High impact pp square pipe and its preparation method

Abstract

The application belongs to the technical field of pipes and specifically relates to a high-impact PP square-mouth drainage pipe and a preparation method thereof; the drainage pipe is prepared from the following raw materials in parts by mass: polypropylene resin 55-70 parts, polyolefin elastomer 5-15 parts, ethylene-acrylic acid copolymer 1-3 parts, modified talc powder 5-10 parts, aromatic diamide beta nucleating agent 0.1-0.3 parts, polyester nucleating agent 0.5-1 part, antioxidant 0.6-1 part, and calcium stearate 1-1.5 parts; the PP square-mouth drainage pipe prepared by the application has excellent tensile strength, impact resistance, bending modulus and anti-aging performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pipe materials, and particularly relates to a high-impact PP square mouth drainage pipe and a preparation method thereof. BACKGROUND

[0002] Traditional drainage pipes such as reinforced concrete pipes and cast iron pipes have certain strength, but are heavy in weight, inconvenient to transport, have rough inner walls, large water flow resistance, and are prone to cause impurities to adhere and form scales. In addition, the corrosion resistance is poor, especially when conveying sewage containing acid and alkali components, the pipes are easily corroded and damaged, affecting the service life of the pipes. Polypropylene (PP) has the advantages of easy processing, light weight, wear resistance, and no scale formation, and at present, polypropylene pipes are gradually emerging and are applied to fields such as building drainage, municipal pipe network, agricultural irrigation, and industrial liquid transportation.

[0003] However, the existing polypropylene drainage pipes still have some defects in performance, and the performance of some products decays quickly under extreme temperature or high corrosion conditions, and cannot meet the drainage requirements. In order to overcome these defects, modification methods such as filling, reinforcing, blending, copolymerization, and crosslinking are often used, such as adding calcium carbonate and glass fibers to enhance the tensile strength and impact resistance of polypropylene materials.

[0004] A Chinese patent application file with the application publication number CN110105672A discloses an improved copolymerized polypropylene injection pipe, which comprises the following raw materials: 70-80 parts of high-impact copolymerized polypropylene resin, 10-16 parts of alpha nucleating agent, 6-12 parts of barium sulfate, 6-12 parts of toughening agent, 0.2-0.8 parts of antioxidant, 0.1-0.5 parts of coupling agent, and 0.2-0.8 parts of processing aid. Although the use of alpha nucleating agent TMA-3 in the technical solution can improve the rigidity, ductility, and heat resistance, the impact resistance of alpha crystal polypropylene, especially at low temperature, is weaker than that of beta crystal. Although the addition of polyolefin elastomer can make up for the deficiency in impact resistance, the toughening effect of the polyolefin elastomer depends on the uniformity of dispersion, and the inorganic filler barium sulfate used in the technical solution has a large density and high surface energy. If the dispersion is not uniform, agglomeration may occur, which can weaken the toughening effect of the polyolefin elastomer, and may cause brittle fracture of the material in low-temperature or high-stress impact scenarios, and it is difficult to meet the use requirements in extreme environments. SUMMARY

[0005] The existing polypropylene pipes have the problem of weak impact resistance at low temperature. In order to solve this problem, the application provides a high-impact PP square mouth drainage pipe and a preparation method thereof.

[0006] In order to achieve the purpose of the application, the following technical solutions are adopted in the application:

[0007] In a first aspect, the present application provides a high-impact PP square drain pipe, which is prepared from the following raw materials in parts by mass:

[0008] 55-70 parts of polypropylene resin, 5-15 parts of polyolefin elastomer, 1-3 parts of ethylene-acrylic acid copolymer, 5-10 parts of modified talc powder, 0.1-0.3 parts of aromatic diamide β nucleating agent, 0.5-1 part of polyester nucleating agent, 0.6-1 part of antioxidant, and 1-1.5 parts of calcium stearate.

[0009] By adopting the above technical solution, the polypropylene resin is used as a matrix, the polyolefin elastomer is dispersed in the PP matrix to absorb impact energy; the ethylene-acrylic acid copolymer can be used as a compatibilizer to combine with the groups on the surface of the polyolefin elastomer and the modified talc powder, thereby reducing the interfacial tension, making the polyolefin elastomer more uniformly dispersed, avoiding performance fluctuations caused by phase separation, and ensuring the toughening effect; the aromatic diamide β nucleating agent and the polyester nucleating agent synergistically act to increase the β crystal content, thereby further improving the impact resistance of the pipe.

[0010] The preparation method of the polyester nucleating agent comprises the following steps:

[0011] (1) Dry diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and a catalyst respectively to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and the catalyst;

[0012] (2) Under the condition of nitrogen, mix the dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and the catalyst uniformly, perform a prepolymerization reaction by heating, close the nitrogen, perform a second reaction by vacuumizing, cool, and dry to obtain the polyester nucleating agent.

[0013] By adopting the above technical solution, the polyester nucleating agent is prepared by polycondensation of diphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxy diphenyl ether, and contains benzene rings and ester groups in the molecule, which can provide nucleation sites for PP, induce β crystal growth, and the ester groups can interact with groups such as carboxyl groups in the ethylene-acrylic acid copolymer to improve the dispersibility of the polyester nucleating agent in PP.

[0014] Preferably, in the step (2), the molar ratio of diphenyl-2,5 dicarboxylic acid to 4,4'-dihydroxy diphenyl ether is 1:(1-1.05).

[0015] By adopting the above technical solution, the reaction can be ensured to be sufficient at this ratio, which is helpful to form polyester nucleating agents with moderate molecular weight and uniform distribution: a slight excess of 4,4'-dihydroxy diphenyl ether can ensure that diphenyl-2,5 dicarboxylic acid more fully participates in the polycondensation reaction as an acid component in the reaction, reduces the residual unreacted carboxylic acid groups, and improves the raw material conversion rate.

[0016] Preferably, in the step (2), the catalyst is prepared by mixing zinc acetate, antimony trioxide and antimony acetate.

[0017] By adopting the above technical solution, the zinc acetate has strong activation ability on the carboxyl group, can quickly promote the esterification reaction of the carboxyl group and the hydroxyl group, and accelerate the generation of oligomers; the antimony trioxide and the antimony acetate are synergistic, can catalyze the ester exchange reaction in the high-temperature polycondensation stage, the organic carboxylate of the antimony acetate makes it have better dispersibility and more uniform catalysis; the antimony trioxide has higher stability under vacuum conditions and can continuously promote the removal of water; compared with a single catalyst, the two can make the distribution of the catalytic active center more uniform and improve the reaction efficiency.

[0018] Preferably, the amount of zinc acetate is 0.1%-0.3% of the total mass of biphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxydiphenyl ether, the amount of antimony trioxide is 0.2%-0.4% of the total mass of biphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxydiphenyl ether, and the amount of antimony acetate is 0.1%-0.2% of the total mass of biphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxydiphenyl ether.

[0019] By adopting the above technical solution, the three are compounded in the ratio, which can ensure that the entire reaction stage is fully carried out and avoid the problem of insufficient activity of a single catalyst in a certain stage; too high a catalyst dosage can easily lead to an increase in the residual amount of metal ions, affect the purity of the polyester nucleating agent, and reduce the structural regularity of the nucleating agent; too low a catalyst dosage can easily lead to incomplete polycondensation reaction, small molecular weight of the product, and irregular structure.

[0020] Preferably, in the step (2), the temperature of the prepolymerization reaction is 185-200℃, and the time of the prepolymerization reaction is 2-3h.

[0021] By adopting the above technical solution, the prepolymerization reaction can form a stepwise temperature regulation with the subsequent secondary reaction at this temperature, avoid local overheating caused by sudden temperature rise, and smoothly transition the reaction from the "prepolymerization" stage to the "polycondensation" stage; the oligomer generation amount can be stabilized within this time range.

[0022] Preferably, in the step (2), the temperature of the secondary reaction is 240-255℃, and the time of the secondary reaction is 4-6h.

[0023] By adopting the above technical solution, the oligomer molecular chain segment movement ability is significantly enhanced at this temperature, and the reaction activity of the terminal hydroxyl group and the terminal ester group is greatly improved; within this time range, the oligomer can complete the process of connecting between oligomers and continuously removing trace water molecules, and move the balance to the chain growth direction; avoid the generation of side reactions caused by excessive reaction.

[0024] Preferably, the preparation method of the modified talc powder comprises the following steps:

[0025] Mix the silane coupling agent with the aqueous ethanol solution, adjust the pH to 4-5 to obtain a silane coupling agent solution; mix the talc powder with the silane coupling agent solution, dry to obtain the modified talc powder.

[0026] By using the above technical solution, the surface of the talc powder is modified by the silane coupling agent, the organic functional groups of the silane coupling agent molecules stretch outward, and the compatibility with the polypropylene matrix and other materials is improved.

[0027] Preferably, the amount of the silane coupling agent is 0.5%-2% of the mass of the talc powder; the mass fraction of the aqueous ethanol solution is 90%, and the ratio of the amount of the silane coupling agent to the aqueous ethanol solution is 1g:(7-8)mL.

[0028] By using the above technical solution, if the amount of the silane coupling agent is too low, the talc powder is prone to agglomeration in the polypropylene material; if the amount is too high, the excess silane coupling agent is prone to self-polymerization, and the excess coupling agent is prone to being left in the composite material, becoming a stress concentration point and causing the impact resistance to decrease.

[0029] In a second aspect, the present application provides a preparation method of the high-impact PP rectangular sewer pipe, comprising the following steps:

[0030] S1: uniformly mix polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc powder, aromatic diamide β nucleating agent, polyester nucleating agent, antioxidant, and calcium stearate, perform mixing, extrusion, and granulation to obtain granules;

[0031] S2: extrude the granules to form a high-impact PP rectangular sewer pipe.

[0032] By using the above technical solution, the preparation process is simple, the raw materials are uniformly dispersed, and the prepared sewer pipe has high impact resistance and other properties.

[0033] Preferably, in the step S2, the temperature of the extrusion is 175-220°C.

[0034] By using the above technical solution, the temperature can realize stable production of the high-impact PP rectangular sewer pipe.

[0035] The reaction formula of the above polyester nucleating agent is as follows:

[0036]

[0037] In summary, the beneficial effects of the present application are:

[0038] (1) The polypropylene pipe of the application is prepared by the synergistic effect of the polyolefin elastomer and the beta crystal toughening and the talc powder reinforcing, and the antioxidants and other additives are compounded, so that the prepared PP pipe has excellent tensile strength, impact resistance, bending modulus and anti-aging property and the like.

[0039] (2) The polyester nucleating agent of the application is prepared by polycondensation reaction, can generate beta crystal, refine the crystal grains, and the aromatic diamide beta nucleating agent can efficiently induce the generation of beta crystal, and the two can improve the beta crystal content and stability, and enhance the toughening effect; the rigid main chain of the polyester nucleating agent can also form a pi-pi stacking effect with the amide group of the aromatic diamide beta nucleating agent, thereby improving the compatibility of the nucleating agent with PP.

[0040] (3) The silane coupling agent is used to form a uniform coating layer on the surface of the talc powder, so as to improve the interface compatibility of the talc powder and the PP matrix, so that the talc powder is uniformly dispersed in the mixing process, and the fluctuation of the mechanical properties of the material caused by the particle agglomeration can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a morphology diagram of the pure polypropylene resin of the application at 130 DEG C isothermal crystallization.

[0042] Figure 2 It is a morphology diagram of the polypropylene resin of the application only adding polyester nucleating agent at 130 DEG C isothermal crystallization.

[0043] Figure 3 It is an infrared spectrum diagram of the polyester nucleating agent of the application.

[0044] Figure 4 It is a WAXD diagram of the pure polypropylene resin and the polypropylene resin only adding polyester nucleating agent of the application after 130 DEG C isothermal crystallization; wherein, the m curve represents the polypropylene resin only adding polyester nucleating agent, and the n curve represents the pure polypropylene resin. DETAILED DESCRIPTION

[0045] The technical scheme of the application will be explained in detail below with reference to several representative embodiments of the application.

[0046] The experimental methods used in the following examples and comparative examples are conventional methods unless otherwise specified. The materials, reagents and the like used in the following examples and comparative examples can be obtained from commercial channels unless otherwise specified.

[0047] The biphenyl-2,5 dicarboxylic acid used in the following examples and comparative examples has a CAS number of 4445-51-6.

[0048] TMB-5 used in the following examples and comparative examples is a polypropylene beta crystal nucleating agent TMB-5.

[0049] Preparation Example 1

[0050] A preparation method of the modified talc powder in the present preparation example is as follows:

[0051] 2g of silane coupling agent KH550 was mixed with 14mL of 90% ethanol aqueous solution, stirred for 30min, and the pH was adjusted to 4 to obtain a silane coupling agent solution; 100g of dried talc powder was added into a reaction kettle, the temperature was raised to 65℃, the silane coupling agent solution was added dropwise, and stirring was continued for 45min; then it was transferred to a vacuum drying oven and dried at 80℃ for 10h to obtain the modified talc powder.

[0052] Preparation Example 2

[0053] 2g of silane coupling agent KH550 was mixed with 16mL of 90% ethanol aqueous solution, stirred for 30min, and the pH was adjusted to 5 to obtain a silane coupling agent solution; 100g of dried talc powder was added into a reaction kettle, the temperature was raised to 65℃, the silane coupling agent solution was added dropwise, and stirring was continued for 45min; then it was transferred to a vacuum drying oven and dried at 80℃ for 10h to obtain the modified talc powder.

[0054] Example 1

[0055] A high-impact PP square-mouth sewer pipe in the present example was prepared from the following raw materials:

[0056] 6.3kg of polypropylene resin, 1.2kg of polyolefin elastomer, 0.2kg of ethylene-acrylic acid copolymer, 0.8kg of modified talc powder, 0.02kg of polypropylene β-crystal nucleating agent TMB-5 (TMB-5), 0.08kg of polyester nucleating agent, 0.08kg of antioxidant, and 0.15kg of calcium stearate.

[0057] A preparation method of the high-impact PP square-mouth sewer pipe in the present example is as follows:

[0058] S1: The polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc powder, TMB-5, polyester nucleating agent, antioxidant, and calcium stearate were mixed uniformly, mixed, extruded, and pelletized to obtain granules;

[0059] S2: The granules were extruded to form a high-impact PP square-mouth sewer pipe; the extrusion temperature was 175-220℃.

[0060] A preparation method of the polyester nucleating agent in the present example is as follows:

[0061] (1) Diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxydiphenyl ether, zinc acetate, antimony trioxide and antimony acetate were respectively placed in a vacuum drying oven and dried at 80°C for 6h to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxydiphenyl ether, zinc acetate, antimony trioxide and antimony acetate;

[0062] (2) 242.23g of dried diphenyl-2,5 dicarboxylic acid, 206.25g of 4,4'-dihydroxydiphenyl ether, 0.9g of zinc acetate, 1.35g of antimony trioxide and 0.45g of antimony acetate were added to a three-necked flask, high-purity nitrogen was introduced to replace air, stirring was continuously performed at a stirring speed of 150rpm, a salt bath was turned on for heating, the temperature was raised to 190°C and reaction was performed for 3h; after the prepolymerization reaction was completed, nitrogen was turned off, an oil pump was turned on for vacuumizing, the temperature was raised to 255°C and reaction was performed for 5h, during which the stirring speed was maintained at 220rpm; after the reaction was completed, the heating device was turned off, natural cooling was performed to 150°C under vacuum, nitrogen was introduced to break the vacuum, natural cooling was performed to room temperature, and drying was performed at 120°C for 8h in a vacuum drying oven to obtain the polyester nucleating agent.

[0063] Figure 3 The infrared spectrum of the polyester nucleating agent; Figure 3 The peak at 3220cm -1 is the stretching vibration peak of -OH, the peak at 1709cm -1 is the stretching vibration peak of C=O, the peak at 1594cm -1 , the peak at 1502cm -1 , and the peaks at other nearby positions are the stretching vibration peaks of benzene ring skeleton; the peaks at 1247cm -1 and 1050cm -1 are the asymmetric and symmetric stretching vibration peaks of ether bond; the peak at 837cm -1 is the bending vibration peak of benzene ring hydrogen; the above indicates that the polyester nucleating agent is successfully synthesized.

[0064] Example 2

[0065] A high-impact PP socket sewer pipe of this example was prepared from the following mass of raw materials:

[0066] Polypropylene resin 5.5kg, polyolefin elastomer 1kg, ethylene-acrylic acid copolymer 0.3kg, modified talc 1kg, TMB-5 0.03kg, polyester nucleating agent 0.05kg, antioxidant 0.06kg, calcium stearate 0.1kg.

[0067] The preparation method of a high-impact PP socket sewer pipe of this example is as follows:

[0068] S1: uniformly mix polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc, TMB-5, polyester nucleating agent, antioxidant, calcium stearate, perform mixing, extrusion, granulation, obtain granules;

[0069] S2: extrude the granules to obtain high-impact PP square drain pipe; the extrusion temperature is 175-220℃.

[0070] The preparation method of the polyester nucleating agent in this embodiment is as follows:

[0071] (1) Diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether, zinc acetate, antimony trioxide and antimony acetate were placed in a vacuum drying box at 80℃ for 6h to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether, zinc acetate, antimony trioxide and antimony acetate;

[0072] (2) 242.23g of dried diphenyl-2,5 dicarboxylic acid, 202.21g of 4,4'-dihydroxy diphenyl ether, 0.45g of zinc acetate, 1.76g of antimony trioxide and 0.86g of antimony acetate were added to a three-necked flask, high-purity nitrogen was introduced to replace the air, stirring was continued at a stirring speed of 150rpm, the salt bath was turned on for heating, the temperature was raised to 200℃ for 2h; after the prepolymerization reaction was completed, the nitrogen was turned off, the oil pump was turned on for vacuumizing, the temperature was raised to 240℃ for 5h, and the stirring speed was maintained at 220rpm during the period; after the reaction was completed, the heating device was turned off, the vacuum state was maintained for natural cooling to 150℃, nitrogen was introduced to break the vacuum, and natural cooling was performed to room temperature, which was placed in a vacuum drying box at 120℃ for 8h to obtain the polyester nucleating agent.

[0073] Example 3

[0074] The high-impact PP square drain pipe in this embodiment is prepared from the following mass of raw materials:

[0075] Polypropylene resin 7kg, polyolefin elastomer 1.05kg, ethylene-acrylic acid copolymer 0.3kg, modified talc 1kg, TMB-5 0.03kg, polyester nucleating agent 0.1kg, antioxidant 0.09kg, calcium stearate 0.12kg.

[0076] The preparation method of the high-impact PP square drain pipe in this embodiment is as follows:

[0077] S1: uniformly mix polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc, TMB-5, polyester nucleating agent, antioxidant, calcium stearate, perform mixing, extrusion, granulation, obtain granules;

[0078] S2: The granules are extruded into a high-impact PP square outlet sewer pipe; the extrusion temperature is 175-220℃.

[0079] The preparation method of the polyester nucleating agent of the embodiment is as follows:

[0080] (1) Diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether, zinc acetate, antimony trioxide, and antimony acetate are respectively placed in a vacuum drying box and dried at 80℃ for 6h to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether, zinc acetate, antimony trioxide, and antimony acetate.

[0081] (2) 242.23g of dried diphenyl-2,5 dicarboxylic acid, 212.32g of 4,4'-dihydroxy diphenyl ether, 1.36g of zinc acetate, 1.14g of antimony trioxide, and 0.69g of antimony acetate are added to a three-necked flask, high-purity nitrogen gas is introduced to replace the air, stirring is continuously performed at a stirring speed of 150rpm, a salt bath is turned on for heating, the temperature is raised to 185℃ and reaction is performed for 3h; after the prepolymerization reaction is completed, the nitrogen gas is turned off, an oil pump is turned on for vacuumizing, the temperature is raised to 245℃ and reaction is performed for 6h, during which the stirring speed is maintained at 220rpm; after the reaction is completed, the heating device is turned off, the vacuum state is maintained and natural cooling is performed to 150℃, nitrogen gas is introduced to break the vacuum, natural cooling is performed to room temperature, and drying is performed in a vacuum drying box at 120℃ for 8h to obtain a polyester nucleating agent.

[0082] Embodiment 4

[0083] The high-impact PP square outlet sewer pipe of the embodiment is prepared from the following mass of raw materials:

[0084] Polypropylene resin 6.8kg, polyolefin elastomer 1.5kg, ethylene-acrylic acid copolymer 0.1kg, modified talc 0.5kg, TMB-5 0.01kg, polyester nucleating agent 0.07kg, antioxidant 0.1kg, calcium stearate 0.15kg.

[0085] The preparation method of the high-impact PP square outlet sewer pipe of the embodiment is as follows:

[0086] S1: The polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc, TMB-5, polyester nucleating agent, antioxidant, and calcium stearate are uniformly mixed, mixed, extruded, and granulated to obtain granules;

[0087] S2: The granules are extruded into a high-impact PP square outlet sewer pipe; the extrusion temperature is 175-220℃.

[0088] The preparation method of the polyester nucleating agent of the embodiment is as follows:

[0089] (1) Diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxydiphenyl ether, zinc acetate, antimony trioxide and antimony acetate were placed in a vacuum drying oven at 80°C for 6h to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxydiphenyl ether, zinc acetate, antimony trioxide and antimony acetate;

[0090] (2) 242.23g of dried diphenyl-2,5 dicarboxylic acid, 210.3g of 4,4'-dihydroxydiphenyl ether, 1.13g of zinc acetate, 0.91g of antimony trioxide and 0.46g of antimony acetate were added to a three-necked flask, high-purity nitrogen was introduced to replace the air, stirring was continued at a stirring speed of 150rpm, the salt bath was turned on for heating, the temperature was raised to 190°C and reacted for 3h; after the prepolymerization reaction was completed, the nitrogen was turned off, the oil pump was turned on to create a vacuum, the temperature was raised to 255°C and reacted for 5h, during which the stirring speed was maintained at 220rpm; after the reaction was completed, the heating device was turned off, the vacuum state was maintained and the temperature was naturally lowered to 150°C, nitrogen was introduced to break the vacuum, and the temperature was naturally lowered to room temperature, and then placed in a vacuum drying oven at 120°C for 8h to obtain the polyester nucleating agent.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that TMB-5 and the polyester nucleating agent are not added in this comparative example.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that TMB-5 is not added in this comparative example.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 1 is that the polyester nucleating agent is not added in this comparative example.

[0097] Comparative Example 4

[0098] The difference between this comparative example and Example 1 is that the modified talc is not added in this comparative example.

[0099] Comparative Example 5

[0100] The difference between this comparative example and Example 1 is that the polyolefin elastomer is not added in this comparative example.

[0101] Related Performance Tests

[0102] 1. Optical Morphology Test

[0103] The crystal morphology of the pure polypropylene resin and the polypropylene resin with only the polyester nucleating agent added (preparation method same as Example 1) was observed using a hot stage polarizing microscope. Figure 1 The morphology of the pure polypropylene resin at 130°C isothermal crystallization is shown in Figure 1, Figure 2Morphology of the polypropylene resin with only added polyester nucleating agent isothermally crystallized at 130℃.

[0104] By Figure 1 With Figure 2 It can be seen that the crystal size of the pure polypropylene resin is α crystal form, and the crystal size of the sample with added polyester nucleating agent is reduced and the number of crystals is increased, which shows that the polyester nucleating agent prepared by the application has significant nucleating effect on polypropylene.

[0105] 2. Wide-angle X-ray diffraction analysis

[0106] The crystal form of the pure polypropylene resin and the polypropylene resin with only added polyester nucleating agent was tested by wide-angle X-ray diffractometer. Figure 4 The WAXD spectrum of the pure polypropylene resin and the polypropylene resin with only added polyester nucleating agent after isothermal crystallization at 130℃; wherein, the m curve represents the polypropylene resin with only added polyester nucleating agent, and the n curve represents the pure polypropylene resin.

[0107] By Figure 4 As can be seen from the WAXD curve of the pure polypropylene resin, five diffraction peaks appear, with 2θ values of 14°, 16.8°, 18.4°, 21.1° and 21.8°, respectively, representing the (110), (040), (130), (131) and (111) crystal plane diffraction peaks of α crystal, which is a typical α crystal form. The polypropylene resin with added polyester nucleating agent has a larger (300) crystal plane diffraction peak at 2θ value of 16°, which is a typical β crystal form characteristic, indicating that the polyester nucleating agent is a β type nucleating agent.

[0108] 3. Mechanical property test

[0109] The high impact PP pipes prepared by examples 1-4 and comparative examples 1-5 were tested for related properties. The tensile yield strength was tested according to GB / T 1040.1-2018; the bending property was tested according to GB / T 9341-2008; the impact property was tested according to GB / T 1043.1-2008, and the test results are shown in table 1.

[0110] Table 1 Test results

[0111]

[0112] As can be seen from table 1, the PP pipes prepared by the application have excellent tensile strength, impact resistance and other properties.

[0113] The above has made the exemplary description to the present application, should indicate that, in not departing from the core of the present application, any simple variation, modification or other field technicians can not spend the equivalent replacement of creative labor, all fall into the protection scope of the present application.

Claims

1. A high-impact PP socket drain, characterised in that, The high-impact PP soil pipe is prepared from the following raw materials by mass fraction: polypropylene resin 55-70 parts, polyolefin elastomer 5-15 parts, ethylene-acrylic acid copolymer 1-3 parts, modified talc powder 5-10 parts, aromatic diamide β nucleating agent 0.1-0.3 parts, polyester nucleating agent 0.5-1 part, antioxidant 0.6-1 part, calcium stearate 1-1.5 parts; The preparation method of the polyester nucleating agent comprises the following steps: (1) dry diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and catalyst respectively to obtain dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and catalyst; (2) under the condition of nitrogen, mix the dried diphenyl-2,5 dicarboxylic acid, 4,4'-dihydroxy diphenyl ether and catalyst uniformly, warm up for prepolymerization, close the nitrogen, vacuumize for secondary reaction, cool down, dry to obtain polyester nucleating agent; The preparation method of the modified talc powder comprises the following steps: mix silane coupling agent and ethanol aqueous solution uniformly, adjust pH to 4-5 to obtain silane coupling agent solution; mix talc powder and silane coupling agent solution uniformly, dry to obtain modified talc powder; wherein the amount of silane coupling agent is 0.5%-2% of the mass of talc powder.

2. A high impact PP socket pipe according to claim 1, characterized in that, In the step (2), the molar ratio of diphenyl-2,5 dicarboxylic acid to 4,4'-dihydroxy diphenyl ether is 1:(1-1.05).

3. A high impact PP socket pipe according to claim 1, characterized in that, In the step (2), the catalyst is prepared by mixing zinc acetate, antimony trioxide and antimony acetate.

4. A high impact PP socket pipe according to claim 3, characterized in that, The amount of zinc acetate is 0.1%-0.3% of the total mass of diphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxy diphenyl ether, the amount of antimony trioxide is 0.2%-0.4% of the total mass of diphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxy diphenyl ether, and the amount of antimony acetate is 0.1%-0.2% of the total mass of diphenyl-2,5 dicarboxylic acid and 4,4'-dihydroxy diphenyl ether.

5. A high impact PP socket pipe according to claim 1, characterized in that, In the step (2), the temperature of the prepolymerization is 185-200℃, and the time of the prepolymerization is 2-3h.

6. A high impact PP socket pipe according to claim 1, characterized in that, In the step (2), the temperature of the secondary reaction is 240-255℃, and the time of the secondary reaction is 4-6h.

7. A high impact PP socket pipe according to claim 1, characterized in that, The mass fraction of the ethanol aqueous solution is 90%, and the amount ratio of the silane coupling agent to the ethanol aqueous solution is 1g:(7-8)mL.

8. A process for the production of a high-impact PP socket pipe according to any one of claims 1 to 7, characterized in that, Comprise the following steps: S1: mix polypropylene resin, polyolefin elastomer, ethylene-acrylic acid copolymer, modified talc powder, aromatic diamide β nucleating agent, polyester nucleating agent, antioxidant, calcium stearate uniformly, mix, extrude, granulate to obtain granules; S2: extrude the granules to form a high-impact PP soil pipe.

9. A process for the preparation of a high impact PP socket pipe according to claim 8, characterized in that, In the step S2, the temperature of the extrusion is 175-220℃.

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