CN111423547A

CN111423547A - Antibacterial polypropylene block copolymer and preparation method thereof

Info

Publication number: CN111423547A
Application number: CN202010307505.8A
Authority: CN
Inventors: 卢静
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2020-07-17

Abstract

The invention discloses an antibacterial polypropylene block copolymer and a preparation method thereof; the block copolymer of the p-hydroxystyrene and the polypropylene (PP) of the organic antibacterial agent is prepared, the block copolymer enables the polypropylene material to have antibacterial effect, and the defects of poor heat resistance, poor compatibility with a polypropylene (PP) matrix and poor soaking and washing resistance of a common organic antibacterial agent are overcome by a block copolymerization polymerization method; meanwhile, the poly-p-hydroxystyrene has the oxygen resistance and the dry etching resistance, the polypropylene (PP) has the oxygen resistance and the dry etching resistance due to the introduction of the poly-p-hydroxystyrene, and the polypropylene (PP) resin material contains hydrogen bond elements due to the introduction of the poly-p-hydroxystyrene, so that the antibacterial property and the biocompatibility of the polymer are improved.

Description

Antibacterial polypropylene block copolymer and preparation method thereof

Technical Field

The invention belongs to the field of high molecular chemical synthesis, and particularly relates to an antibacterial polypropylene block copolymer and a preparation method thereof.

Background

The biological protective mask is a mask for protecting the respiratory tract of a person in a biological pollution environment and can be divided into a passive biological protective mask and an active antibacterial biological protective mask according to the functions of the mask. (1) Passive biological protective mask: the mask is a protective mask which is commonly used at present, and is mainly used for filtering out physical particles or harmful pathogenic bacteria in the air in a physical filtering mode. (2) Active antibacterial biological protective mask: the mask is added with certain antibacterial components to endow the mask with an active antibacterial function.

CN101089038B discloses an antibacterial polypropylene material and a preparation method thereof, wherein an inorganic antibacterial agent and an organic antibacterial agent are added into polypropylene, so that the polypropylene material has an antibacterial effect, and an organic antibacterial agent with excellent antibacterial performance, rapidness and durability is obtained. But no chemical bond exists between the antibacterial molecules and the polypropylene base material, the dispersion uniformity of the antibacterial agent is not easy to ensure, and in addition, the loss problem of the antibacterial component is difficult to avoid, and the long-term antibacterial performance of the product is directly influenced. The organic antibacterial material has the characteristics of good sterilization effect, high antibacterial broad spectrum, strong initial bactericidal power, easy dispersion and the like, but also has a plurality of defects, such as poor chemical stability and thermal stability, easy volatilization and decomposition and difficult long-acting realization.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a block copolymer of p-hydroxystyrene and PP, which overcomes the defects of poor heat resistance, poor compatibility with a PP matrix and no soaking and washing resistance of a common organic antibacterial agent; meanwhile, the poly-p-hydroxystyrene has the oxygen resistance and the dry etching resistance, the PP has the oxygen resistance and the dry etching resistance due to the introduction of the poly-p-hydroxystyrene, and the PP resin material contains hydrogen bond elements due to the introduction of the poly-p-hydroxystyrene, so that the antibacterial property and the biocompatibility of the polymer are improved.

The invention aims to provide an antibacterial polypropylene block copolymer.

The invention also aims to provide a preparation method of the antibacterial polypropylene block copolymer.

The above purpose of the invention is realized by the following technical scheme:

an antibacterial polypropylene block copolymer, the structural formula of which is shown as the following formula (I):

wherein n is 50-2000, and m is 100-50000.

The reaction process and the preparation method of the antibacterial polypropylene block copolymer are as follows:

preparation of S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate.

Under alkaline conditions, with 3-mercaptopropionic acid and CS₂As a raw material, S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate is prepared.

2. And (3) preparing a polypropylene macromolecular chain transfer agent.

Toluene is used as a solvent, pyridine is used as an acid binding agent, and single-terminal hydroxyl polypropylene and RAFT reagent (namely, a reverse addition-fragmentation chain transfer reagent) S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate are subjected to esterification reaction to obtain the polypropylene macromolecule transfer agent.

3. Preparation of a Block copolymer of Polypropylene and poly-4-t-butoxystyrene.

The method comprises the steps of taking toluene/DMF as a solvent, 4-tert-butoxystyrene as a monomer, a polypropylene macromolecular chain transfer agent as a chain transfer agent and azobisisobutyronitrile as an initiator, and reacting for 4-6 hours at 80-90 ℃ under the conditions of no water, no oxygen and nitrogen protection to obtain the polypropylene and poly-4-tert-butoxystyrene block copolymer.

4. And (3) preparing the antibacterial polypropylene block copolymer.

The antibacterial polypropylene block copolymer is prepared by taking dioxane as a solvent and carrying out acidolysis on polypropylene and poly (4-tert-butoxystyrene) by hydrogen bromide.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the polypropylene and poly-p-hydroxystyrene block copolymer with antibacterial effect prepared by the invention overcomes the defects of thermolabile property, poor compatibility with PP matrix and soaking and washing resistance of common organic antibacterial agents.

(2) The poly-p-hydroxystyrene has the oxygen resistance and the dry etching resistance, the PP has the oxygen resistance and the dry etching resistance due to the introduction of the poly-p-hydroxystyrene, and the PP resin material contains hydrogen bond elements due to the introduction of the poly-p-hydroxystyrene, so that the antibacterial property and the biocompatibility of the polymer are improved.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of an antibacterial polypropylene block copolymer.

FIG. 2 is an infrared spectrum of the antibacterial polypropylene block copolymer.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

13.25g of 3-mercaptopropionic acid, 100m of L distilled water and 20g of 50% NaOH solution were placed in a 500m L three-necked flask, stirred for 30min and slowly added dropwise to 7.5m L CS₂And stirred overnight. And (3) slowly dropwise adding 19.13g of 2-bromopropionic acid, reacting overnight, acidifying the product with concentrated hydrochloric acid for 30min at room temperature, carrying out suction filtration to collect the product, washing with deionized water, and carrying out vacuum drying. 10.58g of a yellow solid was obtained in 25.3% yield.¹H-NMR(400MHz,CDCl₃),(ppm):12.62(s,1H,COOH),12.04(s,1H,COOH),4.68(m,1H,CH),3.20(t,2H,CH₂),2.47(t,2H,CH₂),1.43(d,3H,CH₃).¹³C-NMR(100MHz,CDCl₃),(ppm):224.10,172.97,171.67,49.07,35.88,32.59,18.07.

Example 2

And (3) preparing a polypropylene macromolecular chain transfer agent.

S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate (1.11g,4.0mmol) and 20ml of anhydrous tetrahydrofuran THF were added to a 50ml jar equipped with a stirrer, and thionyl chloride SOCl was slowly added dropwise with constant stirring₂(2.9ml,40.0mmol), heating to 70 deg.C, refluxing for 1.5h, after reaction, distilling under reduced pressure to remove SOCl₂And THF to give a yellow oily product, which was dissolved in an appropriate amount of toluene solution.

A100 m L flask with a stirrer and a single-ended hydroxy polypropylene PP-OH (2.39g,0.8mmol) in N₂Adding 30ml of anhydrous toluene under the atmosphere, heating to 70 ℃, continuously stirring, adding 1.2ml of pyridine after complete dissolution, stirring for 30min, slowly dropwise adding the yellow oily product dissolved in the toluene solution, stirring for 2h at 85 ℃, cooling the product to room temperature after reaction, continuously dissolving/precipitating with toluene/methanol twice, and drying at 50 ℃ in vacuum to constant weight to obtain 2.72g of pale yellow solid powder, wherein the yield is 77.9 percent, namely the polypropylene macromolecular transfer agent.

Example 3

Preparation of a Block copolymer of Polypropylene and poly-4-t-butoxystyrene.

A10 ml Schlenk bottle with a stirrer was charged with the macromolecular chain transfer agent for polypropylene (0.4284g,0.05mmol) prepared in example 2, 4-t-butoxystyrene (0.8813g,5mmol), AIBN (0.0017g,0.01mmol) and 5m L toluene/DMF (10/1), after three cycles of liquid nitrogen freezing-evacuating-thawing, the bottle was placed in a preset oil bath at 80 ℃ for polymerization, after 4 hours of reaction, the bottle was immediately taken out and immersed in anhydrous liquid nitrogen for cooling, the crude product was repeatedly precipitated in ether, and the purified product was freeze-dried to obtain 0.9037g of block copolymer of polypropylene and poly-4-t-butoxystyrene with a yield of 69.0%.

Example 4

And (3) preparing the antibacterial polypropylene block copolymer.

The polypropylene block copolymer (0.206g,0.00206mmol) prepared in example 3 and poly-4-t-butoxystyrene, 50m L dioxane and 5m L concentrated hydrochloric acid were charged separately in a 100ml Schlenk flask with a stirrer and after three cycles of freezing-pump-thawing with liquid nitrogen, N₂Reacting in an oil bath at 80 ℃ in an atmosphere overnight, concentrating, precipitating the polymer in water, neutralizing the polymer solution with 5% NaOH until the pH value is 6-7, filtering the polymer, and drying at 50 ℃ in vacuum until the weight is constant to obtain 0.1458g of the polypropylene and poly 4-tert-butoxystyrene block copolymer with the yield of 70.8%.

Example 5

And (3) determination of antibacterial effect: the effect test selects gram positive bacteria as a sterilization object, and the antibacterial performance of the gram positive bacteria is researched by adopting a bacteriostasis zone test method. The size of the inhibition zone around the sample is measured by a meter ruler, in order to ensure the accuracy of data, the width of the inhibition zone of each sample is measured for 6 times in different directions at intervals of 60 degrees, and the size of the inhibition zone is the average value of the widths of the inhibition zones of the samples and the size of the measured inhibition zone. The test results are shown in Table 1.

TABLE 1

Polymer and method of making same	Polypropylene and poly-p-hydroxystyrene block copolymer	Polypropylene
			Antibacterial circle (mm)	7	20

The results in table 1 show that the antibacterial polypropylene block copolymer prepared in example 4 has a good antibacterial effect.

Example 6

And (3) detecting the antioxidant performance: respectively weighing the antibacterial polypropylene block copolymer and the polypropylene with the same mass, and drying in an electric drying oven at 180 ℃ for 2 hours. As a result, the antibacterial polypropylene block copolymer is almost not yellowed, and the yellowing of the polypropylene is serious. The antibacterial polypropylene block copolymer is proved to have good oxygen resistance.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. An antimicrobial polypropylene block copolymer, wherein the polypropylene block copolymer has the structure of formula (I):

wherein n is 50-2000, and m is 100-50000.

2. The method for preparing the antibacterial polypropylene block copolymer according to claim 1, comprising the steps of:

(1) under alkaline conditions, with 3-mercaptopropionic acid and CS₂The S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate is prepared by taking the raw material as a raw material, and is characterized by having a structure shown as a formula (II):

(2) toluene is used as a solvent, pyridine is used as an acid binding agent, and single-terminal hydroxyl polypropylene and RAFT reagent (namely, a reverse addition-fragmentation chain transfer reagent) S-propionic acid-S '- (α -methyl- α' -acetic acid) -trithiocarbonate are subjected to esterification reaction to obtain the polypropylene macromolecule transfer agent, which is characterized by having a structure shown in a formula (III):

wherein n is 50-2000.

(3) The preparation method is characterized in that toluene/DMF is used as a solvent, 4-tert-butoxystyrene is used as a monomer, a polypropylene macromolecular chain transfer agent is used as a chain transfer agent, azobisisobutyronitrile is used as an initiator, and the reaction is carried out for 4-6 hours at 80-90 ℃ under the conditions of no water, no oxygen and nitrogen protection to obtain the polypropylene and poly-4-tert-butoxystyrene block copolymer, and the preparation method is characterized by having a structure shown in a formula (VI):

wherein n is 50-2000, and m is 100-50000.

(4) The antibacterial polypropylene block copolymer is prepared by taking dioxane as a solvent and carrying out acidolysis on polypropylene and poly (4-tert-butoxystyrene) by hydrogen bromide, and is characterized by having a structure shown in a formula (I):

wherein n is 50-2000, and m is 100-50000.

3. The preparation method of the antibacterial polypropylene block copolymer according to claim 2, wherein in the step (3), the molar ratio of the azobisisobutyronitrile, the polypropylene macromolecule transfer agent and the 4-tert-butoxystyrene is 1:5: 500-1200, the volume ratio of toluene/DMF is 8/1, and the concentration of the 4-tert-butoxystyrene in the polymerization reaction system is 1 mmol/L.