Polymer with bidirectional reversible shape memory effect and preparation method thereof

Abstract

The invention discloses a polymer with a bidirectional reversible shape memory effect. The polymer comprises at least one amorphous phase and a crystal phase, wherein the glass-transition temperature of the amorphous phase is higher than the melting temperature of the crystal phase and the difference is at least 20 DEG C. The preparation method of the polymer comprises the step of preparing a single-crystal thermosetting bidirectional reversible shape memory molecule by taking the high-temperature amorphous phase as a stress phase to replace the high-temperature crystal phase in a bi-crystal thermosetting reversible shape memory molecule. The glass-transition temperature of the amorphous phase of the polymer can be continuously controlled through different comonomers; the control of the proportion of the two phases, the crosslinking densities and the transition temperature of the crystal phase can be realized under the premise of ensuring that the glass-transition temperature of the amorphous phase is higher than the transition temperature of the crystal phase. The polymer is light in material weight, easy to process and low in cost, has excellent insulation property and thermal insulation effect and has wide potential application value in the fields of biomedicine, cable industry and packaging industry.

Description

technical field [0001] The invention belongs to the field of new functional materials, and relates to an intelligent material and a preparation method thereof, in particular to a polymer material with two-way reversible shape memory effect and a preparation method thereof. Background technique [0002] The shape memory polymer in the traditional sense can form a temporary shape under the combined action of heating above its thermal transition temperature and external force, and this temporary shape can be fixed after cooling (below its thermal transition temperature). The final temporary shape can be restored to its original shape under certain external conditions (such as reheating), and its corresponding thermal transition temperature (such as glass transition temperature or crystallization temperature) is usually called the shape memory transition temperature. The shape memory polymer known for half a century can only change between a temporary shape and its permanent sha...

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Problems solved by technology

[0010] 1. The adjustability of the phase transition temperature is poor. The phase transition temperature of polymer crystallization can usually be adjusted in a small range by introducing a small amount of comonomer, but too much comonomer will completely destroy the crystallization. Therefore, according to the actual application It is likely that it is almost impossible to simultaneously adjust the two crystallographic phase transition temperatures over a wide range;

[0011] 2. Since the polymer cannot be completely crystallized, and the crystallinity of the two phases is also likely to change with the thermomechanical conditions of the reversible shape memory, the twin-crystal thermosetting system is not suitable for the quantitative mechanism research of the reversible shape memory.

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