Ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group and applications of chelating heavy metals

Patent metadata

Field	Value
Publication number	US-11236206-B2
Application number	US-202016994678-A
Country	US
Kind code	B2
Filing date	Aug 17, 2020
Priority date	Dec 2, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

An ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group and its applications as a heavy metal chelating agent are disclosed, which relates to the field of chemical and environmental protection technology. The hyperbranched polymer has a chemical formula of C[CH2OCH2CH2OCOCH2CH2N(CSSM)CH2CH2NHCSSM]4, wherein M is Na+, K+ or NH4+. A preparation method of the hyperbranched polymer is simple, the raw materials are easily available, and it is easy to be industrialized. The hyperbranched polymer is able to be used as a heavy metal chelating agent. Its special three-dimensional space structure is able to alternately chelate with heavy metals to form a large three-dimensional molecular conjugate with low solubility, strong stability, and compactness, which is able to effectively treat wastewater and waste containing heavy metals.

First claim

What is claimed is:

1. An ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group, which has a chemical formula of C[CH 2 OCH 2 CH 2 OCOCH 2 CH 2 N(CSSM)CH 2 CH 2 NHCSSM] 4 , wherein M is Na + , K + or NH 4 + ; and a structural formula of

2. A preparation method of an ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group, wherein:
the ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group has a chemical formula of C[CH 2 OCH 2 CH 2 OCOCH 2 CH 2 N(CSSM)CH 2 CH 2 NHCSSM] 4 , wherein M is Na + , K + or NH 4 + ; and a structural formula of

the preparation method comprises steps of:
(1) under nitrogen protection, adding ethylenediamine (EDA) and a first amount of low-carbon alcohol to a reaction vessel with a stirrer, a reflux device and a thermometer, evenly stirring, slowly adding a low-carbon alcohol solution containing ethoxylated pentaerythritol tetraacrylate (EO-PETA) drop by drop, performing a first addition reaction; and then removing low-carbon alcohol solvent and excessive ethylenediamine through vacuum distillation, and obtaining a light amber viscous product, which is an intermediate product ethoxylated pentaerythritol tetra((N-(2-aminoethyl))-3-alaninate) hyperbranched polymer;
(2) slowly adding water, alkaline solution and carbon disulfide drop by drop to the ethoxylated pentaerythritol tetra((N-(2-aminoethyl))-3-alaninate) hyperbranched polymer obtained by the step of (1), performing a second addition reaction, and obtaining an aqueous solution of the ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group; and
(3) adding a second amount of low-carbon alcohol to the aqueous solution of the ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group obtained by the step (3), evenly stirring, precipitating a solid product, filtering and drying the solid product to obtain the ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group.

3. The preparation method according to claim 2 , wherein each of the first amount of low-carbon alcohol in the step (1) and the second amount of low-carbon alcohol in the step (2) is one member selected from the group consisting of methanol, ethanol, propanol and ethylene glycol.

4. The preparation method according to claim 2 , wherein a molar ratio of ethylenediamine and ethoxylated pentaerythritol tetraacrylate in the step (1) is in a range of (4-10): 1.

5. The preparation method according to claim 2 , wherein the first addition reaction in the step (1) has a reaction temperature in a range of 25-35° C., and a reaction time in a range of 24 to 48 h.

6. The preparation method according to claim 2 , wherein the vacuum distillation in the step (1) has a temperature in a range of 80 to 100° C., and a time in a range of 3 to 5 h.

7. The preparation method according to claim 2 , wherein the alkaline solution in the step (2) is sodium hydroxide solution, potassium hydroxide solution or ammonium hydroxide.

8. The preparation method according to claim 7 , wherein in the step (2), a molar ratio of the ethoxylated pentaerythritol tetra((N-(2-aminoethyl))-3-alaninate) hyperbranched polymer, carbon disulfide and alkaline is in a range of 1:(8.0-9.0):(8.0-9.0).

9. The preparation method according to claim 2 , wherein the second addition reaction in the step (2) has a reaction temperature in a range of 25-40° C., and a reaction time in a range of 3 to 5 h.

10. A method for treating heavy metal wastewater and heavy metal waste, comprising applying an ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group as a heavy metal chelating agent, wherein:
the ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group has a chemical formula of C[CH 2 OCH 2 CH 2 OCOCH 2 CH 2 N(CSSM)CH 2 CH 2 NHCSSM] 4 , wherein M is Na + , K + or NH 4 + ; and a structural formula of

Assignees

• Univ Tongji
• Shandong Xintai Water Treat Technology Co Ltd

Inventors

• Zhang Bingru
• Cui Jin
• Li Fengting

Classifications

• C02F1/5272

  using specific organic precipitants · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title

• C08G83/006

  After treatment of hyperbranched macromolecules · CPC title

• C02F1/56 Primary

  Macromolecular compounds · CPC title

• C08G83/005 Primary

  Hyperbranched macromolecules · CPC title