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Preparation method of poly(N-isopropyl acrylamide) with narrow molecular weight distribution

A technology of isopropylacrylamide and narrow molecular weight distribution, which is applied in the field of polymer preparation, can solve the problems of difficult removal of metal catalysts, influence on product stability, and limitations, and achieve narrow molecular weight distribution, simple post-processing, and good monodispersity Effect

Inactive Publication Date: 2016-09-28
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Atom transfer radical polymerization is limited due to the difficulty of removing the metal catalyst used, and the presence of active halogen end groups in the final polymer will affect the stability of the product

Method used

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  • Preparation method of poly(N-isopropyl acrylamide) with narrow molecular weight distribution
  • Preparation method of poly(N-isopropyl acrylamide) with narrow molecular weight distribution
  • Preparation method of poly(N-isopropyl acrylamide) with narrow molecular weight distribution

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] In the reaction kettle, dissolve 0.5 parts of N-isopropylacrylamide monomer in 2.5 parts of 1,4-dioxane, add 0.035 parts of S-n-dodecyl-S'-(α,α' -Dimethyl-α"-acetic acid) trithiocarbonate and 0.008 parts of initiator AIBN, reacted at 65°C for 0.5h under nitrogen protection, and then heated up to 70°C for 6h. After diluting the reaction solution appropriately, drop by drop Put it into 20 parts of glacial ether, let it stand for 24h, and vacuum-dry it to obtain the product after suction filtration. The relative molecular weight of the poly(N-isopropylacrylamide) obtained is about 5000, the molecular weight distribution is narrower, and the monodispersity is better . figure 1 For the infrared spectrogram of the PINIPAM made, it can be seen from the figure that the vibration peak of C=O is at 1649cm -1 Nearby, the stretching vibration peak of N-H is at 1549cm -1 nearby, -CH(CH 3 ) 2 The vibration characteristic peak is at 1368cm -1 nearby; 1622cm -1 The stretching vib...

Embodiment 2

[0021] In the reaction kettle, dissolve 0.5 parts of N-isopropylacrylamide monomer in 2.5 parts of N,N-dimethylformamide, add 0.035 parts of S,S'-(α,α'-dimethyl- α”-acetic acid) trithiocarbonate and 0.008 parts of initiator AIBN, under the protection of nitrogen, react at 65°C for 0.5h, then raise the temperature to 70°C for 6h. After diluting the reaction solution appropriately, add 20 parts of glacial ether drop by drop , standing for 24 hours, vacuum drying after suction filtration to obtain the product. The relative molecular weight of the prepared poly(N-isopropylacrylamide) is about 5000, the molecular weight distribution is narrow, and the monodispersity is good.

Embodiment 3

[0023] In the reaction kettle, dissolve 0.5 parts of N-isopropylacrylamide monomer in 2.5 parts of 1,4-dioxane, add 0.035 parts of S-dodecyl-S”-isopropionic acid-trisulfide Alternative carbonate and 0.008 parts of initiator AIBN, under the protection of nitrogen, react at 65°C for 0.5h, then raise the temperature to 70°C for 6h. After diluting the reaction solution appropriately, drop it into 20 parts of glacial ether, let it stand for 24h, pump After filtration, the product is obtained by vacuum drying. The obtained poly(N-isopropylacrylamide) has a relative molecular mass of about 5000, a narrow molecular weight distribution and good monodispersity.

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Abstract

The invention relates to a preparation method of poly(N-isopropyl acrylamide) with narrow molecular weight distribution. The preparation method comprises the steps of: adding 0.5-1 part by mass of N-isopropyl acrylamide monomer, 0.0175-0.035 part by mass of trithiocarbonate, 0.004-0.008 part by mass of initiator and 2.5-5 parts by mass of solvent into a reaction kettle, carrying out reaction in presence of nitrogen gas at 65 DEG C for 0.5-1h, then heating up to 70 DEG C for reaction for 6-8h, dropping into 20-40 parts of precipitator, standing for 24h; and carrying out suction filtration and drying to obtain the poly(N-isopropyl acrylamide) with narrow molecular weight distribution. When the molecular weight of the prepared poly(N-isopropyl acrylamide) is about 5000, 10000 and 20000, the molecular weight distribution index PDI is respectively 1.0-1.5, the molecular weight distribution is narrower, the monodispersity is good, the system in the reaction process is uniform, complex purification process in the experimental process is simplified, and the experiment is simple and highly efficient.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a preparation method of poly(N-isopropylacrylamide) with narrow molecular weight distribution. Background technique [0002] Thermosensitive polymers have attracted widespread attention in recent years due to their great potential in biomedical applications such as drug loading, molecular recognition, enzyme immobilization, drug delivery, tissue engineering, and nanoreactors. Among them, the most representative polymer The compound is poly(N-isopropylacrylamide) (PNIPAM) and its copolymers. In 1967, Scarpa et al. first observed that linear PNIPAM has a temperature-sensitive phenomenon of low phase transition temperature. In 1978, Tanaka first discovered that PNIPAM had temperature sensitivity and solvent concentration sensitivity when studying polyacrylamide hydrogel, and proposed In 1984, Hirokawa, Tanaka et al. reported for the first time that non-ionic PNIPAM had a volume pha...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F120/54C08F2/38
CPCC08F120/54C08F2/38C08F2438/03C08F2500/03
Inventor 黄定海李纳川宋丽柳盼盼
Owner TIANJIN UNIV