Highly dispersed zinc oxide nanocomposite polyester chip and preparation method thereof

Abstract

The application discloses a kind of high-dispersed zinc oxide nanocomposite polyester chips and preparation method thereof.The application is aimed at improving the dispersing ability and compatibility of ZnO nanoparticles in polyester matrix by suitable and effective surface modification, achieving good dispersion of antibacterial components in polyester matrix during in-situ coating process, and maintaining good spinning and antibacterial performance.ZnO nanoparticles after surface modification are dispersed again in D 90 The modified polyester chips have a size of 100-500 nm and an intrinsic viscosity of about 0.6-1.5 dL / g.The ZnO nanocomposite polyester chips can be used for the preparation of polyester fibers, which have improved antibacterial performance while maintaining good mechanical properties and color phase, ultimately improving product quality and reducing cost.In addition, the prepared polyester fibers have excellent antibacterial effect on escherichia coli and staphylococcus aureus.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of antibacterial polyester chips, and particularly relates to a ZnO nano-composite polyester chip with high dispersibility, a preparation method and application thereof, and particularly to the preparation of antibacterial polyester fibers using the nano-composite polyester chip. BACKGROUND

[0002] Polyester has been widely used in various fields due to its high breaking strength, good elasticity, good heat resistance, wear resistance, light resistance, fabric size stability, moderate resilience and other advantages. With the enhancement of people's awareness of environmental protection and safety, antibacterial PET fibers are in great demand and have broad market prospects. Antibacterial polyester fibers refer to fibers that have antibacterial function by introducing modified agents with antibacterial function into the fiber matrix or combining with the fiber surface, and their antibacterial performance usually depends on the performance of the introduced antibacterial agents.

[0003] Common antibacterial agents mainly include natural antibacterial agents, organic antibacterial agents and inorganic antibacterial agents. Among them, inorganic antibacterial agents are more and more valued due to their high efficiency, broad spectrum and stability. Zinc oxide (ZnO) is an inorganic antibacterial agent with high oxidation-reduction potential, good physical and chemical stability, low cost and no toxicity. According to the section where the antibacterial agent is added in the production process of polyester fibers, the preparation methods of antibacterial fibers mainly include in-situ polymerization, in-situ coating, composite spinning and post-treatment. The method of preparing antibacterial fibers by in-situ polymerization can make the antibacterial components fully dispersed, and less antibacterial agents can achieve good antibacterial effect; but the addition of antibacterial components will also affect the polymerization process of polyester, reduce the spinnability, and increase the instability of subsequent spinning. The composite spinning method has high precision requirements for the spinneret, and often has expensive equipment and difficult processing. The post-treatment method is simple to operate and easy to implement, and is widely used, but it has problems such as poor antibacterial durability and washing fastness. According to the adding method of antibacterial components, in-situ coating can be divided into two types, one is to directly mix the antibacterial agent with the polyester melt according to a certain proportion to prepare antibacterial fibers; the other is to mix pure polyester with high-concentration antibacterial agent to prepare antibacterial chips, and then adjust the proportion of antibacterial chips and pure polyester to prepare antibacterial fibers with target components. However, due to the small size of inorganic nanoparticles with good antibacterial performance, particle aggregation is prone to occur during processing.

[0004] The present application combines the surface modification technology of inorganic nanoparticles, and introduces a steric hindrance layer by selecting a reactive long-chain silane coupling modifier to chemically graft and modify the surface of ZnO nanoparticles, so as to improve the compatibility of the nanoparticles with the PET matrix and avoid particle aggregation during processing. Then, the modified ZnO nanoparticles are added to the polyester matrix by in-situ addition and in-situ coating to prepare antibacterial polyester chips. SUMMARY

[0005] The present application aims to provide a high dispersibility zinc oxide nanocomposite polyester chip and a preparation method thereof. The method combines surface chemical grafting modification of ZnO nanoparticles to improve the compatibility of the nanoparticles with the matrix, and adds the modified ZnO nanoparticles to PET through in-situ addition and in-situ coating, to achieve uniform dispersion of the antibacterial agent in the polyester matrix, avoid agglomeration during processing, and improve the spinning performance and antibacterial performance of the polyester chip.

[0006] To achieve the above-mentioned application purposes, the technical solution adopted by the present application is as follows:

[0007] The surface modification technology of inorganic nanoparticles is used to perform surface interface chemical grafting and modification on ZnO nanoparticles by selecting a suitable modifier, to introduce functional groups, improve the compatibility of the nanoparticles with the PET matrix, and avoid agglomeration during processing. Furthermore, the addition amount, combination mode and dispersibility of the ZnO nanoparticles are systematically studied to optimize the dispersibility and addition mode of the ZnO nanoparticles in the polyester matrix, and achieve efficient antibacterial modification of the polyester fiber material.

[0008] A high dispersibility zinc oxide nanocomposite polyester chip and a preparation method thereof, the method comprising the following steps:

[0009] (1) ZnO nanoparticles are added to a modification solvent, and a uniform ZnO nanoparticle dispersion liquid is prepared after ultrasonic treatment. Then, an alkyl modifier is added, and the temperature is adjusted to 25-40℃, and the reaction is performed for 0.1-24h. After the reaction, the product is centrifuged and washed to remove unreacted alkyl modifier, and then freeze-dried to obtain silane hydrophobically modified ZnO nanoparticles. The mass amount of the ZnO nanoparticles is 0.05-3.0% of the mass amount of the modification solvent, and the mass amount of the alkyl modifier is 0.01-2% of the mass amount of the ZnO nanoparticles. The alkyl modified ZnO nanoparticles are redispersed in deionized water under ultrasonic assistance, wherein the ultrasonic power is 30-750W, the ultrasonic time is 0.5-90min, and the mass amount of the alkyl modified ZnO nanoparticles is 0.1-10% of the mass amount of the water.

[0010] (2) The alkyl modified ZnO nanoparticles are added to ethylene glycol, and a uniform alkylated ZnO nanoparticle ethylene glycol dispersion liquid is prepared after homogenizer treatment. The mass amount of the alkyl modified ZnO nanoparticles is 0.5-30% of the mass amount of the ethylene glycol. The rotation speed of the homogenizer is 3000-12000rpm, and the homogenization time is 0.5-30min.

[0011] (3) adding purified terephthalic acid, alkylated ZnO ethylene glycol dispersion, and catalyst into a pulping kettle, mixing and stirring sufficiently to carry out esterification reaction. The mass amount of alkylated ZnO nanoparticles is 0.01% to 5% of the mass amount of purified terephthalic acid; the mass amount of catalyst is 0.001% to 0.03% of the mass amount of purified terephthalic acid. The esterification reaction temperature is 240°C to 260°C, and the reaction time is 0.1h to 24h; the polycondensation reaction temperature is 260°C to 280°C, and the reaction time is 0.1h to 24h, and the vacuum degree is 5Pa to 50Pa. After the reaction, the product is pressurized, discharged, cooled, cut into granules, and dried to obtain the antibacterial polyester chip.

[0012] In the present application, the ZnO nanoparticles can be obtained by existing methods, (1) using the improved Farzin Marandi method to synthesize ZnO nanoparticles with a size in the range of 10nm to 50nm

Ultrasonics Sonochemistry., 2016, 32, 86-94

[0013] Considering the modification effect of the surface of the ZnO nanoparticles, the dispersion stability, and the coating efficiency in the esterification process, as a preferred, the average size of the ZnO nanoparticles is controlled in the range of 10nm to 30nm.

[0014] In step (1) of the present application, the modification solvent is preferably at least one or a combination of the following: water, ethanol, isopropanol, ethylene glycol, glycerol, dimethyl sulfoxide, dimethyl formamide.

[0015] In step (1) of the present application, the alkyl modifier is selected from at least one of the following: oleic acid, oleylamine, methyltrimethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, hexyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane.

[0016] In step (1) of the present application, the conditions for ultrasonic treatment are preferably: ultrasonic treatment at a power of 50W to 600W for 0.5min to 60min.

[0017] In step (1) of the present application, considering the dispersibility and modification efficiency of the ZnO nanoparticles in the modification solvent, the mass amount of ZnO nanoparticles is preferably 0.1% to 2% of the mass amount of the modification solvent; the mass amount of the alkyl modifier is 0.02% to 0.5% of the mass amount of the ZnO nanoparticles.

[0018] In step (2) of the present application, the mass amount of the alkyl-modified ZnO nanoparticles is preferably 5% to 12% of the mass amount of the ethylene glycol, considering the modification effect of the alkyl chain on the ZnO nanoparticles.

[0019] In step (2) of the present application, the homogenization condition is preferably that the homogenization treatment is performed at a rotation speed of 5000 rpm to 8000 rpm for 5 to 20 min, considering the dispersibility of the alkylated ZnO nanoparticles in the ethylene glycol.

[0020] In step (3) of the present application, the catalyst is selected from at least one of tetrabutyl titanate, ethylene glycol antimony, and antimony trioxide, and the ethylene glycol antimony is preferred, considering the actual catalytic effect.

[0021] In step (3) of the present application, the mass amount of the alkylated ZnO nanoparticles is preferably 0.08% to 0.5% of the mass amount of the purified terephthalic acid, considering the antibacterial effect of the polyester chip.

[0022] In step (3) of the present application, the mass amount of the catalyst is preferably 0.005% to 0.012% of the mass amount of the purified terephthalic acid, considering the crystallization speed and rheological property of the polyester.

[0023] In step (3) of the present application, the reaction condition is preferably that the reaction is performed at a temperature of 250°C to 260°C for 3 h to 10 h and a vacuum degree of 5 Pa to 30 Pa, considering the conversion rate of the esterification reaction.

[0024] In step (3) of the present application, the reaction condition is preferably that the reaction is performed at a temperature of 260°C to 270°C for 0.5 h to 5 h and a vacuum degree of 5 Pa to 30 Pa, considering the polycondensation of the antibacterial polyester.

[0025] In the present application, the in-situ coating technology of the modified ZnO nanoparticles is first proposed to prepare the antibacterial polyester chip. The long-chain alkyl is used as the modifier, and the physical entanglement or chemical coupling of the surface hydroxyl and the functional group at one end of the long-chain alkyl is used to form the polar brush structure with steric hindrance. The surface coupling density of the alkyl-modified ZnO nanoparticles has an important influence on the dispersibility and stability of the ZnO nanoparticles in the polyester matrix. If the modification is insufficient, part of the ZnO nanoparticles will be aggregated and difficult to be effectively coated in the esterification reaction process. It is found that, compared with other alkyl modifiers, the surface coupling reaction rate of the long-chain alkyl siloxane is more controllable, and a uniform steric hindrance layer can be formed.

[0026] The inventors have found through in-depth research that, in the preparation of alkyl-modified ZnO nanoparticles, the type of modification solvent and the amount of modifier have an effect on the dispersion stability of the system, the particle size of the ZnO nanoparticles and its distribution. Generally speaking, as the amount of modifier increases, the particle size of the ZnO nanoparticles increases, but when the amount of modifier is large, the stability of the system decreases. In addition, it has also been found that as the degree of alkylation modification increases, the dispersibility of the ZnO nanoparticles can be significantly improved, therefore, the appropriate amount of alkylation modifier should be determined according to the dispersion in the polar phase and the demand for antibacterial performance.

[0027] Compared with the prior art, the beneficial effects of the present application mainly lie in: using long alkyl chain silane coupling agent to interact with ZnO nanoparticles for surface modification, regulating the oil-water amphiphilicity and imparting dispersing ability. In the preparation of polyester, the alkylated ZnO nanoparticles are dispersed in ethylene glycol in advance to form polyester chips with good structural stability and good antibacterial effect. The advantages of this method are: the surface of the ZnO nanoparticles is modified by terminal functionalization (reactive groups / antibacterial groups, etc.) modifier for controllable coupling modification, which improves the compatibility of ZnO and PET matrix and realizes efficient dispersion in the PET matrix. ZnO / PET antibacterial chips are prepared by in-situ addition or melt blending in a "one-step method", which avoids the process of preparing polyester-coated ZnO masterbatch and realizes low-cost antibacterial modification of polyester materials. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 . is the D size distribution diagram of zinc oxide nanoparticles in Comparative Example 1 (left) and Example 1 (right). 90 Size distribution diagram.

[0029] Figure 2 . is the antibacterial diagram of the antibacterial polyester chips prepared in Comparative Example 1, Comparative Example 2 and Example. DETAILED DESCRIPTION

[0030] The present application will be further described below in conjunction with specific examples, but the scope of protection of the present application is not limited thereto:

[0031] Example 1:

[0032] ZnO nanoparticles were prepared by adding 1 g of ZnO nanoparticles into 60 g of isopropyl alcohol and sonicating for 20 min at a power of 300 W. The temperature was then adjusted to 30 °C, and 2.3 mg of octadecyltrimethoxysilane was added. The reaction was carried out for 2 h to obtain surface-alkylated ZnO nanoparticles. The product was purified and dried for use. The purified alkyl-modified ZnO nanoparticles were dispersed in 18.9 g of ethylene glycol by homogenizing for 20 min at a shear rate of 6000 rpm to obtain an ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles. A beater was charged with 400 g of purified terephthalic acid, 19.9 g of the ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles, and 25.2 mg of antimony glycolate, which were thoroughly mixed and reacted at 255 °C for 6 h to carry out esterification. The temperature was then increased to 270 °C to carry out polycondensation for 3 h. The vacuum degree during the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain antibacterial polyester chips.

[0033] The morphology of the polyester chips was observed by scanning electron microscopy. The results showed that the ZnO nanoparticle composite polyester chips were uniformly dispersed in the polyester matrix, and no obvious agglomerated particles were observed in the micrographs. Dynamic light scattering was used to measure the D 90 The Escherichia coli (ATCC 25922, E. coli) and Staphylococcus aureus (MCCCB 26003, S. aureus) were cultured in liquid LB medium at 37 °C in a constant-temperature shaker at a rotation speed of 200 rpm for 12 h. The final concentration of the bacterial solution was diluted to 1 x 10 7 CFU / mL -1 The antibacterial rates of the antibacterial polyester chips against E. coli and S. aureus were 96.2% and 95.5%, respectively, as determined according to GB / T 21866-2008, and the chips had excellent antibacterial effects.

[0034] Comparative Example 1

[0035] ZnO nanoparticles were prepared by adding 1 g of ZnO nanoparticles into 18.9 g of ethylene glycol and homogenizing for 20 min at a shear rate of 6000 rpm. A beater was charged with 400 g of purified terephthalic acid, 19.9 g of the ethylene glycol dispersion of the ZnO nanoparticles, and 25.2 mg of antimony glycolate, which were thoroughly mixed and reacted at 255 °C for 6 h to carry out esterification. The temperature was then increased to 270 °C to carry out polycondensation for 3 h. The vacuum degree during the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain antibacterial polyester chips.

[0036] The morphology of the polyester chips was observed by scanning electron microscope. The results showed that the ZnO nano-composite polyester chips had a large number of aggregates in the polyester matrix, and the agglomerated particles were also obviously found in the micrograph. The D 90 The size of the ZnO nanoparticles was 10.8 μm. The antibacterial polyester chips had almost no antibacterial effect on E. coli and S. aureus.

[0037] As shown in Fig. 1, the D Figure 1 size distribution of the ZnO nanoparticles prepared in Comparative Example 1 (left) and Example 1 (right) is shown. 90

[0038] Comparative Example 2:

[0039] The ZnO nanoparticles were prepared by adding 1 g of ZnO nanoparticles into 60 g of isopropanol and ultrasonic treating for 20 min at a power of 300 W. Then the temperature was adjusted to 30°C, 2.3 mg of octadecyltrimethoxysilane was added, and the reaction was carried out for 2 h to obtain the surface alkyl-modified ZnO nanoparticles. The product was purified and dried for use. The purified alkyl-modified ZnO nanoparticles were dispersed in 18.9 g of ethylene glycol under the shearing action of a homogenizer at 3000 rpm for 5 min to obtain an ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles. Into a beaker, 400 g of purified terephthalic acid, 19.9 g of the ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles, and 25.2 mg of ethylene glycol antimony were added and mixed by stirring. The esterification reaction was carried out at 255°C for 6 h. Then the temperature was raised to 270°C for the polycondensation reaction to be carried out for 3 h. The vacuum degree of the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain the antibacterial polyester chips.

[0040] The morphology of the polyester chips was observed by scanning electron microscope. The results showed that the ZnO nano-composite polyester chips had a large number of aggregates in the polyester matrix, and the agglomerated particles were also obviously found in the micrograph. The D 90 The size of the ZnO nanoparticles was 2.3 μm. The antibacterial polyester chips had almost no antibacterial effect on E. coli and S. aureus.

[0041] As shown in Fig. 1, the D Figure 2 size distribution of the ZnO nanoparticles prepared in Comparative Example 1 (left) and Example 1 (right) is shown.

[0042] Example 2:

[0043] ​ZnO nanoparticles were prepared by adding 0.5 g of ZnO nanoparticles into 50 g of propylene glycol and ultrasonicating for 20 min at a power of 300 W. The temperature was then adjusted to 30 °C, and 1.33 mg of hexadecyltrimethoxysilane was added and reacted for 2 h to obtain surface-alkylated ZnO nanoparticles. The product was purified and dried for later use. The purified 1 g of alkyl-modified ZnO nanoparticles were redispersed in 14.9 g of ethylene glycol and homogenized for 20 min at 6000 rpm to obtain an ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles. Into a beaker, 588 g of purified terephthalic acid, 15.9 g of the ethylene glycol dispersion of the alkylated ZnO, and 64.7 mg of ethylene glycol antimony were added and mixed by stirring. Esterification was carried out at 258 °C for 5.5 h. The temperature was then increased to 265 °C for polycondensation for 4 h. The vacuum degree during the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain antibacterial polyester chips.

[0044] The morphology of the polyester chips was observed by scanning electron microscopy. The results showed that the ZnO nanoparticle composite polyester chips were uniformly dispersed in the polyester matrix, and no obvious agglomerated particles were observed in the micrographs. Dynamic light scattering was used to measure the D 90 The antibacterial rate of the antibacterial polyester chips against Escherichia coli and Staphylococcus aureus was 97.5% and 94.3%, respectively, and the chips had excellent antibacterial effect.

[0045] Example 3:

[0046] ZnO nanoparticles were prepared by adding 0.5 g of ZnO nanoparticles into 50 g of propylene glycol and ultrasonicating for 20 min at a power of 300 W. The temperature was then adjusted to 30 °C, and 1.33 mg of hexadecyltrimethoxysilane was added and reacted for 2 h to obtain surface-alkylated ZnO nanoparticles. The product was purified and dried for later use. The purified 1 g of alkyl-modified ZnO nanoparticles were redispersed in 14.9 g of ethylene glycol and homogenized for 20 min at 6000 rpm to obtain an ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles. Into a beaker, 588 g of purified terephthalic acid, 15.9 g of the ethylene glycol dispersion of the alkylated ZnO, and 64.7 mg of ethylene glycol antimony were added and mixed by stirring. Esterification was carried out at 258 °C for 5.5 h. The temperature was then increased to 265 °C for polycondensation for 4 h. The vacuum degree during the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain antibacterial polyester chips.

[0047] The morphology of the polyester chips was observed by scanning electron microscope. The results showed that the ZnO nanocomposite polyester chips were uniformly dispersed in the polyester matrix, and no obvious agglomerated particles were observed in the micrographs. The D 90 The antibacterial rates of the antibacterial polyester chips against E. coli and S. aureus were 93.5% and 90.3%, respectively, and the antibacterial polyester chips had good antibacterial effect.

[0048] Example 4:

[0049] ZnO nanoparticles were prepared by adding 0.87 g of ZnO nanoparticles to 69.6 g of isopropanol and ultrasonically treating for 10 min at a power of 500 W. The temperature was then adjusted to 40°C, and 4.35 mg of hexadecyltrimethoxysilane was added, and the reaction was carried out for 5 h to obtain surface-alkylated ZnO nanoparticles. The product was purified and dried for use. 1 g of the purified alkyl-modified ZnO nanoparticles were redispersed in 10.4 g of ethylene glycol, and homogenized for 15 min at 7500 rpm in a homogenizer under the action of shearing to obtain an ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles. 370 g of purified terephthalic acid, 11.4 g of the ethylene glycol dispersion of the alkyl-modified ZnO nanoparticles, and 27.7 mg of ethylene glycol antimony were added to a beater, and mixed by stirring at 250°C for 8 h to carry out esterification. The temperature was then increased to 275°C to carry out polycondensation for 3 h. The vacuum degree during the reaction was controlled at 10 Pa. After the reaction, the product was pressurized, discharged, cooled, cut into particles, and dried to obtain the antibacterial polyester chips.

[0050] The morphology of the polyester chips was observed by scanning electron microscope. The results showed that the ZnO nanocomposite polyester chips were uniformly dispersed in the polyester matrix, and no obvious agglomerated particles were observed in the micrographs. The D 90 The antibacterial rates of the antibacterial polyester chips against E. coli and S. aureus were 96.4% and 93.8%, respectively, and the antibacterial polyester chips had excellent antibacterial effect.

[0051] Example 5:

[0052] ZnO nanoparticles were prepared by adding 1.33 g ZnO nanoparticles into 391 g ethanol and ultrasonic treatment for 15 min at a power of 350 W, and then the temperature was adjusted to 30 °C, 3.6 mg of dodecyltrimethoxysilane was added, and the reaction was carried out for 2 h to obtain surface alkyl-modified ZnO nanoparticles. The product was purified and dried for use. The purified alkyl-modified ZnO nanoparticles were redispersed in 12.3 g of ethylene glycol, and homogenized for 10 min at 6500 rpm to obtain an alkyl-modified ZnO nanoparticle ethylene glycol dispersion. 458 g of purified terephthalic acid, 13.63 g of the alkyl-modified ZnO ethylene glycol dispersion, and 44.4 mg of ethylene glycol antimony were added to a beater tank, mixed by stirring, and esterification was carried out at 260 °C for 3 h. Then the temperature was raised to 265 °C for polycondensation for 3.5 h. The reaction was carried out at a vacuum degree of 10 Pa. After the reaction, the product was pressurized, discharged, cooled, pelletized, and dried to obtain an antibacterial polyester chip.

[0053] The morphology of the polyester chip was observed by scanning electron microscopy, and the results showed that the ZnO nanoparticle composite polyester chip was uniformly dispersed in the polyester matrix, and no obvious agglomerated particles were observed in the micrograph. Dynamic light scattering was used to measure the D 90 The size of the alkylated ZnO nanoparticles was 525 nm. The antibacterial rate of the antibacterial polyester chip against Escherichia coli and Staphylococcus aureus was 94.3% and 92.7%, respectively, and the antibacterial effect was excellent.

[0054] In summary, by appropriately and effectively modifying the surface of ZnO nanoparticles, the dispersibility and compatibility of the nanoparticles in the polyester matrix were improved, and good dispersion of the antibacterial component in the polyester matrix was achieved during in-situ coating, and good spinning and antibacterial properties were maintained. The D 90 The size of the ZnO nanoparticles dispersed in the ethylene glycol solution after surface modification was 100-500 nm, and the intrinsic viscosity of the modified polyester chip was about 0.6-1.5 dL / g. The ZnO nanoparticle composite polyester chip of the present application can be used to prepare polyester fibers, which have excellent antibacterial properties while maintaining good mechanical properties and color, ultimately improving product quality and reducing costs. In addition, the ZnO / PET antibacterial chip is prepared by in-situ addition or melt blending in a "one-step" method, which avoids the process of preparing polyester-coated ZnO masterbatch, and realizes low-cost antibacterial modification of polyester materials. The prepared polyester fibers have excellent antibacterial effect against Escherichia coli and Staphylococcus aureus.

[0055] In order to facilitate intuitive understanding of the specific embodiments, Table 1 shows specific parameter indexes of the inventive examples and the comparative examples. As can be seen from Table 1, the comparative examples 1 and 2 have no antibacterial effect at all, the inventive examples 1-5 have different degrees of excellent antibacterial effect, and the antibacterial effect of the example 2 is more comprehensive than that of the other examples.

[0056] The inventors have found through in-depth research that, in the preparation of the alkyl-modified ZnO nanoparticles, the type of the modifying solvent and the amount of the modifying agent have influences on the dispersion stability of the system, the particle size of the ZnO nanoparticles and its distribution. Generally speaking, with the increase of the amount of the modifying agent, the particle size of the ZnO nanoparticles increases, but when the amount of the modifying agent is large, the stability of the system decreases. In addition, it has also been found that the dispersibility of the ZnO nanoparticles can be obviously improved with the increase of the degree of the alkylation modification, therefore, the dispersibility in the polar phase and the antibacterial performance requirements should be considered. As can be seen from the multiple examples shown in Table 1, the D50 of the alkyl-modified ZnO of the present application is relatively stable. 90 The size is relatively stable.

[0057] Table 1: Specific parameter index table of examples and comparative examples

[0058]

[0059]

[0060] The above examples of the present application are for illustration of the present application and cannot limit the present application, any change within the meaning and scope equivalent to the claims of the present application should be considered as included in the scope of the claims.

Claims

1. A method for preparing a high dispersion zinc oxide nanocomposite polyester chip, characterized by, The method comprises the following steps: Step 1, adding ZnO nanoparticles into a modified solvent, preparing a uniform ZnO nanoparticle dispersion after ultrasonic treatment, then adding an alkyl modifier, adjusting the temperature to 25-40℃, and reacting for 0.1-24 hours; after the reaction, the product is centrifuged to remove unreacted alkyl modifier, and then freeze-dried to obtain silane hydrophobically modified ZnO nanoparticles; Step 2, adding the alkyl-modified ZnO nanoparticles into ethylene glycol, and preparing a uniform alkylated ZnO nanoparticle ethylene glycol dispersion after homogenizer treatment; Step 3, adding purified terephthalic acid, the alkylated ZnO ethylene glycol dispersion, and a catalyst into a beater, mixing them well, and performing esterification reaction; In step 1, the mass amount of ZnO nanoparticles is 0.1-2% of the mass amount of the modified solvent, and the mass amount of the alkyl modifier is 0.02-0.5% of the mass amount of the ZnO nanoparticles, considering the dispersibility and modification efficiency of the ZnO nanoparticles in the modified solvent; In step 2, the mass amount of the alkyl-modified ZnO nanoparticles is 5-12% of the mass amount of the ethylene glycol, considering the modification effect of the alkyl chain on the ZnO nanoparticles; In step 3, the mass amount of the alkylated ZnO nanoparticles is 0.01-5% of the mass amount of the purified terephthalic acid, and the mass amount of the catalyst is 0.001-0.03% of the mass amount of the purified terephthalic acid.

2. The production method according to claim 1, characterized by: In step 2, the rotating speed of the homogenizer is 3000-12000 rpm, and the homogenization time is 0.5-30 min.

3. The production method according to claim 2, characterized by: In step 3, the esterification reaction temperature is 240-260℃, and the reaction time is 0.1-24 hours; the polycondensation reaction temperature is 260-280℃, and the reaction time is 0.1-24 hours, and the vacuum degree is 5-50 Pa; after the reaction, the product is pressurized, discharged, cooled, pelletized, and dried to obtain the antibacterial polyester chip.

4. The production method according to claim 3, characterized by: In step 1, the modified solvent is selected from at least one or a combination of multiple selected from the group consisting of water, ethanol, isopropanol, ethylene glycol, glycerol, dimethyl sulfoxide, and dimethyl formamide; and the alkyl modifier is selected from at least one selected from the group consisting of oleic acid, oleylamine, methyltrimethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, hexyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, and octadecyltrimethoxysilane.

5. The production method according to claim 4, characterized by: In step 1, the ultrasonic treatment is performed at a power of 50-600 W for 0.5-60 min.

6. The production method according to claim 1, wherein In step 2, the homogenizer treatment is performed at a rotating speed of 5000-8000 rpm for 5-20 min, considering the dispersibility of the alkylated ZnO nanoparticles in the ethylene glycol.

7. The production method according to claim 1, wherein In step 3, the catalyst is selected from at least one selected from the group consisting of tetrabutyl titanate, ethylene glycol antimony, and antimony trioxide; and the mass amount of the alkylated ZnO nanoparticles is 0.08-0.5% of the mass amount of the purified terephthalic acid.

8. The production method according to claim 1, wherein The catalyst mass is 0.005% to 0.012 of the mass of the purified terephthalic acid in Step 3, considering the crystallization speed and rheological properties of the polyester; the reaction conditions are: temperature 250°C to 260°C, reaction time 3h to 10h, and vacuum degree 5Pa to 30Pa, considering the conversion rate of the esterification reaction; and the reaction conditions are: temperature 260°C to 270°C, reaction time 0.5h to 5h, and vacuum degree 5Pa to 30Pa, considering the polycondensation of the antibacterial polyester.

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