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CN-122013367-A - Thermal expansion-retraction silicone rubber material and preparation method and application thereof

CN122013367ACN 122013367 ACN122013367 ACN 122013367ACN-122013367-A

Abstract

The invention belongs to the field of fiber preparation, and particularly discloses a preparation method of a thermal expansion-retraction silicone rubber material, which comprises the steps of taking a silicone rubber prepolymer and thermal expansion microspheres, uniformly mixing to form a prepolymer mixture, connecting the prepolymer mixture to an inner spinning head through a first injection tube, taking sodium alginate aqueous solution to an outer spinning head through a second injection tube, wherein the mass ratio of the thermal expansion microspheres to the prepolymer mixture is 5-10%, pushing out a core-shell fiber under the condition that the flow rate ratio of the inner spinning head to the outer spinning head is 0.8-1.2, and then crosslinking, solidifying and removing the shell to obtain the thermal expansion silicone rubber fiber, wherein the elastic modulus of the crosslinked silicone rubber prepolymer is less than 1MPa. The continuous thermal expansion silicone rubber fiber with stable thermal expansion-retraction capacity and good mechanical properties such as silicone rubber elasticity can be prepared by only low-content thermal expansion microspheres, and secondary macroscopic scale and performance change can be generated when the continuous thermal expansion silicone rubber fiber is heated, so that the continuous thermal expansion silicone rubber fiber has application prospects in the fields of thermal insulation fabrics, thermal driving components, temperature sensors and the like.

Inventors

  • ZHAO GUOXU
  • LI MING
  • WANG LEI

Assignees

  • 海南大学

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. The preparation method of the thermal expansion-retraction silicone rubber material is characterized by comprising the following steps of: S101, uniformly mixing a silicone rubber prepolymer and thermal expansion microspheres to form a prepolymer mixture, connecting the prepolymer mixture to an inner spinning head through a first injection tube, connecting sodium alginate aqueous solution to an outer spinning head through a second injection tube, wherein the mass ratio of the thermal expansion microspheres to the prepolymer mixture is 2-20%, the elastic modulus of the crosslinked silicone rubber prepolymer is less than 1MPa, and the expansion temperature of the thermal expansion microspheres is higher than the heat curing temperature of the silicone rubber. S102, respectively setting an inner spinning head and an outer spinning head, pushing core-shell fibers with fiber-shaped silicon rubber/thermal expansion microsphere prepolymer as an inner core and alginic acid hydrogel as an outer shell into calcium chloride aqueous solution under the condition that the flow rate ratio of the inner spinning head to the outer spinning head is 0.6-1.5, and then obtaining the thermal expansion silicon rubber fibers through crosslinking and solidification, immersing and washing the core-shell fibers with sodium citrate solution, cleaning and airing.
  2. 2. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S102, the mass ratio of the thermal expansion microsphere to the pre-polymerization mixture is 5-10%.
  3. 3. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S102, the flow rate ratio of the inner spinneret to the outer spinneret is 0.8-1.2.
  4. 4. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S101, the inner spinning head is a needle of 16-22G, and the outer spinning head is a needle of 12-16G.
  5. 5. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S101, the particle size of the thermal expansion microsphere before expansion is less than 3% of the diameter of the thermal expansion silicone rubber fiber, and the particle size after expansion is not more than 10% of the diameter of the thermal expansion silicone rubber fiber.
  6. 6. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S101, the mass concentration of the sodium alginate aqueous solution is 1.5wt%, and in the step S102, the mass concentration of the calcium chloride aqueous solution is 2. 2 wt%.
  7. 7. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S101, the viscosity of the pre-polymerization mixture of the silicone rubber pre-polymer and the thermal expansion microsphere is 1 to 12000 Pa S at a shear rate of 0.1S -1 , 1 to 1500 Pa S at a shear rate of 1S -1 , and 1 to 200 Pa S at a shear rate of 10S -1 .
  8. 8. The method for preparing a thermal expansion-contraction silicone rubber material according to claim 1, wherein in the step S101, 2 or more thermal expansion microspheres are selected.
  9. 9. A thermally-induced expansion-retraction silicone rubber material prepared according to the method of any one of claims 1 to 8.
  10. 10. Use of the thermally-induced expansion-contraction silicone rubber material according to claim 9 for preparing a thermal insulation fabric, a thermally-responsive actuator or a temperature sensor.

Description

Thermal expansion-retraction silicone rubber material and preparation method and application thereof Technical Field The invention relates to the field of preparation of high polymer materials, in particular to a thermal expansion-retraction silicone rubber material, a preparation method and application thereof. Background The material with the thermal response material capable of changing the shape and the volume when the temperature is changed has a huge application prospect in the fields of temperature sensing, medicine controlled release, thermal energy storage, soft robots and the like. The thermal expansion microsphere is taken as one of the representative thermal response materials, can generate volume expansion when being heated, and can regulate and control physical properties such as macro-microstructure, density, mechanical property and the like of the materials when being introduced into other polymer matrix materials. At present, a polymer matrix formed by combining a thermoplastic elastomer polymer (such as polyurethane) and thermal expansion microspheres is generally selected, but the thermal expansion process of the thermal expansion microspheres is synchronously carried out in the thermoplastic processing and forming process. This allows the material to be formed into a solid with the thermally expandable microspheres in an expanded state and no longer having thermal expansion capabilities. Even if unexpanded, thermally expanded microspheres can be incorporated, such thermoplastic polymers tend to melt when the thermally expanded microspheres expand upon heating, making it difficult to maintain a solid state. Silicone Rubber (Silicone Rubber) is an elastomer material based on Silicone polymers, which is favored in many fields of application due to its excellent physical and chemical properties. And the preparation of thermally responsive materials with silicone rubber as a substrate is a research hotspot. For example, china patent 202411505841.8 discloses a temperature-responsive expandable silicone rubber-based plugging material and a preparation method thereof, which are prepared by uniformly mixing room temperature vulcanized silicone rubber, expandable polymer microspheres, carbon black and the like as raw materials, adding a cross-linking agent and a catalyst for curing to obtain the temperature-responsive expandable silicone rubber-based plugging agent, and expanding after the temperature rises, thereby playing a role in plugging. However, the silicone rubber-based plugging material is a block with larger size, the structure limits practical application, and the problem that the expansion performance and the elasticity cannot be achieved is solved. Compared with the block material with larger size, the fiber material can be woven into ropes or fabrics, and the application scene is different and wide. The thermal expansion microsphere is introduced into the silicone rubber fiber, so that the diameter, length, density, surface roughness, thermal conductivity and mechanical properties of the fiber and the ball can be regulated and controlled by thermal expansion-retraction, and the thermal expansion microsphere is applied to the fields of sealing, buffering, heat insulation, bionic deformation and the like. However, the difficult problem of poor processability of silicone rubber is limited, and silicone rubber fibers are rarely researched and developed in the field, and thermal expansion fibers based on silicone rubber and a preparation method thereof are not proposed. Although China patent (202111314133.2) establishes a cross-linked polymer spinning technology including silicone rubber, a composite material combining silicone rubber fibers and thermal expansion microspheres and a preparation method are not involved. Therefore, how to combine the silicone rubber with the thermal expansion microspheres to ensure that the expansion rate is not limited by the stress of the silicone rubber and obtain the silicone rubber fiber material with stable and considerable thermal expansion-retraction capability is an urgent problem to be solved. Disclosure of Invention In view of the above, the invention provides a preparation method of a thermal expansion-retraction silicone rubber material, which solves the problems existing in the background technology. The invention provides a preparation method of a thermal expansion-retraction silicone rubber material, which comprises the following steps: S101, uniformly mixing a silicone rubber prepolymer and thermal expansion microspheres to form a prepolymer mixture, connecting the prepolymer mixture to an inner spinning head through a first injection tube, and connecting sodium alginate aqueous solution to an outer spinning head through a second injection tube, wherein the mass concentration of the thermal expansion microspheres and the prepolymer mixture is 2-20%. S102, respectively setting an inner spinning head and an outer spinning head, pushing core-sh