PPR pipe with good impact resistance and preparation method thereof

Abstract

The invention relates to the technical field of pipes, in particular to a PPR pipe with good impact resistance and a preparation method of the PPR pipe. The PPR pipe with good impact resistance is prepared from the following raw material components in parts by mass: 80 to 100 parts of polypropylene resin, 10 to 30 parts of modified polypropylene composition and 0.5 to 1 part of fluorine-containing additive, the modified polypropylene composition is prepared from the following raw material components in parts by mass: 70 to 100 parts of polypropylene resin, 10 to 30 parts of modified carboxylated nano cellulose whisker and 10 to 30 parts of modified aluminum borate whisker. The PPR pipe with good impact resistance has excellent impact resistance under the condition of ensuring the toughness of the pipe, can reduce mechanical wear in the production process, has the characteristic of low precipitation in the pipeline production process, can reduce the probability of producing defective products, and solves the problem of poor impact resistance of the existing PP-R pipeline system.

Description

Technical Field

[0001] The present invention relates to the technical field of pipes, and in particular to a PPR pipe with good impact resistance and a preparation method thereof. Background Art

[0002] Random copolymer polypropylene (PP-R) pipes are widely used in building water supply and drainage, power cable sheathing, industrial fluid transportation, agricultural irrigation and other fields due to their environmental friendliness, light weight, corrosion resistance, smooth inner wall, non-scaling, simple construction and maintenance, and no toxic side effects. However, PPR pipes have been used in the market for many years, and their shortcomings are gradually emerging, especially the poor impact resistance of the pipeline system, which affects the installation and use of the pipeline system in harsh environments (such as in cold areas, tunnel projects where gravel is prone to fall, etc.), further limiting the promotion and application of PPR pipeline systems. Summary of the invention

[0003] In view of the problems raised by the background technology, the purpose of the present invention is to propose a PPR pipe with good impact resistance, which has excellent impact resistance while ensuring the toughness of the pipe, can reduce mechanical wear during the production process, has the characteristics of low precipitation during the pipeline production process, can reduce the probability of producing defective products, and solves the problem of poor impact resistance of the existing PP-R pipeline system.

[0004] Another object of the present invention is to propose a preparation method for preparing the above-mentioned PPR pipe with good impact resistance, which has the advantages of low die head precipitation, good surface finish and appearance quality of the prepared pipe, low mechanical wear and high preparation efficiency.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A PPR pipe with good impact resistance, wherein the raw materials of the PPR pipe include the following components, calculated by weight: 80-100 parts of polypropylene resin, 10-30 parts of modified polypropylene composition and 0.5-1 part of fluorine-containing additive;

[0007] Calculated by weight, the raw materials of the modified polypropylene composition include the following components: 70 to 100 parts of polypropylene resin, 10 to 30 parts of modified carboxylated nanocellulose whiskers and 10 to 30 parts of modified aluminum borate whiskers;

[0008] Calculated by weight, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 10 to 30 parts of carboxylated nanocellulose whiskers and 5 to 15 parts of coupling agent;

[0009] Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 10-30 parts of aluminum borate whiskers and 5-15 parts of coupling agent.

[0010] Further illustration, the preparation method of the carboxylated nanocellulose whiskers includes the following steps:

[0011] Disperse the nanocellulose whiskers in an ethanol solution, adjust the pH value of the solution to 8-11, add sodium chloroacetate after uniform dispersion, and obtain carboxylated nanocellulose whiskers after suction filtration, washing and vacuum drying.

[0012] Further illustration, the average diameter of the nanocellulose whiskers is 4-10 nm, and the average length is 150-250 nm;

[0013] The average diameter of the aluminum borate whiskers is 0.5-1 μm, and the average length is 10-30 μm.

[0014] Further illustration, calculated by mass parts, the raw materials of the PPR pipe include the following components: 100 parts of polypropylene resin, 25 parts of modified polypropylene composition and 0.5 part of fluorine-containing additive;

[0015] Calculated by mass parts, the raw materials of the modified polypropylene composition include the following components: 100 parts of polypropylene resin, 15 parts of modified carboxylated nanocellulose whiskers and 20 parts of modified aluminum borate whiskers;

[0016] Calculated by mass parts, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 20 parts of carboxylated nanocellulose whiskers and 10 parts of coupling agent;

[0017] Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 20 parts of aluminum borate whiskers and 10 parts of coupling agent.

[0018] Further illustration, in the raw materials of the modified carboxylated nanocellulose whiskers, the mass ratio of the carboxylated nanocellulose whiskers to the coupling agent is 2:1;

[0019] In the raw materials of the modified aluminum borate whiskers, the mass ratio of the aluminum borate whiskers to the coupling agent is 2:1.

[0020] Further illustration, calculated by mass parts, the raw materials of the modified polypropylene composition further include 0-3 parts of antioxidant;

[0021] The antioxidant is selected from any one of antioxidant 1010 or antioxidant 168.

[0022] Further illustration, in the raw materials of the modified polypropylene composition, the mass ratio of the polypropylene resin, the modified carboxylated nanocellulose whiskers, the modified aluminum borate whiskers and the antioxidant is 100:15:20:1.5.

[0023] Further illustration, in the raw materials of the modified carboxylated nanocellulose whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570 or titanate coupling agent;

[0024] In the raw materials of the modified aluminum borate whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570 or titanate coupling agent.

[0025] Further illustration, calculated by mass parts, the raw materials for preparing the PPR pipe also include 0 to 3 parts of pigment.

[0026] A method for preparing a PPR pipe with good impact resistance, used for preparing the PPR pipe with good impact resistance, includes the following steps:

[0027] Preparation of modified carboxylated nanocellulose whiskers: According to the raw material formula of the modified carboxylated nanocellulose whiskers, disperse the formulated amount of carboxylated nanocellulose whiskers in absolute ethanol to obtain a suspension, add the formulated amount of coupling agent to the suspension and stir, then perform vacuum filtration and drying to obtain modified carboxylated nanocellulose whiskers;

[0028] Preparation of modified aluminum borate whiskers: According to the raw material formula of the modified aluminum borate whiskers, disperse the dried formulated amount of aluminum borate whiskers in absolute ethanol to obtain an aluminum borate whisker solution; dissolve the formulated amount of coupling agent in absolute ethanol and stir to obtain a coupling agent solution; add the aluminum borate whisker solution to the coupling agent solution under stirring, continue stirring, and obtain modified aluminum borate whiskers after vacuum filtration, washing and vacuum drying;

[0029] Preparation of modified polypropylene composition: According to the raw material formula of the modified polypropylene composition, mix the formulated amount of raw material components to obtain a modified polypropylene composition mixture, and the modified polypropylene composition mixture undergoes melt extrusion, cooling, pelletizing and drying to obtain a modified polypropylene composition;

[0030] Preparation of PPR pipe: According to the raw material formula of the PPR pipe, mix the formulated amount of raw material components to obtain a PPR pipe mixture, and the PPR pipe mixture undergoes melt shearing, molding and cutting to obtain a PPR pipe with good impact resistance.

[0031] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0032] 1. By adding modified carboxylated nanocellulose whiskers and modified aluminum borate whiskers to the resin matrix, they can form a certain bond, reinforce each other and make up for each other's shortcomings. This synergistic effect can significantly improve the impact resistance of the material, further ensure the toughness of the composite material, and give it excellent mechanical properties. The combination of the two whiskers can also improve the long-term pressure resistance of the pipe, the stability of the product, the resistance to heat deformation and the wear resistance.

[0033] 2. By first preparing modified carboxylated nanocellulose whiskers, modified aluminum borate whiskers and polypropylene resin into a masterbatch (modified polypropylene composition), the dispersibility and compatibility of these modified materials in the PP-R resin pellet matrix can be improved. In this way, when these modified materials are used for pipeline processing, the mechanical properties of the pipeline system can be fully improved with a small amount of addition. Just add 10 to 30 parts of the modified polypropylene composition to the raw material formula of the PPR pipe, which can further optimize the production cost of the product. The application of the modified polypropylene composition significantly improves the performance and durability of the pipe, enabling it to maintain stable performance in various complex environments.

[0034] 3. By adding a modified polypropylene composition to the PPR pipe, the modified polypropylene composition is mainly composed of two types of whiskers that have been surface modified. These modified whiskers have excellent dispersibility and interfacial bonding strength, can be fully dispersed in the resin matrix, and firmly bonded to the resin matrix. Through surface modification, the whiskers can penetrate each other and produce a certain bonding effect between the resin matrix. This bonding effect further enhances the bearing capacity of the PPR pipe composite material, enabling it to better withstand external impact. At the same time, the performance of the two whiskers complements each other, which can not only greatly enhance the impact resistance of the pipeline system, but also will not affect the toughness of the pipeline system itself. After the whisker material is made into a masterbatch (modified polypropylene composition) in advance, it can better melt and penetrate with the resin matrix, disperse and evenly distribute in the resin matrix, avoiding the problem of agglomeration or uneven dispersion that may occur when the whisker material is directly added to the raw material of the PPR pipe, and it is more convenient to control the formula ratio and mixing uniformity, thereby ensuring the consistency of the quality and performance of the final product. DETAILED DESCRIPTION

[0035] A PPR pipe with good impact resistance, wherein the raw materials of the PPR pipe include the following components, calculated by weight: 80-100 parts of polypropylene resin, 10-30 parts of modified polypropylene composition and 0.5-1 part of fluorine-containing additive;

[0036] Calculated by weight, the raw materials of the modified polypropylene composition include the following components: 70 to 100 parts of polypropylene resin, 10 to 30 parts of modified carboxylated nanocellulose whiskers and 10 to 30 parts of modified aluminum borate whiskers;

[0037] Calculated by mass parts, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 10-30 parts of carboxylated nanocellulose whiskers and 5-15 parts of coupling agent.

[0038] Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 10-30 parts of aluminum borate whiskers and 5-15 parts of coupling agent.

[0039] As a green and environmentally friendly nanomaterial, nanocellulose whiskers not only have abundant reserves and are naturally renewable, but also exhibit excellent surface area and outstanding mechanical properties. Nanocellulose whiskers are ideal toughening and strengthening materials. However, a large number of hydroxyl groups are contained on the surface of nanocellulose whiskers, and these hydroxyl groups are prone to form hydrogen bond bindings, resulting in the easy occurrence of self-aggregation phenomenon of nanocellulose whiskers. To solve this problem and improve its dispersibility in PPR pipe composite materials, by using the carboxylated nanocellulose whiskers as raw materials, the carboxylated nanocellulose whiskers are used to treat nanocellulose by a carboxylation modification method, which can effectively enhance the dispersibility of nanocellulose in PPR pipe composite materials and further exert its advantages in aspects such as strengthening and toughening.

[0040] After the carboxylated treatment, the surface of the carboxylated nanocellulose whiskers still has a certain hydrophilicity. When the carboxylated nanocellulose whiskers are introduced into the PP-R resin as a reinforcing body, the improvement degree of the mechanical properties of the PPR pipe composite material will be affected by the interfacial bonding situation between the two. The compatibility problem between the hydrophilic carboxylated nanocellulose whiskers and the hydrophobic PP-R results in a poor interfacial bonding force between the two, and the mechanical properties of the composite material cannot be significantly improved. Therefore, in the present invention, by introducing a coupling agent, the surface of the carboxylated nanocellulose whiskers is modified by the active groups of the coupling agent to replace the active hydrogen on the whisker surface, reduce the polarity, thereby reducing its hydrogen bond bonding and enhancing the mutual penetration between the resin and the whiskers.

[0041] By first performing carboxylation modification and coupling agent surface modification on the nanocellulose whiskers, the problem of self-aggregation of the nanocellulose whiskers is solved, and the penetration between the modified carboxylated nanocellulose whiskers and the resin matrix is enhanced. The interfacial bonding force of the PPR pipe composite material is significantly improved, and the modified carboxylated nanocellulose whiskers can greatly strengthen and toughen the PPR pipe composite material, further improving the mechanical properties of the PPR pipe.

[0042] Aluminum borate whiskers are inorganic whiskers with stable chemical properties and excellent mechanical properties. By adding aluminum borate whiskers, the rigidity, dimensional stability and good thermal stability of aluminum borate whiskers can be brought into play in PPR pipe composite materials. Combined with the toughness of the polymer material itself, the mechanical properties of PPR pipes can be effectively improved. Aluminum borate whiskers have an excellent aspect ratio, usually greater than 10 to 35, which makes aluminum borate whiskers have a significant effect in reinforcing composite materials. In addition, aluminum borate whiskers have a high melting point, good strength, chemical corrosion resistance, simple preparation process, and easy access to raw materials. These characteristics make aluminum borate whiskers an ideal reinforcing material. Compared with other whiskers, aluminum borate whiskers are smaller in shape, which allows them to be filled in large quantities. Its filling amount can reach more than twice that of ordinary glass fibers, further enhancing its reinforcing effect in composite materials. Due to its small size, it can overcome the problem that continuous long fibers are difficult to distribute evenly in the resin matrix. This not only improves the surface finish of the product, but also significantly reduces the wear on the mold during processing.

[0043] However, since the surface of aluminum borate whisker usually contains more hydroxyl groups, the surface energy is large, and the wettability to non-polar resin matrix is relatively poor. If directly added to the resin matrix, it is easy to form pores at the two-phase interface, thereby forming a performance weak point in the material, which causes the impact strength to decrease. Therefore, by adopting a coupling agent to process aluminum borate whisker to obtain the modified aluminum borate whisker, the coupling agent molecule can coat the whisker surface, so that the aluminum borate whisker after surface modification can promote the compatibility of resin and whisker, form a firm interface bond between resin and whisker, promote the stress transfer of composite material, strengthen the bearing capacity of whisker, thereby further improve the overall performance of PPR pipe composite material.

[0044] The modified carboxylated nanocellulose whiskers in the modified polypropylene composition have very good toughening and strengthening effects in composite materials, and the modified aluminum borate whiskers are also very good reinforcing materials. By adding the two whiskers to the resin matrix, they can undergo certain bonding, mutually reinforce each other and make up for each other's deficiencies. This synergistic effect can significantly improve the impact resistance of the material, further ensure the toughness of the composite material, and make it have excellent mechanical properties. Since the material sources of nanocellulose whiskers and aluminum borate whiskers are wide and the raw material cost is low, favorable conditions are provided for their large-scale production. Using the modified polypropylene composition for PPR piping system can not only significantly improve the mechanical properties of the PPR piping system, but also reduce production costs, which is conducive to promotion and application.

[0045] In the preparation of the modified polypropylene composition, the main purpose of first preparing a masterbatch (modified polypropylene composition) from the modified carboxylated nanocellulose whiskers, modified aluminum borate whiskers and polypropylene resin is to improve the dispersibility and compatibility of these modified materials in the PP-R resin pellet matrix. In this way, when these modified materials are used in pipe processing, the mechanical properties of the pipe system can be fully enhanced with a relatively small addition amount. Only 10 - 30 parts of the modified polypropylene composition need to be added to the raw material formula of PPR pipes, which can further optimize the production cost of the product.

[0046] Finally, the modified polypropylene composition is added to the PPR pipes. The modified polypropylene composition is mainly composed of two kinds of whiskers modified by surface modification. These modified whiskers have excellent dispersibility and interfacial bonding force, can be fully dispersed in the resin matrix, and firmly bond with the resin matrix. Through surface modification, the whiskers can penetrate each other and produce a certain bonding effect between the resin matrices. This bonding effect further enhances the load-bearing capacity of the PPR pipe composite material, enabling it to better resist external impact forces. At the same time, the properties of the two kinds of whiskers complement each other, which can not only greatly improve the impact resistance of the pipe system, but also not affect the toughness of the pipe system itself. The compounding of the two kinds of whiskers can also improve the long-term pressure resistance performance, stability, heat distortion resistance and wear resistance of the pipes. The application of the modified polypropylene composition significantly improves the performance and durability of the pipes, enabling them to maintain stable performance in various complex environments. After the whisker material is made into a masterbatch (modified polypropylene composition) in advance, it can better melt and penetrate with the resin matrix, disperse and be evenly distributed in the resin matrix, avoiding the problems of agglomeration or uneven dispersion that may occur when directly adding the whisker material to the raw materials of PPR pipes, and more conveniently controlling the formulation ratio and mixing uniformity, thus ensuring the consistency of the quality and performance of the final product.

[0047] To further illustrate, the compound use of modified carboxylated nanocellulose whiskers and modified aluminum borate whiskers in the present invention can significantly enhance and toughen the PP-R resin. However, during the long-term processing, the presence of whiskers may cause continuous wear on the equipment, thus reducing the service life of the mold. To solve this problem, a fluorine-containing additive (PPA) is added to the raw material formula of the PPR pipe. PPA has an extremely low surface energy and can effectively reduce the internal friction between molecules during the resin processing, improving the overall plasticization effect of the composite material. More importantly, PPA will seep from the interior of the melt to the melt surface during processing and form an isolation layer on the metal surface. This helps to reduce the friction of the melt against the screw, barrel, and die head during the melt shearing process, thereby reducing the melt extrusion pressure and having the characteristic of low precipitation during the pipe production process. Using PPA can not only reduce the energy consumption during product production but also effectively reduce mechanical wear. In addition, the addition of PPA can also reduce the precipitation of the product on the die head during the long-term extrusion process, thereby improving the surface smoothness and appearance quality of the pipe. This can reduce the number of shutdowns for cleaning, further improve production efficiency, and reduce the comprehensive cost of product processing.

[0048] The PPR pipe with good impact resistance has excellent impact resistance while ensuring the toughness of the pipe, and can reduce mechanical wear during the production process. It has the characteristic of low precipitation during the pipe production process, can reduce the probability of producing defective products, reduce the number of shutdowns for cleaning, improve production efficiency, further optimize the product cost, and solve the problem of poor impact resistance of the existing PP-R pipe system. The PPR pipe of the present invention can maintain long-term stable operation in harsh environments (such as in cold regions, tunnel projects where gravel is likely to fall, etc.), effectively reducing the possibility of pipeline leakage or rupture.

[0049] To further illustrate, the preparation method of the carboxylated nanocellulose whiskers includes the following steps:

[0050] Disperse the nanocellulose whiskers in an ethanol solution, adjust the pH value of the solution to 8 - 11, add sodium chloroacetate after uniform dispersion, and obtain carboxylated nanocellulose whiskers after suction filtration, washing, and vacuum drying.

[0051] Specifically, the preparation method of the carboxylated nanocellulose whiskers includes the following steps: Disperse the dried nanocellulose whiskers in a 70% ethanol solution, adjust the pH of the solution to 8 - 11 with an alkali solution such as NaOH solution, continue to disperse in a constant temperature water bath at 45°C for 30 min, add sodium chloroacetate and continue to process for 2.5 h to obtain a mixture. Filter the mixture by suction, and wash it thoroughly with deionized water to remove the residual solvent. Place the suction-filtered product in a vacuum drying oven for vacuum drying to obtain carboxylated nanocellulose whiskers.

[0052] Further explanation, in the preparation method of the carboxylated nanocellulose whiskers, the mass ratio of the nanocellulose whiskers to the sodium chloroacetate is (3-5):1. If the amount of the sodium chloroacetate added is too much, the side reactions will increase and the product purity will be reduced. If the amount of the sodium chloroacetate added is too little, the reaction rate will decrease and the degree of carboxylation will be insufficient, which will affect the performance of the carboxylated nanocellulose whiskers.

[0053] Preferably, in the method for preparing the carboxylated nanocellulose whiskers, the amount of the nanocellulose whiskers added is 20 g, the amount of the sodium chloroacetate added is 6 g, the nanocellulose whiskers are dried at 80° C. for 30 min, and then dispersed in 500 mL of 70% ethanol solution.

[0054] Preferably, the nanocellulose whiskers have an average diameter of 4 to 10 nm and an average length of 150 to 250 nm;

[0055] The aluminum borate whiskers have an average diameter of 0.5 to 1 μm and an average length of 10 to 30 μm.

[0056] If the particle size of the nanocellulose whisker and the aluminum borate whisker is too small, the whisker is easily adsorbed on the feed port during the masterbatch preparation process of the modified polypropylene composition, resulting in changes in the product formula ratio, and may even cause the feed to be suspended, thereby affecting the normal production process. If the particle size of the nanocellulose whisker and the aluminum borate whisker is too large, it is not conducive to the modification process of the nanocellulose whisker and the aluminum borate whisker, and will also have a negative impact on the performance of the PPR pipe.

[0057] Preferably, the raw materials of the PPR pipe include the following components, calculated by weight: 100 parts of polypropylene resin, 25 parts of modified polypropylene composition and 0.5 parts of fluorine-containing additive;

[0058] Calculated by weight, the raw materials of the modified polypropylene composition include the following components: 100 parts of polypropylene resin, 15 parts of modified carboxylated nanocellulose whiskers and 20 parts of modified aluminum borate whiskers;

[0059] Calculated by weight, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 20 parts of carboxylated nanocellulose whiskers and 10 parts of coupling agent;

[0060] Calculated by weight, the raw materials of the modified aluminum borate whisker include the following components: 20 parts of aluminum borate whisker and 10 parts of coupling agent.

[0061] When comprehensively considering product performance and cost, the raw materials of the PPR pipe are preferably the above-mentioned formula. The PPR pipe has good toughness, excellent impact resistance and good processing performance. It has little wear on mechanical equipment during the production process, low precipitation during the production process, a low probability of producing defective products, reduces the number of shutdowns for cleaning, and improves production efficiency.

[0062] Preferably, in the raw materials of the modified carboxylated nanocellulose whiskers, the mass ratio of the carboxylated nanocellulose whiskers to the coupling agent is 2:1;

[0063] In the raw materials of the modified aluminum borate whiskers, the mass ratio of the aluminum borate whiskers to the coupling agent is 2:1.

[0064] Furthermore, calculated by mass fraction, the raw materials of the modified polypropylene composition further include 0-3 parts of antioxidant;

[0065] The antioxidant is selected from any one of antioxidant 1010 or antioxidant 168.

[0066] The function of the antioxidant is to inhibit or delay the oxidative degradation process of polymer materials, thereby extending their service life and stability. By adding an antioxidant, the degradation of the modified carboxylated nanocellulose whiskers and the modified aluminum borate whiskers during the melt extrusion process can be reduced, thus ensuring the stable production of the material.

[0067] Preferably, in the raw materials of the modified polypropylene composition, the mass ratio of the polypropylene resin, the modified carboxylated nanocellulose whiskers, the modified aluminum borate whiskers to the antioxidant is 100:15:20:1.5.

[0068] Furthermore, in the raw materials of the modified carboxylated nanocellulose whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570 or titanate coupling agent;

[0069] In the raw materials of the modified aluminum borate whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570 or titanate coupling agent.

[0070] Furthermore, calculated by mass fraction, the preparation raw materials of the PPR pipe further include 0-3 parts of pigment.

[0071] Preferably, calculated by mass fraction, the raw materials of the PPR pipe include the following components: 100 parts of polypropylene resin, 25 parts of modified polypropylene composition, 0.5 part of fluorine-containing additive and 2 parts of pigment;

[0072] Calculated by mass parts, the raw materials of the modified polypropylene composition include the following components: 100 parts of polypropylene resin, 15 parts of modified carboxylated nanocellulose whiskers, 20 parts of modified aluminum borate whiskers, and 1.5 parts of antioxidant;

[0073] Calculated by mass parts, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 20 parts of carboxylated nanocellulose whiskers and 10 parts of coupling agent;

[0074] Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 20 parts of aluminum borate whiskers and 10 parts of coupling agent.

[0075] When the above preferred formula is adopted, the product has good comprehensive performance and low cost.

[0076] A preparation method of a PPR pipe with good impact resistance, used for preparing the PPR pipe with good impact resistance, includes the following steps:

[0077] Preparation of modified carboxylated nanocellulose whiskers: According to the raw material formula of the modified carboxylated nanocellulose whiskers, disperse the formulated amount of the carboxylated nanocellulose whiskers in absolute ethanol to obtain a suspension, add the formulated amount of the coupling agent to the suspension for stirring treatment, perform reduced-pressure filtration and then drying to obtain the modified carboxylated nanocellulose whiskers;

[0078] Preparation of modified aluminum borate whiskers: According to the raw material formula of the modified aluminum borate whiskers, disperse the dried formulated amount of aluminum borate whiskers in absolute ethanol to obtain an aluminum borate whisker solution; dissolve the formulated amount of the coupling agent in absolute ethanol and stir to obtain a coupling agent solution; add the aluminum borate whisker solution to the coupling agent solution under stirring, continue stirring, and obtain the modified aluminum borate whiskers after reduced-pressure filtration, washing and vacuum drying;

[0079] Preparation of modified polypropylene composition: According to the raw material formula of the modified polypropylene composition, mix the formulated amount of raw material components to obtain a mixed material of the modified polypropylene composition, and the mixed material of the modified polypropylene composition undergoes melt extrusion, cooling, pelletizing and drying to obtain the modified polypropylene composition;

[0080] Preparation of PPR pipe: According to the raw material formula of the PPR pipe, mix the formulated amount of raw material components to obtain a mixed material of the PPR pipe, and the mixed material of the PPR pipe undergoes melt shearing, molding and cutting to obtain a PPR pipe with good impact resistance.

[0081] Preferably, the preparation of the modified carboxylated nanocellulose whiskers comprises: taking 20 g of the carboxylated nanocellulose whiskers, adding 500 mL of absolute ethanol, placing them in an ultrasonic homogenizer for dispersion for 5 - 10 min, with the rotation speed of the ultrasonic homogenizer being 3 - 8 r / min to obtain a suspension; transferring the suspension to a stirrer, adding 10 g of a coupling agent to the suspension, stirring at a speed of 300 r / min at room temperature for 4 h, performing vacuum filtration under reduced pressure and drying at 80 °C to obtain the modified carboxylated nanocellulose whiskers.

[0082] Preferably, the preparation of the modified aluminum borate whiskers comprises: drying the aluminum borate whiskers at 80 °C for 2 h, according to the raw material formula of the modified aluminum borate whiskers, dispersing 20 g of the dried aluminum borate whiskers in 300 mL of absolute ethanol under stirring to obtain an aluminum borate whisker solution; dissolving 10 g of a coupling agent in 200 mL of absolute ethanol, stirring at 40 °C for 30 min to obtain a coupling agent solution; adding the aluminum borate whisker solution to the coupling agent solution under stirring, continuing to stir for 4 h, performing vacuum filtration under reduced pressure, washing with deionized water, and performing vacuum drying in a vacuum drying oven to obtain the modified aluminum borate whiskers.

[0083] Preferably, the preparation of the modified polypropylene composition comprises: according to the raw material formula of the modified polypropylene composition, adding the raw material components in the formulated amounts to a high-speed mixer and mixing for 10 - 20 min to obtain a mixed material of the modified polypropylene composition, transferring the mixed material of the modified polypropylene composition to the hopper of an extruder and feeding it into a single-screw extruder, melt-extruding, cooling, pelletizing and drying at 180 - 230 °C to obtain the modified polypropylene composition.

[0084] Preferably, the preparation of the PPR pipe comprises: according to the raw material formula of the PPR pipe, adding the raw material components in the formulated amounts to a high-speed mixer for thorough mixing to obtain a mixed material of the PPR pipe, transferring the mixed material of the PPR pipe to the hopper of an extruder, feeding it into a twin-screw extruder, and after melt shearing, molding and cutting, obtaining a PPR pipe with good impact resistance. The temperature of each extrusion zone is 160 - 230 °C, and the optimal extrusion temperature is 180 - 220 °C. The temperatures of each partition of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) are set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C.

[0085] Due to the significant differences in the surface chemical properties between aluminum borate whiskers and nanocellulose whiskers, their compatibility with the polypropylene resin matrix is poor. When directly blended, problems such as uneven dispersion, interfacial defects, and a sharp increase in melt viscosity are likely to occur, leading to stress concentration and difficulties in extrusion processing. This solution breaks through this technical bottleneck through a differential modification strategy: carboxylating the nanocellulose whiskers to enhance the interfacial polarity matching with polypropylene, and at the same time using a coupling agent to modify the aluminum borate whiskers to reduce the surface polarity and inhibit agglomeration; the modified whiskers are pre-mixed with polypropylene resin powder by a high-speed mixer to achieve microscopically uniform dispersion, and then melt-extruded through a single-screw extruder with segmented temperature control to form a stable masterbatch (modified polypropylene composition). An antioxidant is combined to inhibit processing heat degradation and maintain interfacial stability. At the same time, a fluorine-containing additive (PPA) is added to the pipe extrusion formula to reduce the friction of the whisker material during processing, reduce precipitation, and enable the pipe product to complete the forming process stably and smoothly.

[0086] The preparation method of this PPR pipe with good impact resistance has the advantages of low precipitation at the die head, good surface finish and appearance quality of the prepared pipe, low mechanical wear, and high preparation efficiency during the preparation process of the PPR pipe.

[0087] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0088] For those not specified in the embodiments in terms of specific technologies or conditions, they shall be carried out according to the technologies or conditions described in the literature in this field or according to the product specifications. For the reagents or instruments not specified in terms of the manufacturer, they are all conventional products that can be obtained through commercial channels.

[0089] The raw materials in the examples and comparative examples can all be obtained through commercial channels, among which:

[0090] Nanocellulose whiskers (CNCs): commercially available, with an average diameter of the whisker size of 4 - 10 nm and an average length of 150 - 250 nm;

[0091] Aluminum borate whiskers: commercially available, with an average diameter of the whisker size of 0.5 - 1 μm and an average length of 10 - 30 μm;

[0092] Coupling agent in the raw materials of the modified carboxylated nanocellulose whiskers: silane coupling agent KH-570;

[0093] Coupling agent in the raw materials of the modified aluminum borate whiskers: silane coupling agent KH-570;

[0094] Polypropylene resin in the raw materials of the modified polypropylene composition: polypropylene resin powder, PPR series, F401, Sinopec, melt index 2 - 3 g / 10 min (230 °C, 2.16 kg);

[0095] Antioxidant: antioxidant 1010;

[0096] Polypropylene resin in the raw materials of PPR pipes: polypropylene resin pellets, PPR series, R200P, Hyosung Corporation, South Korea, melt index 0.2 - 0.3 g / 10 min (230 °C, 2.16 kg);

[0097] Fluorine - containing additive: PPA2300MB processing aid, Shanghai Luju Polymer Technology Co., Ltd.;

[0098] Pigment: commercially available pigment.

[0099] Examples 1 - 4

[0100] A preparation method of PPR pipes with good impact resistance, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0101] Preparation of carboxylated nanocellulose whiskers: Dry nanocellulose whiskers at 80 °C for 30 min. Disperse 20 parts of the dried nanocellulose whiskers in 500 mL of 70% ethanol solution, adjust the pH of the solution to 8 - 11 with NaOH solution, continue to disperse in a constant - temperature water bath at 45 °C for 30 min, add 6 parts of sodium chloroacetate and continue to treat for 2.5 h to obtain a mixture. Filter the mixture by suction, and wash it thoroughly with deionized water to remove the residual solvent. Place the suction - filtered product in a vacuum drying oven for vacuum drying to obtain carboxylated nanocellulose whiskers.

[0102] Preparation of modified carboxylated nanocellulose whiskers: Take 20 parts of carboxylated nanocellulose whiskers, add 500 mL of anhydrous ethanol, place them in an ultrasonic homogenizer and disperse for 10 min. The rotation speed of the ultrasonic homogenizer is 6 r / min to obtain a suspension; Transfer the suspension to a stirrer, add 10 parts of coupling agent to the suspension, stir - treat at a speed of 300 r / min at room temperature for 4 h, filter by reduced - pressure suction and dry at 80 °C to obtain modified carboxylated nanocellulose whiskers.

[0103] Preparation of modified aluminum borate whiskers: The aluminum borate whiskers were dried at 80 °C for 2 h. 20 parts of the dried aluminum borate whiskers were added to 300 mL of absolute ethanol, and the whiskers were fully dispersed under stirring to obtain an aluminum borate whisker solution; 10 parts of a coupling agent were dissolved in 200 mL of absolute ethanol, and the solution was stirred at 40 °C for 30 min to obtain a coupling agent solution; the aluminum borate whisker solution was added to the coupling agent solution under stirring, and stirring was continued for 4 h. Then, vacuum filtration was carried out, followed by washing with deionized water, and vacuum drying in a vacuum drying oven to obtain modified aluminum borate whiskers.

[0104] Preparation of modified polypropylene composition: 100 parts of polypropylene resin, 15 parts of modified carboxylated nanocellulose whiskers, 20 parts of modified aluminum borate whiskers, and 1.5 parts of an antioxidant were added to a high-speed mixer and mixed for 20 min to obtain a mixed material of modified polypropylene composition. The mixed material of modified polypropylene composition was transferred to the hopper of an extruder and fed into a single-screw extruder, where it was melt-extruded, cooled, pelletized, and dried at 180 - 230 °C to obtain a modified polypropylene composition.

[0105] Preparation of PPR pipes: According to the formula in Table 1, the raw material components in the formula amount were added to a high-speed mixer and fully mixed to obtain a mixed material for PPR pipes. The mixed material for PPR pipes was transferred to the hopper of an extruder and fed into a twin-screw extruder (where the temperature of each zone of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) was set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C). After melting and shearing, molding, and cutting, PPR pipes with good impact resistance were obtained.

[0106] Table 1 Raw material components of PPR pipes in Examples 1 - 4

[0107]

[0108] Example 5

[0109] A method for preparing PPR pipes with good impact resistance, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0110] Preparation of carboxylated nanocellulose whiskers: The same as the formula and preparation method of carboxylated nanocellulose whiskers in Example 1.

[0111] Preparation of modified carboxylated nanocellulose whiskers: Take 10 parts of carboxylated nanocellulose whiskers, add 500 mL of absolute ethanol, place them in an ultrasonic homogenizer and disperse for 10 min. The rotation speed of the ultrasonic homogenizer is 6 r / min to obtain a suspension; transfer the suspension to a stirrer, add 5 parts of coupling agent to the suspension, stir at a speed of 300 r / min at room temperature for 4 h, perform vacuum filtration under reduced pressure and then dry at 80 °C to obtain modified carboxylated nanocellulose whiskers.

[0112] Preparation of modified aluminum borate whiskers: Dry the aluminum borate whiskers at 80 °C for 2 h. Disperse 10 parts of the dried aluminum borate whiskers in 300 mL of absolute ethanol under stirring to obtain an aluminum borate whisker solution; dissolve 5 parts of coupling agent in 200 mL of absolute ethanol and stir at 40 °C for 30 min to obtain a coupling agent solution; add the aluminum borate whisker solution to the coupling agent solution under stirring and continue stirring for 4 h, perform vacuum filtration under reduced pressure, wash with deionized water, and perform vacuum drying in a vacuum drying oven to obtain modified aluminum borate whiskers.

[0113] Preparation of modified polypropylene composition: Add 70 parts of polypropylene resin, 10 parts of modified carboxylated nanocellulose whiskers, 10 parts of modified aluminum borate whiskers and 3 parts of antioxidant to a high-speed mixer and mix for 20 min to obtain a mixed material of modified polypropylene composition. Transfer the mixed material of modified polypropylene composition to the hopper of an extruder and feed it into a single-screw extruder. Melt extrude, cool, pelletize and dry at 180 - 230 °C to obtain a modified polypropylene composition.

[0114] Preparation of PPR pipes: Add 100 parts of polypropylene resin, 25 parts of modified polypropylene composition, 1 part of fluorine-containing additive and 2 parts of pigment to a high-speed mixer and mix thoroughly to obtain a mixed material for PPR pipes. Transfer the mixed material for PPR pipes to the hopper of an extruder and feed it into a twin-screw extruder (the temperature of each zone of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) is set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C). After melting and shearing, molding and cutting, obtain PPR pipes with good impact resistance.

[0115] Example 6

[0116] A preparation method of PPR pipes with good impact resistance, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0117] Preparation of carboxylated nanocellulose whiskers: The same as the formula and preparation method of the carboxylated nanocellulose whiskers in Example 1.

[0118] Preparation of modified carboxylated nanocellulose whiskers: Take 30 parts of carboxylated nanocellulose whiskers, add 500 mL of absolute ethanol, place them in an ultrasonic homogenizer and disperse for 10 min. The rotation speed of the ultrasonic homogenizer is 6 r / min to obtain a suspension; transfer the suspension to a stirrer, add 15 parts of coupling agent to the suspension, stir at a speed of 300 r / min at room temperature for 4 h, perform vacuum filtration under reduced pressure and dry at 80 °C to obtain modified carboxylated nanocellulose whiskers.

[0119] Preparation of modified aluminum borate whiskers: Dry the aluminum borate whiskers at 80 °C for 2 h. Disperse 30 parts of the dried aluminum borate whiskers in 300 mL of absolute ethanol under stirring to obtain an aluminum borate whisker solution; dissolve 15 parts of coupling agent in 200 mL of absolute ethanol and stir at 40 °C for 30 min to obtain a coupling agent solution; add the aluminum borate whisker solution to the coupling agent solution under stirring and continue to stir for 4 h, perform vacuum filtration under reduced pressure, wash with deionized water, and perform vacuum drying in a vacuum drying oven to obtain modified aluminum borate whiskers.

[0120] Preparation of modified polypropylene composition: Add 100 parts of polypropylene resin, 30 parts of modified carboxylated nanocellulose whiskers, 30 parts of modified aluminum borate whiskers and 3 parts of antioxidant to a high-speed mixer and mix for 20 min to obtain a mixed material of modified polypropylene composition. Transfer the mixed material of modified polypropylene composition to the hopper of an extruder and feed it into a single-screw extruder. Melt extrude, cool, pelletize and dry at 180 - 230 °C to obtain a modified polypropylene composition.

[0121] Preparation of PPR pipes: Add 100 parts of polypropylene resin, 25 parts of modified polypropylene composition, 1 part of fluorine-containing additive and 2 parts of pigment to a high-speed mixer and mix thoroughly to obtain a mixed material for PPR pipes. Transfer the mixed material for PPR pipes to the hopper of an extruder and feed it into a twin-screw extruder (where the temperature of each section of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) is set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C). After melting and shearing, molding and cutting, obtain PPR pipes with good impact resistance.

[0122] Comparative Examples 1 - 3

[0123] Compared with Example 1, the raw material components of the PPR pipes in Comparative Examples 1 - 3 are shown in Table 2 below. The remaining preparation methods and raw material formulas are the same as those in Example 1 to obtain PPR pipes.

[0124] Table 2 Raw Material Components of PPR Pipes in Comparative Examples 1 - 3

[0125]

[0126] Comparative Example 4

[0127] A preparation method of PPR pipes, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0128] The preparation of carboxylated nanocellulose whiskers, the preparation of modified carboxylated nanocellulose whiskers, and the preparation of modified aluminum borate whiskers are the same as those in Example 1, and the step of preparing the modified polypropylene composition is not carried out.

[0129] Preparation of PPR pipes: Add 100 parts of polypropylene resin, 3 parts of modified carboxylated nanocellulose whiskers, 4 parts of modified aluminum borate whiskers, 0.5 part of fluorine-containing additive, and 2 parts of pigment into a high-speed mixer and mix well to obtain a PPR pipe mixture. Transfer the PPR pipe mixture to the hopper of an extruder and enter a twin-screw extruder (the temperature of each zone of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) is set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C). After melting and shearing, molding, and cutting, PPR pipes are obtained.

[0130] Comparative Example 5

[0131] A preparation method of PPR pipes, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0132] Preparation of PPR pipes: Add 100 parts of polypropylene resin, 3 parts of nanocellulose whiskers, 0.5 part of fluorine-containing additive, and 2 parts of pigment into a high-speed mixer and mix well to obtain a PPR pipe mixture. Transfer the PPR pipe mixture to the hopper of an extruder and enter a twin-screw extruder (the temperature of each zone of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) is set as: 60 °C, 160 °C, 190 °C, 195 °C, 200 °C, 210 °C, 210 °C). After melting and shearing, molding, and cutting, PPR pipes are obtained.

[0133] Comparative Example 6

[0134] A preparation method of PPR pipes, comprising the following steps (the addition amounts of the following raw materials are all in parts by mass, and 1 part is equivalent to 1 g):

[0135] Preparation of PPR pipes: 100 parts of polypropylene resin, 4 parts of aluminum borate whiskers, 0.5 part of fluorine-containing additive, and 2 parts of pigment were added to a high-speed mixer and mixed thoroughly to obtain a PPR pipe mixture. The PPR pipe mixture was transferred to the hopper of an extruder and fed into a twin-screw extruder (where the temperature of each zone of the main barrel of the twin-screw extruder (from the feeding port to the die head outlet) was set to: 60°C, 160°C, 190°C, 195°C, 200°C, 210°C, 210°C). After melting and shearing, molding, and cutting, PPR pipes were obtained.

[0136] The following test methods were used to test the tensile strength, notched impact strength at 23°C, notched impact strength at -20°C, falling weight impact performance at -20°C, and hydrostatic test for Examples 1-6 and Comparative Examples 1-6 respectively:

[0137] Tensile property test standard: "GB / T 8804.3-2003 Determination of tensile properties of thermoplastic pipes";

[0138] Notched impact strength at 23°C (Type 1eA, 23°C), notched impact strength at -20°C (Type 1eA, -20°C): "GB / T 18743.1-2022 Determination of the Charpy impact strength of thermoplastic pipes";

[0139] Falling weight impact performance at -20°C: "GB / T 14152-2001 Test method for resistance to external impact of thermoplastic pipes", the number of test samples and the number of damaged samples during the test process were counted, and the impact resistance of the test samples was evaluated by the ratio of the number of damaged samples to the number of test samples (under the same number of test samples, the more the number of damaged samples, the worse the impact resistance);

[0140] Hydrostatic test: "GB / T 6111-2018 Determination of the resistance to internal pressure of thermoplastic piping systems for fluid transportation".

[0141] The test results are shown in Table 3:

[0142] Table 3 Test results of Examples 1-6 and Comparative Examples 1-6

[0143]

[0144] From the test results of Examples 1-4, it can be seen that among the raw materials of PPR pipes, when the addition amount of the modified polypropylene composition increases from 25 parts to 30 parts, the effect of improving the material properties is weak. Considering the factors of production cost and property improvement, when the addition amount of the modified polypropylene composition is 25 parts, the comprehensive performance is good, the product cost is low, and the cost performance is high. From the test results of Examples 1-4 and Comparative Examples 1 and 2, it can be seen that if the addition amount of the modified polypropylene composition is too low, the improvement of the mechanical properties of PPR pipes is not obvious; if the addition amount of the modified polypropylene composition is too high, the mechanical properties of PPR pipes will decline. Continuing to increase the modified polypropylene composition is not helpful for improving the performance of PPR pipes, and at this time, the raw material cost is increased, resulting in a higher production cost.

[0145] From Examples 1-6, it can be seen that the PPR pipes with good impact resistance of the present invention have excellent mechanical properties, high tensile strength, good toughness, good impact resistance, good thermal stability, and good pressure resistance (hydrostatic test at 95 °C for 165 h, hoop stress 3.8 MPa, no rupture and no leakage). During the preparation of Examples 1-6, there are no obvious precipitates on the die head, the surface of the pipe is smooth, and there are no defects in appearance.

[0146] Although the PPR pipes prepared in Comparative Example 3 have good mechanical properties, since no fluorine-containing additive is added during the preparation of the PPR pipes in Comparative Example 3, when the pipes are continuously extruded for 120 h, obvious precipitates appear on the die head, lip lines appear on the surface of the pipe, and there are obvious scratches, which affect the appearance of the pipes and the production continuity.

[0147] In Comparative Example 4, since the modified whiskers (modified carboxylated nanocellulose whiskers and modified aluminum borate whiskers) are not premixed with polypropylene resin to prepare the modified polypropylene composition, it affects the uniform dispersion and penetration of the whiskers in the polypropylene resin matrix during the pipe processing, and the bonding effect between the whiskers is also reduced, thus affecting the mechanical properties of the product.

[0148] In Comparative Examples 5 and 6, since the whisker material is not modified, the compatibility between the unmodified whiskers and the polypropylene resin matrix is poor, the dispersion of the whiskers in the resin matrix is poor, which easily leads to interface defects and stress concentration, reducing the performance of the pipe product. Moreover, when only nanocellulose whiskers or only aluminum borate whiskers are added, the tensile strength and impact resistance of the pipe are significantly deteriorated.

[0149] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A PPR pipe with good impact resistance, characterized in that, Calculated by mass parts, the raw materials of the PPR pipe include the following components: 80 - 100 parts of polypropylene resin, 10 - 30 parts of modified polypropylene composition, and 0.5 - 1 part of fluorine-containing additive; Calculated by mass parts, the raw materials of the modified polypropylene composition include the following components: 70 - 100 parts of polypropylene resin, 10 - 30 parts of modified carboxylated nanocellulose whiskers, and 10 - 30 parts of modified aluminum borate whiskers; Calculated by mass parts, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 10 - 30 parts of carboxylated nanocellulose whiskers and 5 - 15 parts of coupling agent; Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 10 - 30 parts of aluminum borate whiskers and 5 - 15 parts of coupling agent.

2. The PPR pipe with good impact resistance according to claim 1, wherein, The preparation method of the carboxylated nanocellulose whiskers includes the following steps: Disperse the nanocellulose whiskers in an ethanol solution, adjust the pH value of the solution to 8 - 11, add sodium chloroacetate after uniform dispersion, and obtain carboxylated nanocellulose whiskers after suction filtration, washing, and vacuum drying.

3. The PPR pipe with good impact resistance according to claim 2, wherein, The average diameter of the nanocellulose whiskers is 4 - 10 nm, and the average length is 150 - 250 nm; The average diameter of the aluminum borate whiskers is 0.5 - 1 μm, and the average length is 10 - 30 μm.

4. The PPR pipe with good impact resistance according to claim 1, characterized in that, Calculated by mass parts, the raw materials of the PPR pipe include the following components: 100 parts of polypropylene resin, 25 parts of modified polypropylene composition, and 0.5 part of fluorine-containing additive; Calculated by mass parts, the raw materials of the modified polypropylene composition include the following components: 100 parts of polypropylene resin, 15 parts of modified carboxylated nanocellulose whiskers, and 20 parts of modified aluminum borate whiskers; Calculated by mass parts, the raw materials of the modified carboxylated nanocellulose whiskers include the following components: 20 parts of carboxylated nanocellulose whiskers and 10 parts of coupling agent; Calculated by mass parts, the raw materials of the modified aluminum borate whiskers include the following components: 20 parts of aluminum borate whiskers and 10 parts of coupling agent.

5. The PPR pipe with good impact resistance according to claim 1, characterized in that, In the raw materials of the modified carboxylated nanocellulose whiskers, the mass ratio of the carboxylated nanocellulose whiskers to the coupling agent is 2:1; In the raw materials of the modified aluminum borate whiskers, the mass ratio of the aluminum borate whiskers to the coupling agent is 2:

1.

6. The PPR pipe with good impact resistance according to claim 1, characterized in that, Calculated by mass parts, the raw materials of the modified polypropylene composition further include 0 - 3 parts of antioxidant; The antioxidant is selected from any one of antioxidant 1010 or antioxidant 168.

7. The PPR pipe with good impact resistance according to claim 6, characterized in that, In the raw materials of the modified polypropylene composition, the mass ratio of the polypropylene resin, the modified carboxylated nanocellulose whiskers, the modified aluminum borate whiskers to the antioxidant is 100:15:20:1.

5.

8. The PPR pipe with good impact resistance according to claim 1, characterized in that, In the raw materials of the modified carboxylated nanocellulose whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570, or titanate coupling agent; In the raw materials of the modified aluminum borate whiskers, the coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-570, or titanate coupling agent.

9. The PPR pipe with good impact resistance according to claim 1, wherein Calculated by mass parts, the raw materials for preparing the PPR pipe further include 0 to 3 parts of pigment.

10. A preparation method of a PPR pipe with good impact resistance, characterized in that, To prepare the PPR pipe with good impact resistance as described in any one of claims 1 to 9, the following steps are included: Preparation of modified carboxylated nanocellulose whiskers: According to the raw material formula of the modified carboxylated nanocellulose whiskers, disperse the formulated amount of the carboxylated nanocellulose whiskers in absolute ethanol to obtain a suspension. Add the formulated amount of coupling agent to the suspension and stir. After vacuum filtration and drying, obtain the modified carboxylated nanocellulose whiskers; Preparation of modified aluminum borate whiskers: According to the raw material formula of the modified aluminum borate whiskers, disperse the dried formulated amount of aluminum borate whiskers in absolute ethanol to obtain an aluminum borate whisker solution; dissolve the formulated amount of coupling agent in absolute ethanol and stir to obtain a coupling agent solution; add the aluminum borate whisker solution to the coupling agent solution under stirring and continue stirring. After vacuum filtration, washing and vacuum drying, obtain the modified aluminum borate whiskers; Preparation of modified polypropylene composition: According to the raw material formula of the modified polypropylene composition, mix the formulated amount of raw material components to obtain a mixed material of the modified polypropylene composition. The mixed material of the modified polypropylene composition undergoes melt extrusion, cooling, pelletizing and drying to obtain the modified polypropylene composition; Preparation of PPR pipe: According to the raw material formula of the PPR pipe, mix the formulated amount of raw material components to obtain a mixed material of the PPR pipe. The mixed material of the PPR pipe undergoes melt shearing, molding and cutting to obtain a PPR pipe with good impact resistance.

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