阅读说明：本技术 形状记忆微孔复合材料及其制备方法 (Shape memory microporous composite material and preparation method thereof ) 是由 陈淑海 王丹 肖培栋 刘凯良 宋小娜 于 2019-12-20 设计创作，主要内容包括：本发明属于高分子材料技术领域,具体的涉及一种形状记忆微孔复合材料及其制备方法。包括如下重量份的组分：热塑性弹性体材料40-95份,低温热敏性形状记忆材料5-60份,交联剂0.1-1份。通过一步法合成工艺或共混改性挤出工艺将低温热敏性形状记忆材料和交联剂共混于热塑性弹性体材料中,并采用超临界微孔发泡工艺制备了具有形状记忆功能的发泡珠粒,然后进一步制备成微孔复合材料,该材料具有质轻、高回弹、比强度高、形状记忆等特点,通过低温热刺激可使50％压缩永久变形回复率高达100％,该材料所用工艺简单,无毒环保,可广泛应用于鞋材、包装运输、汽车内饰、医疗器械等领域。(The invention belongs to the technical field of high polymer materials, and particularly relates to a shape memory microporous composite material and a preparation method thereof. Comprises the following components in parts by weight: 40-95 parts of thermoplastic elastomer material, 5-60 parts of low-temperature heat-sensitive shape memory material and 0.1-1 part of cross-linking agent. The material has the characteristics of light weight, high resilience, high specific strength, shape memory and the like, the 50% compression permanent deformation recovery rate can reach 100% through low-temperature thermal stimulation, and the material has simple process, is nontoxic and environment-friendly and can be widely applied to the fields of shoe materials, packaging and transportation, automotive upholstery, medical appliances and the like.)

1. A shape memory microporous composite material, characterized by: comprises the following components in parts by weight:

40-95 parts of thermoplastic elastomer material

5-60 parts of low-temperature heat-sensitive shape memory material

0.1-1 part of cross-linking agent.

2. The shape memory microporous composite of claim 1, wherein: the thermoplastic elastomer material is one or more of olefins, vinyl chloride, urethanes, esters, amides, organic fluorine or thermoplastic rubber.

3. The shape memory microporous composite of claim 1, wherein: the low-temperature heat-sensitive shape memory material is one of trans-1, 4-polyisoprene or polynorbornene with different Mooney viscosities, wherein the Mooney viscosity of TPI is withinIn the meantime.

4. The shape memory microporous composite of claim 1, wherein: the cross-linking agent is one or two of dicumyl peroxide, triallyl isocyanurate or di-tert-butyl peroxide.

5. The shape memory microporous composite of claim 1, wherein: the addition amount of the low-temperature heat-sensitive shape memory material is 5-60% of the total mass of the raw materials, and the shape recovery temperature of the low-temperature heat-sensitive shape memory material is between 40 and 100 ℃.

6. A method of preparing the shape memory microporous composite material of claim 1, characterized by: prepared by the following steps:

(1) preparation of blended elastomer beads

Blending the low-temperature heat-sensitive shape memory material and the cross-linking agent in the thermoplastic elastomer material by adopting a one-step synthesis process or a blending modification extrusion process, and obtaining blended elastomer beads with the shape memory function through extrusion granulation;

(2) preparation of shape memory microporous composite material

And adding the blended elastomer beads into a high-pressure kettle dispersed phase, introducing a foaming agent, and performing pressure-maintaining and temperature-raising treatment to prepare the shape memory microporous composite material.

7. The method of preparing a shape memory microporous composite material according to claim 6, characterized in that: the preparation temperature in the step (1) is 140-220 ℃.

8. The method of preparing a shape memory microporous composite material according to claim 6, characterized in that: the one-step synthesis process in the step (1) is to blend a mixture of a low-temperature thermosensitive shape memory material and a crosslinking agent in a thermoplastic elastomer material in a screw molding zone; the blending modification extrusion process is to convey the uniformly mixed thermoplastic elastomer material, the low-temperature heat-sensitive shape memory material and the cross-linking agent to a screw through a feeding port to be blended and molded.

9. The method of preparing a shape memory microporous composite material according to claim 6, characterized in that: in the step (2), the dispersed phase is water, and the addition amount of the blended elastomer beads is 10-50% of the mass of the dispersed phase; the foaming agent is one or two of carbon dioxide, nitrogen or air.

10. The method of preparing a shape memory microporous composite material according to claim 6, characterized in that: and (2) adding water into the autoclave as a dispersed phase, starting stirring, setting the rotating speed to be 50-600r/min, putting the blended elastomer beads into the dispersed phase of the autoclave through a feed inlet, sealing the equipment, opening an air inlet valve, introducing a foaming agent with the pressure of 0.1-0.5MPa, closing the air inlet valve, opening an exhaust valve to replace gas in the autoclave, closing the exhaust valve, introducing the foaming agent with the pressure of 5-12MPa, finally closing all valves, performing pressure maintaining and temperature rising treatment on the material in the autoclave, and quickly relieving the pressure for 5-30s when the temperature reaches 80-150 ℃ and the pressure reaches 8-20MPa to obtain the shape memory microporous composite material.

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a shape memory microporous composite material and a preparation method thereof.

Background

The microcellular elastomer material has excellent performances of light weight, high elasticity, wear resistance, buffering, shock absorption and the like, is represented by microcellular foamed polyurethane Elastomer (ETPU), is widely applied in various industries, wherein the fields of sole materials and plastic runways have already obtained mature application, and particularly, the sole of the popcorn made of the ETPU is once called as the running shoe with the strongest ground surface. However, due to the individual walking habit problems, all sole materials have uneven left and right heights after being worn for a long time, and long time, not only the sole is seriously worn, but also the serious consequences such as humpback, joint damage, lumbar discomfort, spinal diseases and the like are caused, and particularly for teenagers in the growing period, the damage factors of the teenagers have serious negative effects on the body health, so that the properties of resilience, specific strength, compression resistance and the like of the sole materials are widely concerned by learners.

One unique property of shape memory alloys is that they exhibit a "superelasticity" effect at a specific temperature, which is manifested by the ability to carry recoverable strains several or even tens of times greater than those of ordinary metals, and in recent years shape memory polymers have become more and more widely used in various fields, such as medical, architectural, aerospace, transportation, etc., as typified by nitinol. Korean jinxing pick et al developed a shape memory alloy with high elasticity embedded in the shoes thereof to prevent external impact and foot distortion, but have problems of complicated manufacturing process, difference in comfort between the insert and the shoe body, and heavy shoe body. Albert PWinger et al have invented a sole with an induction device that can be connected to a smart device, which can transmit data to the smart device in real time, and install a shape memory material insertion hole in the sole for installation and removal of the shape memory material, but have the problems of high manufacturing cost and complex structure.

Patent CN 108192321A discloses a moulding thermoplastic elastomer shape memory material under low temperature/room temperature, adopts and adds materials such as polycaprolactone, polyurethane in thermoplastic elastomer material as the transition phase, and accessible traditional foaming method preparation foaming foam, though adopt the blend processing technology to prepare out the blend material, but phase transition material's selection material can't satisfy 100% shape recovery ability in this patent, just traditional foaming method adopts chemical foaming technology usually, is difficult to satisfy the environmental protection requirement, has had a large amount of studies in addition to show, the cotton bubble size of bubble that traditional foaming method prepared is big, the cell density is little, resilience and resistance to compression can't compare with micropore foaming material.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art and provides a shape memory microporous composite material; the composite material has the characteristics of light weight, high resilience, high specific strength and shape memory, and the 50% compression set recovery rate can reach 100% through low-temperature thermal stimulation; the invention also provides a preparation method thereof.

The shape memory microporous composite material comprises the following components in parts by weight:

40-95 parts of thermoplastic elastomer material

5-60 parts of low-temperature heat-sensitive shape memory material

0.1-1 part of cross-linking agent.

Wherein:

the thermoplastic elastomer material is a kind of elastomer which has rubber elasticity at normal temperature and can be plasticized and molded at high temperature, and is one or more of olefins (TPO, TPV), vinyl chlorides (TPVC, TCPE), urethanes (TPU), esters (TPEE), amides (TPAE), organic fluorine (TPF) or thermoplastic rubber (TPR).

The low-temperature heat-sensitive shape memory material is one of trans-1, 4-polyisoprene (TPI) or Polynorbornene (PNB) with different Mooney viscosities, wherein the Mooney viscosity of the TPI is within the range

In the meantime.

The adding amount of the low-temperature heat-sensitive shape memory material is 5-60% of the total mass of the raw materials.

The low-temperature thermosensitive shape memory material needs to be chemically crosslinked, and the crosslinking agent is one or two of odorless dicumyl peroxide (DCP), triallyl isocyanurate (TAIC), di-tert-butyl peroxide (DTBP) and other environment-friendly crosslinking agents.

The shape recovery temperature of the low temperature heat sensitive shape memory material is between 40-100 ℃.

The preparation method of the shape memory microporous composite material comprises the following steps:

(1) preparation of blended elastomer beads

Blending the low-temperature heat-sensitive shape memory material and the cross-linking agent in the thermoplastic elastomer material by adopting a one-step synthesis process or a blending modification extrusion process, and obtaining blended elastomer beads with the shape memory function through extrusion granulation;

(2) preparation of shape memory microporous composite material

And adding the blended elastomer beads into a high-pressure kettle dispersed phase, introducing a foaming agent, and performing pressure-maintaining and temperature-raising treatment to prepare the shape memory microporous composite material.

Wherein:

the preparation temperature in the step (1) is 140-220 ℃.

The one-step synthesis process in the step (1) means that a mixture of the low-temperature thermosensitive shape memory material and the crosslinking agent is blended in the thermoplastic elastomer material in a screw molding zone.

The blending modification extrusion process in the step (1) is to convey the uniformly mixed thermoplastic elastomer material, the low-temperature heat-sensitive shape memory material and the cross-linking agent to a screw through a feeding port for blending and forming.

The dispersed phase in the step (2) is water, and the adding amount of the blended elastomer beads is 10-50% of the mass of the dispersed phase.

The foaming agent in the step (2) is one or two of carbon dioxide, nitrogen or air.

As a preferred technical scheme, the preparation method of the shape memory microporous composite material is prepared by the following steps:

(1) preparation of the blended elastomer beads: the low-temperature thermosensitive shape memory material and the cross-linking agent are blended in the thermoplastic elastomer through a thermoplastic elastomer one-step synthesis process or a blending modification extrusion process, the low-temperature thermosensitive shape memory material forms a cross-linked network structure in the thermoplastic elastomer under the action of high temperature of 140-220 ℃, and finally the blended elastomer bead with the shape memory function is obtained through underwater cutting extrusion granulation.

(2) Preparing a shape memory microporous composite material: adding a certain amount of water into an autoclave as a dispersed phase, starting stirring, setting the rotating speed to be 50-600r/min, putting the blended elastomer beads into the dispersed phase of the autoclave through a feed inlet, sealing equipment, opening an air inlet valve, introducing a foaming agent with the pressure of 0.1-0.5MPa, closing the air inlet valve, opening an exhaust valve to replace gas in the autoclave, then closing the exhaust valve, introducing the foaming agent with the pressure of 5-12MPa, finally closing all valves, maintaining the pressure and raising the temperature of the materials in the autoclave, continuously increasing the pressure along with the rise of the temperature, and when the temperature reaches 80-150 ℃ and the pressure reaches 8-20MPa, rapidly releasing the pressure for 5-30s to prepare the shape memory microporous composite material.

Compared with the prior art, the invention has the following beneficial effects:

(1) the shape memory microporous composite material has a strong shape memory function, the shape memory thermal stimulation temperature is 40-100 ℃, the deformation recovery rate is up to 100%, and the shape memory microporous composite material can be repeatedly operated for many times.

(2) The shape memory microporous composite material is prepared by blending a low-temperature thermosensitive shape memory material and a cross-linking agent in a matrix through a thermoplastic elastomer one-step synthesis process or a blending modification extrusion process and successfully preparing foamed beads with a shape memory function by adopting a supercritical microporous foaming process, and has the characteristics of light weight, high resilience, high specific strength, shape memory and the like, and the recovery rate of 50 percent of compression permanent deformation can reach 100 percent through low-temperature thermal stimulation.

(3) The shape memory micropore composite material is non-toxic and environment-friendly, can be widely applied to the fields of shoe materials, packaging transportation, automobile interior decoration, medical appliances and the like, when the shape memory micropore composite material is applied to soles, a low-temperature thermosensitive shape memory material is mixed in a thermoplastic elastomer matrix to prepare a micropore foaming insole, when the shoes are in a low heel bias condition, the problem that the existing insole cannot recover after being pressed bias can be solved through low-temperature thermal stimulation, and the health of human skeletons is indirectly ensured.

(4) The shape memory microporous composite material is applied to the preparation of soles, and the midsoles of the shoes are of an integrated structure, so that the preparation complexity of the embedded shape memory soles is reduced, and the shape memory microporous composite material has excellent performances of light weight, durability, high resilience, shape memory and the like.

(5) The preparation method of the shape memory microporous composite material has the characteristics of simple process and low preparation cost.

Detailed Description

The present invention is further described below with reference to examples.