阅读说明：本技术 一种食品包装袋用聚乙烯材料 (Polyethylene material for food packaging bag ) 是由 史斌 姚启明 史清友 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种食品包装袋用聚乙烯材料,其原料按重量份包括：聚乙烯80-100份、抗冲击改性剂10-20份、填料8-10份、硬脂酸0.1-0.3份、相容剂2-3份,其中,填料为滑石粉、有机化纳米蒙脱土和改性石墨烯。本发明具有良好的机械性能和抗菌性能。(The invention discloses a polyethylene material for food packaging bags, which comprises the following raw materials in parts by weight: 80-100 parts of polyethylene, 10-20 parts of impact modifier, 8-10 parts of filler, 0.1-0.3 part of stearic acid and 2-3 parts of compatilizer, wherein the filler is talcum powder, organic nano montmorillonite and modified graphene. The invention has good mechanical property and antibacterial property.)

1. The polyethylene material for the food packaging bag is characterized by comprising the following raw materials in parts by weight: 80-100 parts of polyethylene, 10-20 parts of impact modifier, 8-10 parts of filler, 0.1-0.3 part of stearic acid and 2-3 parts of compatilizer, wherein the filler is talcum powder, organic nano montmorillonite and modified graphene.

2. The polyethylene material for the food packaging bag according to claim 1, wherein in the preparation process of the modified graphene, 3-chloropropyltrimethoxysilane, tertiary amine and ethanol are uniformly mixed, reacted, and the ethanol is removed to obtain an intermediate material; and uniformly mixing the graphene oxide with the ethanol aqueous solution of the intermediate material, and carrying out grafting reaction to obtain the modified graphene.

3. The polyethylene material for food packaging bags according to claim 2, wherein the molar ratio of 3-chloropropyltrimethoxysilane to tertiary amine is 1.1-1.2: 1.

4. The polyethylene material for food packaging bags according to claim 2 or 3, wherein the weight ratio of the graphene oxide to the intermediate material is 10: 0.5-1.

5. The polyethylene material for food packaging bags according to any one of claims 2 to 4, wherein the reaction is carried out at 60 to 70 ℃ for 40 to 48 hours, and the ethanol is removed to obtain an intermediate material.

6. The polyethylene material for food packaging bags according to any one of claims 2 to 5, wherein the grafting reaction is carried out at 75 to 85 ℃ for 4 to 6 hours.

7. The polyethylene material for the food packaging bag according to any one of claims 1 to 6, wherein the weight ratio of the talcum powder, the organic nano montmorillonite and the modified graphene is 2:1: 1-2.

8. The polyethylene material for food packaging bags according to any one of claims 1 to 7, wherein the impact modifier is a methyl methacrylate-butadiene-styrene copolymer.

9. The polyethylene material for food packaging bags according to any one of claims 1 to 8, wherein the compatibilizer is a polyethylene-grafted maleic anhydride copolymer and a silane coupling agent.

10. The polyethylene material for food packaging bags according to claim 9, wherein the weight ratio of the polyethylene-grafted maleic anhydride copolymer to the silane coupling agent is 1-2: 1.

Technical Field

The invention relates to the technical field of packaging bags, in particular to a polyethylene material for a food packaging bag.

Background

Polyethylene (PE for short) is a thermoplastic resin obtained by polymerizing ethylene. Polyethylene is odorless, nontoxic, wax-like in hand feeling, resistant to low temperature, good in chemical stability and easy to process. Can be made into non-woven fabrics, packaging bags and other products, and is used for packaging rice, flour and other grains. However, the tensile strength of polyethylene is low, and the prepared packaging bag is easy to crack; in addition, the grains are easily contaminated by bacteria and mold during storage, so a new packaging material needs to be provided.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a polyethylene material for food packaging bags, which has good mechanical properties and antibacterial properties.

The invention provides a polyethylene material for a food packaging bag, which comprises the following raw materials in parts by weight: 80-100 parts of polyethylene, 10-20 parts of impact modifier, 8-10 parts of filler, 0.1-0.3 part of stearic acid and 2-3 parts of compatilizer, wherein the filler is talcum powder, organic nano montmorillonite and modified graphene.

Preferably, in the preparation process of the modified graphene, 3-chloropropyltrimethoxysilane, tertiary amine and ethanol are uniformly mixed and reacted, and ethanol is removed to obtain an intermediate material; and uniformly mixing the graphene oxide with the ethanol aqueous solution of the intermediate material, and carrying out grafting reaction to obtain the modified graphene.

In the preparation process of the modified graphene, the tertiary amine can be dodecyl dimethyl tertiary amine, hexadecyl dimethyl tertiary amine and the like.

In the preparation process of the modified graphene, the dosage of ethanol and ethanol aqueous solution is not specified, and the dosage is determined according to specific operation.

Preferably, the molar ratio of 3-chloropropyltrimethoxysilane to tertiary amine is from 1.1 to 1.2: 1.

Preferably, the weight ratio of the graphene oxide to the intermediate material is 10: 0.5-1.

Preferably, the reaction is carried out at 60-70 ℃ for 40-48h, and the ethanol is removed to obtain an intermediate material.

Preferably, the grafting reaction is carried out at 75-85 ℃ for 4-6 h.

Preferably, the weight ratio of the talcum powder to the organic nano montmorillonite to the modified graphene is 2:1: 1-2.

Preferably, the impact modifier is a methyl methacrylate-butadiene-styrene copolymer.

Preferably, the compatibilizer is a polyethylene grafted maleic anhydride copolymer and a silane coupling agent.

Preferably, the weight ratio of the polyethylene grafted maleic anhydride copolymer to the silane coupling agent is 1-2: 1.

The preparation method comprises the following steps: grinding polyethylene, impact modifier and compatilizer, mixing uniformly with filler and stearic acid, extruding into fibers, cooling the fibers, laying the fibers into a net, and needling and reinforcing the net into cloth.

Has the advantages that:

1. the invention selects the methyl methacrylate-butadiene-styrene copolymer to be matched with polyethylene, and greatly improves the mechanical properties of toughness, strength and the like under the action of the compatilizer polyethylene grafted maleic anhydride copolymer and the silane coupling agent.

2. According to the invention, quaternary ammonium salt groups are introduced into the silane coupling agent, and then the modified graphene is grafted with the graphene oxide to obtain the modified graphene, so that the compatibility of the graphene and polyethylene can be greatly improved, and thus the mechanical properties such as toughness of the polyethylene are improved.

3. The talcum powder, the organic nano montmorillonite and the modified graphene are matched with each other, so that the mechanical property of the invention can be further improved; the stearic acid and the organic nano montmorillonite are matched with each other, so that the crystallinity of the polyethylene can be improved, and the toughness of the polyethylene can be further improved.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.

Example 1

A polyethylene material for food packaging bags comprises the following raw materials in parts by weight: 80g of polyethylene, 20g of methyl methacrylate-butadiene-styrene copolymer, 4g of talcum powder, 2g of organic nano montmorillonite, 2g of modified graphene, 0.3g of stearic acid, 1g of polyethylene grafted maleic anhydride copolymer and 1g of silane coupling agent;

in the preparation process of the modified graphene, 0.4268g (0.002mol) of dodecyl dimethyl tertiary amine is dissolved in 100ml of ethanol, 0.4769g (0.0024mol) of 3-chloropropyl trimethoxy silane is added and mixed uniformly, the temperature is raised to 60 ℃ in a water bath, the mixture is kept at the temperature and stirred for 48 hours, and ethanol is removed through reduced pressure evaporation to obtain an intermediate material; and (2) ultrasonically dispersing 5g of graphene oxide in 300ml of ethanol uniformly, then adding 20ml of ethanol aqueous solution containing 0.25g of intermediate material, uniformly mixing, keeping the temperature at 85 ℃, stirring, carrying out grafting reaction for 4 hours, filtering, washing a filter cake, and drying to obtain the modified graphene.

Example 2

A polyethylene material for food packaging bags comprises the following raw materials in parts by weight: 100g of polyethylene, 10g of methyl methacrylate-butadiene-styrene copolymer, 4g of talcum powder, 2g of organic nano montmorillonite, 4g of modified graphene, 0.1g of stearic acid, 2g of polyethylene grafted maleic anhydride copolymer and 1g of silane coupling agent;

wherein in the preparation process of the modified graphene, 0.4268g (0.002mol) of dodecyl dimethyl tertiary amine is dissolved in 100ml of ethanol, then 0.4371g (0.0022mol) of 3-chloropropyl trimethoxy silane is added and mixed uniformly, the temperature is raised to 70 ℃ in a water bath, the mixture is stirred for 40h under the condition of heat preservation, and ethanol is removed by reduced pressure evaporation to obtain an intermediate material; and (2) ultrasonically dispersing 5g of graphene oxide in 300ml of ethanol uniformly, then adding 20ml of ethanol aqueous solution containing 0.5g of intermediate material, uniformly mixing, keeping the temperature at 75 ℃, stirring, carrying out grafting reaction for 6 hours, filtering, washing a filter cake, and drying to obtain the modified graphene.

Example 3

A polyethylene material for food packaging bags comprises the following raw materials in parts by weight: 90g of polyethylene, 15g of methyl methacrylate-butadiene-styrene copolymer, 4g of talcum powder, 2g of organic nano montmorillonite, 3g of modified graphene, 0.2g of stearic acid, 1.5g of polyethylene grafted maleic anhydride copolymer and 1g of silane coupling agent;

in the preparation process of the modified graphene, 0.4268g (0.002mol) of dodecyl dimethyl tertiary amine is dissolved in 100ml of ethanol, 0.4570g (0.0023mol) of 3-chloropropyl trimethoxy silane is added and mixed uniformly, the temperature is raised to 65 ℃ in a water bath, the mixture is kept at the temperature and stirred for 44 hours, and ethanol is removed through reduced pressure evaporation to obtain an intermediate material; and (2) ultrasonically dispersing 5g of graphene oxide in 300ml of ethanol uniformly, then adding 20ml of ethanol aqueous solution containing 0.4g of intermediate material, uniformly mixing, keeping the temperature and stirring at 80 ℃, carrying out grafting reaction for 5 hours, filtering, washing a filter cake, and drying to obtain the modified graphene.

Comparative example 1

The same procedure as in example 3 was repeated, except that modified graphene was not contained.

Comparative example 2

The procedure of example 3 was repeated except that the methylmethacrylate-butadiene-styrene copolymer, the polyethylene-grafted maleic anhydride copolymer and the silane coupling agent were not contained.

Comparative example 3

The procedure of example 3 was otherwise the same as except that "modified graphene" was replaced with "unmodified graphene oxide".

Experiment of

Taking examples 1-3 and comparative examples 1-3, mixing uniformly according to the same method, extruding into fibers, cooling the fibers, laying the fibers into a net, and reinforcing the net by needling to obtain non-woven fabrics with the same size, wherein the gram weights of the non-woven fabrics are all 30g/m²Then manufacturing the packaging bags with the same size; the performance test was performed for each group, and the results are shown in table 1.

a. The breaking strength of each nonwoven group was measured according to FZ/T60005-1991.

b. The packaging bags prepared in each group were filled with 500g of rice, and after sealing, the bag was dropped from a height of 300mm, and 10 parallel samples were prepared by observing whether the packaging bag was broken after dropping.

c. The method for detecting the antibacterial performance comprises the following steps: cutting the non-woven fabrics prepared in the examples 1-3 and the comparative examples 1-3 into cloth blocks with the same size, sterilizing, and adding the cloth blocks into different bacterial suspensions according to the same addition amount for shake cultivation 12 (bacteria are cultivated at 37 ℃ and fungi are cultivated at 28 ℃); then 100 mul of bacterial liquid is respectively transferred to 10ml of liquid culture medium to be evenly shaken and cultured (bacteria are cultured for 24h at the constant temperature of 37 ℃ and fungi are cultured for 4 days at the constant temperature of 28 ℃), the colony count is counted, the bacteriostasis rate is calculated, and the pure polyethylene non-woven fabric is used as a blank control group, and the bacteriostasis rate is (the colony count of the pure polyethylene non-woven fabric-the colony count of each group)/the colony count of the pure polyethylene non-woven fabric is 100%.

TABLE 1 test results

As can be seen from the above table, the present invention has good mechanical properties and antibacterial properties.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.