Cross-linking point controllable shape memory polymer and preparation method thereof

Abstract

The invention discloses a preparation method of a cross-linking point controllable shape memory polymer. The preparation method comprises the following steps of: step (a) carrying out free radical polymerization on an acrylate monomer, an n-arm initiator and a catalytic system A to obtain an n-arm structural unit, and carrying out substitution reaction on the n-arm structural unit and sodium azideto obtain an n-arm structural unit having an azide group at the tail end; step (b) reacting an n-arm compound having a hydroxyl group at the tail end with propargyl bromide under the action of the alkalinity of sodium hydroxide to obtain an n-arm structural unit having an alkynyl group at the tail end; and step (c) adding the n-arm structural unit having the azide group at the tail end, the n-armstructural unit having the alkynyl group at the tail end, a catalytic system B and a solvent to a reaction bottle, and uniformly stirring to obtain the shape memory polymer material. The number of the azide group or alkynyl group at the tail end of the polymer is precisely controlled by an atom transfer active radical polymerization and copper-catalyzed azide-alkyne dipolar cycloaddition couplingtechnique, and thus, the number of network cross-linking points is controlled.

Description

technical field [0001] The invention belongs to the technical field of shape-memory polymers, in particular to a shape-memory polymer with precisely controllable crosslinking points and a preparation method thereof. Background technique [0002] As a new type of intelligent material, shape memory polymer material can respond to external stimuli and return to a preset state by adjusting its own state parameters (such as shape, position, strain, etc.). In recent years, shape memory polymers (SMPs) have become a new hotspot in the research, development and application of polymer materials because of their diverse stimulation methods, large deformation, easy processing, light weight and low price. It has extensive and potential application value in the fields of aerospace, biomedicine, information storage and 3D printing. [0003] With the in-depth research on the relationship between polymer network structure and performance, how to obtain shape memory materials with excellent...

AI Technical Summary

Problems solved by technology

Network points are generally divided into chemical cross-linking and physical cross-linking. Among them, chemical cross-linking as a rigid cross-linking point will restrict the movement of molecular chains and limit the deformation of the material; while physical cross-linking can achieve high deformation, but because of Its poor stability will cause molecular chain slippage during the shaping process, resulting in poor shape recovery performance of the material