阅读说明：本技术 一种含氟接枝聚烯烃材料的制备方法 (Preparation method of fluorine-containing grafted polyolefin material ) 是由 应淑妮 陈国贵 冯金茂 黄咸伟 于 2020-11-06 设计创作，主要内容包括：本发明提供了一种含氟接枝聚烯烃材料的制备方法,包括：将聚烯烃粉料置于等离子体装置中,抽真空直至真空度小于等于200mTorr,依次通入氩气和含氟气体,通过等离子放电,使聚烯烃粉料表面预先接枝含氟单体；将制得的聚烯烃粉料置于空气中,使其表面的自由基转变成过氧键；向处理过的聚烯烃粉体中加入适量含氟单体、苯乙烯、过氧化物引发剂,进行预混得到含氟预混物；采用改性纳米氧化物与含氟预混物进行挤出共混反应,将得到的挤出物依次经过牵引、冷却、干燥和切粒制得含氟接枝聚烯烃材料。本发明工艺简单,所制备的聚烯烃改性剂,具有较高的含氟接枝率,可以作为功能母粒与聚烯烃共混,改善聚烯烃材料的表面性能。(The invention provides a preparation method of a fluorine-containing grafted polyolefin material, which comprises the following steps: placing polyolefin powder in a plasma device, vacuumizing until the vacuum degree is less than or equal to 200mTorr, sequentially introducing argon and fluorine-containing gas, and grafting fluorine-containing monomers on the surface of the polyolefin powder in advance through plasma discharge; placing the prepared polyolefin powder in the air to convert the free radicals on the surface of the polyolefin powder into peroxide bonds; adding a proper amount of fluorine-containing monomer, styrene and peroxide initiator into the treated polyolefin powder, and premixing to obtain a fluorine-containing premix; the modified nano oxide and the fluorine-containing premix are subjected to extrusion blending reaction, and the obtained extrudate is subjected to traction, cooling, drying and grain cutting in sequence to obtain the fluorine-containing grafted polyolefin material. The invention has simple process, and the prepared polyolefin modifier has higher fluorine-containing grafting rate, can be used as functional master batch to be blended with polyolefin, and improves the surface performance of polyolefin materials.)

1. The preparation method of the fluorine-containing grafted polyolefin material is characterized by comprising the following steps of:

step 1, placing polyolefin powder in a plasma device, vacuumizing until the vacuum degree is less than or equal to 200mTorr, sequentially introducing argon and fluorine-containing gas, and grafting fluorine-containing monomers on the surface of the polyolefin powder in advance by plasma discharge to generate a large amount of free radicals;

step 2, taking out the polyolefin powder obtained in the step 1, and placing the polyolefin powder in the air to convert free radicals on the surface of the polyolefin powder into peroxide bonds;

step 3, adding a proper amount of fluorine-containing monomer and peroxide initiator into the treated polyolefin powder, and premixing to obtain a fluorine-containing premix;

step 4, taking a proper amount of fluorine-containing silane coupling agent and blending with the nano oxide to modify the nano oxide;

and 5, carrying out extrusion blending reaction on the fluorine-containing premix prepared in the step 3 and the nano oxide obtained in the step 4, and sequentially carrying out traction, cooling, drying and grain cutting on the obtained extrudate to obtain the fluorine-containing grafted polyolefin material.

2. The method for preparing a fluorine-containing graft polyolefin material according to claim 1, wherein the polyolefin powder is at least one selected from the group consisting of low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, heat resistant polyethylene, ultra high molecular weight polyethylene, homo polypropylene, block co-polypropylene, random co-polypropylene and polybutene.

3. The method for preparing fluorine-containing grafted polyolefin material according to claim 1, wherein in the step 1, the volume ratio of argon gas to fluorine-containing gas is 1:4-4: 1.

4. The method as claimed in claim 1, wherein in step 1, the plasma treatment power is 100-200W and the treatment time is 150-300 s.

5. The method for preparing fluorine-containing grafted polyolefin material according to claim 1, wherein in the step 1, the fluorine-containing gas is trifluoropropene and/or hexafluoropropene.

6. The method for preparing a fluorine-containing graft polyolefin material according to claim 1, wherein in the step 3, the fluorine-containing monomer is at least one selected from the group consisting of trifluoroethyl acrylate, hexafluorobutyl acrylate, dodecafluoroheptyl methacrylate, octafluoropentyl methacrylate, tridecafluorooctyl acrylate, tridecafluorooctyl methacrylate, and polyperfluorodecylethylene.

7. The method of claim 1, wherein in the step 3, the peroxide initiator is at least one selected from the group consisting of dicumyl peroxide, di-t-butylperoxyisopropyl benzene, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, and t-butylperoxybenzoate.

8. The method for preparing fluorine-containing grafted polyolefin material according to claim 1, wherein in the step 3, the temperature of the premixing is 20-60 ℃ and the mixing time is 30-60 min.

9. The method for preparing fluorine-containing grafted polyolefin material according to claim 1, wherein in the step 4, the nano oxide is at least one of nano silicon oxide, nano zirconium oxide and nano zinc oxide.

10. The method for preparing fluorine-containing grafted polyolefin material according to claim 1, wherein in the step 4, the size of the nano oxide is 10nm-200nm, the adding proportion of the coupling agent is 0.5-2% of the weight of the nano oxide, and the blending time of the fluorine-containing silane coupling agent and the nano oxide is 30-60 min.

Technical Field

The invention relates to the technical field of high polymer material grafting modification, in particular to a preparation method of a fluorine-containing grafted polyolefin material.

Background

The modified material of the polyolefin material mostly adopts a low molecular weight functional modifier, but the functional modifier often has a 'wet brushing' effect during blending modification, so that macroscopic phase separation of the polyolefin and the modified material occurs, and the overall modification effect is influenced. In order to improve the compatibility between the functional material and the matrix and to exert the effect of the modified material to a greater extent, in the prior art, the functional material is grafted to the surface of the polyolefin particle by plasma treatment and solution grafting so as to control the grafting rate of the reaction monomer and ensure that the polyolefin particle is grafted with the fluorine-containing group. However, the solution grafting has strict requirements on production sites, a large reaction device is required, waste liquid treatment is required, the overall investment is large, the environmental evaluation requirements are met, and the large-scale production is limited to a certain extent.

Disclosure of Invention

In view of this, the invention provides a preparation method of fluorine-containing grafted polyolefin material, aiming at improving the fluorine-containing grafting rate of the polyolefin material and reducing the production cost.

The invention provides a preparation method of a fluorine-containing grafted polyolefin material, which comprises the following steps: step 1, placing polyolefin powder in a plasma device, vacuumizing until the vacuum degree is less than or equal to 200mTorr, sequentially introducing argon and fluorine-containing gas, and grafting fluorine-containing monomers on the surface of the polyolefin powder in advance by plasma discharge to generate a large amount of free radicals;

step 2, taking out the polyolefin powder obtained in the step 1, and placing the polyolefin powder in the air to convert free radicals on the surface of the polyolefin powder into peroxide bonds;

step 3, adding a proper amount of fluorine-containing monomer, styrene and peroxide initiator into the treated polyolefin powder, and premixing to obtain a fluorine-containing premix;

step 4, taking a proper amount of fluorine-containing silane coupling agent and blending with the nano oxide to modify the nano oxide;

and 5, carrying out extrusion blending reaction on the fluorine-containing premix prepared in the step 3 and the nano oxide obtained in the step 4, and sequentially carrying out traction, cooling, drying and grain cutting on the obtained extrudate to obtain the fluorine-containing grafted polyolefin material.

Further, in the above production method, the polyolefin powder is at least one selected from the group consisting of low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, heat-resistant polyethylene, ultrahigh molecular weight polyethylene, homo-polypropylene, block co-polypropylene, random co-polypropylene and polybutene.

Further, in the above preparation method, in the step 1, the volume ratio of the argon gas to the fluorine-containing gas is 1:4 to 4: 1.

Further, in the above preparation method, in the step 1, the plasma processing power is 100-.

Further, in the above preparation method, in the step 1, the fluorine-containing gas is trifluoropropene and/or hexafluoropropene.

In the above preparation method, in the step 3, the fluorine-containing monomer is at least one functional group obtained by graft polymerization of a fluorine-containing and double-bond reactive monomer such as trifluoroethyl acrylate, hexafluorobutyl acrylate, dodecafluoroheptyl methacrylate, octafluoropentyl methacrylate, tridecafluorooctyl acrylate, tridecafluorooctyl methacrylate, polyperfluorodecyldecyl ethylene, or the like.

Further, in the above preparation method, in the step 3, the peroxide initiator is at least one selected from the group consisting of dicumyl peroxide, di-tert-butylperoxyisopropyl benzene, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane and tert-butylperoxybenzoate.

Further, in the preparation method, in the step 3, the temperature of the premixing is 20-60 ℃, and the mixing time is 30-60 min.

Further, in the above preparation method, in the step 4, the nano oxide is at least one of nano silicon oxide, nano zirconium oxide and nano zinc oxide.

Further, in the preparation method, in the step 4, the size of the nano oxide is 10nm-200nm, the adding proportion of the coupling agent is 0.5% -2%, and the blending time of the fluorine-containing silane coupling agent and the nano oxide is 30min-60 min.

According to the preparation method of the fluorine-containing grafted polyolefin material, peroxide groups are generated on the surface of polyolefin powder through plasma treatment, and the fluorine-containing groups are pre-grafted on the surface of the powder; by introducing the peroxide group, the compatibility of a peroxide initiator and modified polyolefin powder can be improved, the dispersion of the initiator in a matrix material is improved, and the problem that crosslinking or degradation is caused due to overhigh local free radical concentration in the traditional peroxide-initiated grafting reaction is solved; in addition, after the fluorine-containing chain segment is grafted on the surface of the powder, according to the principle of similarity and compatibility, the dispersion effect of the fluorine-containing monomer in the polyolefin resin in the subsequent reaction extrusion process can be improved, and the grafting rate of the fluorine-containing monomer is improved; furthermore, the pre-grafted powder is modified by introducing a nano oxide to form a surface micro-nano structure, so that the hydrophobic property of the product is improved.

Drawings

FIG. 1 is a photograph of the water contact angle of a commercial HDPE (high density polyethylene) in the prior art after banbury tabletting;

FIG. 2 is a photograph of water contact angle of the fluorosilicone modified material prepared in example 1 of the present invention after blending with HDPE (addition ratio 5: 95) and tabletting;

FIG. 3 is a photograph of the water contact angle of the fluorine-containing modified material prepared in example 2 of the present invention after blending with HDPE (addition ratio of 8: 92) and tabletting;

FIG. 4 is a photograph of the water contact angle of a commercial PPR (random copolymer polypropylene) banbury tablet of the prior art;

FIG. 5 is a photograph of the water contact angle of the fluorine-containing modified material prepared in example 4 of the present invention after blending with PPR (addition ratio: 10: 90) and tabletting.

Detailed Description

While the preferred embodiments of the present invention are described below, it should be understood that various changes and modifications can be made by one skilled in the art without departing from the principles of the invention, and such changes and modifications are also considered to be within the scope of the invention.

The invention provides a preparation method of a fluorine-containing grafted polyolefin material, which comprises the following steps:

step 1, placing polyolefin powder in a plasma device, vacuumizing until the vacuum degree is less than or equal to 200mTorr, sequentially introducing argon and fluorine-containing gas, and grafting fluorine-containing monomers on the surface of the polyolefin powder in advance by plasma discharge to generate a large amount of free radicals.

Specifically, the polyolefin powder is at least one selected from the group consisting of low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, heat-resistant polyethylene, ultra-high molecular weight polyethylene, homo-polypropylene, block co-polypropylene, random co-polypropylene and polybutene.

For example, in this example, a 200 mesh Low Density Polyethylene (LDPE) powder having a melt index of 10g/10min is selected; 200 mesh Linear Low Density Polyethylene (LLDPE) powder with a melt index of 20g/10 min; 200 mesh, 300 ten thousand molecular weight ultra high molecular weight polyethylene (UHMDPE) powder; 100 meshes, 15g/10min of homopolymerized polypropylene (PP-H) powder.

In this step, the fluorine-containing gas may be trifluoropropene and/or hexafluoropropene. The volume ratio of the argon gas to the fluorine-containing gas is 1:4-4:1, preferably 1:2-2: 1. In practice, considering that the plasma chamber is small, the plasma discharge treatment can be performed in batches according to the feeding amount of the polyolefin powder.

In this step, since the plasma power is lower, the radicals generated on the surface are less, and the power is higher, the temperature of the sample surface is increased, preferably, the plasma processing power is 100-. It can be seen that the generation amount of free radicals on the surface of the polyolefin powder and the grafting amount of the fluorine-containing chain segment are adjusted by adjusting the plasma treatment conditions, the ratio of argon to fluorine-containing monomer, the gas pressure and the like in the step.

And 2, taking out the polyolefin powder prepared in the step 1, and placing the polyolefin powder in the air to convert free radicals on the surface of the polyolefin powder into peroxide bonds.

Specifically, the polyolefin powder to which the fluorine-containing monomer has been grafted in advance is allowed to stand in the air for 5 to 1440min, preferably 10 to 120min, so that the radicals on the surface of the polyolefin powder are sufficiently converted into peroxide bonds.

And 3, adding a proper amount of fluorine-containing monomer and peroxide initiator into the treated polyolefin powder, and premixing to obtain the fluorine-containing premix.

Specifically, in order to increase the graft ratio, an appropriate amount of styrene may be added to step 3. Preferably, the first and second liquid crystal materials are,

the weight ratio of the polyolefin powder, the fluorine-containing monomer, the styrene and the peroxide initiator is 75-95: 5-15: 0-10: 0.1-0.5.

Preferably, the fluorine-containing monomer is at least one selected from fluorine-containing monomers having a double bond such as trifluoroethyl acrylate, hexafluorobutyl acrylate, dodecafluoroheptyl methacrylate, octafluoropentyl methacrylate, tridecafluorooctyl acrylate, tridecafluorooctyl methacrylate, and polyperfluorodecyldecyl ethylene.

In the step, the temperature of premixing is 20-60 ℃, and the mixing time is 30-60 min.

And 4, taking a proper amount of fluorine-containing silane coupling agent and blending with the nano oxide to modify the nano oxide.

Specifically, the nano oxide may be at least one of nano silicon oxide, nano zirconium oxide, and nano zinc oxide. Preferably, the size of the nano-oxide is 10nm to 200 nm. The fluorine-containing silicon coupling agent may be at least one of fluoropropyltriethoxysilane, trifluoropropylmethyldimethoxysilane, and heptadecafluorodecyltrimethoxysilane.

The fluorine-containing silane coupling agent can also be prepared by ring-opening polymerization of trifluoropropylcyclotrisiloxane anion and then hydrosilylation reaction with acryloyloxypropyl trimethoxysilane.

In specific implementation, under the protection of nitrogen, 50g of trifluoropropylmethylcyclotrisiloxane (D3F) and 50ml of tetrahydrofuran are sequentially added into a reaction vessel, the reaction vessel is placed into an ice-water bath, 50ml of n-butyllithium-n-hexane solution is added, and anion ring-opening polymerization reaction is initiated to react for 4 hours; adding 15ml of dimethylchlorosilane for end capping, reacting for 8 hours, and purifying to obtain hydrogen-containing silane; under the protection of nitrogen, 60g of toluene and 180g of acryloxypropyltrimethoxysilane are added into another reactor, Karstedt catalyst is added, 60g of the prepared hydrogen-containing silane is dropwise added, reaction is continued for 12 hours after dropwise addition, and the fluorine-containing silane coupling agent is obtained after reduced pressure distillation.

In the step, the adding proportion of the coupling agent is 0.5-2% of the weight of the nano oxide, and the blending time of the fluorine-containing silane coupling agent and the nano oxide is preferably 30-60 min.

And 5, carrying out extrusion blending reaction on the fluorine-containing premix prepared in the step 3 and the nano oxide obtained in the step 4, and sequentially carrying out traction, cooling, drying and grain cutting on the obtained extrudate to obtain the fluorine-containing grafted polyolefin material.

In the step, the weight proportion of the nano oxide in the extrusion blending reaction is 0-10% of the weight of the blend, and preferably, the nano oxide accounts for 2-8% of the weight of the blend; the screw speed may be set to 20-100 rpm.

In the invention, polyolefin powder is placed in a plasma device, argon and fluorine-containing monomers are sequentially introduced at the same time, and partial fluorine-containing chain segments are grafted in advance while free radicals are generated on the surface of the polyolefin powder through glow discharge; because the free radical generated on the surface of the polyolefin can generate peroxide bond in the air, and has higher affinity with a peroxide initiator, the dispersion effect between the peroxide and the polyolefin powder can be improved, thereby being beneficial to improving the dispersion of the fluorine-containing monomer in the polyolefin resin in the subsequent reactive extrusion process and improving the final fluorine-containing grafting amount. The fluorine-containing modified material has lower surface energy, realizes the hydrophobic property of the material to a certain extent, further improves the low surface property of the material, simultaneously further realizes the material surface construction by introducing the nano material, combines the low surface energy material and the micro-nano structure reconstruction dual technology, achieves an ideal dispersion effect by proper interface modification, is favorable for ensuring the overall stability of the modified material, finally adopts reaction extrusion to replace solution polymerization, avoids using a large amount of solvents, saves the procedures of waste liquid treatment and the like, and reduces the overall production cost.

The invention is described in detail below in several specific examples:

example 1

1) Putting 10kg of 200-mesh LDPE powder with a melt index of 10g/10min into a plasma device in batches, vacuumizing to remove air in a cavity until the vacuum degree is 100mTor, introducing argon to ensure that the pressure of the cavity is 200mTor, and finally introducing hexafluoropropylene to ensure that the pressure of the cavity reaches 300 mTor; carrying out 100W plasma treatment for 300s to graft a fluorine-containing monomer on the surface of the polyolefin powder and generate a large amount of free radicals;

2) placing the processed LDPE powder in the air for 60min, and converting the free radicals on the surface of the powder into peroxide bonds;

3) putting 90 parts of processed LDPE powder into a high-speed mixer, adding 10 parts of hexafluorobutyl acrylate and 5 parts of styrene, stirring for 30 minutes at normal temperature, adding 0.1 part of dicumyl peroxide, continuously mixing, heating to 50 ℃, mixing and stirring for 30 minutes to obtain premixed powder;

4) under the protection of nitrogen, 50g of trifluoropropylmethylcyclotrisiloxane (D3F) is added into a 500ml single-neck flask, 50ml of tetrahydrofuran is added, the single-neck flask is placed into an ice water bath, 50ml of n-butyllithium-n-hexane solution is added, and the ring-opening polymerization reaction of anions is initiated, and the reaction time is 4 hours; then adding 15ml of dimethylchlorosilane for end capping, reacting for 8 hours, and purifying to obtain hydrogen-containing silane; under the protection of nitrogen, 60g of toluene and 180g of acryloxypropyltrimethoxysilane are added into a 500ml flask, after a catalyst is added, 60g of hydrosilane is added dropwise for 4 hours, and then the reaction is continued for 12 hours. Carrying out reduced pressure distillation to obtain a fluorine-containing silane coupling agent;

5) 1 part of fluorine-containing silane coupling agent and 99 parts of 100nm nano silicon oxide are blended for 30 min;

6) inputting 95 parts of premixed powder and 5 parts of nano silicon oxide powder treated by a coupling agent into an extruder through a feeding port for reaction and blending, rotating the screw at 50rpm, and drawing, cooling, drying and granulating the extrudate to obtain the fluorine-containing grafted polyolefin material;

7) the prepared fluorine-containing grafted polyolefin material is used as a modifier to be blended with an HDPE material (the weight ratio of the fluorine-containing grafted polyolefin material to the HDPE material is 5: 95) to be tableted, a contact angle is tested, and the results in figures 1 and 2 show that the contact angle of the surface of the HDPE material is obviously improved after the prepared modifier is added into the HDPE material and is increased from 90.43 degrees to 107.27 degrees.

Example 2

1) Putting 10kg of 200-mesh LDPE powder with a melt index of 10g/10min into a plasma device in batches, vacuumizing to remove air in a cavity until the vacuum degree is 100mTor, introducing gas to ensure that the pressure of the cavity is 200mTor, and finally introducing hexafluoropropylene to ensure that the pressure of the cavity reaches 350 mTor; carrying out 150W plasma treatment for 150s to graft a fluorine-containing monomer on the surface of the polyolefin powder and generate a large amount of free radicals;

2) placing the treated LLDPE powder in the air for 60min, and converting the free radicals on the surface of the powder into peroxide bonds;

3) putting the treated LLDPE powder of 85 parts into a high-speed mixer, adding 15 parts of dodecafluoroheptyl acrylate and 5 parts of styrene, stirring for 30 minutes at normal temperature, adding 0.15 part of 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, continuously mixing, and mixing and stirring for 30 minutes to obtain premixed powder;

4) under the protection of nitrogen, 50g of trifluoropropylmethylcyclotrisiloxane (DF 3) is added into a 500ml single-neck flask, 50ml of tetrahydrofuran is added, the single-neck flask is placed into an ice water bath, 50ml of n-butyllithium-n-hexane solution is added, and the ring-opening polymerization reaction of anions is initiated, and the reaction time is 4 hours; then adding 15ml of dimethylchlorosilane for end capping, reacting for 8 hours, and purifying to obtain hydrogen-containing silane; under the protection of nitrogen, 60g of toluene and 180g of acryloxypropyltrimethoxysilane are added into a 500ml flask, after a catalyst is added, 60g of hydrosilane is added dropwise for 4 hours, and then the reaction is continued for 12 hours. Carrying out reduced pressure distillation to obtain a fluorine-containing silane coupling agent;

5) 2 parts of fluorine-containing silane coupling agent, 98 parts of 100nm nano-zirconia and nano-silica are mixed for 30 min;

6) inputting 92 parts of premixed powder and 8 parts of nano powder treated by a coupling agent into an extruder through a feeding port for reaction and blending, wherein the rotating speed of a screw is 70rpm, and the extrudate is subjected to traction, cooling, drying and grain cutting to prepare a fluorine-containing grafted polyolefin material;

7) the prepared fluorine-containing grafted polyolefin material is used as a modifier to be blended with an HDPE material (the weight ratio of the fluorine-containing modifier to the HDPE material is 8:92 respectively), a contact angle is tested, and as can be seen from figure 3, after the prepared modifier is added into the HDPE material, the contact angle of the surface of the HDPE material is improved to 117.75 degrees.

Example 3

1) Putting 10kg of UHMDPE powder with 200 meshes and the molecular weight of 300 ten thousand in a plasma device, vacuumizing to remove air in a cavity until the vacuum degree is 100mTor, introducing gas to ensure that the pressure of the cavity is 200mTor, and finally introducing hexafluoropropylene to ensure that the pressure of the cavity reaches 350 mTor; carrying out plasma treatment of 200W for 180s to graft a fluorine-containing monomer on the surface of the polyolefin powder and generate a large amount of free radicals;

2) placing the treated UHMWPE powder in the air for 60min, and converting the free radicals on the surface of the powder into peroxide bonds;

3) putting 95 parts of treated UHMWPE powder into a high-speed mixer, adding 5 parts of trifluoroethyl acrylate, stirring at normal temperature for 30 minutes, adding 0.1 part of bis-tert-butylperoxyisopropyl benzene, continuously mixing, heating to 50 ℃, and mixing and stirring for 30 minutes to obtain premixed powder;

4) and inputting the premixed powder into an UHMWPE extruder through a feeding port for reaction and blending, setting the rotating speed of a screw to be 70rpm, and directly extruding the sheet. The overall melt pressure in the extrusion process is reduced, and the surface of the extruded sheet is smoother.

Example 4

1) Placing 10kg of PP-H powder with 100 meshes and 15g/10min of melt index into a plasma device, vacuumizing to remove air in a cavity until the vacuum degree is 100mTor, introducing gas to ensure that the pressure of the cavity is 300mTor, and finally introducing hexafluoropropylene to ensure that the pressure of the cavity reaches 400 mTor; carrying out 150W plasma treatment for 150s to graft a fluorine-containing monomer on the surface of the polyolefin powder and generate a large amount of free radicals;

2) placing the treated PP-H powder in the air for 300min, wherein free radicals on the surface of the powder are converted into peroxide bonds;

3) putting 90 parts of the treated PP-H powder into a high-speed mixer, adding 10 parts of dodecafluoroheptyl acrylate, stirring for 30 minutes at normal temperature, adding 0.2 part of di-tert-butylperoxyisopropyl benzene, continuously mixing, and stirring for 30 minutes to obtain premixed powder;

4) under the protection of nitrogen, 50g of trifluoropropylmethylcyclotrisiloxane (DF 3) is added into a 500ml single-neck flask, 50ml of tetrahydrofuran is added, the single-neck flask is placed into an ice water bath, 50ml of n-butyllithium-n-hexane solution is added, and the ring-opening polymerization reaction of anions is initiated, and the reaction time is 4 hours; then adding 15ml of dimethylchlorosilane for end capping, reacting for 8 hours, and purifying to obtain hydrogen-containing silane; under the protection of nitrogen, 60g of toluene and 180g of acryloxypropyltrimethoxysilane are added into a 500ml flask, after a catalyst is added, 60g of hydrosilane is added dropwise for 4h, and then the reaction is continued for 12 h. Carrying out reduced pressure distillation to obtain a fluorine-containing silane coupling agent;

5) 0.5 part of fluorine-containing silane coupling agent and 99.5 parts of 100nm nano silicon oxide are blended for 30 min;

6) inputting 95 parts of premixed powder and 5 parts of nano silicon oxide powder treated by a coupling agent into an extruder through a feeding port for reaction and blending, wherein the rotating speed of a screw is 70rpm, and the extrudate is subjected to traction, cooling, drying and grain cutting to prepare a fluorine-containing grafted polyolefin material;

7) the prepared fluorine-containing grafted polyolefin material and the PPR material are blended (the weight ratio of the fluorine-containing grafted polyolefin material to the PPR material is 10: 90) and tableted, and the contact angle is tested, and as can be seen from figures 4 and 5, after the prepared fluorine-containing grafted polyolefin modifier is added into the PPR material, the contact angle of the surface of the PPR material is improved to 111.46 degrees.

The preparation method disclosed by the invention is simple in preparation steps, controllable in fluorine-containing monomer grafting rate and capable of realizing large-scale production, the prepared fluorine-containing modified material can be used as functional master batches to be blended with polyolefin, the surface energy of a polyethylene material is improved, the melt flow property of the polyolefin material is improved, the anti-scaling and anti-fouling capabilities of polyolefin resin are improved, and the fluorine-containing modified material can be widely applied to a plurality of fields such as household appliances, pipeline transportation, food packaging and marine culture and has a wide application prospect.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.