WO2018099223A1 - Biodegradable additive and plastic product added with same - Google Patents

Abstract

The present invention relates to a biodegradable additive prepared from copper powders, iron powders, a silane coupling agent, a titanate coupling agent, and low density polyethylene as raw materials, wherein the biodegradable additive comprises the following components: 8-12% by mass of the copper powder, 8-12% by mass of the iron powder, 0.5-1.5% by mass of the silane coupling agent, 0.5-1.0% by mass of the titanate coupling agent, and the balance of the low density polyethylene. The present invention also relates to a method for preparing the biodegradable additive and a plastic product prepared by adding the biodegradable additive, particularly a polyethylene film product, which has good biodegradability without producing white pollution.

Description

Biodegradable additive and plastic product added with the additive Technical field

The present invention relates to a biodegradable additive capable of imparting biodegradability to a plastic article. The present invention also relates to a plastic article prepared by adding the biodegradable additive, and more particularly to a polyethylene plastic film prepared by adding the biodegradable additive.

Background technique

Plastic is a cheap and good material. However, with the widespread use of plastic products such as plastic convenience bags and plastic films, the problem of "white pollution" has become increasingly prominent. This is due to the inherent life of the plastic product (from the finished product to the complete natural decomposition) is much longer than its service life. The inherent durability of plastics has long existed in nature and has accumulated more and more if it is not treated. At present, the methods to solve this problem mainly include deep burial and incineration, but deep burying of cultivated land, polluting groundwater, changing soil structure, affecting normal plant growth, and high cost; incineration is currently the most widely used white pollution control method. The advantage is that the processing speed is fast and the cost is low, but the significant disadvantage is that it brings additional air pollution.

A technical solution for biodegradable plastics has been proposed. Since biodegradable plastics can be naturally degraded under the influence of natural conditions such as ultraviolet rays, rainwater, and the like, and no pollutants are generated after degradation, this problem can be fundamentally solved. Currently, biodegradable plastics have been developed such as polylactic acid, polybutylene succinate, polycaprolactone, polyvinyl alcohol, carbon dioxide copolymer, aliphatic aromatic copolymer, etc., which have the following advantages: (1) degradation After the volume is reduced, it can save land occupation land and save land resources; (2) no need to incinerate, reduce harmful gas emissions; (3) can be made into compost to return to nature.

However, current biodegradable plastics have the following problems: (1) high production cost; (2) poor physical and mechanical properties compared to conventional plastic products, such as tensile strength, elongation at break, and elongation at break of most biodegradable plastics. The bursting and tearing strength, light transparency, wet strength, etc. are all low, affecting Its scope of application.

Summary of the invention

In view of the above problems, an object of the present invention is to provide a biodegradable additive, and a plastic article prepared by adding the biodegradable additive.

In order to achieve the above object, the present invention adopts the following technical solutions:

According to a specific embodiment of the present invention, there is provided a biodegradable additive prepared by using copper powder, iron powder, a silane coupling agent, a titanate coupling agent and a low density polyethylene as raw materials, wherein each component is prepared. For example, the copper powder is 8 to 12% by mass, the iron powder is 8 to 12% by mass, the silane coupling agent is 0.5 to 1.5% by mass, and the titanic acid coupling agent is 0.5 to 1.0% by mass. The balance is low density polyethylene.

A biodegradation additive according to an embodiment of the present invention, wherein the composition of the components is as follows: copper powder 10% by mass, iron powder 10% by mass, silane coupling agent 1% by mass, titanate coupling agent 0.6 % by mass, the balance is low density polyethylene.

A biodegradation additive according to an embodiment of the present invention, wherein the copper powder has a particle diameter of 3 μm or less, and the iron powder has a particle diameter of 3 μm or less.

A biodegradation additive according to an embodiment of the present invention, wherein the silane coupling agent is 3-aminopropyltriethoxysilane, and the titanate coupling agent is isopropyl tris(dioctyl coke) Phosphate acyloxy) titanate.

According to a specific embodiment of the present invention, there is provided a method for preparing the above biodegradable additive, comprising the steps of: Step 1: weighing each component in proportion, and then using a silane coupling agent and a titanate coupling agent Copper powder and iron powder are surface-treated; Step 2: mixing the surface treated copper powder and iron powder with low-density polyethylene in a mixer; Step 3: passing the material after being uniformly mixed through the second step through the twin-screw The granulator is made into pellets.

A method of preparing the above biodegradable additive according to an embodiment of the present invention, wherein the mixing time in the second step is 10 minutes.

A method of producing the above biodegradable additive according to an embodiment of the present invention, wherein, in the third step, the twin-screw granulator has an aspect ratio of 40.

A method of preparing the above biodegradable additive according to an embodiment of the present invention, wherein, in the third step, the temperature of the two zones of the twin-screw granulator is set to be the highest, that is, 180 ° C, one zone ratio two zones The temperature is 5~15°C, the temperature in the third zone and the fourth zone is the same as that in the second zone. From the beginning of the five zones to the nose, the temperature gradually decreases according to the temperature gradient, and the temperature of the head is kept constant.

According to a specific embodiment of the present invention, there is provided a plastic article comprising 2 to 10% by mass of the biodegradation additive described above.

According to a specific embodiment of the present invention, there is provided a polyethylene plastic film product prepared by the above-mentioned biodegradation additive, calcium carbonate powder and LDPE, wherein the ratio of each component is: the organism The degradation additive is 2 to 10% by mass, and the calcium carbonate powder is 3% by mass, and the balance is LDPE.

The biodegradation additive provided by the invention can impart biodegradability to a plastic product, and the plastic product prepared by adding the biodegradation additive can be oxidatively decomposed and decomposed by ultraviolet irradiation or the like under natural conditions without incineration or burial treatment. No pollutants are produced during the process.

DRAWINGS

1 is a graph showing the relationship between the concentration of adenosine triphosphate (ATP) and time in a bacterial culture control experiment of the membrane A and the blank group of the present invention;

Fig. 2 is a graph showing the relationship between the concentration of adenosine triphosphate (ATP) and the time in a bacterial culture control test of the film B and the blank group of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Preparation of biodegradable additives

The biodegradation additive of the present invention is prepared from the following raw materials: 8 to 12% by mass of copper powder having a particle diameter of 3 μm or less, 8 to 12% by mass of iron powder having a particle diameter of 3 μm or less, and silane coupling agent 0.5 to ～. 1.5% by mass, the titanic acid coupling agent is 0.5 to 1.0% by mass, and the balance is low density polyethylene.

According to a further preferred embodiment of the present invention, the amount of the copper powder is 10% by mass, the amount of the iron powder is 10% by mass, and the silane coupling agent is 3-aminopropyltriethoxysilane in an amount of 1 mass. %, the titanate coupling agent is isopropyl tris(dioctylpyrophosphate acyloxy) titanate in an amount of 0.6% by mass, and the low density polyethylene is a low density polyethylene having a lower melting point. 78.4% by mass, and prepared by the following steps:

Step 1: Mixing the predetermined mass percentage of copper powder and iron powder uniformly and surface treatment with silane coupling agent and titanic acid coupling agent (copper powder and iron powder can also be combined with silane coupling agent and titanic acid coupling agent, respectively) Performing a surface treatment); Step 2: mixing the mixture obtained in the first step and a predetermined mass percentage of the low density polyethylene in a blender for 10 minutes; Step 3: passing the uniformly mixed material obtained in the second step through the twin-screw granulation The mechanism is granulated, ie, made into a biodegradable additive. The particles are preferably particles having the same or similar particle size as the polyethylene plastic particles. In this step, the length ratio of the triple-screw granulator is 40, the temperature in the second zone is set to the highest, and the control is 180 ° C, and the setting is maintained. The temperature of the zone is about 10 °C lower than the temperature of the second zone. The temperature of the third zone and the fourth zone is basically the same as that of the second zone. From the fifth zone until the nose gradually decreases according to the gradient, the temperature of the head is kept constant (130-150). °C).

The biodegradation additive is an environmentally-friendly modified polymer new material particle, which can be directly added to various plastics such as polyethylene in a proportion of 2 to 10% by mass, so that the conventional plastic product becomes a biodegradable plastic in a natural environment. product.

Preparation of biodegradable plastic products

Further, a method of producing a degradable plastic article using the biodegradable additive of the present invention is explained using the following examples, but the present invention is not limited thereto.

Example 1

Biodegradable polyethylene film A

Table 1: Composition of biodegradable polyethylene film A

Component	Content (% by mass)
Biodegradable additive	2

Calcium carbonate powder	3
LDPE	95

The components of the respective materials as shown in Table 1 were thoroughly mixed, and then added to a single-screw extruder (the length to diameter ratio of the extruder was 20 to 30), and a biodegradable film having a thickness of 25 μm was blown.

Example 2

Biodegradable polyethylene film B

Table 2: Composition of biodegradable polyethylene film A

Component	Content (% by mass)
Biodegradable additive	10
Calcium carbonate powder	3
LDPE	87

The film forming process was the same as above except that the component content was as shown in Table 2.

Biodegradability test

The life cycle of general plastic film products can be divided into three parts, namely the storage period (usually six months to one and a half years), the use period (such as half a year) and the final disposal. According to the use period, the film A and the film B are subjected to (1) first thermal oxygen treatment, (2) photothermal treatment, and (3) second thermal oxygen treatment, respectively. The conditions for the thermal oxygen treatment are in accordance with American Standard ASTM D5510-94 (2001).

The sample was placed in an oven at a temperature of 70 ± 2 ° C for a period of 30 days. The oven passes the air every three days. Then photothermal treatment is carried out. Photothermal treatment is a fluorescent ultraviolet light exposure treatment, reference to the American standard ASTM D5208-01. The light source used was a UV lamp emitting 340 nm with a strength of 0.78 ± 0.02 W/m ² · mm, a blackboard temperature of 50 ± 3 ° C, and a radiation exposure of 300 hours. Finally, the sample exposed to the fluorescent ultraviolet light was placed in an oven at a temperature of 70 ± 2 ° C for a period of 15 days. The oven passes the air every three days. The properties of Film A and Film B at each stage of the test are shown in Table 3 below.

Table 3: Performance test of biodegradable polyethylene films A and B after light and heat treatment

Note*: The film has broken into pieces and the elongation value cannot be measured.

As can be seen from Table 3, the biodegradable plastic film of the present invention has a markedly decreased elongation under ultraviolet light and heat treatment conditions, indicating that it can be rapidly decomposed into pieces after being lost in the natural light-heat condition. The photodegradation of the film product after oxidative degradation by FTIR (Fourier Transform Infrared Spectroscopy) absorption curve increased at 1714 cm ^-1 , indicating that oxidative degradation caused an increase in relative carboxylic acid groups, relative to the production of carboxylic acid groups. And the addition of biodegradable properties to non-biodegradable polyethylene film products.

In summary, the test results show that the biodegradable polyethylene film of the present invention can be rapidly broken and decomposed under thermal oxidative degradation and photooxidative degradation, and can obtain biodegradability, and is a biodegradable polyethylene film product.

The plastic samples were subjected to an acquired biodegradation test after (1) 30 days of the first thermal oxygen treatment, (2) 300 hours of photothermal treatment, and (3) 15 days of the second thermal oxygen treatment. The acquired biodegradation test is divided into three parts. The first part measures the concentration of adenosine triphosphate in the culture solution containing the oxidatively degraded film sample; the second part measures the ratio of adenosine monophosphate to adenosine monophosphate after 180 days; the third part measures the viability of the bacteria after 180 days.

The above plastic sample was pulverized and passed through a metal sieve having a pore size of about 1 mm. A powdered plastic sample is added to the culture solution for bacterial culture, and an equal amount of bacteria (such as Rhodococcus) is added to each test vessel, and the test is started (0 days), 4 days, 8 days, 12 days, The concentration of adenosine triphosphate in the solution at 30 days, 60 days, 90 days, 120 days, and 180 days. Each set of test samples was set to a corresponding blank group containing no carbon source.

Figure 1 shows the relationship between adenosine triphosphate (ATP) concentration and time in the membrane A and blank groups. Figure 2 shows the relationship between ATP concentration and time in the membrane B and blank groups. Figure 1 and Figure 2 show that in the six-month test period, the concentration of adenosine triphosphate in the culture solution containing the film A and film B after oxidation is not containing the film A and film B after oxidation. The concentration of adenosine triphosphate in the blank flask was more than three times. Adenosine triphosphate is an energy transport molecule of all living organisms on the earth. It is an essential molecule for microorganisms. Its quantity is directly related to the number of living cells. All living organisms must maintain cell integrity, biological survival and fission and other biological functions through adenosine triphosphate. Both rely on the energy of adenosine triphosphate.

Therefore, the test results show that the oxidized film A and film B of the present invention can be sufficiently bio-utilized by microorganisms as nutrients.

At the end of the 180 day test, the ratio of adenosine monophosphate (AMP) to adenosine triphosphate (ATP) in the culture solution containing the oxidized film sample was tested. The AMP/ATP ratio of the culture solution containing the film A sample and the film B sample was 2.4 and 2.2, respectively. An AMP/ATP ratio of less than 3 indicates that the oxidized plastic provides sufficient energy to the microorganisms, demonstrating that the bacteria are at an energy level.

At the end of the 180-day test, the bacterial population in the culture medium containing the membrane A sample and the membrane B sample was visible after a few days of incubation in a (27 ± 1) °C incubator, and the viability test showed positive. It was proved that film A and film B were not toxic to microorganisms after oxidation, and the bacteria did not affect the reproductive ability of the bacteria after passing through the medium containing the oxidized polyethylene sample for 6 months.

Acquired biodegradation tests demonstrate that Film A and Film B are acquired biodegradable materials. The environmentally-friendly modified polymer new material of the invention can be used to produce biodegradable polyethylene materials after being added to ordinary polyethylene polymer materials.

The biodegradable additive of the invention is not only suitable for the production of degradable polyethylene film materials, but also suitable for other kinds of plastic products such as environmentally-friendly packaging materials, disposable plastic products, agricultural disposable films (especially mulch products) and the like. plastic products. In the natural environment, these products undergo an oxidation reaction by light or heat, causing an increase in relative carboxylic acid groups, and obtaining biodegradable properties of the biodegradable plastic article. These environmentally friendly plastic products eventually degrade into carbon dioxide, water and humus by further thermal oxidative degradation, photothermal oxidative degradation or biodegradation.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The invention is intended to be modified or equivalently substituted without departing from the spirit and scope of the invention. Within the scope of protection.

Claims (10)

1. The invention relates to a biodegradation additive, which is prepared by using copper powder, iron powder, silane coupling agent, titanic acid coupling agent and low density polyethylene as raw materials, wherein the components are as follows: copper powder 8 to 12% by mass, 8 to 12% by mass of iron powder, 0.5 to 1.5% by mass of a silane coupling agent, and 0.5 to 1.0% by mass of a titanic acid coupling agent, and the balance is low-density polyethylene.
2. The biodegradation additive according to claim 1, wherein the composition is as follows: copper powder 10% by mass, iron powder 10% by mass, silane coupling agent 1% by mass, titanate coupling agent 0.6% by mass, the balance being low density polyethylene.
3. The biodegradable additive according to claim 1 or 2, wherein the copper powder has a particle diameter of 3 μm or less, and the iron powder has a particle diameter of 3 μm or less.
4. The biodegradation additive according to claim 3, wherein the silane coupling agent is 3-aminopropyltriethoxysilane, and the titanate coupling agent is isopropyltris(dioctyl) Pyrophosphoryloxy) titanate.
5. A method of preparing the biodegradable additive of any of claims 1-4, comprising the steps of:

   Step 1: Weigh the components in proportion, and then surface-treat the copper powder and the iron powder with a silane coupling agent and a titanate coupling agent;

   Step 2: mixing the surface treated copper powder and iron powder with low density polyethylene in a blender;

   Step 3: The material after being uniformly mixed by the second step is granulated by a twin-screw granulator.
6. The method according to claim 5, wherein the mixing time in the second step is 10 minutes.
7. The method according to claim 5, wherein in said step three, said twin-screw granulator has an aspect ratio of 40.
8. The method according to claim 5, wherein in said step three, The temperature of the second zone of the twin-screw granulator is set to the highest, that is, 180 °C, one zone is 5-15 °C lower than the second zone, and the temperature of the third zone and the fourth zone is the same as that of the second zone. From the five zones to the temperature gradient of the nose. Gradually lower, keeping the head temperature constant.
9. A plastic product comprising 2 to 10% by mass of the biodegradation additive according to any one of claims 1 to 4.
10. A polyethylene plastic film product, which is prepared by the biodegradation additive according to any one of claims 1 to 4, calcium carbonate powder and LDPE, wherein the ratio of each component is: the organism The degradation additive is 2 to 10% by mass, and the calcium carbonate powder is 3% by mass, and the balance is LDPE.

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