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Preparation of water-soluble RAFT (reversible addition-fragmentation) chain transfer agent and synthesis method for polyacrylic acid with low molecular weight

A technology of chain transfer agent and polyacrylic acid, which is used in water treatment, agriculture, papermaking, daily chemicals, textiles, and coatings. The effect of high yield and simple preparation method

Inactive Publication Date: 2012-08-15
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Acrylic acid (AA) has a high chain growth rate constant for RAFT polymerization in aqueous solution, and gels are easily formed during the polymerization process, so it is very challenging to achieve controllable polymerization

Method used

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  • Preparation of water-soluble RAFT (reversible addition-fragmentation) chain transfer agent and synthesis method for polyacrylic acid with low molecular weight
  • Preparation of water-soluble RAFT (reversible addition-fragmentation) chain transfer agent and synthesis method for polyacrylic acid with low molecular weight
  • Preparation of water-soluble RAFT (reversible addition-fragmentation) chain transfer agent and synthesis method for polyacrylic acid with low molecular weight

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] (1) Preparation of RAFT chain transfer agent

[0023] 1) Under the protection of nitrogen, add 1 part of benzene, 0.025 part of tetrabutylammonium bromide, 0.5 part of acetone, 1 part of chloroform, 0.3 part of carbon disulfide into the reaction kettle, and ice bath for 1.5 h.

[0024] 2) After the ice bath is over, add 4 parts of NaOH solution, keep the temperature not exceeding 25°C during the process, and stir for 12 hours.

[0025] 3) Add 10 parts of distilled water and 1 part of sulfuric acid, and continue stirring for 0.7h.

[0026] 4) Collect the product after filtration and drying, and obtain the product after further extraction and purification.

[0027] (2) Preparation of polyacrylic acid

[0028] 1) In a reaction kettle, dissolve 1 part of acrylic acid monomer in 2 parts of distilled water, add 0.1 part of RAFT chain transfer agent prepared by the above method and 0.04 part of initiator AIBN.

[0029] 2) Under the protection of nitrogen, react at 65°C for ...

Embodiment 2

[0032] (1) Preparation of RAFT chain transfer agent

[0033] 1) Under the protection of nitrogen, add 1.5 parts of benzene, 0.02 parts of tetrabutylammonium hydroxide, 0.5 parts of acetone, 1 part of chloroform, and 0.3 parts of carbon disulfide into the reaction kettle, and ice bath for 1 hour.

[0034] 2) After the ice bath is over, add 1 part of KOH solution, keep the temperature not exceeding 25°C during this process, and stir for 12 hours.

[0035] 3) Add 5 parts of distilled water and 1 part of concentrated hydrochloric acid, and continue stirring for 1 h.

[0036] 4) Collect the product after filtration and drying, and obtain the product after further extraction and purification.

[0037] (2) Preparation of polyacrylic acid

[0038] 1) In a reaction kettle, dissolve 0.5 part of acrylic acid monomer in 2 parts of distilled water, add 0.1 part of RAFT chain transfer agent prepared by the above method and 0.05 part of initiator BPO.

[0039] 2) Under nitrogen protection...

Embodiment 3

[0042] (1) Preparation of RAFT chain transfer agent

[0043] 1) Under the protection of nitrogen, add 3 parts of benzene, 0.04 parts of tetrabutylammonium hydroxide, 0.5 parts of acetone, 1 part of chloroform, and 0.3 parts of carbon disulfide into the reaction kettle, and ice bath for 3 hours.

[0044] 2) After the ice bath is over, add 1 part of NaOH solution, keep the temperature not exceeding 25°C during the process, and stir for 12 hours.

[0045] 3) Add 9 parts of distilled water and 2 parts of sulfuric acid, and continue stirring for 0.5h.

[0046] 4) Collect the product after filtration and drying, and obtain the product after further extraction and purification.

[0047] (2) Preparation of polyacrylic acid

[0048] 1) In a reaction kettle, dissolve 0.75 parts of acrylic acid monomer in 3 parts of distilled water, add 0.05 parts of RAFT chain transfer agent prepared by the above method and 0.05 parts of initiator AIBN.

[0049] 2) Under the protection of nitrogen, r...

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Abstract

The invention relates to preparation of active RAFT (reversible addition-fragmentation) chain transfer agent and a preparation method for polyacrylic acid with low molecular weight. The preparation method for the polyacrylic acid with the low molecular weight includes: in a reaction kettle, dispersing various reaction monomers into organic solvent and adding phase transfer catalyst to carry out a phase transfer reaction to synthesize trithiocarbonate RAFT reagent under the protection of gas; and carrying out free radical polymerization of acrylic monomers with prepared RAFT chain transfer agent and catalyst, and finally preparing the polyacrylic acid with the low molecular weight by controlling conditions such as reaction temperature, reaction time and the proportion of various substances. The preparation method for the polyacrylic acid has the advantages that water-soluble trithiocarbonate serving as the RAFT chain transfer agent is extremely easy in decomposition, therefore, chain transfer efficiency is high, free radical polymerization can be effectively controlled, yield of a product prepared by the phase transfer method is high, and the method is simple in process without excessive aftertreatment and easier to meet follow-up testing of an experiment. The prepared polyacrylic acid is low in relative molecular weight within the range of 30000-50000, narrow in molecular weight distribution and good in monodispersity.

Description

technical field [0001] The invention relates to many fields such as daily chemicals, coatings, textiles, papermaking, agriculture, water treatment, etc., and in particular relates to the preparation of a water-soluble RAFT chain transfer agent and the synthesis method of low molecular weight polyacrylic acid. Background technique [0002] Polyacrylic acid has been widely used this year because of its good water solubility and excellent dispersion, flocculation and thickening effects. Slightly cross-linked polyacrylic acid has the characteristics of non-toxicity, biocompatibility, and environmental friendliness, and has broad application prospects in the field of biomedicine. In addition, its strong thickening ability and high conductivity greatly improve battery performance, causing great concern. UHMW (10 7 Above) is mainly used for water absorbent, high molecular weight (10 6 ~10 7 ) is mainly used for flocculation, medium molecular weight (10 4 ~10 6 ) has a thicken...

Claims

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Application Information

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IPC IPC(8): C07C329/00C08F2/38C08F120/06
Inventor 黄定海宋丹徐红艳陈帮烈付建建
Owner TIANJIN UNIV