Antibacterial and anti-aging polypropylene material and preparation method thereof

Abstract

The application relates to the technical field of polypropylene, and discloses an antibacterial and anti-aging polypropylene material and a preparation method thereof.The polypropylene material contains, in parts by weight, 100 parts of polypropylene, 1.5-4 parts of chitosan quaternary ammonium salt, 0.6-2 parts of styrene sodium sulfonate grafted polypropylene and 0.4-0.7 parts of an antioxidant.The styrene sodium sulfonate grafted polypropylene and the chitosan quaternary ammonium salt have electrostatic interaction, the chitosan quaternary ammonium salt is used as a compatilizer to improve the compatibility between the chitosan quaternary ammonium salt and the polypropylene material, the antibacterial performance of the material is enhanced, and the breeding of bacteria and molds can be reduced.The compatibility between the chitosan quaternary ammonium salt and the polypropylene is good, the adverse influence of the chitosan quaternary ammonium salt on the mechanical performance of the polypropylene is reduced, the chitosan quaternary ammonium salt contains a heat-resistant naphthalene ring structure, the heat-aging performance of the polypropylene material is improved, and the polypropylene material has good practical application in toilet seat covers and other sanitary products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polypropylene, in particular to an antibacterial and anti-aging polypropylene material and a preparation method thereof. BACKGROUND

[0002] Polypropylene has good mechanical strength, wear resistance and chemical stability, and is widely used in toilet cover and other bathroom products, masks and other health products, and preservative film and other packaging product fields. Traditional toilet and other bathroom products are in contact with water for a long time, the environment is humid, and bacteria and mold are easy to breed, which will affect the physical and mental health of users. The current polypropylene material has poor antibacterial, mildew-proof and other properties, and poor hydrophilic and skin-friendly properties, which is not conducive to its practical application in bathroom and health products.

[0003] Adding chitosan, zinc oxide, titanium dioxide and other antibacterial agents to polypropylene can solve the problem of poor antibacterial performance. Chitosan, quaternary ammonium salt chitosan and other natural polysaccharide derivatives have good biocompatibility and excellent antibacterial performance, and are widely used in polypropylene, polyurethane, phenolic resin and other high molecular materials. Traditional quaternary ammonium salt chitosan is usually prepared by reacting the amino group of chitosan with 2,3-epoxypropyl trimethyl ammonium chloride, but it has the problem of poor heat resistance. The present application aims to use quaternary ammonium salt chitosan containing naphthyl to solve the problems of poor antibacterial and mildew-proof performance, mechanical strength, heat aging resistance and other properties of polypropylene material. SUMMARY

[0004] (I) Technical problems solved:

[0005] In view of the shortcomings of the prior art, the present application provides an antibacterial and anti-aging polypropylene material and a preparation method thereof, so that the polyethylene material has excellent antibacterial and mildew-proof performance while maintaining good heat resistance and aging resistance.

[0006] (II) Technical scheme: An antibacterial and anti-aging polypropylene material and a preparation method thereof, comprising 100 parts of polypropylene, 1.5-4 parts of chitosan quaternary ammonium salt, 0.6-2 parts of styrene sodium sulfonate grafted polypropylene, and 0.4-0.7 parts of antioxidant, by weight.

[0007] The preparation method is as follows: polypropylene, chitosan quaternary ammonium salt, styrene sodium sulfonate grafted polypropylene and antioxidant are added to a mixer and mixed, then extruded in a twin-screw extruder with a temperature of 160-195℃ in zone 1-6 and a screw rotation speed of 200-300r / min, and granulated to obtain the antibacterial and anti-aging polypropylene material.

[0008] Preferably, the preparation method of the chitosan quaternary ammonium salt is as follows: chitosan is added to a 30-40% mass fraction sodium hydroxide solution, isopropanol is added after stirring, heating to the reaction temperature, then 2-epoxypropyl (naphthyl) dimethyl quaternary ammonium salt is added, and hydrochloric acid is added dropwise to the solution after stirring to control the pH to be 6.5-7, then filtered, washed with ethanol, and dried to obtain the chitosan quaternary ammonium salt.

[0009] Preferably, the amount of chitosan is 100 parts, and the amount of 2-epoxypropyl (naphthyl) dimethyl quaternary ammonium salt is 300-600 parts by weight.

[0010] Preferably, the reaction temperature is 80-90 DEG C, and the reaction time is 12-18 h.

[0011] Preferably, the preparation method of the 2-epoxypropyl (naphthyl) dimethyl quaternary ammonium salt is as follows: 100 parts of N,N-dimethyl-1-(naphth-1-yl) methylamine and 59-78 parts of epichlorohydrin are added to isopropanol, heated to 70-80 DEG C, reacted for 4-7 h, distilled under reduced pressure, and the product is recrystallized in an ethanol aqueous solution to obtain the 2-epoxypropyl (naphthyl) dimethyl quaternary ammonium salt. The reaction formula is as follows:

[0012]

[0013] Preferably, the preparation method of the sodium styrene sulfonate grafted polypropylene is as follows: water, sodium p-styrene sulfonate and benzophenone are added to ethanol, stirred to prepare a grafting solution, the mass concentration of sodium p-styrene sulfonate in the grafting solution is controlled to be 80-300 g / L, the mass concentration of benzophenone is controlled to be 0.06-0.4 g / L, then polypropylene film is added, irradiation grafting is carried out under a nitrogen atmosphere and a UV lamp for 15-30 min, the polypropylene film is taken out, washed with water and ethanol, and dried to obtain the sodium styrene sulfonate grafted polypropylene.

[0014] (Three) Technical effects: the epoxy group of the 2-epoxypropyl (naphthyl) dimethyl quaternary ammonium salt is reacted with the amino group of chitosan to obtain chitosan quaternary ammonium salt containing a naphthyl group, then the chitosan quaternary ammonium salt is blended and granulated with polypropylene and sodium styrene sulfonate grafted polypropylene to obtain antibacterial and anti-aging polypropylene material.

[0015] The sodium styrene sulfonate grafted polypropylene contains sodium sulfonate groups, and has electrostatic interaction with the chitosan quaternary ammonium salt, so that the polypropylene molecular chain is modified on the surface of the chitosan quaternary ammonium salt, the sodium styrene sulfonate grafted polypropylene is used as a compatilizer, the compatibility between the chitosan quaternary ammonium salt and the polypropylene material is improved, the chitosan quaternary ammonium salt is uniformly dispersed in the polypropylene material matrix, more antibacterial active sites are provided, the antibacterial performance of the material is significantly improved, the antibacterial rates of escherichia coli and staphylococcus aureus are high, the growth of bacteria and mold can be reduced, and the practical application of the polypropylene material in antibacterial life and bathroom products is expanded.

[0016] The sodium styrene sulfonate grafted polypropylene improves the compatibility between the chitosan quaternary ammonium salt and the polypropylene, reduces the adverse effect of the chitosan quaternary ammonium salt on the mechanical properties of the polypropylene, so that the polypropylene material still has high tensile strength, the chitosan quaternary ammonium salt contains a heat-resistant naphthalene ring structure, and the addition of the chitosan quaternary ammonium salt to the polypropylene material is beneficial to improving the heat resistance, after heat aging treatment, the polypropylene material can maintain good tensile strength and excellent heat aging resistance, and the added sodium styrene sulfonate grafted polypropylene contains sodium sulfonate hydrophilic groups and hydrophilic chitosan quaternary ammonium salt, so that the water contact angle of the polypropylene material is reduced, the surface hydrophilicity and skin friendliness are improved, and the product experience of users is improved. The obtained polypropylene material has good practical application in toilet seat covers and other life and bathroom products. DETAILED DESCRIPTION

[0017] The application will be further described below in combination with specific examples. The raw materials and reagents used in the following examples and comparative examples are all commercially available products. The polypropylene is BH3820, Ningbo Keming Plasticizing Co., Ltd. The chitosan has an effective ingredient content of 99%, Jiangsu Weizhinun Biological Technology Co., Ltd.

[0018] Example 1

[0019] (1) 20 g of N,N-dimethyl-1-(naphthalen-1-yl)methylamine, 11.8 g of epichlorohydrin were added to 30 mL of isopropyl alcohol, heated to 80 DEG C, and reacted for 4 h, while condensing refluxing, and then distilled under reduced pressure. The product was recrystallized in a 70% volume fraction of an ethanol aqueous solution to obtain 2-epoxypropyl(naphthylmethyl)dimethyl quaternary ammonium salt.

[0020] (2) 10 g of chitosan was added to 25 mL of a 40% mass fraction sodium hydroxide solution, stirred, isopropyl alcohol was added, heated to 90 DEG C, and then 30 g of 2-epoxypropyl(naphthylmethyl)dimethyl quaternary ammonium salt was added. After stirring for 12 h, 37% mass fraction hydrochloric acid was added dropwise to the solution to control the pH of the solution to 7. After filtration, the product was washed with ethanol and dried to obtain chitosan quaternary ammonium salt.

[0021] (3) Into 300 mL of ethanol, 150 mL of water, sodium p-styrenesulfonate, benzophenone were added, and stirred to prepare a grafting solution, the mass concentration of sodium p-styrenesulfonate in the grafting solution was controlled to be 80 g / L, the mass concentration of benzophenone was 0.06 g / L, then a polypropylene film was added, and irradiation grafting was carried out under a nitrogen atmosphere for 15 min under a UV lamp with a power of 600 W, the polypropylene film was taken out, washed with water and ethanol, and dried to obtain a sodium p-styrenesulfonate grafted polypropylene.

[0022] (4) 1 kg of polypropylene, 15 g of chitosan quaternary ammonium salt, 6 g of sodium p-styrenesulfonate grafted polypropylene, and 6 g of antioxidant 1076 were added to a mixer and mixed, and then extruded in a twin-screw extruder, the temperature of 1-6 zones was 160℃, 170℃, 185℃, 195℃, 195℃, 190℃, and the screw rotation speed was 300 r / min, and then pelletized to obtain an antibacterial and anti-aging polypropylene material.

[0023] Example 2

[0024] (1) Into 40 mL of isopropanol, 20 g of N,N-dimethyl-1-(naphthalen-1-yl)methylamine and 15.6 g of epichlorohydrin were added, heated to 70℃, and reacted for 7 h, and then the product was recrystallized in a 70% volume fraction of an ethanol aqueous solution to obtain 2-epoxypropyl(naphthylmethyl)dimethyl quaternary ammonium salt.

[0025] (2) Into 35 mL of a 30% mass fraction sodium hydroxide solution, 10 g of chitosan was added, stirred, and then isopropanol was added, heated to 80℃, and then 45 g of 2-epoxypropyl(naphthylmethyl)dimethyl quaternary ammonium salt was added, stirred and reacted for 18 h, and then a 37% mass fraction hydrochloric acid was added dropwise to the solution to control the pH of the solution to be 6.5, and then filtered, washed with ethanol, and dried to obtain chitosan quaternary ammonium salt.

[0026] (3) Into 300 mL of ethanol, 150 mL of water, sodium p-styrenesulfonate, benzophenone were added, and stirred to prepare a grafting solution, the mass concentration of sodium p-styrenesulfonate in the grafting solution was controlled to be 200 g / L, the mass concentration of benzophenone was 0.25 g / L, then a polypropylene film was added, and irradiation grafting was carried out under a nitrogen atmosphere for 30 min under a UV lamp with a power of 600 W, the polypropylene film was taken out, washed with water and ethanol, and dried to obtain a sodium p-styrenesulfonate grafted polypropylene.

[0027] (4) 1 kg of polypropylene, 25 g of chitosan quaternary ammonium salt, 12 g of sodium p-styrenesulfonate grafted polypropylene, and 4 g of antioxidant 1076 were added to a mixer and mixed, and then extruded in a twin-screw extruder, the temperature of 1-6 zones was 160℃, 170℃, 185℃, 195℃, 195℃, 190℃, and the screw rotation speed was 200 r / min, and then pelletized to obtain an antibacterial and anti-aging polypropylene material.

[0028] Example 3

[0029] (1) 10 g of chitosan was added to 30 mL of a 40% by mass sodium hydroxide solution, isopropyl alcohol was added after stirring, heated to 85°C, then 60 g of 2-epoxypropyl (naphthyl methyl) dimethyl quaternary ammonium salt (same preparation method as Example 1) was added, stirred for 18 h, 37% by mass hydrochloric acid was added dropwise to the solution, the pH of the solution was controlled to 7, after filtration, washed with ethanol, dried, to obtain chitosan quaternary ammonium salt.

[0030] (2) 100 mL of water, sodium p-styrenesulfonate, benzophenone were added to 300 mL of ethanol, stirred to prepare a grafting solution, the mass concentration of sodium p-styrenesulfonate in the grafting solution was controlled to 300 g / L, the mass concentration of benzophenone was 0.4 g / L, then polypropylene film was added, irradiation grafting was carried out under a nitrogen atmosphere for 30 min under a UV lamp with a power of 600 W, the polypropylene film was taken out, washed with water and ethanol, and dried to obtain sodium p-styrenesulfonate grafted polypropylene.

[0031] (3) 1 kg of polypropylene, 40 g of chitosan quaternary ammonium salt, 20 g of sodium p-styrenesulfonate grafted polypropylene, and 7 g of antioxidant 1076 were added to a mixer and mixed, then extruded in a twin-screw extruder with a temperature of 160°C, 170°C, 185°C, 195°C, 195°C, and 190°C in zones 1-6, and a screw rotation speed of 200 r / min, and then pelletized to obtain an antibacterial and anti-aging polypropylene material.

[0032] Comparative Example 1, which is different from Example 1 is that chitosan quaternary ammonium salt and sodium p-styrenesulfonate grafted polypropylene are not added.

[0033] (1) 1 kg of polypropylene and 6 g of antioxidant 1076 were added to a mixer and mixed, then extruded in a twin-screw extruder with a temperature of 160°C, 170°C, 185°C, 195°C, 195°C, and 190°C in zones 1-6, and a screw rotation speed of 300 r / min, and then pelletized to obtain a polypropylene material.

[0034] Comparative Example 2, which is different from Example 1 is that chitosan quaternary ammonium salt is not added.

[0035] (2) 1 kg of polypropylene, 6 g of sodium p-styrenesulfonate grafted polypropylene, and 6 g of antioxidant 1076 were added to a mixer and mixed, then extruded in a twin-screw extruder with a temperature of 160°C, 170°C, 185°C, 195°C, 195°C, and 190°C in zones 1-6, and a screw rotation speed of 300 r / min, and then pelletized to obtain a polypropylene material.

[0036] Comparative Example 3, the difference between this comparative example and Example 1 is that no sodium styrene sulfonate grafted polypropylene is added.

[0037] (1) 1 kg of polypropylene, 15 g of chitosan quaternary ammonium salt, and 6 g of antioxidant 1076 were mixed in a mixer, and then extruded in a twin-screw extruder with a temperature of 160℃, 170℃, 185℃, 195℃, 195℃, and 190℃ in zones 1-6, and a screw speed of 300 r / min, and then pelletized to obtain a polypropylene material.

[0038] Comparative Example 4, the difference between this comparative example and Example 1 is that chitosan is used instead of chitosan quaternary ammonium salt.

[0039] (1) 1 kg of polypropylene, 15 g of chitosan, 6 g of sodium styrene sulfonate grafted polypropylene, and 6 g of antioxidant 1076 were mixed in a mixer, and then extruded in a twin-screw extruder with a temperature of 160℃, 170℃, 185℃, 195℃, 195℃, and 190℃ in zones 1-6, and a screw speed of 300 r / min, and then pelletized to obtain a polypropylene material.

[0040] Comparative Example 5, the difference between this comparative example and Example 1 is that 2,3-epoxypropyl trimethyl ammonium chloride is used instead of 2-epoxypropyl (naphthylmethyl) dimethyl quaternary ammonium salt when preparing the chitosan quaternary ammonium salt.

[0041] (1) 10 g of chitosan was added to 25 mL of a 40% by mass sodium hydroxide solution, stirred, and then isopropyl alcohol was added, heated to 90℃, and then 30 g of 2,3-epoxypropyl trimethyl ammonium chloride was added, stirred for 12 h, and then 37% by mass hydrochloric acid was added dropwise to the solution to control the pH of the solution to 7, filtered, washed with ethanol, and dried to obtain chitosan quaternary ammonium salt.

[0042] (2) 1 kg of polypropylene, 15 g of chitosan quaternary ammonium salt, and 6 g of sodium styrene sulfonate grafted polypropylene, and 6 g of antioxidant 1076 were mixed in a mixer, and then extruded in a twin-screw extruder with a temperature of 160℃, 170℃, 185℃, 195℃, 195℃, and 190℃ in zones 1-6, and a screw speed of 300 r / min, and then pelletized to obtain a polypropylene material.

[0043] The polypropylene materials prepared in Examples 1-3 and Comparative Examples 1-6 were respectively injected into an injection molding machine at a temperature of 200℃ to form a sample strip.

[0044] The antibacterial performance of the polypropylene materials was tested according to the film pasting method of QB / T 2591-2003 standard, with the polypropylene material of Comparative Example 1 as a blank control sample. Examples 1-3 and Comparative Examples 2-5 were respectively used as antibacterial plastic samples.

[0045] Table 1

[0046]

[0047] From the above table, the polypropylene material of examples 1-3 is added with chitosan quaternary ammonium salt and sodium styrene sulfonate grafted polypropylene, the polypropylene is grafted with sodium sulfonate groups, and the chitosan quaternary ammonium salt has electrostatic interaction, so that the polypropylene molecular chain is modified on the surface of the chitosan quaternary ammonium salt, the sodium styrene sulfonate grafted polypropylene acts as a compatibilizer, the compatibility between the chitosan quaternary ammonium salt and the polypropylene material is improved, the chitosan quaternary ammonium salt is uniformly dispersed in the polypropylene material matrix, has more antibacterial active sites, and significantly improves the antibacterial performance of the material. The antibacterial rates of escherichia coli and staphylococcus aureus show very high sterilization performance.

[0048] Comparative example 2 does not add chitosan quaternary ammonium salt, and the antibacterial performance of the polypropylene material is poor.

[0049] Comparative example 3 adds chitosan quaternary ammonium salt, and the antibacterial performance is obviously improved, but the antibacterial rates of escherichia coli and staphylococcus aureus are lower than those of example 1. Since sodium styrene sulfonate grafted polypropylene is not added, the compatibility between the chitosan quaternary ammonium salt and the polypropylene is poor, the dispersibility in the material matrix is not good, the antibacterial active sites are less than those of example 1, and the antibacterial rates are slightly lower.

[0050] Comparative example 4 uses chitosan instead of chitosan quaternary ammonium salt, which does not contain quaternary ammonium salt groups, resulting in lower antibacterial rates than example 1.

[0051] Comparative example 5 also significantly improves the antibacterial rates and antibacterial performance of the polypropylene material.

[0052] According to GB / T 1040.1-2006 standard, the tensile strength of the sample strip is tested. The sample strip is placed in a blast drying oven, heat aged at 80°C for 168h, then placed at room temperature for 24h, and then the tensile strength is tested.

[0053] The sample strip is molded into a film shape, and the water contact angle is tested according to GB / T 30693-2014 standard.

[0054] Table 2

[0055]

[0056]

[0057] The polypropylene material of embodiments 1-3 added styrene sodium sulfonate grafted polypropylene, which played the role of a compatibilizer, improved the compatibility between the chitosan quaternary ammonium salt and the polypropylene, reduced the adverse effects of the chitosan quaternary ammonium salt on the mechanical properties of the polypropylene, so that the polypropylene material still had very high tensile strength, and the chitosan quaternary ammonium salt contained a heat-resistant naphthalene ring structure, which was beneficial to improving the heat resistance when added to the polypropylene material. After heat aging treatment, the polypropylene material could maintain good tensile strength and exhibit excellent heat aging resistance. In addition, the styrene sodium sulfonate grafted polypropylene contained a sodium sulfonate hydrophilic group, and the chitosan quaternary ammonium salt was hydrophilic, which could reduce the water contact angle of the polypropylene material and improve the surface hydrophilicity and skin friendliness.

[0058] Compared with Comparative Example 1, the tensile strength of the polypropylene material of Comparative Example 1-2 decreased significantly after heat aging treatment. Comparative Example 3 did not add styrene sodium sulfonate grafted polypropylene, and the compatibility of the chitosan quaternary ammonium salt with the polypropylene material was poor, resulting in low tensile strength of the material. Comparative Example 4 added chitosan, which did not contain a quaternary ammonium salt group, could not interact with the styrene sodium sulfonate grafted polypropylene by static electricity, and could not play the role of a compatibilizer. The compatibility of the chitosan with the polypropylene material was poor, resulting in low tensile strength of the polypropylene material. The chitosan quaternary ammonium salt of Comparative Example 5 did not contain a heat-resistant naphthalene ring structure, and did not improve the heat resistance of the polypropylene material. After heat aging treatment, the tensile strength retention rate of the material was low.

[0059] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, therefore the protection scope of the present application should be limited by the scope defined by the claims.

Claims

1. An antibacterial and anti-aging polypropylene material, characterized in that, The antibacterial and anti-aging polypropylene material comprises 100 parts of polypropylene, 1.5-4 parts of chitosan quaternary ammonium salt, 0.6-2 parts of sodium styrene sulfonate grafted polypropylene, and 0.4-0.7 parts of antioxidant, by weight. The preparation method of the chitosan quaternary ammonium salt comprises the following steps: adding chitosan into a sodium hydroxide solution, stirring, adding isopropyl alcohol, heating to a reaction temperature, then adding 2-epoxypropyl (naphthylmethyl) dimethyl quaternary ammonium salt, adding hydrochloric acid dropwise into the solution after stirring and reaction, filtering, washing, and drying to obtain the chitosan quaternary ammonium salt. The preparation method of the 2-epoxypropyl (naphthylmethyl) dimethyl quaternary ammonium salt comprises the following steps: adding N,N-dimethyl-1-(naphth-1-yl) methylamine and epichlorohydrin into isopropyl alcohol, heating to 70-80℃, reacting for 4-7 hours, distilling under reduced pressure, and recrystallizing to obtain the 2-epoxypropyl (naphthylmethyl) dimethyl quaternary ammonium salt.

2. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The mass fraction of the sodium hydroxide solution is 30-40%.

3. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The amount of the chitosan is 100 parts, and the amount of the 2-epoxypropyl (naphthylmethyl) dimethyl quaternary ammonium salt is 300-600 parts, by weight.

4. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The reaction temperature is 80-90℃, and the reaction time is 12-18 hours.

5. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The pH of the solution is controlled to 6.5-7 by adding hydrochloric acid dropwise.

6. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The amount of the N,N-dimethyl-1-(naphth-1-yl) methylamine is 100 parts, and the amount of the epichlorohydrin is 59-78 parts, by weight.

7. The antibacterial and anti-aging polypropylene material according to claim 1, characterized in that, The preparation method of the sodium styrene sulfonate grafted polypropylene comprises the following steps: adding water, sodium p-styrene sulfonate and benzophenone into ethanol, stirring to prepare a grafting solution, then adding a polypropylene film, irradiating and grafting under a nitrogen atmosphere and a UV lamp for 15-30 minutes, taking out the polypropylene film, washing, and drying to obtain the sodium styrene sulfonate grafted polypropylene.

8. The antibacterial and anti-aging polypropylene material according to claim 7, characterized in that, The mass concentration of the sodium p-styrene sulfonate in the grafting solution is 80-300 g / L, and the mass concentration of the benzophenone is 0.06-0.4 g / L.

9. A process for the preparation of an antibacterial and anti-aging polypropylene material as claimed in any one of claims 1-8, characterized in that, The preparation method comprises the following steps: adding the polypropylene, the chitosan quaternary ammonium salt, the sodium styrene sulfonate grafted polypropylene, and the antioxidant into a mixer, then extruding and granulating in a double-screw extruder, wherein the temperature of the first to sixth zones is 160-195℃, and the screw rotation speed is 200-300 r / min, to obtain the antibacterial and anti-aging polypropylene material.

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