Preparation method of long-acting antibacterial polypropylene material

Abstract

The preparation method comprises the following steps: adding an organic solvent into a reaction container, then introducing propylene gas, adding a second monomer allyl-5-chlorocyclopentadiene, then adding a metallocene catalyst, and carrying out a polymerization reaction so as to prepare the polypropylene material with a side chain containing a chlorine element. The obtained long-acting antibacterial polypropylene material is very uniform in antibacterial group distribution and excellent in antibacterial property, has a long-term antibacterial effect, and can be well applied to products with strict requirements on the antibacterial property, such as medical treatment, food and the like.

Description

Technical Field

[0001] The invention relates to the field of novel polypropylene synthesis, and in particular to a long-acting antibacterial polypropylene material and a preparation method thereof. Background Art

[0002] Polypropylene is increasingly used in medical and food fields due to its good chemical stability, low price, excellent mechanical properties and strong processability. Especially in recent years, the use of polypropylene in food and medical packaging has also increased. These fields have increasingly stringent requirements for the antibacterial properties of polypropylene, requiring not only excellent short-term antibacterial properties, but also long-term antibacterial properties.

[0003] The Chinese patent application number CN201310538155.6 discloses a method for preparing a nano zinc oxide antibacterial polypropylene resin. In terms of weight, 0.1-0.5 parts of nano zinc oxide treated with a coupling agent, 100 parts of polypropylene resin raw material, and 0.1-0.4 parts of other auxiliary additives are fully mixed in a high-speed mixer, extruded by a twin-screw extruder, cooled and pelletized, and the pellets are dried to obtain the nano zinc oxide antibacterial polypropylene resin of the present invention. The antibacterial rate of the nano zinc oxide antibacterial polypropylene resin product reaches more than 90%, and the product is non-toxic, has no color change, and is safe and hygienic.

[0004] The Chinese patent application number CN201010234999.8 discloses an antibacterial polypropylene resin and a preparation method thereof, wherein a small molecule organic antibacterial agent is fully mixed with an auxiliary monomer, and after the mixture is uniformly mixed, an initiator is added and fully mixed to obtain a mixture; then the weighed polypropylene resin is added to the first feeding port of a reaction-type twin-screw extruder, and the uniformly mixed mixture is added to the second feeding port, and thermomechanical mixing, reaction, extrusion, cooling and pelletizing are performed, and finally the pellets are dried to obtain the antibacterial polypropylene resin of the present invention. The antibacterial and antibacterial efficiency of the antibacterial polypropylene resin product is more than 99%, and it has both broad-spectrum, high-efficiency and long-lasting antibacterial functions and high safety.

[0005] At present, how to improve the durability of antibacterial polypropylene while ensuring antibacterial efficiency and ensure product safety to a greater extent has become a research hotspot. Summary of the invention

[0006] To achieve the above-mentioned purpose, the present invention provides a long-lasting antibacterial polypropylene material, which not only has excellent antibacterial efficiency, but also does not contain heavy metal ions such as silver, so that the final product is safe and healthy; and because the antibacterial group is directly connected to the polymer molecular chain segment, it will not have the problem of precipitation like other small molecule antibacterial agents, and can ensure the long-lasting antibacterial property of the product.

[0007] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a method for preparing a long-lasting antibacterial polypropylene material, which comprises adding an organic solvent into a reaction container, then introducing propylene gas, and then adding allyl-5-chlorocyclopentadiene monomer and a catalyst to carry out a polymerization reaction to obtain polypropylene with chlorine in the side chain.

[0009] In the present invention, the obtained side chain chlorine-containing polypropylene can also be melt-blended with ordinary polypropylene. Due to the similar molecular structure, the antibacterial component can be fully dispersed in the ordinary polypropylene matrix, so that the maximum antibacterial efficiency of the composite material can be ensured while using as little antibacterial polymer as possible.

[0010] In the present invention, the organic solvent is an alkane with 5 to 10 carbon atoms and / or an aromatic hydrocarbon with 6 to 10 carbon atoms; wherein the alkane with 5 to 10 carbon atoms is selected from one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, and n-decane, and the aromatic hydrocarbon organic solvent with 6 to 10 carbon atoms is selected from one or more of benzene, toluene, xylene, ethylbenzene, n-propylbenzene, and isopropylbenzene.

[0011] Furthermore, the mass ratio of the total mass of the added allyl-5-chlorocyclopentadiene monomer to the mass ratio of the organic solvent is preferably 5 to 20:100; the polymerization reaction temperature is gradient controlled: the temperature of the first stage is 25°C to 35°C, preferably 29°C to 31°C, and the reaction time is 9 to 11 min; the temperature of the second stage is 40°C to 50°C, preferably 44°C to 46°C, and the reaction time is 4 to 6 min; the temperature of the third stage is 55°C to 65°C, preferably 59°C to 61°C, and the reaction time is 9 to 11 min; the temperature of the fourth stage is 75°C to 85°C, preferably 79 to 81°C, and the reaction time is 9 to 11 min; the heating rate of the whole process is controlled at 9 to 11 min 11°C / min, and the polymerization gauge pressure is 0.1 to 5 MPa.

[0012] Furthermore, the catalyst comprises a metallocene catalyst and a cocatalyst, wherein the metallocene catalyst is added in an amount of 10 to 50 μmol, preferably 20 to 40 μmol, and is specifically selected from a transition metal-π bond compound with a transition metal M as the central atom, wherein M is Ti, Zr or Hf; further preferably, the transition metal-π bond compound with a transition metal M as the central atom is selected from Cp 2 TiCl 2 , C 2 H 4 (Me 4 Cp) 2 MCl 2 , C 2 H 4 (Ind) 2 MCl 2 , C2 H 4 (2,4,7-Me 3 -Ind) 2 MCl 2 , Me 2 Si(Flu) 2 MCl 2 , Me 2 SiC 2 (Ind) 2 MCl 2 , Me 2 Si(2-MeInd) 2 MCl 2 , Me 2 Si(2,5-Me-Cp) 2 MCl 2 , Me 2 Si(4,7-Me 2 -Ind) 2 MCl 2 , Me 2 Si(2-Me-4-Naph-Ind) 2 ZrCl 2 In the above compounds, Me = methyl, Ph = phenyl, Cp = cyclopentadienyl, Ind = indenyl, H 4 Ind = 4,5,6,7-tetrahydroindene, Flu = fluorenyl, Naph = naphthyl.

[0013] The co-catalyst comprises an alkylaluminoxane compound, preferably one or more of methylaluminoxane and isobutylaluminoxane.

[0014] In the present invention, the amount of the co-catalyst added is calculated based on the molar ratio of Al to M in the metallocene catalyst, Al:M=10-2000:1, preferably 500-1000:1.

[0015] On the other hand, the present invention also provides a long-acting antibacterial polypropylene material, wherein the content of allyl-5-chlorocyclopentadiene monomer is 0.5-5 mol%.

[0016] The polypropylene material of the present invention can also be used as antibacterial masterbatch for antibacterial modification of other polyolefin materials including polypropylene.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention polymerizes chlorine-containing functional monomers into the molecular chain of polypropylene through a highly efficient metallocene catalyst (chlorine groups will inhibit the activity of traditional ZN catalysts but will not affect the polymerization activity of metallocene catalysts), wherein the functional monomers are evenly distributed on the long chain of polypropylene;

[0019] (2) The side chain chlorine-containing polypropylene synthesized by the present invention can be melt-blended with ordinary polypropylene. During the blending process, since the main molecular chains of the two polymers are very similar, the dispersion effect of the antibacterial polymer in the polypropylene matrix will be greatly improved, so the material synthesized by this patent has very good antibacterial properties; DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with examples. The following examples are only used as illustrations of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] Source of raw materials:

[0022] Toluene, Sinopharm Chemical Reagent Co., Ltd.

[0023] Methylaluminoxane, Zhengzhou Aikemu Chemical Co., Ltd.;

[0024] C 2 H 4( Ind) 2 ZrCl 2 , Shanghai MacLean Biochemical Technology Co., Ltd.;

[0025] Allyl-5-chlorocyclopentadiene, Hong Kong Chemhere Product List;

[0026] Allyl cyclopentadiene, Hong Kong Chemhere Product List;

[0027] Homopolymer polypropylene, Tianjin Petrochemical.

[0028] Example 1

[0029] In a 5L reactor, add 2L toluene, add 160mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 0.1MPa, add 80mL of allyl-5-chlorocyclopentadiene monomer, and add 160μmol of metallocene agent C. 2 H 4( Ind) 2 ZrCl 2 , 30℃ for 10min; heating at a heating rate of 10℃ / min, the temperature was raised to 45℃ for 5min, then continued to rise to 60℃ for 10min, and finally raised to 80℃ for 10min. After the reaction, the polymer solution was transferred to acetone solution, stirred at room temperature for 2 hours to fully deactivate the catalyst. The product was collected, washed and dried to obtain 140g of the product.

[0030] According to hydrogen nuclear magnetic spectrum analysis, in the polymerization product, the content of allyl-5-chlorocyclopentadiene is about 1.5 mol%, and the content of propylene is about 98.5 mol%.

[0031] Example 2

[0032] In a 5L reactor, add 2L toluene, add 160mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 5MPa, add 80mL of allyl-5-chlorocyclopentadiene monomer, and add 120μmol of metallocene agent C. 2 H 4( Ind) 2 ZrCl 2 , 30℃ for 10min; heating at a heating rate of 10℃ / min, the temperature was raised to 45℃ for 5min, then continued to rise to 60℃ for 10min, and finally raised to 80℃ for 10min. After the reaction, the polymer solution was transferred to acetone solution, stirred at room temperature for 2 hours to fully deactivate the catalyst. The product was collected, washed and dried to obtain 275g of the product.

[0033] According to hydrogen nuclear magnetic spectrum analysis, in the polymerization product, the content of allyl-5-chlorocyclopentadiene is about 4.3 mol%, and the content of propylene is about 95.7 mol%.

[0034] Example 3

[0035] In a 5L reactor, add 2L toluene, add 160mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 0.1MPa, add 80mL of allyl-5-chlorocyclopentadiene monomer, and add 160μmol of metallocene agent C. 2 H 4( Ind) 2 ZrCl 2 , 30℃ for 10min; heating at a heating rate of 10℃ / min, the temperature was raised to 45℃ for 10min, then continued to rise to 60℃ for 20min, and finally raised to 80℃ for 15min. After the reaction, the polymer solution was transferred to acetone solution, stirred at room temperature for 2 hours to fully deactivate the catalyst. The product was collected, washed and dried to obtain 401g of the product.

[0036] According to hydrogen nuclear magnetic spectrum analysis, the content of allyl-5-chlorocyclopentadiene in the polymerization product is about 1.2 mol%, and the content of propylene is about 98.8 mol%.

[0037] Example 4

[0038] In a 5L reactor, add 2L toluene, add 80mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 0.1MPa, add 80mL of allyl-5-chlorocyclopentadiene monomer, add 160μmol of metallocene agent C2H4(Ind)2ZrCl2, react at 30℃ for 10min; heat at a heating rate of 10℃ / min, the temperature rises to 45℃ for 5min, continues to rise to 60℃ for 10min, and finally rises to 80℃ for 10min. After the reaction, transfer the polymer solution to acetone solution, stir at room temperature for 2 hours to fully deactivate the catalyst. Collect the product, wash and dry to obtain 130g of the product.

[0039] According to hydrogen nuclear magnetic spectrum analysis, in the polymerization product, the content of allyl-5-chlorocyclopentadiene is about 0.8 mol%, and the content of propylene is about 98.2 mol%.

[0040] Comparative Example 1

[0041] In a 5L reactor, add 2L toluene, add 160mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 0.1MPa, add 80mL of allyl cyclopentadiene monomer, add 120μmol of metallocene agent C 2 H 4( Ind) 2 ZrCl 2 , 30℃ for 10min; heating at a heating rate of 10℃ / min, the temperature was raised to 45℃ for 5min, then continued to rise to 60℃ for 10min, and finally raised to 80℃ for 10min. After the reaction, the polymer solution was transferred to acetone solution, stirred at room temperature for 2 hours to fully deactivate the catalyst. The product was collected, washed and dried to obtain 98g of the product.

[0042] According to hydrogen nuclear magnetic spectrum analysis, the content of allyl cyclopentadiene in the polymerization product is about 0.9 mol%, and the content of propylene is about 99.1 mol%.

[0043] Comparative Example 2

[0044] In a 5L reactor, add 2L toluene, add 160mL of 1.0mol / L methylaluminoxane under stirring, introduce propylene gas to 0.1MPa, add 80mL of allyl-5-chlorocyclopentadiene monomer, and add 120μmol of metallocene agent C. 2 H 4( Ind) 2 ZrCl 2 , react at 30°C for 60 min; stir in ketone solution at room temperature for 2 hours to fully deactivate the catalyst. Collect the product, wash and dry to obtain 121 g of the product.

[0045] According to hydrogen nuclear magnetic spectrum analysis, the content of allyl-5-chlorocyclopentadiene in the polymerization product is about 0.1 mol%, and the content of propylene is about 99.9 mol%.

[0046] Table 1 Antibacterial efficiency and product performance of Examples 1 to 4 and Comparative Examples 1 to 2

[0047]

[0048] Example 2 shows that increasing the reaction pressure while keeping other conditions unchanged can improve the polymerization activity and the insertion rate of the comonomer.

[0049] Example 3 shows that when other conditions remain unchanged, increasing the reaction time can improve the polymerization yield, but as the catalyst activity decays, the copolymerization ability of the catalyst also decreases, so the comonomer content of the final polymerization product decreases.

[0050] Example 4 shows that as the content of the co-catalyst decreases, the polymerization activity and copolymerization ability of the main catalyst both decrease.

[0051] Comparison between Comparative Example 1 and Example 1 shows that the introduction of chlorine-containing monomers can improve the polymerization activity and copolymerization ability of the catalyst to a certain extent. Comparative Example 1 has no chlorine element in its structure and has basically no antibacterial property.

[0052] Comparison between Comparative Example 2 and Example 1 shows that only through a series of temperature control measures can the active sites of the catalyst be fully activated, so that the catalyst has sufficient ability to polymerize monomers containing chlorine and having large steric hindrance.

Claims

1. A method for preparing a long-lasting antibacterial polypropylene material, characterized in that: The method comprises the following steps: adding an organic solvent into a reaction container, then introducing propylene gas, and then adding allyl-5-chlorocyclopentadiene monomer and a catalyst to carry out polymerization reaction to obtain polypropylene with chlorine in the side chain.

2. The preparation method according to claim 1, characterized in that The organic solvent is an alkane with 5 to 10 carbon atoms and / or an aromatic hydrocarbon with 6 to 10 carbon atoms; wherein the alkane with 5 to 10 carbon atoms is selected from one or more of n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, and n-decane, and the aromatic hydrocarbon organic solvent with 6 to 10 carbon atoms is selected from one or more of benzene, toluene, xylene, ethylbenzene, n-propylbenzene, and isopropylbenzene.

3. The preparation method according to claim 1 or 2, characterized in that: The mass ratio of the total mass of the added allyl-5-chlorocyclopentadiene monomer to the mass ratio of the organic solvent is preferably 5-20:100; and / or, the polymerization reaction temperature is gradient controlled: the temperature of the first stage is 25°C-35°C, preferably 29°C-31°C, and the reaction time is 9-11 min; the temperature of the second stage is 40°C-50°C, preferably 44°C-46°C, and the reaction time is 4-6 min; the temperature of the third stage is 55°C-65°C, preferably 59°C-61°C, and the reaction time is 9-11 min; the temperature of the fourth stage is 75°C-85°C, preferably 79-81°C, and the reaction time is 9-11 min; the heating rate of the whole process is controlled at 9-11 min 11°C / min, and the polymerization gauge pressure is 0.1-5 MPa.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The catalyst comprises a metallocene catalyst and a co-catalyst, wherein the metallocene catalyst is added in an amount of 10 to 50 μmol, preferably 20 to 40 μmol, and is specifically selected from a transition metal-π bond compound with a transition metal M as the central atom, wherein M is Ti, Zr or Hf; further preferably, the transition metal-π bond compound with a transition metal M as the central atom is selected from Cp2TiCl2, C2H4(Me4Cp)2MCl2, C2H4(Ind)2MCl2, C2H4(2,4,7-Me3-Ind)2MCl2, Me2Si (Flu)2MCl2, Me2SiCH2(Ind)2MCl2, Me2Si(2-MeInd)2MCl2, Me2Si(2,5-Me-Cp)2MCl2, Me2Si(4,7-Me2-Ind)2MCl2, Me2Si(2-Me-4-Naph-Ind)2ZrCl2; in the above compounds, Me = methyl, Ph = phenyl, Cp = cyclopentadienyl, Ind = indenyl, H4Ind = 4,5,6,7-tetrahydroindene, Flu = fluorenyl, Naph = naphthyl.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The co-catalyst comprises an alkylaluminoxane compound, preferably one or more of methylaluminoxane and isobutylaluminoxane.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The amount of the co-catalyst added is calculated based on the molar ratio of Al to M in the metallocene catalyst, Al:M=10-2000:1, preferably 500-1000:

1.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The content of allyl-5-chlorocyclopentadiene monomer in the long-acting antibacterial polypropylene material is 0.5-5 mol%.

8. Polypropylene prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the polypropylene prepared by the preparation method according to any one of claims 1 to 7 as an antibacterial masterbatch for antibacterial modification of polyolefin materials.

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