Ph response graft copolymer as well as preparation method and use thereof

Abstract

The invention provides a preparation method of a pH response graft copolymer based on methacrylic acid amino ester. The preparation method comprises the following steps: firstly dissolving methacrylic acid macrogol ester and methacrylic acid amino ester in a solvent; adding a divinyl cross-linking agent; taking a thiols compound as a chain transfer agent, and triggering a polymerization reaction with a radical initiator; controlling the molar ratio of the cross-linking agent to the chain transfer agent to control the reaction so as to obtain the graft copolymer. When the pH of the graft copolymer is smaller than 6, aggregates with the hydrodynamic radius of 130-140 nm are aggregated; when the pH of the graft copolymer is about 7, the shapes of the aggregates change suddenly; and when the pH of the graft copolymer is greater than 8, the hydrodynamic radius of the aggregates becomes about 20 nm, and good pH response performance is represented. Moreover, the reactivity site points of amino groups, and carboxyl groups and the like on the surface of the graft copolymer are easily subjected to macromolecular modification, functional groups are introduced, and the graft copolymer has a wide application prospect in the fields of materials science, medical science, biology and the like.

Description

technical field [0001] The invention belongs to the preparation technology of pH-responsive polymer materials, in particular to a preparation method of pH-responsive graft copolymer nanoparticles based on methacrylic acid amino ester. Background technique [0002] The pH-responsive polymer materials are mainly some weak acid or weak base polyelectrolytes. Such polymers are solvated, hydrophilic, and swollen when they are in an ionic state in aqueous solution, and desolvated, hydrophobic, and tightened in a neutral state. And the transition between the two states shows a high degree of nonlinearity, that is to say, the performance of the polymer changes suddenly in a very narrow pH range. The pH-responsive polymer materials that can form core-shell particles at a specific pH value are a very important class. Due to the suitable microscopic size and wide functional diversity of this material, it can be used in nanoreactors, surfaces Active agents, imaging photonic probes, and...

AI Technical Summary

Problems solved by technology

Although the above method can obtain block or graft copolymers with clear structure, it needs to use living radical polymerization methods such as ATRP or RAFT, the reaction system is more complicated, and there are many post-treatment steps. Applications in fields such as controllable drug carriers

In addition, Jonathan V. M. Weaver et al. synthesized a series of branched copolymers based on polyethylene glycol methyl ether methacrylate and DEAEMA through improved free radical polymerization. The branched copolymers hydrophobically aggregated DEAEMA to form particles when the pH was greater than 7. Nanoparticles with a diameter of about 20 nm, and when the pH is less than 7, the protonation of the DEAEMA segment changes from the original hydrophobicity to hydrophilicity, so in theory the particle size should become larger, but due to the water solubility of the entire macromolecule when the pH is less than 7 The performance is too good, the ability to scatter light is poor, and the real particle size of the particle cannot be known by techniques such as dynamic light scattering

Images