CN113956631A

CN113956631A - PET (polyethylene terephthalate) foam material as well as preparation method and application thereof

Info

Publication number: CN113956631A
Application number: CN202111473411.9A
Authority: CN
Inventors: 王均奇; 沈恋; 张小宾
Original assignee: Goode Eis Suzhou Corp ltd
Current assignee: Goode Eis Suzhou Corp ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-01-21
Anticipated expiration: 2041-11-29
Also published as: CN113956631B

Abstract

The invention provides a PET (polyethylene terephthalate) foaming material and a preparation method and application thereof, wherein the PET foaming material comprises a combination of polyethylene terephthalate, pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride, an accelerator, cyclopentane and liquid carbon dioxide in specific parts, wherein the pyromellitic dianhydride is added into a polyethylene terephthalate substrate to match with the phenylacetylene modified trimellitic anhydride, and the combination of the cyclopentane and the liquid carbon dioxide in specific parts is selected as a foaming agent, so that the obtained PET foaming material has ultrafine and uniform cells and excellent compression strength, tensile strength and shear strength according to a supercritical foaming principle; and the manufacturing process and control of the PET foaming material are relatively simple, so that automatic operation can be realized, and the PET foaming material is suitable for batch production.

Description

PET (polyethylene terephthalate) foam material as well as preparation method and application thereof

Technical Field

The invention belongs to the technical field of foaming materials, and particularly relates to a PET foaming material and a preparation method and application thereof.

Background

In the past decades, plastic products have been widely used, and with the intensive research and exploration on plastic products, it has been found that many cheap and practical plastic products appear in front of people, wherein the foaming material has the characteristics of excellent structural performance, light weight, wide application and the like, and becomes a special product with great development prospect.

According to different raw materials used for foaming, the foaming materials can be divided into thermoplastic foaming materials such as PVC foaming materials, PET foaming materials, PU foaming materials, PP foaming materials, PS foaming materials and the like; according to different purposes, there are heat insulating materials, fireproof flame retardant materials, fireproof materials and the like; from the structural point of view of the foaming material, the foaming material is a resin product with 1010 to 1012 dimensional pore structures per cubic centimeter, the pore size is 10-0.1 mu m, and compared with the common solid non-foaming material, the foaming material has more excellent mechanical property, acoustic property, thermal insulation property and optical property.

In the production of foamed materials, chlorocarbons (CFCs) were used as physical blowing agents at the earliest and chlorofluorocarbons (HCFCs) were used later in place of chlorocarbons, but these blowing agents themselves destroy the oxygen layer and are gradually prohibited from being used in the production of foamed products, and hydrocarbon blowing agents, which are combined with chlorofluorocarbons and chlorocarbons, are flammable and have an influence on the environment, and are gradually discarded as blowing agents in the production of foamed materials.

People are beginning to turn their eyes to the production of greener, cleaner foams, such as supercritical CO₂And (3) foaming technology. Frequently used media for supercritical technology, such as CO₂、N₂And C₅H, they have the advantage of good micropore nucleation, and are an ideal production process of the foaming material.

Polyethylene terephthalate (PET) is a polycondensation product, a linear macromolecular material of high crystallinity and high melting point. The PET foaming material is used as a thermoplastic material and has the characteristics of high specific strength, light weight, excellent electrical insulation, chemical resistance, fatigue resistance, abrasion resistance, high temperature resistance and the like. At present, the composite material is used for producing fibers, various containers and packaging materials, and is also a very good lightweight structural material, thermal insulation material and the like.

CN101885855A discloses a preparation method of a sandwich material PET foam of a wind power generation blade, which is to introduce supercritical CO into a PET sheet in a high-pressure preheating environment₂The fluid is maintained for a period of time and then heat treated by a rapid depressurization process to reduce the solubility of the gas in the polymer to initiate bubble nucleation and growth. CN101885855A discloses a preparation method of a novel wind power generation blade sandwich material PET foam, which is to introduce supercritical CO into a PET sheet in a high-pressure preheating environment₂And N₂The fluid is maintained for a period of time and then heat treated by a rapid depressurization process to reduce the solubility of the gas in the polymer to initiate bubble nucleation and growth. However, the two PET foams provided in the above prior art have disadvantages such as large cell size, poor room temperature toughness, and easy occurrence of collapse after high temperature.

Therefore, the development of a PET foam material with ultrafine pores, good toughness and high-temperature deformation is a technical problem which needs to be solved urgently in the field.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a PET foam material, and a preparation method and application thereof, wherein the PET foam material with ultrafine and uniform cells, high toughness, excellent temperature resistance and excellent high-temperature deformability is prepared by selecting liquid carbon dioxide and cyclopentane as foaming agents and nucleating the liquid carbon dioxide and the cyclopentane in a supercritical state.

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

in a first aspect, the invention provides a PET foam material, which comprises the following components in parts by weight:

wherein the polyethylene terephthalate may be 925 parts by weight, 927 parts by weight, 929 parts by weight, 931 parts by weight, 933 parts by weight, 935 parts by weight, 937 parts by weight, 939 parts by weight, 941 parts by weight, 943 parts by weight, 945 parts by weight, or the like.

The pyromellitic dianhydride may be 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, or the like.

The phenylacetylene-modified trimellitic anhydride can be 8.2 parts by weight, 8.4 parts by weight, 8.6 parts by weight, 8.8 parts by weight, 9 parts by weight, 9.2 parts by weight, 9.4 parts by weight, 9.6 parts by weight, 9.8 parts by weight, or the like.

The accelerator may be 8.2 parts by weight, 8.4 parts by weight, 8.6 parts by weight, 8.8 parts by weight, 9 parts by weight, 9.2 parts by weight, 9.4 parts by weight, 9.6 parts by weight, or 9.8 parts by weight, and the like.

The cyclopentane can be 9, 10, 11, 12, 13, or 14 parts by weight, and the like.

The liquid carbon dioxide may be 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, or the like.

The PET foam material provided by the invention comprises the combination of polyethylene terephthalate, pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride, an accelerator, cyclopentane and liquid carbon dioxide in specific parts, and the liquid carbon dioxide and cyclopentane in specific parts are matched to serve as foaming agents to nucleate and foam in a supercritical state, so that the PET foam material has good solubility and plasticizing effect in a matrix, is very good in nucleation effect, and is further beneficial to forming the PET foam material with ultrahigh closed cell rate, superfine (about 310 mu m), uniform, high in toughness, free-form property at high temperature and no performance reduction.

The polyethylene glycol terephthalate provided by the invention can be 415HP produced by Sandebo polymer materials GmbH in Dongguan city.

Preferably, the accelerator comprises 2, 2' - (1, 3-phenylene) -bisoxazoline.

In a second aspect, the present invention provides a method for preparing the PET foam material according to the first aspect, the method comprising the following steps:

(1) mixing polyethylene glycol terephthalate, pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride and an accelerator to obtain a mixed material;

(2) and (2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1) for foaming treatment, and extruding into strips to obtain the PET foaming material.

Preferably, the temperature of the mixing in step (1) is 70 to 80 ℃, such as 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃ or 79 ℃ and the like.

Preferably, the mixing time in step (1) is 6-10 min, such as 6.5min, 7min, 7.5min, 8min, 8.5min, 9min or 9.5 min.

Preferably, the foaming treatment of step (2) further comprises a step of air permeation treatment.

Preferably, the time of the air permeation treatment is 2-4 h, such as 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h or 3.8 h.

Preferably, the temperature of the air-permeation treatment is 20 to 30 ℃, for example, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃ or 29 ℃.

Preferably, the pressure of the air permeation treatment is 11 to 15Mpa, such as 11.5Mpa, 12Mpa, 12.5Mpa, 13Mpa, 13.5Mpa, 14Mpa or 14.5 Mpa.

Preferably, the foaming treatment in step (2) is performed at a temperature of 120 to 140 ℃, for example, 122 ℃, 124 ℃, 126 ℃, 128 ℃, 130 ℃, 132 ℃, 134 ℃, 136 ℃ or 138 ℃.

Preferably, the foaming treatment time in the step (2) is 10-20 s, such as 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s or 19 s.

Preferably, the pressure for extruding into the bar in the step (2) is 8-25 Mpa, such as 9Mpa, 10Mpa, 12Mpa, 14Mpa, 16Mpa, 18Mpa, 20Mpa, 22Mpa or 24 Mpa.

Preferably, said extruding into strands of step (2) is carried out in a screw extruder.

Preferably, the rotation speed of the screw extruder is 80 to 165rpm, such as 85rpm, 90rpm, 95rpm, 100rpm, 105rpm, 110rpm, 115rpm, 120rpm, 125rpm, 130rpm, 135rpm, 140rpm, 145rpm, 150rpm, 155rpm, 160rpm, and the like.

Preferably, the cooling speed of the die head of the screw extruder is 8-16 ℃/min.

Preferably, the extrusion into strips further comprises the steps of cooling, material cutting, polishing, welding and slicing.

As a preferred technical scheme of the invention, the preparation method comprises the following steps:

(1) mixing polyethylene terephthalate, pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride and an accelerant for 6-10 min at 70-80 ℃ to obtain a mixed material;

(2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1), carrying out gas permeation treatment for 2-4 h at 20-30 ℃ and 11-15 Mpa, carrying out foaming treatment for 10-20 s at 120-140 ℃, extruding into strips in a screw extruder with the rotating speed of 80-165 rpm, cooling, cutting off materials, polishing, welding and slicing to obtain the PET foaming material.

In a third aspect, the present invention is a use of a foamed material according to the first aspect in a flame retardant product, a thermal insulation product or a fire protection product.

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

(1) the PET foaming material provided by the invention comprises the combination of polyethylene glycol terephthalate, pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride, an accelerant, cyclopentane and liquid carbon dioxide in specific parts, and the liquid carbon dioxide and cyclopentane are matched to be used as foaming agents to carry out supercritical foaming, so that the PET foaming material has good solubility and plasticizing effect in a supercritical state, and the nucleation effect is also very good; and meanwhile, the liquid carbon dioxide and cyclopentane have high solubility in the polyethylene glycol terephthalate matrix, so that the PET foam material with ultrahigh closed-cell rate, high density and high toughness is formed.

(2) The manufacturing process and control of the PET foaming material provided by the invention are relatively simple, and can realize batch standard operation and basically realize an automatic operation mode; the PET foam material has good normal temperature toughness, good processability and good high temperature plasticity, can be randomly modified according to a mould, has stable performance after being cooled, and can be applied to automobile parts after being compounded with other materials;

(3) specifically, the density of the PET foam material provided by the invention is 100-115 Kg/m3, the compressive strength is 1.31-1.44 MPa, the compressive modulus is 81-90 MPa, the tensile strength is 2.41-2.88 MPa, the tensile modulus is 141-152 MPa, the shear strength is 0.98-1.22 MPa, the shear modulus is 35-44 MPa, the shear strain is 34-39%, and the closed pore rate is 85-90%.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The PET foam material comprises the following components in parts by weight:

the preparation method of the PET foam material provided by the embodiment comprises the following steps:

(1) mixing polyethylene terephthalate (415 HP, Sandebo Polymer materials Ltd., Dongguan city), pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride and 2, 2' - (1, 3-phenylene) -bisoxazoline in a high-pressure preheating container at 75 ℃ for 7min to obtain a mixed material;

(2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1), carrying out air permeation treatment for 2.5h under the constant pressure condition that the temperature is 24.5 ℃ and the pressure is 12Mpa, carrying out foaming heat treatment on the mixture for about 16s under the condition of 130 ℃, and extruding the mixture into strips to obtain the PET foaming material.

Example 2

A PET foam differing from example 1 only in that cyclopentane was added in an amount of 12.5 parts by weight, liquid carbon dioxide was added in an amount of 12.5 parts by weight, and the other components, amounts and preparation methods were the same as example 1.

Example 3

A PET foam, which is different from example 1 only in that pyromellitic dianhydride was added in an amount of 21 parts by weight, phenylacetylene-modified trimellitic anhydride was added in an amount of 9 parts by weight, and other components, amounts and preparation methods were the same as example 1.

Example 4

The PET foam material comprises the following components in parts by weight:

(1) mixing polyethylene terephthalate (415 HP, Sandebo Polymer materials Ltd., Dongguan city), pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride and 2, 2' - (1, 3-phenylene) -bisoxazoline in a high-pressure preheating container at 75 ℃ for 6min to obtain a mixed material;

(2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1), carrying out air permeation treatment for 3h under the constant pressure condition that the temperature is 24.5 ℃ and the pressure is 12Mpa, carrying out foaming heat treatment on the mixture for about 18s under the condition of 130 ℃, and extruding the mixture into strips to obtain the PET foaming material.

Example 5

A PET foam differing from example 4 only in that liquid carbon dioxide was added in an amount of 11 parts by weight, polyethylene terephthalate was added in an amount of 936 parts by weight, and the other components, amounts and preparation methods were the same as example 4.

Example 6

A PET foamed material which is different from example 4 only in that the temperature of the air permeation treatment in the step (4) is 23 ℃, and other components, amounts and preparation methods are the same as those of example 4.

Example 7

The PET foam material comprises the following components in parts by weight:

(1) mixing polyethylene terephthalate (415 HP, Sandebo Polymer materials Ltd., Dongguan city), pyromellitic dianhydride, phenylacetylene modified trimellitic anhydride and 2, 2' - (1, 3-phenylene) -bisoxazoline in a high-pressure preheating container at 75 ℃ for 10min to obtain a mixed material;

(2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1), carrying out air permeation treatment for 3h under the constant pressure condition that the temperature is 24 ℃ and the pressure is 12Mpa, carrying out foaming heat treatment on the mixture for about 18s under the condition that the temperature is 130 ℃, and extruding the mixture into strips to obtain the PET foaming material.

Example 8

A PET foam differing from example 7 only in that the amount of polyethylene terephthalate added was 935 parts by weight, the amount of pyromellitic dianhydride added was 21 parts by weight, and the other components, amounts and preparation methods were the same as example 7.

Comparative example 1

A PET foam, which is different from example 1 only in that liquid carbon dioxide is added in an amount of 25 parts by weight, cyclopentane is not added, and other components, amounts and preparation methods are the same as example 1.

Comparative example 2

A PET foam, which is different from example 1 only in that cyclopentane is added in an amount of 25 parts by weight, liquid carbon dioxide is not added, and other components, amounts and preparation methods are the same as example 1.

Comparative example 3

A PET foam, which is different from example 1 only in that pyromellitic dianhydride was added in an amount of 30 parts by weight, phenylacetylene-modified trimellitic anhydride was not added, and other components, amounts and preparation methods were the same as example 1.

Comparative example 4

A PET foam, which is different from example 1 only in that the amount of the phenylacetylene modified trimellitic anhydride added is 30 parts by weight, pyromellitic dianhydride is not added, and other components, amounts and preparation methods are the same as example 1.

And (3) performance testing:

(1) density: testing according to the density testing method in the ISO 845 standard;

(2) compressive strength and compressive modulus: testing was performed according to the method provided in Standard ASTM 1621;

(3) tensile strength and tensile modulus: the test was carried out according to the method provided in ASTM C297;

(4) shear strength, shear modulus and shear strain: testing was performed according to the method provided in ASTM C273;

(5) closed pore rate: the test was carried out according to the test method provided in ASTM D6226.

The PET foamed materials provided in examples 1-8 and comparative examples 1-4 were tested according to the test method provided above, and the test results are shown in Table 1:

TABLE 1

As can be seen from the data in table 1:

specifically, the density of the PET foam obtained in examples 1 to 8 was 100 to 115Kg/m³The high-strength steel plate has the compression strength of 1.31-1.44 MPa, the compression modulus of 81-90 MPa, the tensile strength of 2.41-2.88 MPa, the tensile modulus of 141-152 MPa, the shear strength of 0.98-1.22 MPa, the shear modulus of 35-44 MPa, the shear strain of 34-39% and the closed cell rate of 85-90%.

Comparing example 1 with comparative examples 1-2, it can be seen that the density of the PET foam material obtained by adding only liquid carbon dioxide as a foaming agent without adding cyclopentane (comparative example 1) and the density of the PET foam material obtained by adding only cyclopentane as a foaming agent without adding liquid carbon dioxide (comparative example 2) are reduced, and the tensile strength, tensile modulus, compressive strength, compressive modulus, shear strength, shear modulus and shear strain are all greatly reduced, which indicates that the mechanical properties are greatly reduced; and the closed cell rate is also greatly reduced.

In comparison between example 1 and comparative examples 3 to 4, it was found that the mechanical properties of the PET foam obtained by adding only pyromellitic dianhydride without adding phenylacetylene-modified trimellitic anhydride (comparative example 3) and the PET foam obtained by adding only phenylacetylene-modified trimellitic anhydride without adding pyromellitic dianhydride (comparative example 4) were also significantly reduced and the closed cell ratio was low.

In conclusion, the PET foaming material obtained only in the range of the components and the dosage defined by the invention has excellent mechanical properties and ultrahigh closed cell ratio.

The applicant states that the invention is illustrated by the above examples to a PET foam and its preparation and application, but the invention is not limited to the above examples, i.e. it does not mean that the invention must be implemented by means of the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The PET foam material is characterized by comprising the following components in parts by weight:

2. the PET foam of claim 1, wherein the accelerator comprises 2, 2' - (1, 3-phenylene) -bisoxazoline.

3. A method for preparing the PET foam material according to claim 1 or 2, wherein the method comprises the following steps:

4. The method according to claim 3, wherein the temperature of the mixing in the step (1) is 70 to 80 ℃;

preferably, the mixing time in the step (1) is 6-10 min.

5. The method according to claim 3 or 4, wherein the step (2) further comprises a step of air-bleeding treatment before the foaming treatment;

preferably, the time of the air permeation treatment is 2-4 h;

preferably, the temperature of the air permeation treatment is 20-30 ℃;

preferably, the pressure of the air permeation treatment is 11-15 MPa.

6. The method according to any one of claims 3 to 5, wherein the temperature of the foaming treatment in the step (2) is 120 to 140 ℃;

preferably, the time of the foaming treatment in the step (2) is 10-20 s.

7. The method according to any one of claims 3 to 6, wherein the pressure for extruding into the strands in the step (2) is 8 to 25 MPa;

preferably, said extruding into strands of step (2) is carried out in a screw extruder;

preferably, the rotating speed of the screw extruder is 80-165 rpm;

8. A method according to any one of claims 3 to 7, wherein the extrusion into a rod further comprises the steps of cooling, breaking, polishing, welding and slicing.

9. The method according to any one of claims 3 to 8, characterized by comprising the steps of:

(2) adding cyclopentane and liquid carbon dioxide into the mixture obtained in the step (1), carrying out air permeation treatment for 2-4 h at 20-30 ℃ and 11-15 Mpa, carrying out foaming treatment for 10-20 s at 120-140 ℃, finally extruding into strips in a screw extruder with the rotating speed of 80-165 rpm, cooling, cutting off materials, polishing, welding and slicing to obtain the PET foaming material.

10. Use of a foamed material according to claim 1 or 2 in flame retardant, thermal insulation or fire protection products.