CN115819913A - Biodegradable PBS-based modified film for garbage bags - Google Patents

Abstract

The invention discloses a biodegradable PBS-based modified film for garbage bags, which belongs to the technical field of degradable films and comprises the following raw materials in parts by mass: 80-120 parts of modified PBS particles, 7.2-10.8 parts of luteolin Parts, 26.16-39.24 parts of PBAT granules, its preparation comprises the following steps: step A1, adding luteolin after melting the modified PBS granules, to obtain PBS composite material granules; step A2, blending PBS composite material granules and PBAT granules; Step A3, after drying the blend, use a film blowing machine to obtain a PBS-based modified film, wherein the modified PBS particles prepared by maleic anhydride can be used as the main raw material to improve the compatibility of the system, and adding PBAT can improve the composite film. The toughness of the material, and the addition of luteolin, which has a wide range of sources and low price, is used to reduce production costs.

Description

A PBS-based modified film for biodegradable garbage bags

technical field

The invention belongs to the technical field of degradable films, in particular to a biodegradable PBS-based modified film for garbage bags.

Background technique

Plastic garbage bags are indispensable in people's lives. Because they have no pungent smell and are easy to use, they provide convenience for daily life. However, traditional garbage bags are difficult to degrade and use a large amount, causing very serious environmental pollution. and the greenhouse effect, so it is imperative to promote the application of biodegradable garbage bags, and it is also one of the effective ways for the green development of materials. Biodegradable materials have good performance during use and can be naturally degraded after use. Molecular materials, which can significantly reduce environmental pollution. Among various degradable polymer materials, polybutylene succinate (PBS) is a degradable material with excellent comprehensive performance, but due to the crystallinity of PBS 40-60%, relatively regular structure, brittle, and high production cost, thus limiting its popularization and application.

Contents of the invention

The purpose of the present invention is to provide a biodegradable PBS-based modified film for garbage bags to solve the problems of high brittleness and high production cost of PBS in the background technology.

The purpose of the present invention can be achieved through the following technical solutions:

A biodegradable PBS-based modified film for garbage bags, comprising the following raw materials in parts by mass: 96.95-108.05 parts of modified PBS particles, 7.2-10.8 parts of luteolin, and 26.16-39.24 parts of PBAT particles;

Its preparation process comprises the following steps:

Step A1, heating the modified PBS granules to 150-160° C., after melting completely, adding luteolin, mixing evenly, melt-extruding with a twin-screw extruder and granulating to obtain PBS composite material granules;

Step A2. Dry the PBS composite material granules and PBAT granules in an oven at 70-90°C for 18-20 hours to achieve a constant weight, and add the dried PBS composite material granules and PBAT granules into a torque rheometer for melt blending , Modified PBS particles as a compatibilizer can effectively improve the interfacial compatibility of the polymer and improve the mechanical properties of the material;

Step A3, extruding the blend, cooling and granulating to obtain the desired blend granules, putting the blend granules into a film blowing machine and blowing them into a film to obtain a PBS-based modified film.

Further, the preparation of the modified PBS particles comprises the following steps:

Mix maleic anhydride, dicumyl peroxide and PBS, then use a twin-screw extruder to melt extrude at 155-165°C and granulate to obtain modified PBS particles, in which dicumyl peroxide is used as the initiator Agents can initiate the polymerization of maleic anhydride grafted PBS.

Further, the mass ratio of maleic anhydride, dicumyl peroxide and PBS is 1.5-2.5:0.45-0.55:95-105.

Further, the luteolin is the extract of honeysuckle leaves, and honeysuckle is selected because the leaves of honeysuckle are large, easy to harvest, and easy to obtain, and the content of luteolin in the leaves of honeysuckle is relatively high, but they are often regarded as by-products of honeysuckle. wasted.

Further, the extraction of luteolin comprises the following steps:

Soak the dried and crushed honeysuckle leaves in a mixed solution of methanol and sodium hydroxide for 10-12 hours, then ultrasonically extract and heat them for 30-40 minutes at 50-65°C, filter with suction and concentrate, and filter with a microporous membrane to obtain Osmanthus osmanthus Grass.

Further, the dosage ratio of the honeysuckle leaves, methanol and sodium hydroxide solution is 0.5-1g: 10-25mL: 1-5mL, and the mass fraction of the sodium hydroxide solution is 20-30%.

Beneficial effects of the present invention:

In the present invention, PBS composite material granules are obtained by introducing luteolin, an extract of honeysuckle leaves, into modified PBS granules. As a natural antioxidant, luteolin has a wide source and low price, and luteolin can be used as a heterogeneous component when added to the composite material. PBS has an inductive effect, forming heterogeneous nucleation points at its contact surface, which acts as a nucleating agent. High-efficiency nucleating agents can effectively change the crystal size of PBS, increase the crystallization speed, refine the structure, and make the appearance of the product more beautiful. Improved smoothness and transparency;

The polybutylene terephthalate adipate (PBAT) that the present invention adopts has the flexibility of long methylene chain and the rigidity of aromatic ring, and the rigid aromatic component can improve the fusing point of PBS, improve the mechanical property of PBS At the same time, it will not affect the biodegradability of PBS, and the soft aliphatic component can improve the brittleness and degradation performance of PBS;

The present invention adopts modified PBS particle as main raw material, because the PBS particle of maleic anhydride grafting can increase the interfacial compatibility of polymer, thereby the melting temperature of composite material, tensile strength and elongation at break are improved, by The garbage bag prepared by using the composite material has the advantages of environmental protection and biodegradability, so it will not cause a burden to the environment.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

A preparation method of modified PBS particles, comprising the following steps:

1.5 parts of maleic anhydride, 0.45 parts of dicumyl peroxide and 95 parts of PBS were mixed, then melt-extruded and granulated at 155°C with a twin-screw extruder to obtain modified PBS particles.

Example 2

A preparation method of modified PBS particles, comprising the following steps:

2 parts of maleic anhydride, 0.5 parts of dicumyl peroxide and 100 parts of PBS were mixed, then melt-extruded and granulated at 160°C with a twin-screw extruder to obtain modified PBS particles.

Example 3

A preparation method of modified PBS particles, comprising the following steps:

2.5 parts of maleic anhydride, 0.55 parts of dicumyl peroxide and 105 parts of PBS were mixed, then melt-extruded and granulated at 165°C with a twin-screw extruder to obtain modified PBS particles.

Example 4

A kind of luteolin, prepared through the following steps:

Soak 0.5g of dried and crushed honeysuckle leaves in 10mL of methanol and 1mL of 20% sodium hydroxide mixed solution for 10h, then ultrasonically extract and heat at 50°C for 30min, filter and concentrate with 0.45μm microporous filter Membrane filtration to obtain luteolin.

Example 5

A kind of luteolin, prepared through the following steps:

Soak 0.75g of dried and crushed honeysuckle leaves in 17.5mL of methanol and 3mL of 25% sodium hydroxide mixed solution for 11h, then ultrasonically extract and heat at 57.5°C for 35min, filter and concentrate with 0.45μm microporous Membrane filtration to obtain luteolin.

Example 6

A kind of luteolin, prepared through the following steps:

Soak 1g of dried and crushed honeysuckle leaves in 25mL of methanol and 5mL of 30% sodium hydroxide mixed solution for 12h, then ultrasonically extract and heat at 65°C for 40min, filter and concentrate with 0.45μm microporous membrane Filter to obtain luteolin.

Example 7

A kind of PBS-based modified film for biodegradable garbage bags is prepared through the following steps:

Step A1. Heat 96.95 parts of modified PBS granules to 150°C. After melting completely, add 7.2 parts of luteolin. After mixing evenly, melt and extrude with a twin-screw extruder and granulate to obtain modified PBS composite material granules ;

Step A2, 87.2 parts of PBS composite material granules and 26.16 parts of PBAT granules were dried in an oven at 70°C for 20 hours to achieve a constant weight, and the dried PBS composite material granules and PBAT granules were added to a torque rheometer for melt blending;

Step A3, extruding the blend, cooling and granulating to obtain the desired blend granules, putting the blend granules into a film blowing machine and blowing them into a film to obtain a PBS-based modified film.

Example 8

A kind of PBS-based modified film for biodegradable garbage bags is prepared through the following steps:

Step A1. Heat up 102.5 parts of modified PBS granules to 155° C., after melting completely, add 9 parts of luteolin, mix evenly, melt and extrude with a twin-screw extruder and granulate to obtain PBS composite material granules;

Step A2, drying 109 parts of PBS composite material granules and 27.7 parts of PBAT granules in an oven at 80°C for 21 hours to achieve constant weight, adding the dried PBS composite material granules and PBAT granules to a torque rheometer for melt blending;

Step A3, extruding the blend, cooling and granulating to obtain the desired blend granules, putting the blend granules into a film blowing machine and blowing them into a film to obtain a PBS-based modified film.

Example 9

A kind of PBS-based modified film for biodegradable garbage bags is prepared through the following steps:

Step A1. Heat up 108.05 parts of modified PBS granules to 160° C., after melting completely, add 10.8 parts of luteolin, mix evenly, melt and extrude with a twin-screw extruder and granulate to obtain PBS composite material granules;

Step A2, drying 109 parts of PBS composite material granules and 39.24 parts of PBAT granules in an oven at 90°C for 22 hours to achieve constant weight, adding the dried PBS composite material granules and PBAT granules to a torque rheometer for melt blending;

Step A3, extruding the blend, cooling and granulating to obtain the desired blend granules, putting the blend granules into a film blowing machine and blowing them into a film to obtain a PBS-based modified film.

Comparative example 1

Compared with Example 7, this comparative example did not add PBAT in the preparation process of the PBS-based modified film for biodegradable garbage bags, and the rest of the steps and parameters were the same. The garbage bags are modified with PBS-based film.

Comparative example 2

Compared with Example 8, this comparative example does not add luteolin in the preparation process of the PBS-based modified film for biodegradable garbage bags, and all the other steps and parameters are the same. Biodegradable garbage bags with PBS-based modified films.

First carry out DSC test on the sample, weigh the samples of Example 7-Example 9 and Comparative Example 1-Comparative Example 2, press them into a sample sheet in a sample pan, and test under the protection condition of high-purity nitrogen. Set the heating rate to 10°C/min, from room temperature 23°C to 200°C, set the cooling rate to 10°C/min, drop from 200°C to -50°C, and finally increase the temperature again at a rate of 10°C/min to 200°C;

Carry out mechanical performance test to sample again, with reference to GB/TI3022-91 standard, the sample prepared in embodiment 7-embodiment 9 and comparative example 1-comparative example 2 is cut into dumbbell shape, carries out with the tensile speed of 10mm/min Test, measure and calculate the elongation at break of the modified PBS samples. The results are shown in Table 1:

Table 1

project Example 4 Example 5 Example 6 Comparative example 1 Comparative example 2 Elongation at break/% 394.6 414.6 434.6 77.7 380.7 Tm/℃ 115.71 117.2 116.62 116.7 105.3

As can be seen from Table 1, compared with Comparative Example 1 and Comparative Example 2, the elongation at break of the PBS-based modified film for biodegradable garbage bags prepared in Example 7-Example 9 is higher, and the melting point is lower. High, this is due to the addition of PBAT and luteolin in the preparation process of Example 7-Example 9 to modify PBS, and luteolin can be used as a heterogeneous component to induce PBS in the composite material. Heterogeneous nucleation points are formed at the surface, which acts as a nucleating agent, causing the PBS polymer to crystallize due to steric hindrance, ensuring the degradability of the composite material and improving the overall performance of the composite material, while PBAT has a long-term The flexibility of the methylene chain and the rigidity of the aromatic ring have good ductility and high flexibility, and its melt flow rate is high. Modifying PBS with PBAT can significantly improve the toughness of PBS.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Moreover, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also items not expressly listed. other elements, or also include elements inherent in such a process, method, article, or apparatus.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (6)

1. A biodegradable PBS-based modified film for garbage bags, characterized in that, in parts by mass, comprising the following raw materials: 96.95-108.05 parts of modified PBS particles, 7.2-10.8 parts of luteolin, 26.16 parts of PBAT particles -39.24 copies; The PBS-based modified film comprises the following steps: Step A1. After heating the modified PBS granules to completely melt, add luteolin, mix evenly, melt extrude and granulate with a twin-screw extruder to obtain PBS composite material granules; Step A2, drying the PBS composite material granules and PBAT granules in an oven at 70-90°C to constant weight, adding the dried modified PBS granules and PBAT granules to a torque rheometer for melt blending to obtain a blend ; Step A3, extruding the blend, cooling and granulating to obtain the desired blend granules, putting the blend granules into a film blowing machine and blowing them into a film to obtain a PBS-based modified film. 2. a kind of biodegradable garbage bag PBS-based modified film according to claim 1, is characterized in that: the preparation of described modified PBS particle comprises the following steps: Mix maleic anhydride, dicumyl peroxide and PBS, then use a twin-screw extruder at 155-165° C. to melt and extrude and granulate to prepare modified PBS granules. 3. a kind of biodegradable garbage bag according to claim 2 is characterized in that: the mass ratio of described maleic anhydride, dicumyl peroxide and PBS is 1.5-2.5: 0.45-0.55:95-105. 4. A kind of biodegradable garbage bag PBS-based modified film according to claim 1, characterized in that: said luteolin is honeysuckle leaf extract, comprising the following steps: Soak the dried and crushed leaves of honeysuckle in a mixed solution of methanol and sodium hydroxide for 10-12 hours, then ultrasonically extract at 50-65°C for 30-40 minutes, concentrate by suction and filter with a microporous membrane to obtain Mignonette white. 5. A biodegradable PBS-based modified film for garbage bags according to claim 4, characterized in that: the mass ratio of the honeysuckle leaves, methanol and sodium hydroxide solution is 0.5-1:10-25 : 1-5, the mass fraction of the sodium hydroxide solution is 20-30%. 6. A biodegradable PBS-based modified film for garbage bags according to claim 1, characterized in that: in step A1, the modified PBS particles are heated to 150-160°C.