CN105536742B - A kind of sewage disposal screen cloth and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of sewage disposal screen cloth, it is characterised in that it is obtained by tricot machine 3 D weaving, and the thickness of screen cloth is 10~50mm, and sewage disposal is more than 1800mms with screen cloth permeable amount^‑1, bursting strength is more than 2000N.Using screen cloth structure, in sewage disposal process, the warp thread on vertical direction can be good at being contacted with the heavy metal in sewage, avoid conventional fabrics due to being reduced caused by overlay structure with waste water surface, the problem of causing adsorption effect to weaken.

Description

Mesh cloth for sewage treatment and preparation method thereof

technical field

The invention relates to the technical field of sewage production, in particular to a mesh cloth for sewage treatment and a preparation method thereof.

Background technique

With the continuous progress of society and the rapid development of industry, the pollution caused by the discharge of heavy metal wastewater has posed a serious threat to the ecosystem and public health. Heavy metals in water have become one of the most serious environmental problems in my country. Therefore, heavy metal wastewater Governance has been highly valued by researchers at home and abroad. In order to more effectively prevent and control heavy metal pollution in water bodies, our country has introduced a number of legal systems for the treatment of heavy metals in water. At present, the treatment methods of heavy metal wastewater mainly include chemical precipitation, ion exchange, solvent extraction, chemical redox and adsorption methods, etc. Among them, the adsorption method has the advantages of easy operation, low energy consumption, low residue, high adsorption capacity and reusability. One of the most economical, efficient, widely used and well-studied technologies. At present, a variety of adsorbents including activated carbon, chitosan, natural zeolite, biosorbent, chelating resin, etc. have been widely used in the treatment of heavy metal wastewater. The adsorption capacity of these adsorbents mainly depends on their own Physical properties and surface functional groups.

Compared with traditional resins, foams, and traditional fibers, polymer fibers are increasingly used in heavy metal wastewater treatment due to their advantages such as high specific surface area, high porosity, easy preparation, and easy physical/chemical modification. At present, the fiber materials used for heavy metal adsorption are mainly materials containing multifunctional groups such as hydroxyl and amino groups, such as cellulose, polyacrylonitrile, and polyimide; and for traditional fiber materials, due to their preparation process through Spinning and then weaving to prepare membranes or fabrics can be applied to the treatment of heavy metals in water bodies. The spinning and weaving process is complicated and there are many processes. Therefore, it is of great significance to develop a fluffy material preparation technology that can realize the integration of material shape and function, and apply it to the adsorption of heavy metals for rapid response to water pollution and rapid treatment of emergency situations.

The mesh material has an excellent three-dimensional organizational structure, which is beneficial to the filtration of sewage and also facilitates the filtration of silt. At present, there are many studies on the use of mesh for sewage, but they mainly focus on the development of fiber preparation mesh with low latitude. cloth to improve the specific surface area of the fiber itself; the present invention uses a hyperbranched polymer with 30 phosphonic acid end groups as a modifying agent, and prepares a mesh cloth for sewage treatment through the weaving method of the mesh cloth, which has excellent adsorption performance, and the sewage High processing efficiency, recyclable.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a mesh cloth for sewage treatment and a preparation method thereof.

The purpose of the present invention is achieved through the following technical solutions:

A mesh cloth for sewage treatment, characterized in that it is obtained by three-dimensional weaving by a warp knitting machine, the thickness of the mesh cloth is 10-50mm, the water permeability of the mesh cloth for sewage treatment is greater than 1800mm·s ^-1 , and the bursting strength is greater than 2000N.

A kind of preparation method of mesh cloth for sewage treatment is characterized in that, its specific steps are:

(1) Preparation of phosphonic acid-terminated hyperbranched dendrimers

The structural formula of phosphonic acid terminal hyperbranched dendrimers is as shown in Figure 1:

The application of the phosphonic acid terminal hyperbranched dendritic polymer is mainly applied to the adsorption treatment of heavy metal ions in water;

Passivating agent with high algebra, due to the high content of phosphonic acid groups in the molecule, it has a strong chelation effect with heavy metal ions, and the chelation number of a single molecule of metal ions is large, and the formed chelating group has a large molecular space volume, so it is acid-resistant Good alkali stability and good migration resistance, especially in the process of chelation, due to the dendritic structure, it has very excellent ion barrier effect and filter ion effect on heavy metals in the molecule, so the more dendritic structures are designed and the more The stronger the phosphonic acid chelating group, the stronger the chelating effect, and the stronger the acid and alkali resistance stability, so the present invention has 30 phosphonic acid groups, and has 3 main branches, 9 twigs of phosphonic acid end groups The repair effect of hyperbranched dendrimers on heavy metals is obvious due to conventional metal passivation repair agents;

(a) Preparation of terminal double bond star polymer

Using trimethylolpropane triacrylate TMPTA and aminotriphenylamine as raw materials, methanol as a solvent, in a reaction device with stirring and condensing reflux, under the protection of nitrogen, the temperature of the reaction system is controlled at -10 ~ 5 ° C, first Divide the methanol solution of aminotriphenylamine into three equal parts, then add the methanol solution of aminotriphenylamine dropwise in batches to the methanol solution of trimethylolpropane triacrylate TMPTA, and add the methanol solution of aminotriphenylamine dropwise for the first time When adding the solution, the temperature of the dropping process is controlled to be -10~-5°C, and the dropping time is 30~60 minutes. When the methanol solution of aminotriphenylamine is added dropwise for the second time, the temperature of the dropping process is controlled to be -5~0°C , the dropping time is 30-45min, when the methanol solution of aminotriphenylamine is added dropwise for the third time, the temperature of the dropping process is controlled to be 0-5°C, the dropping time is 20-30min, and the dropwise addition of aminotriphenylamine After methanol solution, the reaction system was moved to a temperature of 25°C for 4-10 hours. After the methanol solution of aminotriphenylamine has been added dropwise, the reaction system is moved to 25°C, and the reaction is continued for 10 to 20 hours; after the reaction is completed, a golden yellow product will precipitate in the system, filter and wash with methanol, and the light golden yellow product is in the Vacuum drying at 40°C to obtain a golden-yellow terminal double bond star polymer, the chemical reaction equation for the preparation of the terminal double bond star polymer is shown in Figure 2:

The molar ratio of described trimethylolpropane triacrylate TMPTA and aminotriphenylamine is 1:0.25～0.30;

The mole fraction of the trimethylolpropane triacrylate methanol solution is 0.25～1.25mol/L;

The mole fraction of the methanol solution of aminotriphenylamine is 0.10-1.50mol/L;

(b) Synthesis of amine-terminated star dendrimers

In the reactor with stirring and reflux condenser, the reaction temperature is controlled at 0-5°C, under the condition of nitrogen protection and stirring, the methanol solution of ethylenediamine is added first, and then the terminal bismuth prepared in step (a) is Add the bonded star polymer, stir, and mix well; then react at 25°C for 20-30 hours, and then distill under reduced pressure at 80-100°C for 3-5 hours to remove methanol and excess ethylenediamine to obtain yellow viscous Thick product, namely amine-terminated star-shaped dendrimers;

The mole fraction of ethylenediamine in the ethylenediamine methanol solution is 0.5-5.0mol/L;

The molar ratio of the star-end double bond dendrimer to ethylenediamine is 1:10～12;

Ethylenediamine compounds have wide sources, low cost, mild chemical reaction in the preparation process, and controllable preparation process, so the cost in the preparation process is low, which is conducive to industrial production and large-scale promotion, and has a very large cost advantage for improving the marketization of products .

(c) Synthesis of phosphonic acid-terminated hyperbranched dendrimers

Add phosphorous acid into concentrated hydrochloric acid and mix evenly, control the concentration of phosphorous acid in concentrated hydrochloric acid to be 0.25-1.25mol/L, concentrated hydrochloric acid is 10-12mol/L hydrochloric acid solution, and then add dropwise at 0-10°C The aqueous solution of the amine-terminated star-shaped dendrimer prepared in step (b), the aqueous solution mass fraction of the amine-terminated star-shaped dendrimer is 20 to 45%, and the aqueous solution of the amine-terminated star-shaped dendrimer is added dropwise The process is completed dropwise within 30 minutes; then, under the condition of stirring at 85-90°C, formaldehyde solution is added dropwise. 105-110°C, reflux for 2-4 hours, after the reflux, close the reflux device, open the HCl absorption bottle, concentrate the reaction mixture, the concentration temperature is 105-110°C, concentrate until no HCl is released, cool to room temperature, and obtain the solid content It is an aqueous solution of 25% to 55% light yellow transparent liquid phosphonic acid terminal hyperbranched dendritic polymer;

Solid content is the mass percent of phosphonic acid end group hyperbranched dendritic polymer in aqueous solution;

(2) Preparation of modified PVA fiber

Use 1799 type PVA particles as raw material, use water as solvent, dissolve at 90-98°C, control the mass fraction of PVA spinning solution to 15-20%, and then add the phosphonic acid synthesized in the above step (1) The end-group hyperbranched dendritic polymer is dissolved and wet-spun, and the aqueous solution of sodium sulfate is used as the coagulation liquid, and the modified PVA fiber is prepared by coagulating the coagulation liquid, stretching and winding;

The wet spinning speed is 0.5-10m/min, and the spinning liquid temperature is 25-35°C; the coagulation process uses two coagulations, and the coagulation liquid concentration in the first coagulation process is 1.0-1.5g/L , the coagulation temperature in the first coagulation process is 40-50°C, the fiber residence time in the first coagulation process is 12-18s; the coagulation liquid concentration in the second coagulation process is 0.9-1.3g/L, The solidification temperature in the process is 85-95°C, and the residence time in the second solidification process is 10-15s; the stretching process is divided into the first wet stretching process, the second dry stretching process, and the first wet stretching process. During the stretching process, the stretching ratio is 0.5-1.0 times, and the stretching temperature is 120-150°C. In the second dry stretching process, the stretching ratio is 1.5-2.0 times, and the stretching temperature is 180-230°C;

PVA fiber has excellent water swelling properties, which is conducive to the contact of phosphonic acid-terminated hyperbranched dendrimers with heavy metal ions, thereby improving the adsorption of heavy metal ions by mesh cloth. At the same time, in the wet spinning process, Since the PVA fiber forms a large number of micropores during the solidification process, the depressions and micropores on the fiber surface are improved, thereby improving the contact surface of the phosphonic acid-terminated hyperbranched dendritic polymer with the heavy metals in the sewage, and improving the adsorption of the mesh. .

(3) Preparation of mesh cloth for sewage treatment

The sample is produced on the KARL MAYER RD6DPLM double-needle bed warp knitting machine imported from Germany, and the required mesh for sewage treatment is prepared through three steps of warping, weaving and finishing; the warping tension is controlled during the warping process It is 0.08～0.18g/den, and the warp yarn, weft yarn and binding yarn are made into mesh during the weaving process. The warp yarn is in a vertical structure, and the weft yarn is in a horizontal structure. 300-450 yarns/cm, the weft yarn density is 300-450 yarns/cm, the binding yarn density is 500-600 yarns/cm, the warp is modified PVA fiber, and the weft is polyester monofilament, The binding yarn is modified PVA fiber;

Compared with prior art, positive effect of the present invention is:

With the mesh structure, during the sewage treatment process, the warp yarns in the vertical direction can be well in contact with the heavy metals in the sewage, avoiding the problem of the reduction of the contact surface with the sewage caused by the overlapping structure of the traditional fabric, resulting in the weakening of the adsorption effect. ;

The invention discloses a mesh cloth for sewage treatment and a preparation method thereof. The mesh structure is adopted. During the sewage treatment process, the warp yarns in the vertical direction can be used to make good contact with the heavy metals in the sewage, and the traditional fabrics are avoided due to overlapping. The reduction of the contact surface with the sewage caused by the structure leads to the problem of weakening the adsorption effect; using a hyperbranched dendritic polymer with 30 terminal phosphonic acid groups as a modifier for PVA fibers, utilizing the excellent water swelling properties of PVA, and PVA fibers A large number of micropores are formed during the wet spinning solidification process, and the depressions and micropores on the surface of the fiber are improved, thereby improving the contact surface of the phosphonic acid-terminated hyperbranched dendrimer and the heavy metal in the sewage, and improving the adsorption of the mesh Function, through the wet spinning method, the steric hindrance of hyperbranched polymer macromolecules and the hydrogen bond interaction between molecules are used to fix the phosphonic acid terminal hyperbranched dendrimers, avoiding the migration of modifiers, and due to the spherical shape The rolling effect of phosphonic acid-terminated hyperbranched dendrimers in the spinning high-stretching process migrates to the surface of the fiber, reducing the contact resistance between phosphonic acid-terminated hyperbranched dendrimers and heavy metal ions in water, which is conducive to the formation of A more stable chelating compound can improve the sewage treatment performance of the mesh cloth; it has broad application prospects for the treatment of heavy metal ions in water and other fields.

Description of drawings

Fig. 1 is the structural formula of phosphonic acid end group hyperbranched dendrimers;

Fig. 2 is the chemical reaction equation of the preparation of terminal double bond star polymer;

Fig. 3 is the preparation chemical reaction equation of amine-terminated star dendrimer;

Fig. 4 is the chemical reaction equation that phosphonic acid end group hyperbranched dendrimers prepare;

The proton nuclear magnetic resonance (1H NMR) spectrum of Fig. 5 terminal double bond star polymer of the present invention;

The proton nuclear magnetic resonance (1H NMR) spectrum of Fig. 6 amine-terminated star dendrimer of the present invention;

The hydrogen nuclear magnetic resonance (1H NMR) spectrum of Fig. 7 phosphonic acid end group hyperbranched dendrimers of the present invention;

detailed description

The specific embodiments of the mesh cloth for sewage treatment and the preparation method thereof of the present invention are provided below.

Example 1

A mesh cloth for sewage treatment, characterized in that it is obtained by three-dimensional weaving by a warp knitting machine, the thickness of the mesh cloth is 10mm, the water permeability of the mesh cloth for sewage treatment is greater than 1800mm·s ^-1 , and the bursting strength is greater than 2000N.

A kind of preparation method of mesh cloth for sewage treatment is characterized in that, its specific steps are:

(1) Preparation of phosphonic acid-terminated hyperbranched dendrimers

The structural formula of phosphonic acid terminal hyperbranched dendrimers is as shown in Figure 1:

The application of the phosphonic acid terminal hyperbranched dendritic polymer is mainly applied to the adsorption treatment of heavy metal ions in water;

Passivating agent with high algebra, due to the high content of phosphonic acid groups in the molecule, it has a strong chelation effect with heavy metal ions, and the chelation number of a single molecule of metal ions is large, and the formed chelating group has a large molecular space volume, so it is acid-resistant Good alkali stability and good migration resistance, especially in the process of chelation, due to the dendritic structure, it has very excellent ion barrier effect and filter ion effect on heavy metals in the molecule, so the more dendritic structures are designed and the more The stronger the phosphonic acid chelating group, the stronger the chelating effect, and the stronger the acid and alkali resistance stability, so the present invention has 30 phosphonic acid groups, and has 3 main branches, 9 twigs of phosphonic acid end groups The repair effect of hyperbranched dendrimers on heavy metals is obvious due to conventional metal passivation repair agents;

(a) Preparation of terminal double bond star polymer

Using trimethylolpropane triacrylate TMPTA and aminotriphenylamine as raw materials, methanol as a solvent, in a reaction device with stirring and condensing reflux, under the protection of nitrogen, the temperature of the reaction system is controlled at -10 ~ 5 ° C, first Divide the methanol solution of aminotriphenylamine into three equal parts, then add the methanol solution of aminotriphenylamine dropwise in batches to the methanol solution of trimethylolpropane triacrylate TMPTA, and add the methanol solution of aminotriphenylamine dropwise for the first time When adding the solution, the temperature of the dropping process is controlled to be -10~-5°C, and the dropping time is 30~60 minutes. When the methanol solution of aminotriphenylamine is added dropwise for the second time, the temperature of the dropping process is controlled to be -5~0°C , the dropping time is 30-45min, when the methanol solution of aminotriphenylamine is added dropwise for the third time, the temperature of the dropping process is controlled to be 0-5°C, the dropping time is 20-30min, and the dropwise addition of aminotriphenylamine After methanol solution, the reaction system was moved to a temperature of 25°C for 4-10 hours. After the methanol solution of aminotriphenylamine has been added dropwise, the reaction system is moved to 25°C, and the reaction is continued for 10 to 20 hours; after the reaction is completed, a golden yellow product will precipitate in the system, filter and wash with methanol, and the light golden yellow product is in the Vacuum drying at 40°C to obtain a golden-yellow terminal double bond star polymer, the chemical reaction equation for the preparation of the terminal double bond star polymer is shown in Figure 2:

The molar ratio of described trimethylolpropane triacrylate TMPTA and aminotriphenylamine is 1:0.25;

The mole fraction of described trimethylolpropane triacrylate methanol solution is 0.25mol/L;

The mole fraction of the methanol solution of the aminotriphenylamine is 0.10mol/L;

(b) Synthesis of amine-terminated star dendrimers

In the reactor with stirring and reflux condenser, the reaction temperature is controlled at 0-5°C, under the condition of nitrogen protection and stirring, the methanol solution of ethylenediamine is added first, and then the terminal bismuth prepared in step (a) is Add the bonded star polymer, stir, and mix well; then react at 25°C for 20-30 hours, and then distill under reduced pressure at 80-100°C for 3-5 hours to remove methanol and excess ethylenediamine to obtain yellow viscous Thick product is the amine-terminated star-shaped dendrimer; the chemical reaction equation for the preparation of the amine-terminated star-shaped dendrimer is as shown in Figure 3:

The mole fraction of ethylenediamine in the described ethylenediamine methanol solution is 0.5mol/L;

The molar ratio of described star-end double bond dendritic polymer and ethylenediamine is 1:10;

Ethylenediamine compounds have wide sources, low cost, mild chemical reaction in the preparation process, and controllable preparation process, so the cost in the preparation process is low, which is conducive to industrial production and large-scale promotion, and has a very large cost advantage for improving the marketization of products .

(c) Synthesis of phosphonic acid-terminated hyperbranched dendrimers

Add phosphorous acid into concentrated hydrochloric acid and mix evenly, control the concentration of phosphorous acid in concentrated hydrochloric acid to be 0.25-1.25mol/L, concentrated hydrochloric acid is 10-12mol/L hydrochloric acid solution, and then add dropwise at 0-10°C The aqueous solution of the amine-terminated star-shaped dendrimer prepared in step (b), the aqueous solution mass fraction of the amine-terminated star-shaped dendrimer is 20 to 45%, and the aqueous solution of the amine-terminated star-shaped dendrimer is added dropwise The process is completed dropwise within 30 minutes; then, under the condition of stirring at 85-90°C, formaldehyde solution is added dropwise. 105-110°C, reflux for 2-4 hours, after the reflux, close the reflux device, open the HCl absorption bottle, concentrate the reaction mixture, the concentration temperature is 105-110°C, concentrate until no HCl is released, cool to room temperature, and obtain the solid content Be the aqueous solution of the phosphonic acid terminal hyperbranched dendritic polymer of 25～55% light yellow transparent liquid; The chemical reaction equation of the preparation of phosphonic acid terminal hyperbranched dendritic polymer is as shown in Figure 4:

(2) Preparation of modified PVA fiber

Use 1799 type PVA particles as raw material, use water as solvent, dissolve at 90-98°C, control the mass fraction of PVA spinning solution to 15-20%, and then add the phosphonic acid synthesized in the above step (1) The end-group hyperbranched dendritic polymer is dissolved and wet-spun, and the aqueous solution of sodium sulfate is used as the coagulation liquid, and the modified PVA fiber is prepared by coagulating the coagulation liquid, stretching and winding;

The wet spinning speed is 0.5-10m/min, and the spinning liquid temperature is 25-35°C; the coagulation process uses two coagulations, and the coagulation liquid concentration in the first coagulation process is 1.0-1.5g/L , the coagulation temperature in the first coagulation process is 40-50°C, the fiber residence time in the first coagulation process is 12-18s; the coagulation liquid concentration in the second coagulation process is 0.9-1.3g/L, The solidification temperature in the process is 85-95°C, and the residence time in the second solidification process is 10-15s; the stretching process is divided into the first wet stretching process, the second dry stretching process, and the first wet stretching process. During the stretching process, the stretching ratio is 0.5-1.0 times, and the stretching temperature is 120-150°C. In the second dry stretching process, the stretching ratio is 1.5-2.0 times, and the stretching temperature is 180-230°C;

PVA fiber has excellent water swelling properties, which is conducive to the contact of phosphonic acid-terminated hyperbranched dendrimers with heavy metal ions, thereby improving the adsorption of heavy metal ions by mesh cloth. At the same time, in the wet spinning process, Since the PVA fiber forms a large number of micropores during the solidification process, the depressions and micropores on the fiber surface are improved, thereby improving the contact surface of the phosphonic acid-terminated hyperbranched dendritic polymer with the heavy metals in the sewage, and improving the adsorption of the mesh. .

(3) Preparation of mesh cloth for sewage treatment

The sample is produced on the KARL MAYER RD6DPLM double-needle bed warp knitting machine imported from Germany, and the required mesh for sewage treatment is prepared through three steps of warping, weaving and finishing; the warping tension is controlled during the warping process It is 0.08～0.18g/den, and the warp yarn, weft yarn and binding yarn are made into mesh during the weaving process. The warp yarn is in a vertical structure, and the weft yarn is in a horizontal structure. 300-450 yarns/cm, the weft yarn density is 300-450 yarns/cm, the binding yarn density is 500-600 yarns/cm, the warp is modified PVA fiber, and the weft is polyester monofilament, The binding yarn is modified PVA fiber;

Figure 5 is the hydrogen nuclear magnetic resonance (1H NMR) spectrum of the terminal double-bond star polymer; the molecular structural formula of the terminal double-bond star polymer combines the 1H-NMR spectrum of the molecule, and the chemical shifts of various hydrogens in the molecule are shown in the figure Show, wherein the chemical shift of hydrogen on the benzene ring in the aminotriphenylamine is 6.18ppm (b) and 6.24ppm (b), and symmetrical double split occurs in the molecule; The chemical shift of the amino group on the aminotriphenylamine is 4.03ppm ( f), and the Michael addition reaction of aminotriphenylamine and trimethylolpropane triacrylate produced new chemical bonds in the molecule, and the characteristic absorption peak of methylene appeared, and its corresponding chemical shift was 2.46ppm (h) and 3.43ppm (g), and the ratio of the peak area of the amino characteristic absorption peak f on the corresponding aminotriphenylamine in the spectrum to the peak area of the characteristic absorption peak g and h of the methylene group is 1:2.00:2.03 , the ratio of the group structures of various amino groups to methylene groups in the corresponding molecular structure is 1:2:2, and 5.76ppm(d), 6.44ppm(a) and 6.05ppm(c) in the spectrum correspond to molecules The chemical shift of the double bond in the middle, and the ratio of the peak area corresponding to the chemical shift 6.05ppm (c) to the peak area corresponding to the chemical shift 4.03ppm (f) is 3.08:1, so the corresponding molecular Chinese double bond and secondary amino group The numerical ratio is 3:1, so a Michael addition reaction has taken place between aminotriphenylamine and a double bond in trimethylolpropane triacrylate, and the synthesized product is the designed target product terminal double bond star polymer.

Figure 6 is the hydrogen nuclear magnetic resonance (1H NMR) spectrum of the amine-terminated star-shaped dendrimer; as can be seen from the NMR spectrum of the amine-terminated star-shaped dendrimer, Michael addition has occurred between the double bond in the molecule and ethylenediamine Therefore, the characteristic absorption peak of the double bond is detected in the spectrum, and the Michael addition reaction generates methylene, that is, the chemical shift of the double bond is changed from 5.76ppm(d) to 6.44ppm (a) and 6.05ppm (c) shifted to 2.97ppm (a', d') and 2.36ppm (c'), and the molecule has no characteristic absorption peaks of double bonds, and the amino group in the molecular structure of ethylenediamine is detected in the molecule Chemical shift 2.05ppm (h) and ethyl chemical shift 2.80ppm, characteristic absorption peak of 2.77ppm (j). Therefore, it is shown that the Michael addition reaction of ethylenediamine in the star-shaped end double-bond dendritic polymer occurs, and the reaction proceeds in the designed direction.

Fig. 7 is the proton nuclear magnetic resonance (1H NMR) collection of spectra of phosphonic acid terminal hyperbranched dendrimers; Phosphonous acid and formaldehyde take place addition reaction under acidic conditions, make reaction generate the characteristic absorption peak of methylene, in the molecule The hydroxyl characteristic absorption peak of the phosphonous acid that produces is 1.89ppm (m), and does not detect the characteristic absorption peak in the amino molecule; The methylene group produced by the reaction of amino group with phosphonous acid and formaldehyde is 3.41ppm (i), the amino group on the aminoethyl amino group of the amino-terminated star dendritic polymer reacts with phosphonous acid and formaldehyde to produce the methylene group The chemical shift is 2.44ppm(k), and the ratio of the peak area of i to the peak area of k is 0.34:3.06, and the number ratio of the corresponding methylene groups with different chemical shifts is 1:9, thus proving that the synthesized The homogeneous phosphonous acid in the phosphonic acid-terminated hyperbranched dendrimer molecule reacts to produce a hyperbranched polymer molecule with a phosphonous acid structure, that is, the reaction proceeds according to the design direction and generates the required phosphine Acid-terminated hyperbranched dendrimers.

Example 2

A mesh cloth for sewage treatment, characterized in that it is obtained by three-dimensional weaving by a warp knitting machine, the thickness of the mesh cloth is 50mm, the water permeability of the mesh cloth for sewage treatment is greater than 1800mm·s ^-1 , and the bursting strength is greater than 2000N.

A kind of preparation method of mesh cloth for sewage treatment is characterized in that, its specific steps are:

(1) Preparation of phosphonic acid-terminated hyperbranched dendrimers

The structural formula of phosphonic acid terminal hyperbranched dendrimers is as shown in Figure 1:

The application of the phosphonic acid terminal hyperbranched dendritic polymer is mainly applied to the adsorption treatment of heavy metal ions in water;

Passivating agent with high algebra, due to the high content of phosphonic acid groups in the molecule, it has a strong chelation effect with heavy metal ions, and the chelation number of a single molecule of metal ions is large, and the formed chelating group has a large molecular space volume, so it is acid-resistant Good alkali stability and good migration resistance, especially in the process of chelation, due to the dendritic structure, it has very excellent ion barrier effect and filter ion effect on heavy metals in the molecule, so the more dendritic structures are designed and the more The stronger the phosphonic acid chelating group, the stronger the chelating effect, and the stronger the acid and alkali resistance stability, so the present invention has 30 phosphonic acid groups, and has 3 main branches, 9 twigs of phosphonic acid end groups The repair effect of hyperbranched dendrimers on heavy metals is obvious due to conventional metal passivation repair agents;

(a) Preparation of terminal double bond star polymer

Using trimethylolpropane triacrylate TMPTA and aminotriphenylamine as raw materials, methanol as a solvent, in a reaction device with stirring and condensing reflux, under the protection of nitrogen, the temperature of the reaction system is controlled at -10 ~ 5 ° C, first Divide the methanol solution of aminotriphenylamine into three equal parts, then add the methanol solution of aminotriphenylamine dropwise in batches to the methanol solution of trimethylolpropane triacrylate TMPTA, and add the methanol solution of aminotriphenylamine dropwise for the first time When adding the solution, the temperature of the dropping process is controlled to be -10~-5°C, and the dropping time is 30~60 minutes. When the methanol solution of aminotriphenylamine is added dropwise for the second time, the temperature of the dropping process is controlled to be -5~0°C , the dropping time is 30-45min, when the methanol solution of aminotriphenylamine is added dropwise for the third time, the temperature of the dropping process is controlled to be 0-5°C, the dropping time is 20-30min, and the dropwise addition of aminotriphenylamine After methanol solution, the reaction system was moved to a temperature of 25°C for 4-10 hours. After the methanol solution of aminotriphenylamine has been added dropwise, the reaction system is moved to 25°C, and the reaction is continued for 10 to 20 hours; after the reaction is completed, a golden yellow product will precipitate in the system, filter and wash with methanol, and the light golden yellow product is in the Vacuum drying at 40°C to obtain a golden-yellow terminal double bond star polymer, the chemical reaction equation for the preparation of the terminal double bond star polymer is shown in Figure 2:

The molar ratio of described trimethylolpropane triacrylate TMPTA and aminotriphenylamine is 1:0.30;

The mole fraction of described trimethylolpropane triacrylate methanol solution is 1.25mol/L;

The molar fraction of the methanol solution of the aminotriphenylamine is 1.50mol/L;

(b) Synthesis of amine-terminated star dendrimers

In the reactor with stirring and reflux condenser, the reaction temperature is controlled at 0-5°C, under the condition of nitrogen protection and stirring, the methanol solution of ethylenediamine is added first, and then the terminal bismuth prepared in step (a) is Add the bonded star polymer, stir, and mix well; then react at 25°C for 20-30 hours, and then distill under reduced pressure at 80-100°C for 3-5 hours to remove methanol and excess ethylenediamine to obtain yellow viscous Thick product is the amine-terminated star-shaped dendrimer; the chemical reaction equation for the preparation of the amine-terminated star-shaped dendrimer is as shown in Figure 3:

The molar fraction of ethylenediamine in the described ethylenediamine methanol solution is 5.0mol/L;

The molar ratio of described star-shaped end double bond dendritic polymer and ethylenediamine is 1:12;

Ethylenediamine compounds have wide sources, low cost, mild chemical reaction in the preparation process, and controllable preparation process, so the cost in the preparation process is low, which is conducive to industrial production and large-scale promotion, and has a very large cost advantage for improving the marketization of products .

(c) Synthesis of phosphonic acid-terminated hyperbranched dendrimers

Add phosphorous acid into concentrated hydrochloric acid and mix evenly, control the concentration of phosphorous acid in concentrated hydrochloric acid to be 0.25-1.25mol/L, concentrated hydrochloric acid is 10-12mol/L hydrochloric acid solution, and then add dropwise at 0-10°C The aqueous solution of the amine-terminated star-shaped dendrimer prepared in step (b), the aqueous solution mass fraction of the amine-terminated star-shaped dendrimer is 20 to 45%, and the aqueous solution of the amine-terminated star-shaped dendrimer is added dropwise The process is completed dropwise within 30 minutes; then, under the condition of stirring at 85-90°C, formaldehyde solution is added dropwise. 105-110°C, reflux for 2-4 hours, after the reflux, close the reflux device, open the HCl absorption bottle, concentrate the reaction mixture, the concentration temperature is 105-110°C, concentrate until no HCl is released, cool to room temperature, and obtain the solid content Be the aqueous solution of the phosphonic acid terminal hyperbranched dendritic polymer of 25～55% light yellow transparent liquid; The chemical reaction equation of the preparation of phosphonic acid terminal hyperbranched dendritic polymer is as shown in Figure 4:

(2) Preparation of modified PVA fiber

Use 1799 type PVA particles as raw material, use water as solvent, dissolve at 90-98°C, control the mass fraction of PVA spinning solution to 15-20%, and then add the phosphonic acid synthesized in the above step (1) The end-group hyperbranched dendritic polymer is dissolved and wet-spun, and the aqueous solution of sodium sulfate is used as the coagulation liquid, and the modified PVA fiber is prepared by coagulating the coagulation liquid, stretching and winding;

The wet spinning speed is 0.5-10m/min, and the spinning liquid temperature is 25-35°C; the coagulation process uses two coagulations, and the coagulation liquid concentration in the first coagulation process is 1.0-1.5g/L , the coagulation temperature in the first coagulation process is 40-50°C, the fiber residence time in the first coagulation process is 12-18s; the coagulation liquid concentration in the second coagulation process is 0.9-1.3g/L, The solidification temperature in the process is 85-95°C, and the residence time in the second solidification process is 10-15s; the stretching process is divided into the first wet stretching process, the second dry stretching process, and the first wet stretching process. During the stretching process, the stretching ratio is 0.5-1.0 times, and the stretching temperature is 120-150°C. In the second dry stretching process, the stretching ratio is 1.5-2.0 times, and the stretching temperature is 180-230°C;

PVA fiber has excellent water swelling properties, which is conducive to the contact of phosphonic acid-terminated hyperbranched dendrimers with heavy metal ions, thereby improving the adsorption of heavy metal ions by mesh cloth. At the same time, in the wet spinning process, Since the PVA fiber forms a large number of micropores during the solidification process, the depressions and micropores on the fiber surface are improved, thereby improving the contact surface of the phosphonic acid-terminated hyperbranched dendritic polymer with the heavy metals in the sewage, and improving the adsorption of the mesh. .

(3) Preparation of mesh cloth for sewage treatment

The sample is produced on the KARL MAYER RD6DPLM double-needle bed warp knitting machine imported from Germany, and the required mesh for sewage treatment is prepared through three steps of warping, weaving and finishing; the warping tension is controlled during the warping process It is 0.08～0.18g/den, and the warp yarn, weft yarn and binding yarn are made into mesh during the weaving process. The warp yarn is in a vertical structure, and the weft yarn is in a horizontal structure. 450 threads/cm, the density of the weft yarn is 450 threads/cm, the density of the binding yarn is 600 threads/cm, the warp thread is a modified PVA fiber, the weft thread is a polyester monofilament, and the binding thread is Modified PVA fiber.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be considered Within the protection scope of the present invention.

Claims (1)

1. a kind of preparation method of sewage disposal screen cloth, it is characterised in that it is concretely comprised the following steps：

（One）The preparation of phosphonic acids end group hyperbranched dendritic polymer

（Two）The preparation of modified PVA fiber

The PVA particles of 1799 models are used, using water as solvent, to be dissolved for raw material under the conditions of 90~98 DEG C, control PVA is spun The mass fraction of silk liquid is 15~20%, then adds above-mentioned steps（One）The phosphonic acids end group hyperbranched dendritic polymerization of synthesis Thing, after dissolving, wet spinning is carried out, using the aqueous solution of sodium sulphate as solidification liquid, is solidified through solidification liquid, stretches and wind preparation Obtain modified PVA fiber；

Described wet spinning speed is 0.5~10m/min, 25~35 DEG C of spinning solution temperature；Described solidifying process uses two Secondary solidification, solidification liquid concentration is 1.0~1.5g/L in first of process of setting, and setting temperature is 40 in first of process of setting ~50 DEG C, the fiber retention time is 12~18s in first of process of setting；Solidification liquid concentration is 0.9 in second process of setting ~1.3g/L, setting temperature is 85~95 DEG C in second process of setting, in second process of setting the residence time be 10~ 15s；Described drawing process is divided into first time wet tensile, second of dry drawing stretching process, stretching times during first time wet tensile Number is 0.5~1.0 times, and draft temperature is 120~150 DEG C, during second described of dry tensile draw ratio be 1.5~ 2.0 times, draft temperature is 180~230 DEG C；

（Three）The preparation of sewage disposal screen cloth

Using sample is produced on German import KARL MAYER RD6 DPLM type double rib warp looms, by warping, weave and whole Required sewage disposal screen cloth is prepared in three steps of reason；Controlled during described warping tension in Warping for 0.08~ 0.18g/den, and through warp thread during weaving, weft yarn and ties up yarn and is manufactured into screen cloth, and warp thread is in vertical shape structure, and weft yarn is in Horizontal structure, warp thread and weft yarn are connected by tying up yarn, and the density of warp thread is 300~450/cm, the density of weft yarn for 300~ 450/cm, the density for tying up yarn is 500~600/cm, and described warp thread is modified PVA fiber, and described weft yarn is terylene list Silk, described yarn of tying up is modified PVA fiber；

The preparation of described phosphonic acids end group hyperbranched dendritic polymer

（a）The preparation of terminal double bond star polymer

Using tetramethylol methane tetraacrylate and triaminotriphenyl amine as raw material, methanol is solvent, anti-with condensing reflux with stirring Answer in device, protected down with nitrogen, the temperature for controlling reaction system is -10~5 DEG C, first the methanol solution point of triaminotriphenyl amine For three equal parts, the methanol solution of triaminotriphenyl amine is then added dropwise into the methanol solution of tetramethylol methane tetraacrylate in batches, When the methanol solution of triaminotriphenyl amine being added dropwise for the first time, the temperature for control dropwise addition process is -10~-5 DEG C, time for adding for 30~ 60min, when the methanol solution of triaminotriphenyl amine being added dropwise for the second time, the temperature for controlling dropwise addition process is -5~0 DEG C, and time for adding is 30~45min, when the methanol solution of triaminotriphenyl amine is added dropwise in third time, the temperature for control dropwise addition process is 0~5 DEG C, during dropwise addition Between be 20~30min, each time be added dropwise triaminotriphenyl amine methanol solution after, reaction system reacts 4 at a temperature of moving to 25 DEG C ~10 h；After the drop that the methanol solution of triaminotriphenyl amine is all added dropwise finishes, reaction system is moved at 25 DEG C, continue reaction 10~ 20h；Golden yellow product is had after the completion of reaction in system to separate out, filtering, and washed with methanol, light golden yellow product is true at 40 DEG C Sky is dried, and obtains the terminal double bond star polymer of golden yellow；

Described tetramethylol methane tetraacrylate and the molar ratio of triaminotriphenyl amine are 1:0.25~0.30；

The molar fraction of described tetramethylol methane tetraacrylate methanol solution is 0.25~1.25mol/L；

The molar fraction of the methanol solution of described triaminotriphenyl amine is 0.10~1.50mol/L；

（b）Hold the synthesis of amido star dendritic

With stirring, in the reactor of reflux condensing tube, controlling reaction temperature is 0~5 DEG C, in nitrogen protection and stirring condition Under, first add ethylenediamine methanol solution, then again by step（a）The terminal double bond star polymer of preparation adds, and stirs, mixing Uniformly；Then at 25 DEG C, react 20~30 h, then under conditions of 80~100 DEG C be evaporated under reduced pressure 3~5 h remove methanol and Unnecessary ethylenediamine, clear yellow viscous product is obtained, as hold amido star dendritic；

The molar fraction of ethylenediamine is 0.5~5.0mol/L in described ethylenediamine methanol solution；

Described star terminal double bond dendritic and the molar ratio of ethylenediamine are 1:10~12；

Ethylene diamine compound source is wide, and cost is low, is chemically reacted in preparation process gentle, preparation technology is controllable, therefore prepares Cost in journey is low, beneficial to industrialized production and large-scale promotion, has very big cost for the marketization for lifting product Advantage；

（c）The synthesis of phosphonic acids end group hyperbranched dendritic polymer

Phosphorous acid is added in concentrated hydrochloric acid and is well mixed, it is 0.25~1.25mol/L to control phosphorous acid concentration in concentrated hydrochloric acid, Concentrated hydrochloric acid is 10~12mol/L hydrochloric acid solution, and then under the conditions of 0~10 DEG C, step is added dropwise（b）The end amido star of preparation The aqueous solution of dendritic, the aqueous solution mass fraction of end amido star dendritic is 20~45%, holds amido star The aqueous solution of shape dendritic is added dropwise process and is added dropwise to complete in 30min；Then again under 85~90 DEG C of stirring condition, Formalin is added dropwise, rear reaction system, then insulation reaction 1~2 hour under the conditions of 90 DEG C is added dropwise in formalin, most After be warming up to 105~110 DEG C, flow back 2~4 hours, after backflow terminates, closing volume device opens HCl absorption bottles, and concentration is anti- Mixed liquor is answered, 105~110 DEG C of thickening temperature, after being concentrated into no HCl releasings, room temperature is cooled to, obtains solid content as 25~55% Light yellow transparent liquid phosphonic acids end group hyperbranched dendritic polymer the aqueous solution.