyl)triethoxysilane; The monomer containing double bonds and hydroxyl groups is one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, 2-methyl-2-propene-1-ol, hydroxypropyl acrylate, hydroxypropyl methacrylate, allyl lactate, hydroxypolyethylene glycol methacrylate, and methoxypolypropylene glycol methacrylate; The first initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile.

5. The resin material for water quality testing according to claim 1, characterized in that: In step S2, the mass ratio of the stabilizer to the double bond-containing silane coupling agent, the double bond-containing and hydroxyl-containing monomer, the crosslinking agent, and the first initiator is 1:20-40:20-40:10-20:0.4-4.

6. The resin material for water quality testing according to claim 1, characterized in that: In step S2, the second initiator is at least one of benzoyl peroxide and tert-butyl benzoyl peroxide; The acrylic monomer is one or more of acrylic acid, methacrylic acid, 2-(trifluoromethyl)acrylic acid, cinnamic acid, maleic acid, and itaconic acid.

7. The resin material for water quality testing according to claim 1, characterized in that: In step S2, the mass ratio of the cross-linked copolymer microsphere mixture, the acrylic monomer, and the second initiator is 1:30-50:0.3-2.

5.

8. The method for preparing a resin material for water quality testing according to any one of claims 1 to 7, characterized in that: The steps include: The cross-linked carboxylic acid resin is ground into powder, mixed evenly with an alkali-resistant binder, a thickener and an auxiliary agent, and the mixture is extruded to form a columnar resin material.

9. The method for preparing a resin material for water quality testing according to claim 8, characterized in that: The thickener is one or both of carboxymethyl cellulose and polyacrylamide; The auxiliary agent is one or more of phosphate ester, fatty amide and sodium dodecylbenzene sulfonate.

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