Thermo-sensitive chain extender and polyurethane hydrogel with double sensitivity of temperature and pH

Abstract

The invention discloses a thermo-sensitive chain extender and polyurethane hydrogel with double sensitivity of temperature and pH. The hydrogel is prepared by the following methods: mixing 15-20.6 percent of polyethylene glycol, 6.7-9.2 percent of polyhydric carboxylic acid, 25.2-34.6 percent of multi-isocyanate and dibutyltin dilaurate used as a catalyst to perform pre-condensation polymerization reaction; adding organic solvent to stop reaction to obtain a pre-polymer; adding 15.3-36.5 percent of a thermo-sensitive chain extender to perform chain extension reaction; adding 3.1-4.3 percent of polyhydric alcohol amine stop end after the pre-polymer is subjected to the chain extension; and then, adding 11.6-19.4 percent of a curing crosslinking agent to perform crosslinking reaction to obtain polyurethane hydrogel with double sensitivity of temperature and pH. The thermo-sensitive chain extender is prepared by the method, and a method for introducing the thermo-sensitive chain extenderin polyurethane is provided, and the softness and hardness of the material are controlled in a post-crosslinking mode, so that the defects that introduction of groups and cross-linking solidity are carried out at the same time in the conventional way of excitation of double bonds are overcame, and the polyurethane hydrogel with double sensitivity of temperature and pH is prepared.

Description

technical field [0001] The invention relates to a temperature-sensitive chain extender and a temperature- and pH-sensitive polyurethane hydrogel. Background technique [0002] Polyurethane (PU) has good biocompatibility and excellent physical and mechanical properties. It has good physiological acceptability to the human body and can maintain the stability of long-term human implantation. The surface of the hydrogel is not easy to adhere to proteins and cells, so it will show good biocompatibility when in contact with blood, body fluids and human tissues; in addition, the hydrogel is very soft because it contains a large amount of water, and is similar to In biological tissues, it can reduce adverse reactions as a human implant. Most polyurethane hydrogels have environmental responsiveness. According to the response to external stimuli, hydrogels can be divided into: temperature-responsive hydrogels, pH-responsive hydrogels, light-responsive hydrogels, Pressure-responsive...

AI Technical Summary

Problems solved by technology

[0003] At present, most temperature- and pH-sensitive polyurethane hydrogels are prepared by persulfate-induced crosslinking of polyacrylate and N-isopropaneacrylamide. The polyurethane hydrogel prepared by this method is only part of the structure. It has a polyurethane molecular chain, not a pure polyurethane hydrogel, which affects the biocompatibility of polyurethane to a certain extent

In addition, by stimulating double bond cross-linking, due to the problem of proportion, it is difficult to conduct variable separation research on the performance and temperature sensitivity of the cross-linked material

Images