Multifunctional slow-release scale-inhibiting and rust-preventing material suitable for high-salt-content water treatment and preparation method of multifunctional slow-release scale-inhibiting and rust-preventing material

Abstract

The invention belongs to the technical field of water treatment, and particularly relates to a multifunctional slow-release scale inhibiting and rust preventing material suitable for high-salt-content water treatment and a preparation method thereof.The preparation method comprises the following steps that S1, raw materials are prepared, specifically, a scale inhibitor, a rust inhibitor, a hydrophobic slow-release carrier polymer, a lubricating agent and a coupling agent are prepared; s2, modification treatment of a scale inhibitor: treating the scale inhibitor by adopting a coupling agent; s3, premixing: mixing a hydrophobic slow-release carrier polymer, the scale inhibitor treated in the step S2, the antirust agent and the lubricant to obtain a mixture; s4, injection molding: melting the mixture at high temperature, injecting into a template, and cooling and shaping to obtain the multifunctional slow-release scale inhibition material. According to the invention, by optimizing the structural design of the hydrophobic slow-release carrier and modifying the scale inhibitor, controllable slow release of the medicament is realized, the problem of rapid failure of the traditional medicament due to factors such as water flow scouring and temperature change is avoided, the medicament supplementing frequency is reduced, and the manpower and material cost for equipment maintenance is reduced.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment and its preparation method. Background Technology

[0002] With the increasing complexity of industrial water treatment needs, traditional scale inhibition technologies face problems such as insufficient long-term effectiveness and limited functionality. Especially in scenarios like circulating cooling water and reverse osmosis systems, equipment faces the dual threat of scaling and metal corrosion, making it difficult for a single scale inhibitor or corrosion inhibitor to meet the synergistic protection requirements. Polyethylene, due to its chemical inertness, ease of processing, and low cost, has become an ideal choice for a slow-release carrier. By integrating scale inhibitors and rust inhibitors into the PE matrix, long-lasting slow-release materials with both scale prevention and corrosion inhibition functions can be developed, reducing frequent dosing and maintenance costs, aligning with the trend of industrial water treatment towards higher efficiency and intelligence. However, the above technologies still have significant drawbacks: First, uncontrollable release: traditional agents are prone to rapid failure after addition due to water flow erosion or temperature changes, failing to achieve long-term slow release and requiring frequent replenishment, resulting in high maintenance costs; Second, limited functionality: most scale inhibitors only target scaling inhibition and lack simultaneous rust prevention, especially for high-salinity water sources, as salt increases water conductivity and promotes electrochemical corrosion.

[0003] Among the currently disclosed technologies, microcapsule encapsulation uses polymers such as PMMA to encapsulate scale inhibitors, improving their heat resistance and controlling the release rate. However, the carrier has poor compatibility with PE and is prone to breakage during processing, leading to burst release. Porous carrier loading involves preparing organic porous anionic microspheres through fine emulsion polymerization, loading cationic corrosion inhibitors, and utilizing electrostatic adsorption to achieve ion concentration-responsive release. However, the microspheres are unevenly dispersed in PE, and may fail due to swelling and breakage after long-term use. Development of environmentally friendly scale inhibitors: Although phosphorus-free scale inhibitors such as epoxy succinic acid, polyaspartic acid, and carboxylated carbon quantum dots are biodegradable, they are not adaptable to high-hardness water or high-temperature environments and are difficult to efficiently combine with rust-inhibiting components. Summary of the Invention

[0004] To address the problems mentioned in the background art, this invention proposes a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment and its preparation method. By optimizing the hydrophobic slow-release carrier structure design and modifying the scale inhibitor, the controlled slow release of the agent is achieved, avoiding the problem of rapid failure of traditional agents due to water flow erosion, temperature changes, and other factors. This reduces the frequency of agent replenishment and lowers the manpower and material costs of equipment maintenance.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for preparing a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment, comprising the following steps:

[0006] (1) Raw material preparation: Prepare scale inhibitors, rust inhibitors, hydrophobic slow-release carrier polymers, lubricants and coupling agents;

[0007] (2) Modification of scale inhibitor: The scale inhibitor is treated with a coupling agent to improve its compatibility with the hydrophobic slow-release carrier polymer;

[0008] (3) Premixing: The hydrophobic slow-release carrier polymer, the scale inhibitor, the rust inhibitor and the lubricant treated in step (2) are mixed to obtain a mixture;

[0009] (4) Injection molding: After the mixture is melted at high temperature, it is injected into the template, cooled and shaped to obtain a multifunctional slow-release scale inhibitor.

[0010] Furthermore, by mass percentage, the hydrophobic slow-release carrier polymer accounts for 75-85 wt%, the scale inhibitor accounts for 8-12 wt%, the rust inhibitor accounts for 5-8 wt%, the lubricant accounts for 0.5-1 wt%, the coupling agent accounts for 4-10%, and the balance is water.

[0011] Furthermore, the scale inhibitor includes phosphate scale inhibitors, carboxylic acid scale inhibitors, or lignin sulfonate scale inhibitors; phosphate scale inhibitors include FOF scale inhibitors.

[0012] Furthermore, the rust inhibitor includes sodium molybdate, sodium nitrite, sodium benzoate, or triethanolamine.

[0013] Furthermore, the hydrophobic slow-release carrier polymer includes polyethylene, polypropylene, or polyamide.

[0014] Furthermore, the lubricant includes zinc stearate, calcium stearate, paraffin wax, or polyethylene wax.

[0015] Further, in step (2), the coupling agent is titanate coupling agent NDZ-201; the amount of the coupling agent is 1-3% of the scale inhibitor mass, the treatment is carried out in a mixer, and the treatment time is 5-10 min; in step (4), the high temperature melting temperature is 180-200℃.

[0016] Furthermore, the particle size of the FOF scale inhibitor is ≤10μm; the particle size of the sodium molybdate rust inhibitor is ≤5μm; and the melt index of the polyethylene is 0.5-2.

[0017] The present invention also provides a multifunctional slow-release scale inhibitor and rust preventive material suitable for high salinity water treatment, comprising: by mass percentage, 75-85 wt% of hydrophobic slow-release carrier polymer, 8-12 wt% of scale inhibitor, 5-8 wt% of rust inhibitor, 0.5-1 wt% of lubricant, and 4-10% of coupling agent.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] (1) This invention achieves controlled and slow release of the agent by optimizing the design of the hydrophobic slow-release carrier structure and the modification treatment of the scale inhibitor, avoiding the problem of rapid failure of traditional agents due to water flow scouring, temperature changes and other factors, reducing the frequency of agent replenishment, and reducing the manpower and material costs of equipment maintenance.

[0020] (2) The technical solution of the present invention effectively addresses the problem of electrochemical corrosion of equipment caused by high conductivity in water with high salinity, as well as the problem of scale aggravation caused by salt precipitation effect, and achieves synergistic protection of scale inhibition and rust prevention, breaking the application limitations of traditional single-function agents.

[0021] (3) This invention is compatible with a variety of hydrophobic slow-release carrier polymers, scale inhibitors and rust inhibitors. The formula can be adjusted within the range of limited process parameters and raw material ratios according to the water characteristics and equipment materials required in the actual application scenario. At the same time, it ensures the stability of the material in a high salt content environment and has a wide range of applications. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] All raw materials used in this embodiment are industrial-grade conventional products, including:

[0024] The titanate coupling agent selected is NDZ-201 (industrial grade, purity ≥98%).

[0025] FOF scale inhibitor (industrial grade, particle size ≤10μm after air jet milling);

[0026] Sodium molybdate (industrial grade, particle size ground to ≤5μm);

[0027] Polyethylene (PE, industrial grade, melt index 0.5-2 g / 10 min, 230℃ / 2.16 kg).

[0028] Polypropylene (PP, industrial grade, melt index 1.0-3.0 g / 10 min, 230℃ / 2.16 kg);

[0029] Polyamide (PA6, industrial grade, melt index 2.0-4.0 g / 10 min, 230℃ / 2.16 kg);

[0030] Zinc stearate, calcium stearate (industrial grade, purity ≥99%);

[0031] Carboxylic acid scale inhibitors are selected from polyacrylic acid (PAA, molecular weight 3000-5000).

[0032] Lignosulfonates (industrial grade, sulfonation degree ≥85%)

[0033] Sodium nitrite (industrial grade, purity ≥99%).

[0034] Example 1: Preparation of a multifunctional slow-release scale-inhibiting and rust-preventing material using polyethylene as a carrier, FOF as a scale inhibitor, and sodium molybdate as a rust inhibitor.

[0035] S1. Raw material preparation;

[0036] Prepare the following raw materials by weight percentage: 80wt% polyethylene (PE) (melt index 1.0g / 10min), 10wt% FOF scale inhibitor (particle size 8μm), 6wt% sodium molybdate (particle size 3μm), 0.8wt% zinc stearate, 3.2wt% titanate coupling agent NDZ-201, and the balance is deionized water (to bring the total to 100wt%). The FOF scale inhibitor and sodium molybdate are separately treated by air jet milling and grinding to ensure the particle size meets the requirements and to prevent agglomeration during subsequent mixing.

[0037] S2, scale inhibitor modification treatment;

[0038] Add the prepared FOF scale inhibitor to a high-speed mixer, turn on the stirrer, and set the speed to 1500 r / min. Slowly add NDZ-201 titanate coupling agent (0.2 wt%), which accounts for 2% of the FOF mass. Based on the total raw material mass, maintain the temperature at 25°C and continue mixing for 8 minutes to complete the surface modification of the FOF and improve its compatibility with the hydrophobic polyethylene carrier.

[0039] S3, premixed;

[0040] In the aforementioned high-speed mixer, polyethylene, sodium molybdate, zinc stearate, and the remaining titanate coupling agent (3.0 wt%, based on the total raw material mass) were added sequentially. The stirring speed was adjusted to 2000 r / min, the mixing temperature was 30℃, and the mixture was continuously mixed for 15 min to obtain a uniformly dispersed mixture. During the process, samples were taken for observation to ensure that the mixture had no obvious particle agglomeration and a uniform color.

[0041] S4, Injection molding;

[0042] The premixed material was added to the injection molding machine (model HTF86X1). The barrel temperature was set as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, mold temperature 40℃, injection pressure 80MPa, holding time 5s, and melting time approximately 5min. The melting time was determined by observing the melt state. After the mixture was completely melted, it was injected into a custom cylindrical mold with a diameter of 20mm and a height of 50mm. It was allowed to cool naturally to room temperature for approximately 20min. After demolding, the multifunctional slow-release scale inhibitor sample 1 was obtained.

[0043] This embodiment uses polyethylene as a carrier to synergistically load an organophosphate scale inhibitor and a sodium molybdate rust inhibitor, achieving a two-component controlled slow-release effect. Its core objective is to simultaneously address the problems of accelerated electrochemical corrosion and increased scaling caused by high salinity: sodium molybdate forms a passivation film on the metal surface to inhibit Cl⁻ corrosion, FOF interferes with scale crystal growth, and the hydrophobic carrier resists salt ion impacts, enabling the material to maintain long-term protection in flowing high-salt water, effectively reducing maintenance costs.

[0044] Example 2: Preparation of a multifunctional slow-release scale-inhibiting and rust-preventing material using polypropylene as a carrier, carboxylic acid (PAA) as a scale inhibitor, and sodium nitrite as a rust inhibitor.

[0045] S1. Raw material preparation;

[0046] Prepare the following raw materials by weight percentage: 78wt% polypropylene (PP) (melt index 2.0g / 10min), 11wt% polyacrylic acid (PAA) (scale inhibitor), 7wt% sodium nitrite (rust inhibitor), 0.9wt% calcium stearate, 3.1wt% titanate coupling agent NDZ-201, and the balance is deionized water (to bring the total to 100wt%).

[0047] S2, scale inhibitor modification treatment;

[0048] Add the PAA scale inhibitor to a high-speed mixer (1400 r / min), and add NDZ-201 titanate coupling agent (0.165 wt%, based on the total raw material mass) at 1.5% of the PAA mass. Mix at 25°C for 6 min to complete the PAA modification and improve its interfacial bonding with the PP carrier.

[0049] S3, premixed;

[0050] PP, sodium nitrite, calcium stearate and the remaining coupling agent (2.935 wt% based on the total raw material mass) were added to a high-speed mixer and mixed at 1900 r / min and 30°C for 12 min to obtain a uniform mixture.

[0051] S4, Injection molding;

[0052] Injection molding machine barrel temperature: Zone 1 185℃, Zone 2 195℃, Zone 3 200℃, mold temperature 45℃, injection pressure 85MPa, holding time 6s; after the mixture is melted, it is injected into the mold of the same example 1, cooled to room temperature and then demolded to obtain sample 2.

[0053] Example 3: Preparation of a multifunctional slow-release scale inhibitor and rust inhibitor material using polyamide as a carrier, lignin sulfonate as a scale inhibitor, and sodium benzoate as a rust inhibitor.

[0054] S1. Raw material preparation;

[0055] Prepare the following raw materials by mass percentage: 82wt% polyamide (PA6) (melt index 3.0g / 10min), 8wt% lignosulfonate (scale inhibitor), 5wt% sodium benzoate (rust inhibitor), 0.6wt% zinc stearate, 4.4wt% titanate coupling agent NDZ-201, and the balance is deionized water (to bring the total to 100wt%).

[0056] S2, scale inhibitor modification treatment;

[0057] Lignosulfonate was added to a high-speed mixer (1600 r / min), and titanate coupling agent NDZ-201 (0.24 wt% of total raw material mass) was added dropwise at 3% of its mass. The mixture was then mixed at 25°C for 10 min to complete the modification.

[0058] S3, premixed;

[0059] PA6, sodium benzoate, zinc stearate and the remaining coupling agent (4.16 wt% based on the total raw material mass) were added, and the mixture was stirred at 2100 r / min and 30°C for 18 min to obtain a uniform mixture.

[0060] S4, Injection molding;

[0061] Injection molding machine barrel temperature: Zone 1 190℃, Zone 2 200℃, Zone 3 205℃ (suitable for PA6 melting requirements), mold temperature 50℃, injection pressure 90MPa, holding time 7s; after melting, it is injected into the mold, cooled and demolded to obtain sample 3.

[0062] The samples obtained in Examples 1-3 were subjected to performance tests.

[0063] The performance testing methods refer to the following standards:

[0064] Scale inhibition rate: According to GB / T16632-2008 "Determination of Scale Inhibition Performance of Water Treatment Agents - Calcium Carbonate Deposition Method", the test water was simulated high-salinity water (NaCl concentration 5000 mg / L, Ca...). 2+ Concentration 800 mg / L, Mg 2+(Concentration 400 mg / L, temperature 40℃, standing for 72 h)

[0065] Corrosion rate: According to GB / T18175-2014 Determination of corrosion inhibition performance of water treatment agents by rotating plate method, the test material is 20# carbon steel plate, simulating high salinity water (same as scale inhibition rate test), temperature 40℃, rotation speed 150r / min, test cycle 30 days;

[0066] Slow-release cycle: By continuously monitoring the concentration changes of scale inhibitors and rust inhibitors (such as sodium molybdate) in the water, the slow-release cycle is determined to end when the concentration of the agent drops to the effective protection threshold (scale inhibitor ≥ 5 mg / L, rust inhibitor ≥ 3 mg / L).

[0067] Table 1 shows the performance test results of Sample 1, Sample 2 and Sample 3.

[0068]

[0069] The three embodiments described above employed different combinations of hydrophobic slow-release carrier polymers, scale inhibitors, and rust inhibitors. All were prepared using a process of "scale inhibitor modification - premixing - injection molding" to obtain multifunctional slow-release scale inhibitor materials. Test results showed that all samples exhibited excellent scale inhibition and rust prevention performance in high-salinity water (NaCl concentration 5000 mg / L), with scale inhibition rates ≥87.8% and corrosion rates ≤0.028 mm / a. Furthermore, the slow-release period was as long as 52-60 days, superior to the traditional "single-dose" treatment method.

[0070] This invention uses the titanate coupling agent NDZ-201 to surface-modify the scale inhibitor, solving the compatibility problem between polar scale inhibitors and non-polar hydrophobic carriers and avoiding agent agglomeration or "sudden release". At the same time, the dense structure of the hydrophobic carrier (PE / PP / PA6) can resist the osmotic impact of high salt ions, realizing the slow release of the agent. The synergistic loading of scale inhibitor and rust inhibitor simultaneously solves the dual problems of scaling and corrosion in high saline water, reducing the operation and maintenance costs of industrial water treatment.

[0071] Those skilled in the art can fine-tune the types of raw materials or parameters within the range of the raw material ratio (75-85wt% hydrophobic carrier, 8-12wt% scale inhibitor, 5-8wt% rust inhibitor, 0.5-1wt% lubricant, 4-10% coupling agent) and process parameters (modification time 5-10min, melting temperature 180-200℃) defined in this invention, according to the actual application scenario (such as water salinity, temperature, and equipment material), and achieve the technical effects of this invention.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment, characterized in that, Includes the following steps: S1. Raw material preparation: Prepare scale inhibitors, rust inhibitors, hydrophobic slow-release carrier polymers, lubricants, and coupling agents; S2. Scale inhibitor modification treatment: The scale inhibitor is treated with a coupling agent; S3. Premixing: Mix the hydrophobic slow-release carrier polymer, the scale inhibitor, rust inhibitor and lubricant treated in step S2 to obtain a mixture; S4. Injection molding: After the mixture is melted at high temperature, it is injected into a mold, cooled and shaped to obtain a multifunctional slow-release scale inhibitor material; Of which, by mass percentage, the hydrophobic slow-release carrier polymer accounts for 75-85 wt%, the scale inhibitor accounts for 8-12 wt%, the rust inhibitor accounts for 5-8 wt%, the lubricant accounts for 0.5-1 wt%, the coupling agent accounts for 4-10%, and the balance is water.

2. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 2, characterized in that, The scale inhibitors include phosphate scale inhibitors, carboxylic acid scale inhibitors, or lignin sulfonate scale inhibitors; phosphate scale inhibitors include FOF scale inhibitors.

3. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 3, characterized in that, The rust inhibitor includes sodium molybdate, sodium nitrite, sodium benzoate, or triethanolamine.

4. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 4, characterized in that, The hydrophobic slow-release carrier polymer includes polyethylene, polypropylene, or polyamide.

5. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 5, characterized in that, The lubricant includes zinc stearate, calcium stearate, paraffin wax, or polyethylene wax.

6. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 1, characterized in that, In S2, the coupling agent is titanate coupling agent NDZ-201; the amount of the coupling agent is 1-3% of the scale inhibitor mass, the treatment is carried out in a mixer, and the treatment time is 5-10 min; in S4, the high-temperature melting temperature is 180-200℃.

7. The preparation method of a multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment according to claim 6, characterized in that, The particle size of the FOF scale inhibitor is ≤10μm; the particle size of the sodium molybdate rust inhibitor is ≤5μm; and the melt index of the polyethylene is 0.5-2.

8. A multifunctional slow-release scale inhibitor and rust preventive material suitable for high-salinity water treatment, characterized in that, include: By mass percentage, the hydrophobic slow-release carrier polymer accounts for 75-85 wt%, the scale inhibitor accounts for 8-12 wt%, the rust inhibitor accounts for 5-8 wt%, the lubricant accounts for 0.5-1 wt%, and the coupling agent accounts for 4-10%.

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