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CN-122011742-A - External stress-free two-way shape memory polyurethane/nanocomposite and preparation method thereof

CN122011742ACN 122011742 ACN122011742 ACN 122011742ACN-122011742-A

Abstract

The invention discloses an external stress-free two-way shape memory polyurethane/nano composite material and a preparation method thereof, wherein polytetrahydrofuran ether glycol and hexamethylene diisocyanate are used as raw materials, a prepolymerization reaction is carried out under the catalysis of dibutyltin dilaurate, 1, 4-butanediol is added into a polyurethane prepolymer system, and the reaction is continued to obtain polytetrahydrofuran ether glycol-based shape memory polyurethane; and then the polytetrahydrofuran ether glycol-based shape memory polyurethane is used as a polymer matrix and is respectively mixed with the carboxylated multi-wall carbon nano tube and the aminated multi-wall carbon nano tube by melting, so that the two-way shape memory polyurethane/nano composite material without external stress is successfully prepared. The two-way shape memory polyurethane/nanocomposite without external stress not only has excellent thermal stability and mechanical property, but also has good shape memory cycle performance. In addition, the preparation method provided by the invention has the advantages of simple process and easiness in operation, and is suitable for large-scale popularization and application.

Inventors

  • LIU HAIHUI
  • LUO JIANXIANG
  • DONG QIANQIAN
  • XU QIANG
  • SUN QINGYI
  • Ju Jiancheng
  • JI XUE

Assignees

  • 天津工业大学

Dates

Publication Date
20260512
Application Date
20260302

Claims (8)

  1. 1. The preparation method of the two-way shape memory polyurethane/nanocomposite without external stress is characterized by comprising the following steps: S1, taking polytetrahydrofuran ether glycol and hexamethylene diisocyanate as raw materials, and carrying out a prepolymerization reaction under the catalysis of dibutyltin dilaurate to obtain a polyurethane prepolymer, then adding 1, 4-butanediol into a polyurethane prepolymer system, and continuing the reaction to obtain polytetrahydrofuran ether glycol based shape memory polyurethane serving as a polymer matrix; S2, blending the carbon-based nanomaterial and polytetrahydrofuran ether glycol-based shape memory polyurethane in a melt blending mode to obtain the non-external-stress two-way shape memory polyurethane/nanocomposite, wherein the carbon-based nanomaterial is a carboxylated multi-wall carbon nanotube or an aminated multi-wall carbon nanotube.
  2. 2. The method for preparing the external stress-free two-way shape memory polyurethane/nanocomposite according to claim 1, wherein the prepolymerization reaction temperature is 70-90 ℃ and the reaction time is 90-120min.
  3. 3. The method for preparing the non-external stress two-way shape memory polyurethane/nanocomposite according to claim 1, wherein the continuous reaction temperature is 70-90 ℃ and the reaction time is 30-60min.
  4. 4. The method for preparing an external stress free two-way shape memory polyurethane/nanocomposite as claimed in claim 1, wherein the molecular weight of the polytetrahydrofuran ether glycol is 650-2000.
  5. 5. The method for preparing the external stress-free two-way shape memory polyurethane/nanocomposite according to claim 1, wherein the molar ratio of polytetrahydrofuran ether glycol, hexamethylene diisocyanate and dibutyltin dilaurate is 0.01-0.1:0.22-0.3:0.012-0.20.
  6. 6. The method for preparing the external stress-free two-way shape memory polyurethane/nanocomposite according to claim 1, wherein the mass ratio of the carbon-based nanomaterial to the polytetrahydrofuran ether glycol-based shape memory polyurethane is 0.1-8:100.
  7. 7. The method for preparing the non-external stress two-way shape memory polyurethane/nanocomposite according to claim 1, wherein the temperature of the melt blending is 65-85 ℃ and the blending time is 36-54h.
  8. 8. An external stress-free two-way shape memory polyurethane/nanocomposite prepared by the method of any one of claims 1-7.

Description

External stress-free two-way shape memory polyurethane/nanocomposite and preparation method thereof Technical Field The invention relates to the field of functional material preparation, and relates to an external stress-free two-way shape memory polyurethane/nanocomposite and a preparation method thereof. Background Shape Memory Polyurethane (SMPU) is a versatile material with excellent properties such as good flexibility, transparency, abrasion resistance and mechanical strength for research and wide application in the fields of smart apparel, flexible displays, electronic textiles, durable wheels, and high performance adhesives. Despite the many applications and potential of SMPUs, PU still has certain limitations, such as poor electrical and thermal conductivity, which limit its potential for full use. The traditional SMPU has the main defects of low stress recovery degree and low reversible strain amount caused by low rigidity, and the application range of the SMPU can be further expanded by using the reinforcing material on the nanometer and microcosmic scale. Nanofillers such as nanoclays, carbon nanotubes, nano-platelet graphene and other inorganic fillers are used to improve the shape memory properties of the miscible blends. These nanoparticles not only enhance the stiffness and mechanical properties of the SMPU, but also effectively enhance the shape memory behavior of the SMPU as a fixed structure. However, in the preparation of polymer nanocomposites, it is an important challenge to achieve a sufficiently uniform dispersion of the nanomaterial in the polymer matrix, due in part to the relatively high surface area of the nanoparticle and the interfacial effect with the polymer matrix, which can easily lead to aggregation and agglomeration of the nanofiller in the polymer matrix. On the other hand, nanoparticles play an important role in driving the shape change of the SMP. The earliest reported method of stimulating SMP shape change was direct heat activation. Although this method is straightforward, the operation needs to be performed in an oven-like or water bath-like environment, and the range of applications is limited. Therefore, the addition of nanoparticles in the SMP matrix to achieve indirect heating becomes necessary and important. For example, indirect heating methods such as electric field, magnetic field, light, microwaves and the like can activate SMPNC materials, so that the actual application requirements can be better met. Disclosure of Invention Aiming at the technical problems in the background technology, the invention aims to provide an external stress-free two-way shape memory polyurethane/nanocomposite and a preparation method thereof. In order to achieve the above purpose, the present invention adopts the following technical scheme: The first aspect of the invention provides a method for preparing an external stress-free two-way shape memory polyurethane/nanocomposite, comprising the following steps: S1, taking polytetrahydrofuran ether glycol (PTMEG) and Hexamethylene Diisocyanate (HDI) as raw materials, and carrying out a prepolymerization reaction under the catalysis of dibutyl tin dilaurate (DBTDL) to obtain a polyurethane prepolymer, then adding 1, 4-Butanediol (BDO) into a polyurethane prepolymer system, and continuing the reaction to obtain polytetrahydrofuran ether glycol-based shape memory polyurethane, namely PTMEG-based SMPU serving as a polymer matrix; S2, blending the carbon-based nanomaterial with PTMEG-based SMPU by adopting a melt blending mode to obtain the non-external stress bidirectional shape memory polyurethane/nanocomposite, wherein the carbon-based nanomaterial is carboxylated multiwall carbon nanotubes (MWNTs-COOH) or aminated multiwall carbon nanotubes (MWNTs-NH 2). Preferably, the prepolymerization temperature is 70-90 ℃ and the reaction time is 90-120min. Preferably, the continuous reaction temperature is 70-90 ℃ and the reaction time is 30-60min. Preferably, the molecular weight of the polytetrahydrofuran ether glycol is 650-2000. Preferably, the molar ratio of polytetrahydrofuran ether glycol (PTMEG), hexamethylene Diisocyanate (HDI) and dibutyltin dilaurate (DBTDL) is 0.01-0.1:0.22-0.3:0.012-0.20. Preferably, the mass ratio of the carbon-based nanomaterial to the polytetrahydrofuran ether glycol-based shape memory polyurethane is 0.1-8:100. Preferably, the melt blending temperature is 65-85 ℃ and the blending time is 36-54h. The invention has the following beneficial effects: (1) The invention takes polytetrahydrofuran ether glycol based shape memory polyurethane as a polymer matrix, and different carbon based nano materials (MWNTs-COOH and MWNTs-NH 2) are fused and blended with the polytetrahydrofuran ether glycol based shape memory polyurethane to successfully prepare the shape memory polyurethane composite material containing different carbon based nano materials and the SMPU composite material compounded with MWCNTs-NH 2 with different c