阅读说明：本技术 一种超临界流体聚合物微孔发泡物及其制备方法 (Supercritical fluid polymer microcellular foam and preparation method thereof ) 是由 胡志飞 郑孙兴 李图文 于 2021-07-16 设计创作，主要内容包括：本发明公开了一种超临界流体聚合物微孔发泡物及其制备方法,涉及微孔发泡物技术领域,其技术方案要点包括如下重量份的组分：聚乙烯-醋酸乙烯酯共聚物60-80份；热塑性聚酯弹性体20-40份；物理发泡剂20-25份；双氧水1.2-2.6份。本发明通过采用聚乙烯-醋酸乙烯酯共聚物、热塑性聚酯弹性体、物理发泡剂和双氧水作为组成成分以设定比例混合后,制备获得有效减小密度的超临界流体聚合物微孔发泡物,进而在氧离子、氢离子、过氧氢根离子的结合下,产生的氧气溢出和水在高温下蒸发,获得密度提升的胚体；以便在反应釜中发泡和冷却成型为显著减小密度的超临界流体聚合物微孔发泡物,并使得该超临界流体聚合物微孔发泡物具有提升产品产量和显著降低能耗的效果。(The invention discloses a supercritical fluid polymer microcellular foam and a preparation method thereof, relating to the technical field of microcellular foam, and the key points of the technical scheme are that the supercritical fluid polymer microcellular foam comprises the following components in parts by weight: 60-80 parts of polyethylene-vinyl acetate copolymer; 20-40 parts of a thermoplastic polyester elastomer; 20-25 parts of a physical foaming agent; 1.2 to 2.6 portions of hydrogen peroxide. According to the invention, after polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer, physical foaming agent and hydrogen peroxide are used as components and mixed according to a set proportion, supercritical fluid polymer microporous foaming matter with effectively reduced density is prepared, and then under the combination of oxygen ions, hydrogen ions and peroxyhydrogen ions, generated oxygen overflows and water evaporates at high temperature, so that a blank with improved density is obtained; so as to foam and cool in the reaction kettle to form the supercritical fluid polymer microcellular foam with obviously reduced density, and the supercritical fluid polymer microcellular foam has the effects of improving the product yield and obviously reducing the energy consumption.)

1. The microporous foaming material of the supercritical fluid polymer is characterized by comprising the following components in parts by weight:

60-80 parts of polyethylene-vinyl acetate copolymer;

20-40 parts of a thermoplastic polyester elastomer;

20-25 parts of a physical foaming agent;

1.2 to 2.6 portions of hydrogen peroxide.

2. A supercritical fluid polymer microcellular foam according to claim 1, wherein: the physical foaming agent comprises calcium carbonate and hollow glass beads in a weight ratio of 1: 1.3-1.8.

3. A supercritical fluid polymer microcellular foam according to claim 2, wherein: the physical foaming agent is obtained by early treatment, wherein the early treatment comprises the steps of mixing the calcium carbonate and the hollow glass beads, sequentially calcining at the temperature of 320-440 ℃, pouring with clear water and cooling to 50-80 ℃ for multiple times of circulation.

4. A supercritical fluid polymer microcellular foam according to claim 3, wherein: also comprises 2.1 to 2.5 portions of silicone oil; and the silicone oil, the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer are blended and then melted to obtain a foaming molten mass.

5. A supercritical fluid polymer microcellular foam according to claim 1, wherein: the hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

6. A method of preparing microcellular foams of supercritical fluid polymers according to any one of claims 1 to 5, comprising the steps of:

blending and melting polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

and placing the blank into a reaction kettle for foaming, and cooling and forming.

7. The method of claim 6, wherein the microcellular foaming product of the supercritical fluid polymer comprises: the melting temperature is 140 ℃, the foaming pressure of the reaction kettle is 16-30MPa, the foaming time is 1-3h, and the foaming temperature is 130-140 ℃.

8. The method of claim 6, wherein the ionizing device comprises:

a head (1) for feeding the foamed melt;

the tail part (2) is used for discharging;

a conveying screw (3) for conveying the foamed melt from the head portion (1) to the tail portion (2) and ionizing the foamed melt to form a charged body;

and a feeding portion (4) for introducing an additive to mix the additive with the foamed melt.

9. The method of claim 8, wherein the microcellular foaming product of supercritical fluid polymer comprises: the conveying screw rod (3) is provided with spiral conveying leaves (31), the spiral conveying leaves (31) are spirally wound on the conveying screw rod (3) along the axis direction of the conveying screw rod (3), the spiral conveying leaves (31) are provided with a plurality of spiral fin bodies (311) which symmetrically penetrate out of two sides of the spiral conveying leaves (31), and the spiral fin bodies (311) are connected with electricity.

10. The method of claim 8, wherein the microcellular foaming product of supercritical fluid polymer comprises: the reaction kettle adopts at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide as a supercritical fluid.

Technical Field

The invention relates to the technical field of microcellular foams, in particular to a supercritical fluid polymer microcellular foam and a preparation method thereof.

Background

In the process of preparing the foams, it is generally necessary to use blowing agents. Blowing agents include both physical blowing agents and chemical blowing agents.

When the foaming agent is prepared by a physical foaming agent, a proper physical foaming method is required. In brief, the physical foaming method is to foam the plastic by a physical method, and there are generally three methods: (1) firstly, dissolving inert gas in a plastic melt or paste under pressure, and releasing gas through decompression so as to form air holes in the plastic for foaming; (2) foaming by vaporizing a low boiling point liquid dissolved in the polymer melt; (3) and foaming by adding hollow spheres to a plastic to form a foam.

Therefore, the physical foaming agent used in the physical foaming method has relatively low cost, particularly low cost of carbon dioxide and nitrogen, flame retardance and no pollution, and thus has high application value; and the physical foaming agent has no residue after foaming, and has little influence on the performance of the foamed plastic. However, the method needs a special injection molding machine and auxiliary equipment, and has great technical difficulty.

When the foaming agent is prepared by a chemical foaming agent, a corresponding chemical foaming method is required. Briefly, the chemical foaming process uses a chemical process to generate a gas to foam the plastic: heating the chemical foaming agent added into the plastic to decompose and release gas for foaming; in addition, the foaming can also be carried out by means of gases released by chemical reactions between the plastic components.

In the prior art, no matter chemical foaming or physical foaming is adopted, a foaming mold is required to be adopted, so that the yield of products is low, the energy consumption is high, and the improvement is needed.

Disclosure of Invention

In view of the disadvantages of the prior art, a first object of the present invention is to provide a supercritical fluid polymer microcellular foamed product having effects of increasing product yield, reducing energy consumption, and reducing density.

In order to achieve the purpose, the invention provides the following technical scheme:

a supercritical fluid polymer microcellular foam comprises the following components in parts by weight:

60-80 parts of polyethylene-vinyl acetate copolymer;

20-40 parts of a thermoplastic polyester elastomer;

20-25 parts of a physical foaming agent;

1.2 to 2.6 portions of hydrogen peroxide.

The invention is further configured to: the physical foaming agent comprises calcium carbonate and hollow glass beads in a weight ratio of 1: 1.3-1.8.

The invention is further configured to: the physical foaming agent is obtained by early treatment, wherein the early treatment comprises the steps of mixing the calcium carbonate and the hollow glass beads, sequentially calcining at the temperature of 320-440 ℃, pouring with clear water and cooling to 50-80 ℃ for multiple times of circulation.

The invention is further configured to: also comprises 2.1 to 2.5 portions of silicone oil; and the silicone oil, the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer are blended and then melted to obtain a foaming molten mass.

The invention is further configured to: the hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

The second purpose of the invention is to provide a preparation method of a supercritical fluid polymer microcellular foam, which comprises the following steps:

blending and melting polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

and placing the blank into a reaction kettle for foaming, and cooling and forming.

The invention is further configured to: the melting temperature is 140 ℃, the foaming pressure of the reaction kettle is 16-30MPa, the foaming time is 1-3h, and the foaming temperature is 130-140 ℃.

The invention is further configured to: the ionization apparatus includes:

a head for feeding of a foamed melt;

the tail part is used for discharging;

a conveying screw for conveying the foamed molten mass from the head portion to the tail portion and ionizing the foamed molten mass to form a charged body;

and a feeding part for introducing the additive to mix the additive with the foamed melt.

The invention is further configured to: the conveying screw is provided with a spiral conveying blade, the spiral conveying blade is spirally wound on the conveying screw along the axis direction of the conveying screw, the spiral conveying blade is provided with a plurality of spiral fins symmetrically penetrating out of two sides of the spiral conveying blade, and the spiral fins are connected with electricity.

The invention is further configured to: the reaction kettle adopts at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide as a supercritical fluid.

In conclusion, the invention has the following beneficial effects: the supercritical fluid polymer microcellular foam capable of effectively reducing the density is prepared by mixing polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer, physical foaming agent and hydrogen peroxide as components in a set proportion; meanwhile, in the preparation process of the supercritical fluid polymer microporous foam, firstly, the calcium carbonate and the hollow glass beads are subjected to surface treatment in a multi-cycle calcining and pouring mode, and are mixed with the foaming melt after being combined with hydrogen peroxide, and in the mixing process, oxygen ions, hydrogen ions and peroxyhydrogen ions formed by thermal decomposition of hydrogen peroxide are combined with a charged body formed by ionization of the foaming melt, so that under the combination of the oxygen ions, the hydrogen ions and the peroxyhydrogen ions, generated oxygen overflows and water is evaporated at high temperature, and a blank with improved density is obtained; so as to foam and cool in the reaction kettle to form the supercritical fluid polymer microcellular foam with obviously reduced density, and the supercritical fluid polymer microcellular foam has the effects of improving the product yield and obviously reducing the energy consumption.

Drawings

Fig. 1 is a schematic structural diagram of the present embodiment.

Description of reference numerals: 1. a head portion; 2. a tail portion; 3. a transfer screw; 31. a spiral conveying blade; 311. a helical fin body; 4. a feeding part.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The following is a detailed description of the supercritical fluid polymer microcellular foamed material and the preparation method thereof according to the embodiment of the present invention:

a supercritical fluid polymer microcellular foam comprises the following components in parts by weight: 60-80 parts of polyethylene-vinyl acetate copolymer, 20-40 parts of thermoplastic polyester elastomer, 20-25 parts of physical foaming agent, 2.1-2.5 parts of silicone oil and 1.2-2.6 parts of hydrogen peroxide.

Wherein the physical foaming agent comprises calcium carbonate and hollow glass beads in a weight ratio of 1: 1.3-1.8. And the physical blowing agent is obtained by pretreatment. The early treatment comprises the steps of mixing calcium carbonate and hollow glass beads, calcining at the temperature of 440 ℃ by using 320-. The number of cycles is at least 3, and when the number of cycles is 5, the best treatment effect is achieved.

The silicone oil is used for being blended with the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer and then melted to obtain a foaming molten mass.

The hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

A preparation method of a supercritical fluid polymer microcellular foam comprises the following steps:

blending polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil, and then melting at 140 ℃ to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

placing the blank into a reaction kettle with the foaming pressure of 16-30MPa for foaming, wherein at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide is used as a supercritical fluid in the reaction kettle, the foaming time is 1-3h, the foaming temperature is 130-140 ℃, and cooling and forming are carried out after foaming is finished.

It is to be mentioned that, as shown in FIG. 1, the ionizing device comprises a head part 1 for feeding the foamed melt, a tail part 2 for discharging, a conveying screw 3 for conveying the foamed melt from the head part 1 to the tail part 2 and ionizing the foamed melt to form a charged body, and a charging part 4 for introducing an additive to mix the additive with the foamed melt.

Wherein the conveyor screw 3 is provided with a helical conveyor flight 31. The spiral conveying blade 31 is spirally wound on the conveying screw 3 along the axial direction of the conveying screw 3, and the spiral conveying blade 31 is provided with a plurality of spiral fins 311 which symmetrically penetrate out from both sides of the spiral conveying blade 31. The spiral fin 311 is electrically connected so that sufficient ionization is achieved after sufficient contact with the foamed melt.

Example one

A supercritical fluid polymer microcellular foam comprises the following components in parts by weight: 60 parts of polyethylene-vinyl acetate copolymer, 20 parts of thermoplastic polyester elastomer, 20 parts of physical foaming agent, 2.1 parts of silicone oil and 1.2 parts of hydrogen peroxide.

Wherein the physical foaming agent comprises calcium carbonate and hollow glass beads according to the weight part ratio of 1: 1.3. And the physical blowing agent is obtained by pretreatment. The early treatment comprises mixing calcium carbonate and hollow glass beads, and performing calcination at 320 ℃ and water spraying and cooling to 50 ℃ in three cycles.

The silicone oil is used for being blended with the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer and then melted to obtain a foaming molten mass.

The hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

A preparation method of a supercritical fluid polymer microcellular foam comprises the following steps:

blending polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil, and then melting at 140 ℃ to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

and placing the blank into a reaction kettle with the foaming pressure of 16MPa for foaming, wherein the reaction kettle adopts at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide as a supercritical fluid, the foaming time is 1h, the foaming temperature is 130 ℃, and the blank is cooled and molded after foaming is finished.

It is to be mentioned that, as shown in FIG. 1, the ionizing device comprises a head part 1 for feeding the foamed melt, a tail part 2 for discharging, a conveying screw 3 for conveying the foamed melt from the head part 1 to the tail part 2 and ionizing the foamed melt to form a charged body, and a charging part 4 for introducing an additive to mix the additive with the foamed melt.

Wherein the conveyor screw 3 is provided with a helical conveyor flight 31. The spiral conveying blade 31 is spirally wound on the conveying screw 3 along the axial direction of the conveying screw 3, and the spiral conveying blade 31 is provided with a plurality of spiral fins 311 which symmetrically penetrate out from both sides of the spiral conveying blade 31. The spiral fin 311 is electrically connected so that sufficient ionization is achieved after sufficient contact with the foamed melt.

Example two

A supercritical fluid polymer microcellular foam comprises the following components in parts by weight: 70 parts of polyethylene-vinyl acetate copolymer, 30 parts of thermoplastic polyester elastomer, 23 parts of physical foaming agent, 2.3 parts of silicone oil and 1.9 parts of hydrogen peroxide.

Wherein the physical foaming agent comprises calcium carbonate and hollow glass beads in a weight ratio of 1: 1.5. And the physical blowing agent is obtained by pretreatment. The early treatment comprises mixing calcium carbonate and hollow glass beads, and performing calcination at 380 ℃ and water pouring cooling to 65 ℃ in five cycles.

The silicone oil is used for being blended with the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer and then melted to obtain a foaming molten mass.

The hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

A preparation method of a supercritical fluid polymer microcellular foam comprises the following steps:

blending polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil, and then melting at 140 ℃ to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

and placing the blank into a reaction kettle with the foaming pressure of 23MPa for foaming, wherein the reaction kettle adopts at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide as a supercritical fluid, the foaming time is 2h, the foaming temperature is 135 ℃, and cooling and forming are carried out after foaming is finished.

It is to be mentioned that, as shown in FIG. 1, the ionizing device comprises a head part 1 for feeding the foamed melt, a tail part 2 for discharging, a conveying screw 3 for conveying the foamed melt from the head part 1 to the tail part 2 and ionizing the foamed melt to form a charged body, and a charging part 4 for introducing an additive to mix the additive with the foamed melt.

Wherein the conveyor screw 3 is provided with a helical conveyor flight 31. The spiral conveying blade 31 is spirally wound on the conveying screw 3 along the axial direction of the conveying screw 3, and the spiral conveying blade 31 is provided with a plurality of spiral fins 311 which symmetrically penetrate out from both sides of the spiral conveying blade 31. The spiral fin 311 is electrically connected so that sufficient ionization is achieved after sufficient contact with the foamed melt.

EXAMPLE III

A supercritical fluid polymer microcellular foam comprises the following components in parts by weight: 80 parts of polyethylene-vinyl acetate copolymer, 40 parts of thermoplastic polyester elastomer, 25 parts of physical foaming agent, 2.5 parts of silicone oil and 2.6 parts of hydrogen peroxide.

Wherein the physical foaming agent comprises calcium carbonate and hollow glass beads in a weight ratio of 1: 1.8. And the physical blowing agent is obtained by pretreatment. The early treatment comprises the steps of mixing calcium carbonate and hollow glass beads, sequentially calcining at 440 ℃, and cooling to 80 ℃ by pouring clear water for multiple times of circulation to obtain the calcium carbonate hollow glass bead. The number of cycles is at least 3, and when the number of cycles is 5, the best treatment effect is achieved.

The silicone oil is used for being blended with the polyethylene-vinyl acetate copolymer and the thermoplastic polyester elastomer and then melted to obtain a foaming molten mass.

The hydrogen peroxide is used for stirring and mixing with the physical foaming agent at normal temperature to obtain the additive.

A preparation method of a supercritical fluid polymer microcellular foam comprises the following steps:

blending polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer and silicone oil, and then melting at 140 ℃ to obtain a foaming molten mass;

stirring and mixing the physical foaming agent and hydrogen peroxide at normal temperature to obtain an additive;

cooling the foamed molten mass and the additive into a blank after passing through an ionization device;

and placing the blank into a reaction kettle with the foaming pressure of 30MPa for foaming, wherein the reaction kettle adopts at least one of supercritical carbon dioxide, supercritical nitrogen and supercritical nitrogen oxide as a supercritical fluid, the foaming time is 3h, the foaming temperature is 140 ℃, and the blank is cooled and molded after foaming is finished.

It is to be mentioned that, as shown in FIG. 1, the ionizing device comprises a head part 1 for feeding the foamed melt, a tail part 2 for discharging, a conveying screw 3 for conveying the foamed melt from the head part 1 to the tail part 2 and ionizing the foamed melt to form a charged body, and a charging part 4 for introducing an additive to mix the additive with the foamed melt.

Wherein the conveyor screw 3 is provided with a helical conveyor flight 31. The spiral conveying blade 31 is spirally wound on the conveying screw 3 along the axial direction of the conveying screw 3, and the spiral conveying blade 31 is provided with a plurality of spiral fins 311 which symmetrically penetrate out from both sides of the spiral conveying blade 31. The spiral fin 311 is electrically connected so that sufficient ionization is achieved after sufficient contact with the foamed melt.

Comparative example 1

The difference between the first comparative example and the second comparative example is that hydrogen peroxide is not added in the first comparative example.

Comparative example No. two

Comparative example two differs from example two in that the physical blowing agent in comparative example two was not pre-treated.

Comparative example No. three

The difference between the third comparative example and the second example is that the spiral fin in the third comparative example is not electrically connected.

Performance testing

1. And (3) testing the density: testing according to ASTM D1622;

2. compressive strength: testing according to GB/T1453-;

3. expansion volume factor: measured in Connaire vision 3D-A1000.

TABLE one examples one to four Performance test results

In conclusion, the supercritical fluid polymer microcellular foam capable of effectively reducing the density is prepared by mixing polyethylene-vinyl acetate copolymer, thermoplastic polyester elastomer, physical foaming agent and hydrogen peroxide as components in a set proportion; meanwhile, in the preparation process of the supercritical fluid polymer microporous foam, firstly, the calcium carbonate and the hollow glass beads are subjected to surface treatment in a multi-cycle calcining and pouring mode, and are mixed with the foaming melt after being combined with hydrogen peroxide, and in the mixing process, oxygen ions, hydrogen ions and peroxyhydrogen ions formed by thermal decomposition of hydrogen peroxide are combined with a charged body formed by ionization of the foaming melt, so that under the combination of the oxygen ions, the hydrogen ions and the peroxyhydrogen ions, generated oxygen overflows and water is evaporated at high temperature, and a blank with improved density is obtained; so as to foam and cool in the reaction kettle to form the supercritical fluid polymer microcellular foam with obviously reduced density, and the supercritical fluid polymer microcellular foam has the effects of improving the product yield and obviously reducing the energy consumption.

References in this application to "first," "second," "third," "fourth," etc., if any, are intended to distinguish between similar elements and not necessarily to describe a particular order or sequence. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Furthermore, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, or apparatus.

It should be noted that the descriptions in this application referring to "first", "second", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

The principle and the implementation of the present application are explained herein by applying specific examples, and the above description of the embodiments is only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.