Dicyandiamide-terephthalaldehyde polycondensate and preparation method thereof

A technology of terephthalaldehyde and dicyandiamide, applied in the direction of flocculation/sedimentation water/sewage treatment, etc., can solve the problems of not using sedimentation, dehydration effect needs to be further improved, dispersion, etc., achieve good flocculation and decolorization effect, and have good application prospects , The effect of reducing the production cost

Pending Publication Date: 2021-09-28
NINGBO POLYTECHNIC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Dicyandiamide-formaldehyde polycondensate (DDF) synthesized from dicyandiamide and formaldehyde has special effects in treating textile dye wastewater. It can provide more cations, neutralize the negative charge in dye wastewater and destabilize it. Excellent performance, but the biggest problem with dicyandiamide formaldehyde polycondensation (DDF) is that the flocs formed when treating wastewater are small and dispersed, and do not use sedimentation, which affects its application
[0004] Chinese patent application document (publication number: 102276777A) discloses a high-efficiency flocculant and its preparation method, which increases the molecular weight of the flocculant by introducing polyamine compounds, increases its viscosity and stability, and overcomes the current dicyanide The amine-formaldehyde condensation polymer flocculant has disadvantages such as low molecular weight, small floc pattern, and slow sedimentation velocity, but it uses a large amount of irritating formaldehyde, and the production process has great safety hazards for the environment and workers, and the dehydration effect needs to be further improved.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] S1. Prepare the following raw materials in parts by mass: 40 parts of dicyandiamide, 8 parts of urea, 12 parts of ammonium chloride, and 40 parts of terephthalaldehyde;

[0025] S2. Preheat the reaction kettle to 40°C, then add dicyandiamide, urea, and ammonium chloride in sequence for stirring, the stirring speed is 80rpm, and terephthalaldehyde is added during the stirring process;

[0026] S3. Raise the temperature of the reactor to adjust the pH to 3.5, then keep the temperature at 85° C. for 2.5 hours, and cool to normal temperature to obtain a colorless, transparent and viscous modified polycondensate of dicyandiamide-terephthalaldehyde.

Embodiment 2

[0028] S1. Prepare the following raw materials in parts by mass: 45 parts of dicyandiamide, 12 parts of urea, 10 parts of ammonium chloride, and 33 parts of terephthalaldehyde;

[0029] S2. Preheat the reaction kettle to 40°C, then add dicyandiamide, urea, and ammonium chloride in turn for stirring, the stirring speed is 85rpm, and terephthalaldehyde is added during the stirring process;

[0030] S3. Raise the temperature of the reactor to adjust the pH to 4, then keep the temperature at 85° C. for 3 hours, and cool to normal temperature to obtain a colorless, transparent and viscous modified polycondensate of dicyandiamide-terephthalaldehyde.

Embodiment 3

[0032] S1. Prepare the following raw materials in parts by mass: 40 parts of dicyandiamide, 10 parts of ethylenediamine, 12 parts of ammonium chloride, and 38 parts of terephthalaldehyde;

[0033] S2. Preheat the reaction kettle to 45°C, then add dicyandiamide, ethylenediamine, and ammonium chloride in sequence to stir at a stirring speed of 85 rpm, and add terephthalaldehyde during the stirring process;

[0034] S3. Raise the temperature of the reactor to adjust the pH to 4.5, then keep the temperature at 85° C. for 3 hours, and cool to normal temperature to obtain a colorless, transparent and viscous modified polycondensate of dicyandiamide-terephthalaldehyde.

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PUM

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Abstract

The invention belongs to the technical field of flocculant preparation, and particularly relates to a dicyandiamide-terephthalaldehyde polycondensate and a preparation method thereof. A novel dicyandiamide-terephthalaldehyde polycondensate (DDP) is generated through condensation polymerization of terephthalaldehyde instead of formaldehyde and dicyandiamide, and the DDP is modified through urea, ethylenediamine and the like which are similar to dicyandiamide in structure, so that the modified dicyandiamide-terephthalaldehyde polycondensate (MDDP) with high linear molecular weight is obtained. The reaction temperature, the reaction time, the use amount of the modifier and the reaction pH value are adjusted to obtain the novel dicyandiamide-terephthalaldehyde polycondensate with better precipitation performance and operation safety. The dicyandiamide-terephthalaldehyde polycondensate prepared by the invention not only has a relatively good flocculation and decoloration effect in a sewage treatment process, but also has a good settling property, and has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of flocculant preparation, and in particular relates to a polycondensate of dicyandiamide-terephthalaldehyde and a preparation method thereof. Background technique [0002] As a big textile country, China's textile capacity is far ahead in the world, but the discharge and pollution of printing and dyeing, textile and dye wastewater are not optimistic. According to statistical surveys, wastewater contains approximately 200 million m 3 textile dyes. For the research on the decolorization of textile printing and dyeing wastewater, a lot of work has been done at home and abroad, but considering the economic cost and treatment effect, flocculation has the potential for industrial application, and the selection of a suitable flocculant is also a key link. [0003] Dicyandiamide-formaldehyde polycondensate (DDF) synthesized from dicyandiamide and formaldehyde has special effects in treating textile dye wastewater...

Claims

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Application Information

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IPC IPC(8): C08G12/16C08G12/12C08G12/06C08G12/34C02F1/56
CPCC08G12/16C08G12/12C08G12/06C08G12/34C02F1/56
Inventor 陈碧芬李爱元董艳杰孙向东苏倡彭振博
Owner NINGBO POLYTECHNIC
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