Preparation method of thermo-sensitive graphene oxide with improved replacement rate by triggering polymerization through advanced modification

Abstract

The invention discloses a preparation method of thermo-sensitive graphene oxide with improved replacement rate by initializing polymerization through advanced modification. Graphene oxide with a medicine carrying property and a PNIPAM (Poly N-Isopropyl Acryl Amide) with thermo-sensitivity are synthesized into a thermo-sensitive medicine carrying composite material through click chemical reaction, belonging to the technical field of macromolecule medicinal materials. An azide group in the prior art is low in replacement rate, and an obtained thermo-sensitive graphene oxide is difficult to further modify. The preparation method is characterized by comprising the following steps of firstly, initializing the NIPAM to be polymerized by using an ATRP (Atom Transfer Radical Polymerization) initiator with an azide group at the tail end of the initiator, so as to obtain the PNIPAM with the azide group at the tail end; secondly, reacting alkynyl molecules with the graphene oxide so as to obtain alkynyl graphene oxide; and finally, combining the PNIPAM with the azide group at the tail end with the alkynyl graphene oxide by using a click chemical reaction method so as to obtain the thermo-sensitive graphene oxide. Due to polymerization initialization through advanced modification, the azide group is high in replacement rate, and the other end of a PNIPAM chain after stem grafting is halogen, so that the thermo-sensitive graphene oxide can be further modified.

Description

technical field [0001] The invention relates to a method for preparing temperature-sensitive graphene oxide which is first modified to initiate polymerization to increase the substitution rate. The graphene oxide with drug loading performance and PNIPAM (poly-N-isopropylacrylamide) with temperature sensitivity are used " "Click chemistry" reaction synthesis of temperature-sensitive drug-loaded composite materials belongs to the technical field of polymer pharmaceutical materials. Background technique [0002] Graphene oxide is usually prepared from graphite through chemical oxidation and ultrasound. Due to different oxidation conditions, the size of the obtained graphene oxide is generally between ten nanometers to hundreds of nanometers or even micrometers. Graphene oxide contains a large number of oxygen-containing active groups, such as carbonyl, carboxyl, hydroxyl and epoxy groups. The research results show that graphene oxide and its derivatives can be absorbed by cel...

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Problems solved by technology

However, graphene oxide is insoluble in water and any organic solvent. If a graphene oxide initiator is used to initiate NIPAM polymerization, the reaction conditions are harsh, and the molecular weight of the polymer in the polymerization reaction cannot be measured, which affects the control of polymer molecular weight.

Although the method of first initiating NIPAM polymerization and then grafting can overcome the uncontrollable shortcoming of the polymer molecular weight of the first method, and can be modified before grafting, once the grafting is completed, the composite product cannot be modified. , can not obtain more excellent performance

For example, NIPAM polymerization is first initiated, and then the terminal halogen of the polymer is replaced with an azide group, followed by a "click chemical" reaction (Click reaction) with the alkynylated graphene oxide to complete the grafting, thereby obtaining temperature-sensitive graphene oxide , however, the reaction of substituting the terminal halogen of the polymer with the azide group is difficult to carry out, and the substitution rate is low, followed by the re-modification of the composite product obtained by this method is more difficult, and it is impossible to obtain more excellent performance

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