CN117511139A - Biodegradable foam board and preparation method thereof - Google Patents

Abstract

The invention discloses a biodegradable foam board and a preparation method thereof, wherein the biodegradable foam board is prepared from the following components in parts by mass: 55-75 parts of PBAT, 15-25 parts of poly-beta-hydroxybutyric acid, 10-20 parts of modified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer. According to the biodegradable foaming sheet material provided by the invention, the biodegradable filling materials and the high-performance nucleating agent are added into the two biodegradable base materials, so that the integral rigidity of the material is improved, the hardness of the sheet material and the stability of a foaming structure are solved, and the problems that the crystallization speed of the material is low and the extrusion molding is difficult are perfectly solved.

Description

Biodegradable foam board and preparation method thereof

Technical Field

The invention relates to the technical field of modification of high polymer materials, in particular to a biodegradable foam board and a preparation method thereof.

Background

The degradable plastics mainly comprise starch-based plastics, PLA, PBAT, PBS, PHA and other categories, and according to the data of the intelligent research consultation, the starch-based plastics, PLA and PBAT are the three most important, and the productivity in 2019 is 38.4%, 25.0% and 24.1%, and the total ratio is approximately 90%. However, the degradation rate is still a relatively large problem restricting the application of degradable plastics.

Disclosure of Invention

In view of the above, the present invention provides a biodegradable foamed sheet and a preparation method thereof, so as to solve the problems set forth in the background art, and not only improve the degradation rate of the sheet, but also improve the mechanical properties of the material.

In order to achieve the above purpose, the present invention provides the following technical solutions:

the invention discloses a biodegradable foam board which is prepared from the following components in parts by mass:

as a further scheme of the invention: the melt mass flow rate of the PBAT is less than or equal to 2g/10min under the conditions of 190 ℃ and 2.16 kg.

As a further scheme of the invention: the melt mass flow rate of the poly-beta-hydroxybutyric acid is less than or equal to 13g/10min under the conditions of 180 ℃ and 10 kg.

As a further scheme of the invention: the preparation method of the modified wheat straw powder comprises the following steps:

crushing wheat straw to obtain powder with the particle size of 300 meshes;

soaking the powder in sodium bicarbonate solution with the mass fraction of 5% for stirring reaction for 3 hours, and then cleaning with deionized water and drying to obtain dry powder; and stirring the sodium bicarbonate solution to remove small molecular organic matters on the surface of the powder in the cleaning process.

Weighing 5 parts by weight of dry powder, putting the dry powder into 100 parts by weight of toluene solution, adding 1 part by weight of maleic anhydride into the toluene solution, stirring the mixture at 80 ℃ for reaction for 6 hours, washing the mixture with absolute ethyl alcohol after the reaction is finished, and drying the mixture to obtain the modified wheat straw powder.

As a further scheme of the invention: the nucleating agent is at least two of xylylene dialkyl urea, halloysite, dibenzyl propylene ether diester hexanol and N-butyl-potassium pyriguazate.

As a further scheme of the invention: the foaming agent is microsphere foaming agent, and the foaming temperature is 150 ℃.

As a further scheme of the invention: the heat stabilizer is at least three of pentaerythritol tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, tri- (2, 4-di-tert-butylphenyl) phosphite and dioctadecyl thiodipropionate.

The invention also discloses a preparation method of the biodegradable foam board, which comprises the following steps:

weighing PBAT, poly-beta-hydroxybutyric acid, modified wheat straw powder, nucleating agent, foaming agent and heat stabilizer according to parts by weight, adding into a high-speed mixer, mixing for 5-10min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding and cooling to obtain a biodegradable foaming plate;

wherein the extrusion temperature of each extrusion zone in the twin-screw extruder is 130-140 ℃, 140-150 ℃, 150-160 ℃ and 150-160 ℃ respectively.

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

according to the biodegradable foaming sheet material provided by the invention, the biodegradable filling materials and the high-performance nucleating agent are added into the two biodegradable base materials, so that the integral rigidity of the material is improved, the hardness of the sheet material and the stability of a foaming structure are solved, and the problems that the crystallization speed of the material is low and the extrusion molding is difficult are perfectly solved. The chemical body of the wheat straw powder is a cellulose substance, a large amount of hydroxyl groups are contained, the reaction of the rest of acid anhydride is an esterification reaction, and the generated ester group can reduce the water absorption of the powder and improve the compatibility of the powder and resin. The raw materials required by the preparation are biodegradable products or micromolecular substances, so that the prepared plate has complete degradation performance after the service life is finished and has excellent environmental protection performance.

Detailed Description

In order that the invention may be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments that are illustrated below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Specific information of the raw materials used in the following examples and comparative examples are as follows:

the brand of PBAT is BT02-203, purchased from vinca chemical industry;

the poly-beta-hydroxybutyric acid was available from BIOMER under the brand name PHB-P209;

the nucleating agent is prepared by mixing tribenzyl fork propyl ether diester hexanol and N-butyl-potassium pyriproxyfate according to the weight ratio of 1:1;

the foaming agent was a microsphere foaming agent, brand MS205D, having a foaming temperature of 160℃and purchased from Korea east.

The heat stabilizer is prepared by mixing n-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (1076), tri- (2, 4-di-tert-butylphenyl) phosphite (168) and dioctadecyl thiodipropionate (DSTDP) according to the weight ratio of 2:2:1.

The preparation method of the modified wheat straw powder comprises the following steps:

crushing wheat straw into powder with the particle size of 300 meshes by using a straw silk kneading machine, soaking the powder in sodium bicarbonate solution with the mass fraction of 5% for stirring reaction for 3 hours, and then cleaning with deionized water and drying. And 5 parts of dried powder is put into 100 parts of toluene solution, 1 part of maleic anhydride is added into the toluene solution, the mixture is stirred and reacts for 6 hours at 80 ℃, the mixture is washed with absolute ethyl alcohol for 3 times after the reaction is finished, and the mixture is dried in a baking oven at 60 ℃ to obtain the modified wheat straw powder.

It will be appreciated that the above raw material reagents are only examples of some embodiments of the invention, so that the technical solution of the invention is more clear, and it is not represented that the invention can only employ the above reagents, and the scope of the claims is in particular. In addition, "parts" described in examples and comparative examples refer to parts by weight unless otherwise specified.

Any range recited in the invention includes any numerical value between the endpoints and any sub-range of any numerical value between the endpoints or any numerical value between the endpoints.

Example 1

Adding 75 parts of PBAT, 15 parts of poly-beta-hydroxybutyric acid, 10 parts of modified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 5min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding, and cooling to obtain the biodegradable foaming plate. Wherein, the extrusion temperatures of the extrusion sections in the twin-screw extruder were 130℃and 140℃respectively 140 ℃, 150 ℃. The product properties are shown in Table 1.

Example 2

Adding 65 parts of PBAT, 20 parts of poly-beta-hydroxybutyric acid, 15 parts of modified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 8min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding, and cooling to obtain the biodegradable foaming plate. Wherein, the extrusion temperature of each extrusion zone in the twin-screw extruder is 135 ℃, 145 ℃, and the like 145 ℃, 155 ℃. The product properties are shown in Table 1.

Example 3

Adding 55 parts of PBAT, 25 parts of poly-beta-hydroxybutyric acid, 20 parts of modified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 10min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding, and cooling to obtain the biodegradable foaming plate. Wherein the extrusion temperature of each extrusion zone in the twin-screw extruder is 140 ℃, 150 ℃, 160 ℃, respectively. The product properties are shown in Table 1.

TABLE 1

Note that: test conditions and test spline dimensions were as follows:

flexural modulus: sample sizes 100mm x 10mm x 4mm, experimental speeds 2mm/min, samples were taken directly from the extruded sheet.

Comparative example 1

Adding 85 parts of PBAT, 15 parts of modified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 8min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding and cooling to obtain the biodegradable foaming plate. Wherein the extrusion temperatures of the extrusion sections in the twin-screw extruder were 135 ℃, 145 ℃, 155 ℃, respectively. The product properties are shown in Table 2.

Comparative example 2

Adding 65 parts of PBAT, 20 parts of poly-beta-hydroxybutyric acid, 15 parts of unmodified wheat straw powder, 0.6 part of nucleating agent, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 8min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding, and cooling to obtain the biodegradable foaming plate. Wherein the extrusion temperatures of the extrusion sections in the twin-screw extruder were 135 ℃, 145 ℃, 155 ℃, respectively. The product properties are shown in Table 2.

Comparative example 3

Adding 65 parts of PBAT, 20 parts of poly-beta-hydroxybutyric acid, 15 parts of modified wheat straw powder, 5 parts of foaming agent and 0.5 part of heat stabilizer into a high-speed mixer, mixing for 8min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding and cooling to obtain the biodegradable foaming plate. Wherein the extrusion temperatures of the extrusion sections in the twin-screw extruder were 135 ℃, 145 ℃, 155 ℃, respectively. The product properties are shown in Table 2.

TABLE 2

Note that: test conditions and test spline dimensions are as in table 1.

It can be seen from examples and comparative examples that the content of poly-beta-hydroxybutyric acid, the quality of wheat straw powder and the addition of nucleating agent all have a great influence on the rigidity of the formed sheet.

Although the present disclosure describes embodiments, not every embodiment is described in terms of a single embodiment, and such description is for clarity only, and one skilled in the art will recognize that the embodiments described in the disclosure as a whole may be combined appropriately to form other embodiments that will be apparent to those skilled in the art.

Therefore, the above description is only of the preferred embodiments of the present application and is not intended to limit the scope of the present application; all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (8)

1. The biodegradable foaming plate is characterized by being prepared from the following components in parts by mass:

2. the biodegradable foamed sheet according to claim 1, wherein said PBAT has a melt mass flow rate of 2g/10min or less at 190 ℃ under 2.16kg conditions.

3. The biodegradable foamed sheet according to claim 1, wherein said poly- β -hydroxybutyrate has a melt mass flow rate of 13g/10min or less at 180 ℃ under 10kg conditions.

4. The biodegradable foamed sheet according to claim 1, wherein said modified straw powder preparation method comprises the steps of:

crushing wheat straw to obtain powder with the particle size of 300 meshes;

soaking the powder in sodium bicarbonate solution with the mass fraction of 5% for stirring reaction for 3 hours, and then cleaning with deionized water and drying to obtain dry powder;

weighing 5 parts by weight of dry powder, putting the dry powder into 100 parts by weight of toluene solution, adding 1 part by weight of maleic anhydride into the toluene solution, stirring the mixture at 80 ℃ for reaction for 6 hours, washing the mixture with absolute ethyl alcohol after the reaction is finished, and drying the mixture to obtain the modified wheat straw powder.

5. The biodegradable foamed sheet according to claim 1, wherein said nucleating agent is at least two of xylylene dialkyl urea, halloysite, tribenzylidene propyl ether diester hexanol, and N-butyl-potassium pyriproxyfate.

6. The biodegradable foamed sheet according to claim 1, wherein said foaming agent is a microsphere foaming agent having a foaming temperature of 150 ℃.

7. The biodegradable foamed sheet according to claim 1, wherein said heat stabilizer is at least three of pentaerythritol tetrakis [ β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], n-stearyl β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, tris- (2, 4-di-t-butylphenyl) phosphite, dioctadecyl thiodipropionate.

8. The method for producing a biodegradable foamed sheet according to any one of claims 1 to 7, comprising the steps of:

weighing PBAT, poly-beta-hydroxybutyric acid, modified wheat straw powder, nucleating agent, foaming agent and heat stabilizer according to parts by weight, adding into a high-speed mixer, mixing for 5-10min at a low speed, adding the uniformly mixed materials into a double-screw plate extruder, mixing, extruding and cooling to obtain a biodegradable foaming plate;

wherein the extrusion temperature of each extrusion zone in the twin-screw extruder is 130-140 ℃, 140-150 ℃, 150-160 ℃ and 150-160 ℃ respectively.