Antibacterial PP modified material and preparation method thereof

Abstract

The invention relates to the technical field of polypropylene materials, and discloses an antibacterial PP modified material and a preparation method thereof.The PP modified material is prepared by taking polypropylene as a base material and taking maleic anhydride grafted polypropylene as a compatilizer, a silane biological antibacterial agent as an additive and inorganic modified filler as auxiliary materials through the processes of mixing and extrusion granulation, the antibacterial modifier can interact with a maleic anhydride group in a compatilizer maleic anhydride grafted polypropylene structure under a melt extrusion high-temperature condition, so that a mutually wound and interwoven three-dimensional network structure can be generated between a silane biological antibacterial agent molecular chain and a polypropylene molecular chain, and the long-acting antibacterial property of polypropylene is guaranteed; and the inorganic modified filler has the effects of dispersing stress and transferring load, and can generate a toughening effect on the polypropylene, so that the mechanical strength of the polypropylene is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene materials, and in particular to an antibacterial PP modified material and a preparation method thereof. Background Art

[0002] In modern home life, the material selection of toilet seats has become the focus of consumers. Polypropylene (PP) occupies an important position in the manufacture of toilet seats due to its non-toxic, harmless, environmentally friendly, durable and affordable characteristics. First of all, polypropylene is a non-toxic and harmless material, which makes it very frequently used in personal care products. As an indispensable bathroom product in the bathroom, the safety of the toilet seat material is of vital importance. The polypropylene toilet seat not only meets this requirement, but also has good heat resistance and wear resistance, and can withstand frequent use and cleaning. Secondly, the polypropylene toilet seat is light in weight, and the installation and disassembly are relatively simple, which is convenient for users to carry out daily maintenance and replacement. In a diverse home environment, the polypropylene toilet seat is suitable for most family bathrooms and is also favored by public facilities such as shopping malls and office buildings.

[0003] Toilets are personal hygiene equipment components that are frequently touched in daily life. Bacteria, viruses and other microorganisms are easily accumulated on their surfaces, which can easily lead to cross-infection. Therefore, the polymer materials used to prepare toilet covers and gaskets should have good antibacterial properties. However, polypropylene itself has poor antibacterial properties and poor mechanical strength. There is a risk of breakage when subjected to large external forces. These defects have gradually restricted its application in the field of toilet manufacturing. Therefore, it is particularly urgent to modify the comprehensive properties of polypropylene, such as antibacterial properties.

[0004] At present, antibacterial modification of polymer materials such as polypropylene is usually achieved by adding antibacterial agents such as silver. However, silver antibacterial agents are heavy metals and will cause certain pollution to the environment after being discarded. There are also small molecule antibacterial agents of the quaternary ammonium salt type, but this type of antibacterial agent itself is easy to volatilize and migrate, and has insufficient stability, making it difficult to achieve efficient antibacterial modification of polypropylene.

[0005] In addition, polypropylene can also be enhanced and modified by adding inorganic fillers, such as silica, graphene, etc. However, there is a serious problem of interface incompatibility between these inorganic materials and polypropylene, so it is actually difficult to effectively exert their own enhancement advantages.

[0006] Based on this, the present invention provides a PP modified material with excellent comprehensive performance, which can solve the problems existing in the prior art. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In view of the deficiencies of the prior art, the present invention provides an antibacterial PP modified material and a preparation method thereof.

[0009] (II) Technical solution

[0010] A method for preparing an antibacterial PP modified material, wherein the PP modified material is made of raw materials including the following parts by weight:

[0011]

[0012] The preparation method comprises the following steps:

[0013] Step 1: Weigh each raw material according to weight and set aside;

[0014] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to be 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, 210±5℃, and 210±5℃, respectively, and the screw speed to be 50-60rpm. After a melt extrusion process, the PP modified material can be obtained.

[0015] As a further solution of the present invention, the specific preparation method of the silane bioantibacterial agent is as follows:

[0016] Add the epoxy-terminated silicone oil and toluene solvent into a reactor filled with nitrogen, start stirring to form a uniform reaction liquid, then add the reactive bioantibacterial agent into the reaction liquid, stir evenly, start heating, raise the temperature to 60-70°C, and then add the phase transfer catalyst to the reaction liquid. After the addition is completed, keep the temperature and stir to react for 4-8 hours, remove the nitrogen, evaporate and remove the solvent, cool and discharge the material, and the silane bioantibacterial agent can be obtained.

[0017] As a further embodiment of the present invention, the number average molecular weight of the epoxy-terminated silicone oil is 1000-2000.

[0018] As a further solution of the present invention, the specific preparation method of the reactive biological antibacterial agent is as follows:

[0019] Citral is added to an ethanol solution with a volume fraction of 60-70%, and the mixture is mechanically stirred to form a uniform mixed solution. L-lysine is then added to the mixed solution. After the addition is completed, nitrogen is introduced for protection. After stirring evenly, the temperature is controlled to 40-50°C, and the mixture is stirred for 8-12 hours. The solvent is evaporated to remove the solvent, the product is collected, extracted with a Soxhlet extractor for 8-12 hours, and then vacuum dried to obtain a reactive biological antibacterial agent.

[0020] As a further embodiment of the present invention, the molar ratio of citral to L-lysine is 1-2:1.

[0021] As a further embodiment of the present invention, the phase transfer catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, tetramethylammonium bromide or tetramethylammonium chloride.

[0022] In the above technical scheme, citral and L-lysine are first used as reactants, and the Schiff base reaction between the active aldehyde group and the active amino group is utilized to obtain a citral derivative containing a substituted carboxyl group, i.e., a reactive bioantibacterial agent. Under the action of a phase transfer catalyst, the substituted carboxyl group in its structure can undergo a ring-opening esterification reaction with the epoxy group in the terminal epoxy silicone oil structure, thereby obtaining a silane bioantibacterial agent containing the natural antibacterial agent citral in its structure.

[0023] As a further solution of the present invention, the specific preparation method of the inorganic modified filler is as follows:

[0024] The talc powder is ultrasonically dispersed in N, N-dimethylformamide to form a uniform dispersion, and then the epoxidized natural rubber is added to the dispersion, and stannous chloride is added at the same time. After the addition is completed, the heating is turned on and the temperature is controlled to 130-140°C. After continuous stirring for 6-9 hours, the heating is stopped, the temperature is lowered and the material is discharged. The solid material is centrifuged out, and the inorganic modified filler can be obtained after washing and vacuum drying.

[0025] As a further embodiment of the present invention, the epoxidation degree of the epoxidized natural rubber is 25%.

[0026] In the above technical solution, stannous chloride is used as a catalyst to catalyze the ring-opening addition of epoxidized natural rubber to the hydroxyl groups on the surface of talcum powder, thereby modifying the natural rubber on the surface of talcum powder to obtain an inorganic modified filler.

[0027] As a further embodiment of the present invention, the antioxidant is any one of a hindered phenol antioxidant or a phosphite antioxidant.

[0028] An antibacterial PP modified material is prepared by adopting the above preparation method.

[0029] (III) Beneficial technical effects

[0030] (1) The present invention prepares a silane bioantimicrobial agent containing a natural antimicrobial agent as an antimicrobial modifier to perform antimicrobial modification on polypropylene. Since hydroxyl substituents are generated during the ring-opening esterification process, these hydroxyl substituents can interact with the maleic anhydride groups in the structure of the maleic anhydride grafted polypropylene as a compatibilizer under high temperature conditions of melt extrusion, thereby enabling the molecular chains of the silane bioantimicrobial agent to form a three-dimensional network structure with the molecular chains of the polypropylene. On the one hand, this entangled and interwoven structure can prevent the precipitation and migration of the antimicrobial agent and ensure the long-term antimicrobial performance of the polypropylene. On the other hand, due to the large number of silicon-oxygen bonds in the structure of the silane bioantimicrobial agent, the hydrophobicity of the polypropylene can be improved to prevent contamination by pollutants and the problem of difficulty in cleaning.

[0031] (2) The present invention obtains an inorganic modified filler by modifying the surface of talcum powder with natural rubber. The presence of natural rubber can form a transition structure between talcum powder and polypropylene, thereby effectively improving the interfacial compatibility between talcum powder and polypropylene, thereby promoting talcum powder to efficiently exert its own advantages as an inorganic filler, and play a role in dispersing stress and transferring load. At the same time, the natural rubber molecular chain has high flexibility and can produce a toughening effect on polypropylene, thereby effectively improving the mechanical strength of polypropylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0033] Figure 1 This is the infrared analysis test diagram of silane biological antibacterial agent. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0035] Preparation Example 1

[0036] Preparation of silane bioantibacterial agent:

[0037] Step 1, add 1g of citral to a 70% ethanol solution, stir mechanically to form a uniform mixture, then add 0.5g of L-lysine to the mixture, pass nitrogen protection, stir evenly, control the temperature to 45°C, keep warm and stir for 9 hours, evaporate and remove the solvent, collect the product, extract it with a Soxhlet extractor for 12 hours, and then vacuum dry it to obtain a reactive biological antibacterial agent;

[0038] Step 2: Add 1.2 g of epoxy-terminated silicone oil with a number average molecular weight of 1000 and toluene solvent into a reactor filled with nitrogen, start stirring to form a uniform reaction liquid, then add 1 g of reactive bioantibacterial agent to the reaction liquid, stir evenly, start heating, raise the temperature to 65°C, and then add 0.1 g of tetrabutylammonium bromide to the reaction liquid. After the addition is completed, keep warm and stir for 6 hours, remove the nitrogen, evaporate to remove the solvent, cool and discharge the material, and the silane bioantibacterial agent can be obtained.

[0039] Figure 1 This is the infrared analysis test diagram of the silane bioantibacterial agent, where 3262cm -1 The characteristic absorption peak at 1747 cm is the C=O characteristic absorption peak produced by the ring-opening esterification reaction. -1 The characteristic absorption peak at 1598 cm is the C=O characteristic absorption peak of the ester group. -1 The characteristic absorption peak at 1065 cm is the characteristic absorption peak of Schiff base C=N. -1 The characteristic absorption peak that appears at is the characteristic absorption peak of silicon and oxygen.

[0040] Preparation Example 2

[0041] Preparation of inorganic modified fillers:

[0042] 3.5 g of talc powder was ultrasonically dispersed in N, N-dimethylformamide to form a uniform dispersion, and then 5 g of epoxidized natural rubber with an epoxidation degree of 25% was added to the dispersion, and 0.01 g of stannous chloride was added at the same time. After the addition, heating was turned on and the temperature was controlled to 140°C. After continuous stirring for 8 hours, heating was stopped, the temperature was lowered and the material was discharged. The solid material was centrifuged out, and the inorganic modified filler was obtained after washing and vacuum drying.

[0043] Example 1

[0044] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0045]

[0046]

[0047] The preparation method comprises the following steps:

[0048] Step 1: Weigh each raw material according to weight and set aside;

[0049] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 50rpm. After a melt extrusion process, the PP modified material can be obtained.

[0050] The preparation method of the silane bioantibacterial agent is shown in Preparation Example 1; the preparation method of the inorganic modified filler is shown in Preparation Example 2; the antioxidant is antioxidant 1010, and the same applies to the following.

[0051] Example 2

[0052] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0053]

[0054] The preparation method comprises the following steps:

[0055] Step 1: Weigh each raw material according to weight and set aside;

[0056] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 500rpm. After a melt extrusion process, the PP modified material can be obtained.

[0057] Example 3

[0058] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0059]

[0060] The preparation method comprises the following steps:

[0061] Step 1: Weigh each raw material according to weight and set aside;

[0062] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 60rpm. After a melt extrusion process, the PP modified material can be obtained.

[0063] Comparative Example 1

[0064] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0065]

[0066] The preparation method comprises the following steps:

[0067] Step 1: Weigh each raw material according to weight and set aside;

[0068] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 500rpm. After a melt extrusion process, the PP modified material can be obtained.

[0069] Comparative Example 2

[0070] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0071]

[0072] The preparation method comprises the following steps:

[0073] Step 1: Weigh each raw material according to weight and set aside;

[0074] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, talcum powder, zinc stearate and antioxidant into a high-speed mixer, stir and mix them evenly, and then feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 500rpm. After a melt extrusion process, the PP modified material can be obtained.

[0075] Comparative Example 3

[0076] An antibacterial PP modified material is made of the following raw materials in parts by weight:

[0077]

[0078] The preparation method comprises the following steps:

[0079] Step 1: Weigh each raw material according to weight and set aside;

[0080] Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to 200°C, 210°C, 220°C, 220°C, 210°C, and 210°C in sequence, and the screw speed to 500rpm. After a melt extrusion process, the PP modified material can be obtained.

[0081] Test Case

[0082] According to standard GB / T 1040.2-2022, tensile properties test is carried out;

[0083] According to the standard GB / T 9341-2008, the bending strength test is carried out;

[0084] According to the standard QB / T 2591-2003, the antibacterial performance test was carried out, and the test bacteria was Staphylococcus aureus;

[0085] The water contact angle is directly measured using a water contact angle meter;

[0086] The test results are recorded in Table 1:

[0087]

[0088]

[0089] From the analysis and test results, it can be seen that the PP modified material made by adding silane bio-antibacterial agent and infinite modified filler has significantly higher mechanical strength, better antibacterial performance, larger water contact angle, and stronger hydrophobic and oleophobic effect, so the material is easier to clean.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

Claims

1. A method for preparing an antibacterial PP modified material, characterized in that: The PP modified material is made of the following raw materials in parts by weight: The preparation method comprises the following steps: Step 1: Weigh each raw material according to weight and set aside; Step 2: Put polypropylene, maleic anhydride grafted EPDM rubber, silane bioantibacterial agent, inorganic modified filler, zinc stearate and antioxidant into a high-speed mixer. After mechanical stirring and mixing evenly, feed them into a twin-screw extruder through a feeding hopper. Control the temperatures of each zone of the extruder to be 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, 210±5℃, and 210±5℃, respectively, and the screw speed to be 50-60rpm. After a melt extrusion process, the PP modified material can be obtained.

2. The method for preparing an antibacterial PP modified material according to claim 1, characterized in that: The specific preparation method of the silane bioantibacterial agent is as follows: Add the epoxy-terminated silicone oil and toluene solvent into a reactor filled with nitrogen, start stirring to form a uniform reaction liquid, then add the reactive bioantibacterial agent into the reaction liquid, stir evenly, start heating, raise the temperature to 60-70°C, and then add the phase transfer catalyst to the reaction liquid. After the addition is completed, keep the temperature and stir to react for 4-8 hours, remove the nitrogen, evaporate and remove the solvent, cool and discharge the material, and the silane bioantibacterial agent can be obtained.

3. The method for preparing an antibacterial PP modified material according to claim 2, characterized in that: The number average molecular weight of the epoxy-terminated silicone oil is 1000-2000.

4. The method for preparing an antibacterial PP modified material according to claim 2, characterized in that: The specific preparation method of the reactive biological antibacterial agent is as follows: Citral is added to an ethanol solution with a volume fraction of 60-70%, and the mixture is mechanically stirred to form a uniform mixed solution. L-lysine is then added to the mixed solution. After the addition is completed, nitrogen is introduced for protection. After stirring evenly, the temperature is controlled to 40-50°C, and the mixture is stirred for 8-12 hours. The solvent is evaporated to remove the solvent, the product is collected, extracted with a Soxhlet extractor for 8-12 hours, and then vacuum dried to obtain a reactive biological antibacterial agent.

5. The method for preparing an antibacterial PP modified material according to claim 4, characterized in that: The molar ratio of citral to L-lysine is 1-2:

1.

6. The method for preparing an antibacterial PP modified material according to claim 2, characterized in that: The phase transfer catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, tetramethylammonium bromide or tetramethylammonium chloride.

7. The method for preparing an antibacterial PP modified material according to claim 1, characterized in that: The specific preparation method of the inorganic modified filler is as follows: The talc powder is ultrasonically dispersed in N, N-dimethylformamide to form a uniform dispersion, and then the epoxidized natural rubber is added to the dispersion, and stannous chloride is added at the same time. After the addition is completed, the heating is turned on and the temperature is controlled to 130-140°C. After continuous stirring for 6-9 hours, the heating is stopped, the temperature is lowered and the material is discharged. The solid material is centrifuged out, and the inorganic modified filler can be obtained after washing and vacuum drying.

8. The method for preparing an antibacterial PP modified material according to claim 7, characterized in that: The epoxidation degree of the epoxidized natural rubber is 25%.

9. The method for preparing an antibacterial PP modified material according to claim 1, characterized in that: The antioxidant is any one of a hindered phenol antioxidant or a phosphite antioxidant.

10. An antibacterial PP modified material as claimed in claim 1, characterized in that: The method is prepared according to any one of claims 1 to 9.

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