Modified polypropylene HPPM square electric power corrugated pipe

Abstract

The invention discloses a modified polypropylene HPPM square electric power corrugated pipe, belongs to the technical field of corrugated pipes, and aims to solve the problem that the polypropylene square electric power corrugated pipe cannot have toughness and excellent mechanical performance when being prepared in the prior art. The adopted nucleating agent has the technical problems of low nucleating efficiency and complex preparation process; the composite material comprises block co-polypropylene, a modified nucleating agent, alkaline glass fibers and related auxiliaries, maleimide, propylene and allyl cinnamate serve as monomers, the block co-polypropylene with high mechanical performance and high toughness is prepared, ethylene diamine and hexachlorocyclotriphosphazene are subjected to nucleophilic substitution, and the composite material is obtained. The preparation method comprises the following steps: preparing polydiamino-containing polyamine phosphazene by using a one-step method, reacting the polyamine phosphazene with phthalic anhydride to obtain a modified nucleating agent with a large number of amide carboxylic acid nucleation centers, and has the advantages of high nucleation efficiency and simplified preparation process.

Description

Technical Field

[0001] The invention relates to the technical field of corrugated pipes, and in particular to a modified polypropylene HPPM square power corrugated pipe. Background Art

[0002] The power corrugated pipe adopts a "square outside and round inside" structural design. The outer wall is a square annular corrugated structure, and the inner wall is a circular flat wall structure, which improves the compressive strength and ring stiffness of the pipe and is widely used in high-voltage DC cables.

[0003] Among them, cross-linked polyethylene has good physical and chemical properties and dielectric properties, and has become the main insulating material for square power corrugated tubes. However, the cross-linking agent used in the cross-linking and the cross-linking by-products produced during the cross-linking process may remain inside the cable insulation, causing space charge accumulation problems and affecting the service life of the cable. The polypropylene corrugated tube made of polypropylene resin as the main raw material has sufficient mechanics and rigidity, excellent flexibility, and has the advantages of strong chemical corrosion resistance, easy installation and good sealing.

[0004] In the preparation of polypropylene HPPM square power corrugated pipe, a certain amount of nucleating agent can be appropriately added. The nucleating agent can be divided into β-nucleating agent and α-nucleating agent. The β-nucleating agent and the surface of the block copolymer polypropylene matrix can interact and crystallize, which can induce polypropylene to form β-crystal. Compared with α-crystal polypropylene, β-crystal polypropylene has more stable elongation at break, impact strength and heat deformation temperature. Polypropylene β-nucleating agent can be divided into amide nucleating agent and carboxylate nucleating agent. Compared with carboxylate nucleating agent, amide β-nucleating agent has the advantage of good thermal stability; however, in the synthesis process of amide nucleating agent, non-environmentally friendly chemical reagents such as acyl chloride and dichlorothionyl will be used. In addition, how to improve the nucleation efficiency of the prepared amide β-nucleating agent and simplify the process flow are also technical problems that need to be solved urgently.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a modified polypropylene HPPM square power corrugated pipe, which is used to solve the technical problems that in the prior art, when preparing polypropylene square power corrugated pipes, it is impossible to make them have both toughness and excellent mechanical properties, and in order to improve the mechanical properties of polypropylene, the nucleating agent used has low nucleating efficiency and complex preparation process.

[0007] The object of the present invention can be achieved by the following technical scheme: a modified polypropylene HPPM square power corrugated pipe, which comprises, by weight, 60-70 parts of block copolymer polypropylene, 0.2-0.5 parts of modified nucleating agent, 5-10 parts of alkaline glass fiber, 0.5-1 parts of heat stabilizer, 1-2 parts of plasticizer, 0.5-1 parts of antioxidant, 0.1-0.5 parts of light stabilizer and 1-1.5 parts of lubricant; The preparation method of the modified nucleating agent comprises the following steps: A1, ethylenediamine and 1,4-dioxane are mixed evenly to obtain an ethylenediamine solution; hexachlorocyclotriphosphazene and 1,4-dioxane are mixed evenly to obtain a hexachlorocyclotriphosphazene solution; the hexachlorocyclotriphosphazene solution is added dropwise to the ethylenediamine solution, and after the addition is completed, the reaction is carried out at a constant temperature of 40-50° C. for 2 hours to obtain a product; the product is distilled under reduced pressure to obtain a white solid polyamine phosphazene; Ethylenediamine and hexachlorocyclotriphosphazene undergo nucleophilic substitution to prepare polyamine phosphazene as follows:

[0008] A2, dissolving phthalic anhydride in tetrahydrofuran to obtain a phthalic anhydride solution; mixing polyamine phosphazene and tetrahydrofuran, stirring at 50-60° C. until completely dissolved, to obtain a polyamine phosphazene solution; dropping the polyamine phosphazene solution dropwise into the phthalic anhydride solution, and after the dropwise addition is completed, continuing the reaction at room temperature for 24 hours to obtain a reaction system; centrifuging the reaction system, washing with deionized water, and vacuum drying at 60° C. to constant weight to obtain a modified nucleating agent.

[0009] When phthalic anhydride reacts with the amino group of polyamine phosphazene, the amino group acts as a nucleophilic group to attack the carbonyl group of phthalic anhydride to generate an amide group and a carboxylic acid group.

[0010] The reaction formula of phthalic anhydride and polyamine phosphazene is as follows:

[0011] Furthermore, in step A1, the usage ratio of ethylenediamine and 1,4-dioxane is 5-10g:25mL, the usage ratio of hexachlorocyclotriphosphazene and 1,4-dioxane is 15-20g:100mL; the usage ratio of ethylenediamine solution and hexachlorocyclotriphosphazene solution is 30mL:120mL; in step A2, the usage ratio of phthalic anhydride and tetrahydrofuran is 15g:100mL; the usage ratio of polyamine phosphazene and tetrahydrofuran is 20-30g:100mL; the usage ratio of polyamine phosphazene solution and phthalic anhydride solution is 115-120mL:120mL.

[0012] Furthermore, the method for preparing the block copolymer polypropylene comprises the following steps: S1, dissolving an auxiliary emulsifier, isohexadecane, in benzyl benzoate to obtain an auxiliary emulsifier solution; dissolving a primary emulsifier, sodium dodecyl sulfate, in deionized water to obtain a primary emulsifier solution; and uniformly mixing the auxiliary emulsifier solution and the primary emulsifier solution to obtain an emulsifier solution; S2, add iodine transfer agent CHI3 and emulsifier solution into the reactor, and ventilate the reactor with propylene three times; react the reactor at 35-40°C for 100-120min to obtain copolymer emulsion I; S3. The maleimide powder is transferred to a reactor, and the copolymer emulsion is reacted at 50-60°C for 100-120min to obtain copolymer emulsion I; allyl cinnamate is added to the reactor, and the copolymer emulsion is reacted at 50-60°C for 130-150min to obtain copolymer emulsion II; 0.5-1%wt of hydroquinone ethanol solution is added to the reactor to terminate the reaction, and the reactor is cooled to room temperature, and the material is discharged to obtain the copolymer emulsion; the copolymer emulsion is subjected to post-processing to obtain block copolymer polypropylene.

[0013] Maleimide, propylene and allyl cinnamate undergo olefin addition reaction to prepare block copolymer polypropylene.

[0014] Furthermore, in step S1, the dosage ratio of the co-emulsifier and benzyl benzoate is 25-30 mL:100 mL; the dosage ratio of sodium dodecyl sulfate and deionized water is 25 g:100 mL; and the dosage ratio of the co-emulsifier solution and the main emulsifier solution is 100-120 mL:120 mL.

[0015] Furthermore, in step S2, the dosage ratio of the iodine transfer agent and the emulsifier solution is 0.3-0.5 g:100-150 mL; the dosage of the maleimide powder is 10-20 g, the dosage of allyl cinnamate is 15-20 mL, and the dosage of the hydroquinone ethanol solution is 5 mL.

[0016] Furthermore, in step S3, the post-process treatment includes: adding 30-50 mL of the copolymer emulsion into acidified ethanol, stirring and settling, and then removing the solvent with a Buchner funnel to obtain a polymer; the polymer is placed in a vacuum oven at 60° C. and dried to constant weight to obtain block copolymer polypropylene.

[0017] Furthermore, the heat stabilizer is tribasic lead sulfate, the plasticizer is butylene glycol sebaceous acid, the antioxidant is antioxidant 330, the light stabilizer is 2,4-dihydroxybenzophenone, and the lubricant is paraffin.

[0018] As another aspect of the present invention, a method for preparing a modified polypropylene HPPM square power corrugated pipe is characterized by comprising the following steps: B1. Mix block copolymer polypropylene, modified nucleating agent, alkaline glass fiber, heat stabilizer, plasticizer, antioxidant, light stabilizer and lubricant evenly, add them into a twin-screw extruder for melt extrusion, the melt extrusion temperature is 200-210° C., and the screw speed is 100 r / min to obtain a composite material; B2. The mixed masterbatch is injected into a strip by an injection molding machine. The injection temperature is 225-240°C, the injection pressure is 30MPa, the injection pressure holding time is 30s, and the cooling time is 20-30s to obtain a modified polypropylene HPPM square power corrugated pipe.

[0019] The present invention has the following beneficial effects: 1. The modified polypropylene HPPM square power corrugated pipe prepared by the present invention comprises block copolymer polypropylene, modified nucleating agent, alkaline glass fiber and related additives. Among them, maleimide, propylene and allyl cinnamate are copolymerized as monomers to prepare triblock block copolymer polypropylene. Polypropylene itself has the disadvantages of large low-temperature brittleness, poor toughness and impact resistance; maleimide and propylene copolymerization, because the main chain of the molecule contains a five-membered ring structure of maleimide ring, limits the rotational movement of the imide group around the main chain of the macromolecule, thereby increasing its own glass transition temperature and further improving the rigidity of the block copolymer polypropylene. Propylene is pre-polymerized, and then maleimide and allyl cinnamate monomers are added for copolymerization; on the one hand, a small amount of allyl cinnamate is dispersed and interspersed on the isotactic molecular chain as a copolymer monomer unit, which destroys the regularity of polypropylene to a certain extent, thereby improving the toughness of polypropylene; and in the regular area where the monomer is not embedded, the block copolymer polypropylene still maintains a high degree of crystallinity, so that it has a high rigidity. In addition, adding alkaline glass fiber into the mixed masterbatch can not only significantly improve the mechanical strength of the finished product, but also make it have a lower water absorption rate.

[0020] 2. The molecular chains of block copolymer polypropylene are closely arranged in the crystal region. In order to induce polypropylene to produce β-crystal in the crystal region, the present invention adds a certain amount of modified nucleating agent when preparing the power bellows. The modified nucleating agent used in the present invention is essentially an amide carboxylate β-nucleating agent. Ethylenediamine and hexachlorocyclotriphosphazene undergo nucleophilic substitution reaction to prepare polyamine phosphazene containing multiple diamino groups; the acid anhydride in phthalic anhydride has high reactivity with the diamino group of amine phosphazene and can react only at room temperature, thereby constructing a modified nucleating agent with multiple amide carboxylic acids and a cyclic structure; the modified nucleating agent generated by the present invention has a large number of amide carboxylic acid nucleation centers, thereby improving the nucleation efficiency of the modified nucleating agent. In addition, the modified nucleating agent designed by the present invention is grafted with active groups to increase its own molecular weight, thereby improving the compatibility of the nucleating agent with the polypropylene matrix. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0022] This embodiment provides a method for preparing a modified nucleating agent for a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: A1, 5g of ethylenediamine and 25mL of 1,4-dioxane were mixed evenly to obtain an ethylenediamine solution; 15g of hexachlorocyclotriphosphazene and 100mL of 1,4-dioxane were mixed evenly to obtain a hexachlorocyclotriphosphazene solution. 30mL of ethylenediamine solution was transferred to a 250mL round-bottom three-necked flask, a thermometer was set at one end of the round-bottom three-necked flask, and a constant pressure dropping funnel was set at one end. 120mL of hexachlorocyclotriphosphazene solution was added dropwise to the round-bottom three-necked flask through the constant pressure dropping funnel. After the addition was completed, an electric heating jacket was set on the outside of the round-bottom three-necked flask, the temperature was set to 50°C, and the reaction was carried out at a constant temperature for 2h to obtain a product. The product was distilled under reduced pressure to obtain a white solid, which was polyamine phosphazene.

[0023] A2, 15g of phthalic anhydride and 100mL of tetrahydrofuran are mixed and stirred at 100r / min at room temperature until the white crystalline powder is completely dissolved to obtain a phthalic anhydride solution; 30g of polyamine phosphazene and 100mL of tetrahydrofuran are mixed and stirred at 60°C until they are completely dissolved to obtain a polyamine phosphazene solution. A 500mL round-bottom flask is equipped with a stirrer and a dropping funnel, and then 110mL of the phthalic anhydride solution is transferred to the round-bottom flask, and then 120mL of the polyamine phosphazene solution is added drop by drop to the round-bottom flask through a dropping funnel, and a white precipitate is produced during the dropping process; after the dropwise addition is completed, the reaction is continued at 200r / min at room temperature for 24h to obtain a reaction system; the reaction system is centrifuged to obtain a white precipitate. The white precipitate is washed three times with deionized water, and then placed in a vacuum oven at 60°C to dry to constant weight to obtain a modified nucleating agent. Example 2

[0024] This embodiment provides a method for preparing a modified nucleating agent for a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: A1, 6g of ethylenediamine and 25mL of 1,4-dioxane were mixed evenly to obtain an ethylenediamine solution; 18g of hexachlorocyclotriphosphazene and 100mL of 1,4-dioxane were mixed evenly to obtain a hexachlorocyclotriphosphazene solution. 30mL of ethylenediamine solution was transferred to a 250mL round-bottom three-necked flask, a thermometer was set at one end of the round-bottom three-necked flask, and a constant pressure dropping funnel was set at one end. 120mL of hexachlorocyclotriphosphazene solution was added dropwise to the round-bottom three-necked flask through the constant pressure dropping funnel. After the addition was completed, an electric heating jacket was set on the outside of the round-bottom three-necked flask, the temperature was set to 45°C, and the reaction was carried out at a constant temperature for 2h to obtain a product. The product was distilled under reduced pressure to obtain a white solid, which was polyamine phosphazene.

[0025] A2, 15g of phthalic anhydride and 100mL of tetrahydrofuran were mixed and stirred at 100r / min at room temperature until the white crystalline powder was completely dissolved to obtain a phthalic anhydride solution; 25g of polyamine phosphazene and 100mL of tetrahydrofuran were mixed and stirred at 55°C until they were completely dissolved to obtain a polyamine phosphazene solution. A 500mL round-bottom flask was equipped with a stirrer and a dropping funnel, and then 118mL of the phthalic anhydride solution was transferred to the round-bottom flask, and then 120mL of the polyamine phosphazene solution was added drop by drop to the round-bottom flask through a dropping funnel. A white precipitate was produced during the dropping process; after the dropwise addition was completed, the reaction was continued at 150r / min at room temperature for 24h to obtain a reaction system; the reaction system was centrifuged to obtain a white precipitate. The white precipitate was washed three times with deionized water, and then dried in a vacuum oven at 60°C to constant weight to obtain a modified nucleating agent. Example 3

[0026] This embodiment provides a method for preparing a modified nucleating agent for a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: A1, 10g of ethylenediamine and 25mL of 1,4-dioxane were mixed evenly to obtain an ethylenediamine solution; 20g of hexachlorocyclotriphosphazene and 100mL of 1,4-dioxane were added and mixed evenly to obtain a hexachlorocyclotriphosphazene solution. 30mL of ethylenediamine solution was transferred to a 250mL round-bottom three-necked flask, a thermometer was set at one end of the round-bottom three-necked flask, and a constant pressure dropping funnel was set at one end. 120mL of hexachlorocyclotriphosphazene solution was added dropwise to the round-bottom three-necked flask through the constant pressure dropping funnel. After the addition was completed, an electric heating jacket was set on the outside of the round-bottom three-necked flask, the temperature was set to 50°C, and the reaction was carried out at a constant temperature for 2h to obtain a product. The product was distilled under reduced pressure to obtain a white solid, which was polyamine phosphazene.

[0027] A2, 15g of phthalic anhydride and 100mL of tetrahydrofuran, mixed and stirred at 100r / min at room temperature until the white crystalline powder was completely dissolved to obtain a phthalic anhydride solution; 30g of polyamine phosphazene and 100mL of tetrahydrofuran were mixed and stirred at 60°C until completely dissolved to obtain a polyamine phosphazene solution. A 500mL round-bottom flask was equipped with a stirrer and a dropping funnel, and then 120mL of the phthalic anhydride solution was transferred to the round-bottom flask, and then 120mL of the polyamine phosphazene solution was added drop by drop to the round-bottom flask through a dropping funnel. A white precipitate was produced during the dropping process; after the dropwise addition was completed, the reaction was continued at -200r / min at room temperature for 24h to obtain a reaction system; the reaction system was centrifuged to obtain a white precipitate. The white precipitate was washed three times with deionized water, and then dried in a vacuum oven at 60°C to constant weight to obtain a modified nucleating agent. Example 4

[0028] This embodiment provides a method for preparing block copolymer polypropylene for modified polypropylene HPPM square power corrugated pipe, comprising the following steps: S1. Dissolve 25 mL of auxiliary emulsifier isohexadecane in 100 mL of benzyl benzoate to obtain an auxiliary emulsifier solution; dissolve 25 g of primary emulsifier sodium dodecyl sulfate in 50 mL of deionized water to obtain a primary emulsifier solution; mix 100 mL of the auxiliary emulsifier solution and 50 mL of the primary emulsifier solution, add them to a beaker, and stir at 200 r / min for 30 minutes to obtain an emulsifier solution.

[0029] S2, a 200mL double-layer jacketed reactor was equipped with a four-blade screw stirring paddle, 0.3g of iodine transfer agent CHI3 and 100mL of emulsifier solution were added to the reactor, the reactor was ventilated three times with propylene, and then the reactor was heated to 35°C, mixed and reacted at 100r / min for 100min to obtain copolymer emulsion I.

[0030] S3, the reactor was heated to 40°C, and then 10g of maleimide powder was transferred to the reactor through a three-way catheter, and the reaction was carried out at 100r / min for 100min to obtain copolymer emulsion I. The reactor was further heated to 50°C, and 15mL of allyl cinnamate was transferred to the reactor through a three-way catheter, and the reaction was continued for 130min to obtain copolymer emulsion II. 5mL of 0.5%wt hydroquinone ethanol solution was added to the reactor to terminate the polymerization; the reactor was cooled to room temperature, and the material was discharged to obtain a copolymer emulsion; the copolymer emulsion was added to 500mL of acidified ethanol, stirred and settled, and the solvent was removed with a Buchner funnel to obtain a polymer; the polymer was placed in a vacuum oven at 60°C and dried until constant weight was obtained to obtain block copolymer polypropylene. Example 5

[0031] This embodiment provides a method for preparing block copolymer polypropylene for modified polypropylene HPPM square power corrugated pipe, comprising the following steps: S1. Dissolve 26 mL of auxiliary emulsifier isohexadecane in 100 mL of benzyl benzoate to obtain an auxiliary emulsifier solution; dissolve 25 g of primary emulsifier sodium dodecyl sulfate in 50 mL of deionized water to obtain a primary emulsifier solution; mix 110 mL of the auxiliary emulsifier solution and 50 mL of the primary emulsifier solution, add them to a beaker, and stir at 150 r / min for 30 min to obtain an emulsifier solution.

[0032] S2, a 200mL double-layer jacketed reactor was equipped with a four-blade propeller stirring paddle, 0.4g of iodine transfer agent CHI3 and 120mL of emulsifier solution were added to the reactor, the reactor was ventilated three times with propylene, and then the reactor was heated to 36°C, mixed and reacted at 150r / min for 105min to obtain copolymer emulsion I.

[0033] S3, the reactor was heated to 450°C, and then 15g of maleimide powder was transferred to the reactor through a three-way catheter, and the reaction was carried out at 110r / min for 115min to obtain copolymer emulsion I. The reactor was further heated to 55°C, and 16mL of allyl cinnamate was transferred to the reactor through a three-way catheter, and the reaction was continued for 140min to obtain copolymer emulsion II. 5mL of 0.6%wt hydroquinone ethanol solution was added to the reactor to terminate the polymerization; the reactor was cooled to room temperature, and the material was discharged to obtain copolymer emulsion; the copolymer emulsion was added to 500mL of acidified ethanol, stirred and settled, and the solvent was removed with a Buchner funnel to obtain a polymer; the polymer was placed in a vacuum oven at 60°C and dried until constant weight was obtained to obtain block copolymer polypropylene. Example 6

[0034] This embodiment provides a method for preparing block copolymer polypropylene for modified polypropylene HPPM square power corrugated pipe, comprising the following steps: S1. Dissolve 30 mL of co-emulsifier isohexadecane in 100 mL of benzyl benzoate to obtain a co-emulsifier solution; dissolve 25 g of main emulsifier sodium dodecyl sulfate in 50 mL of deionized water to obtain a main emulsifier solution; mix 120 mL of the co-emulsifier solution and 50 mL of the main emulsifier solution, add them to a beaker, and stir at 200 r / min for 30 minutes to obtain an emulsifier solution.

[0035] S2, a 200mL double-layer jacketed reactor was equipped with a four-blade screw stirring paddle, 0.5g of iodine transfer agent CHI3 and 150mL of emulsifier solution were added to the reactor, the reactor was ventilated three times with propylene, and then the reactor was heated to 40°C, mixed and reacted at 200r / min for 120min to obtain copolymer emulsion I.

[0036] S3, the reactor was heated to 50°C, and then 20g of maleimide powder was transferred to the reactor through a three-way catheter, and the reaction was carried out at 200r / min for 120min to obtain copolymer emulsion I. The reactor was further heated to 60°C, and 20mL of allyl cinnamate was transferred to the reactor through a three-way catheter, and the reaction was continued for 150min to obtain copolymer emulsion II. 5mL of 1%wt hydroquinone ethanol solution was added to the reactor to terminate the polymerization; the reactor was cooled to room temperature, and the material was discharged to obtain copolymer emulsion; the copolymer emulsion was added to 500mL of acidified ethanol, stirred and settled, and the solvent was removed with a Buchner funnel to obtain a polymer; the polymer was placed in a vacuum oven at 60°C and dried until constant weight was obtained to obtain block copolymer polypropylene. Example 7

[0037] This embodiment provides a preparation process of a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: B1. According to parts by weight, 60 parts of the block copolymer polypropylene prepared in Example 4, 0.2 parts of the modified nucleating agent prepared in Example 1, 5 parts of alkaline glass fiber, 0.5 parts of tribasic lead sulfate, 1 part of butylene glycol sebacate, 0.5 parts of antioxidant 330, 0.1 parts of 2,4-dihydroxybenzophenone and 1 part of paraffin were mixed evenly, and then added to a twin-screw extruder for extrusion granulation, wherein the extrusion temperature was 200° C. and the screw speed of the twin-screw extruder was 100 r / min to obtain a mixed masterbatch.

[0038] B2. The mixed masterbatch is injected into a strip by an injection molding machine, which is the prepared modified polypropylene HPPM square power bellows; wherein the injection temperature is 225°C, and the injection pressure is 30MPa; wherein the injection holding pressure and holding pressure time are 30s, and the cooling time is 20s. Example 8

[0039] This embodiment provides a preparation process of a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: B1. According to parts by weight, 63 parts of block copolymer polypropylene prepared in Example 4, 0.3 parts of modified nucleating agent prepared in Example 1, 6 parts of alkaline glass fiber, 0.6 parts of tribasic lead sulfate, 1.5 parts of butylene glycol sebacate, 0.6 parts of antioxidant 330, 0.2 parts of 2,4-dihydroxybenzophenone and 1.2 parts of paraffin were mixed evenly, and then added to a twin-screw extruder for extrusion granulation, wherein the extrusion temperature was 205°C and the screw speed of the twin-screw extruder was 100r / min to obtain a mixed masterbatch.

[0040] B2. The mixed masterbatch is injected into a strip by an injection molding machine, which is the prepared modified polypropylene HPPM square power bellows; wherein the injection temperature is 230°C, and the injection pressure is 30MPa; wherein the injection holding pressure and holding pressure time are 30s, and the cooling time is 22s. Example 9

[0041] This embodiment provides a preparation process of a modified polypropylene HPPM square power corrugated pipe, comprising the following steps: B1. According to parts by weight, 70 parts of the block copolymer polypropylene prepared in Example 4, 0.5 parts of the modified nucleating agent prepared in Example 1, 10 parts of alkaline glass fiber, 1 part of tribasic lead sulfate, 2 parts of butylene glycol sebacate, 1 part of antioxidant 330, 0.5 parts of 2,4-dihydroxybenzophenone and 1.5 parts of paraffin were mixed evenly, and then added to a twin-screw extruder for extrusion granulation, wherein the extrusion temperature was 210° C. and the screw speed of the twin-screw extruder was 100 r / min to obtain a mixed masterbatch.

[0042] B2. The mixed masterbatch is injected into a strip by an injection molding machine, which is the prepared modified polypropylene HPPM square power bellows; wherein the injection temperature is 240°C, and the injection pressure is 30MPa; wherein the injection holding pressure and holding time are 30s, and the cooling time is 30s.

[0043] Comparative Example 1 Compared with Example 9, in the present invention, the block copolymer polypropylene is replaced by polypropylene of equal mass when preparing the mixed masterbatch.

[0044] Comparative Example 2 Compared with Example 9, the present invention does not add a modified nucleating agent when preparing the mixed masterbatch.

[0045] Comparative Example 3 Compared with Example 9, the present invention does not add alkaline glass fiber when preparing the mixed masterbatch.

[0046] Performance Test: 1. According to GB / T1040-2006 "Determination of tensile properties of plastics", the modified polypropylene HPPM square power bellows prepared in Examples 7-9 and Comparative Examples 1-3 were tested for tensile strength at a tensile rate of 50 mm / min.

[0047] 2. According to GB / T1043.1-2008 "Determination of impact properties of simply supported beams", the modified polypropylene HPPM square power bellows prepared in Examples 7-9 and Comparative Examples 1-3 were tested for impact properties, wherein the pendulum was 4J and the test temperatures were 23°C and -20°C, respectively.

[0048] 3. According to GB / T9341-2008 "Determination of Bending Properties of Plastics", the modified polypropylene HPPM square power corrugated pipes prepared in Examples 7-9 and Comparative Examples 1-3 were tested for bending properties, wherein the bending rate was 2 mm / min. The specific test results are shown in Table 1:

[0049] Data Analysis: A comparative analysis of the data in Table 1 above shows that the modified polypropylene HPPM square power bellows prepared in Examples 7-9 of the present invention have excellent mechanical properties and toughness, as shown by higher values ​​of tensile strength, impact strength and flexural strength; however, in Comparative Example 1, when preparing the mixed masterbatch, polypropylene was used instead of block copolymer polypropylene, which reduced its own toughness and mechanical properties, as shown by reduced values ​​of tensile strength, flexural strength and impact strength under high and low temperature environments.

[0050] In Comparative Example 2, no modified nucleating agent was added in the preparation of the mixed masterbatch. The modified nucleating agent helps to induce polypropylene to produce β-crystal in the crystal region, and the mechanical properties of β-crystal polypropylene are better, so the strength value of the modified polypropylene HPPM square power corrugated pipe prepared in Comparative Example 2 decreases. In Comparative Example 3, no alkaline glass fiber was added in the preparation of the mixed masterbatch, which reduced the impact strength value of the prepared modified polypropylene HPPM square power corrugated pipe, but its toughness did not decrease, as shown by the unchanged tensile strength value and bending strength value.

[0051] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0053] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A modified polypropylene HPPM square power corrugated pipe, characterized in that: According to weight parts, it includes 60-70 parts of block copolymer polypropylene, 0.2-0.5 parts of modified nucleating agent, 5-10 parts of alkaline glass fiber, 0.5-1 parts of heat stabilizer, 1-2 parts of plasticizer, 0.5-1 parts of antioxidant, 0.1-0.5 parts of light stabilizer and 1-1.5 parts of lubricant; The preparation method of the modified nucleating agent comprises the following steps: A1, ethylenediamine and 1,4-dioxane are mixed evenly to obtain an ethylenediamine solution; hexachlorocyclotriphosphazene and 1,4-dioxane are mixed evenly to obtain a hexachlorocyclotriphosphazene solution; the hexachlorocyclotriphosphazene solution is added dropwise to the ethylenediamine solution, and after the addition is completed, the reaction is carried out at a constant temperature of 40-50° C. for 2 hours to obtain a product; the product is distilled under reduced pressure to obtain a white solid polyamine phosphazene; A2, dissolving phthalic anhydride in tetrahydrofuran to obtain a phthalic anhydride solution; mixing polyamine phosphazene and tetrahydrofuran, stirring at 50-60° C. until completely dissolved, to obtain a polyamine phosphazene solution; dropping the polyamine phosphazene solution dropwise into the phthalic anhydride solution, and after the dropwise addition is completed, continuing the reaction at room temperature for 24 hours to obtain a reaction system; centrifuging the reaction system, washing with deionized water, and vacuum drying at 60° C. to constant weight to obtain a modified nucleating agent.

2. A modified polypropylene HPPM square power corrugated pipe according to claim 1, characterized in that: In step A1, the usage ratio of ethylenediamine and 1,4-dioxane is 5-10g:25mL, the usage ratio of hexachlorocyclotriphosphazene and 1,4-dioxane is 15-20g:100mL; the usage ratio of ethylenediamine solution and hexachlorocyclotriphosphazene solution is 30mL:120mL; in step A2, the usage ratio of phthalic anhydride and tetrahydrofuran is 15g:100mL; the usage ratio of polyamine phosphazene and tetrahydrofuran is 20-30g:100mL; the usage ratio of polyamine phosphazene solution and phthalic anhydride solution is 115-120mL:120mL.

3. A modified polypropylene HPPM square power corrugated pipe according to claim 1, characterized in that: The method for preparing the block copolymer polypropylene comprises the following steps: S1, dissolving an auxiliary emulsifier, isohexadecane, in benzyl benzoate to obtain an auxiliary emulsifier solution; dissolving a primary emulsifier, sodium dodecyl sulfate, in deionized water to obtain a primary emulsifier solution; and uniformly mixing the auxiliary emulsifier solution and the primary emulsifier solution to obtain an emulsifier solution; S2, add iodine transfer agent CHI3 and emulsifier solution into the reactor, and ventilate the reactor with propylene three times; react the reactor at 35-40°C for 100-120min to obtain copolymer emulsion I; S3. The maleimide powder is transferred to a reactor, and the copolymer emulsion is reacted at 50-60°C for 100-120min to obtain copolymer emulsion I; allyl cinnamate is added to the reactor, and the copolymer emulsion is reacted at 50-60°C for 130-150min to obtain copolymer emulsion II; 0.5-1%wt of hydroquinone ethanol solution is added to the reactor to terminate the reaction, and the reactor is cooled to room temperature, and the material is discharged to obtain the copolymer emulsion; the copolymer emulsion is subjected to post-processing to obtain block copolymer polypropylene.

4. A modified polypropylene HPPM square power corrugated pipe according to claim 3, characterized in that: In step S1, the dosage ratio of the auxiliary emulsifier to benzyl benzoate is 25-30 mL:100 mL; the dosage ratio of sodium dodecyl sulfate to deionized water is 25 g:100 mL; and the dosage ratio of the auxiliary emulsifier solution to the primary emulsifier solution is 100-120 mL:120 mL.

5. A modified polypropylene HPPM square power corrugated pipe according to claim 4, characterized in that: In step S2, the dosage ratio of the iodine transfer agent and the emulsifier solution is 0.3-0.5 g:100-150 mL; the dosage of the maleimide powder is 10-20 g, the dosage of allyl cinnamate is 15-20 mL, and the dosage of the hydroquinone ethanol solution is 5 mL.

6. A modified polypropylene HPPM square power corrugated pipe according to claim 5, characterized in that: In step S3, the post-process treatment includes: adding 30-50 mL of the copolymer emulsion into acidified ethanol, stirring and settling, and then removing the solvent with a Buchner funnel to obtain a polymer; the polymer is placed in a vacuum oven at 60° C. and dried to constant weight to obtain block copolymer polypropylene.

7. A modified polypropylene HPPM square power corrugated pipe according to claim 1, characterized in that: The heat stabilizer is tribasic lead sulfate, the plasticizer is butylene glycol sebate, the antioxidant is antioxidant 330, the light stabilizer is 2,4-dihydroxybenzophenone, and the lubricant is paraffin.

8. A method for preparing a modified polypropylene HPPM square power corrugated pipe according to any one of claims 1 to 7, characterized in that: The following steps are involved: B1. Mix block copolymer polypropylene, modified nucleating agent, alkaline glass fiber, heat stabilizer, plasticizer, antioxidant, light stabilizer and lubricant evenly, add them into a twin-screw extruder for melt extrusion, the melt extrusion temperature is 200-210° C., and the screw speed is 100 r / min to obtain a composite material; B2. The mixed masterbatch is injected into a strip by an injection molding machine. The injection temperature is 225-240° C., the injection pressure is 30 MPa, the injection pressure holding time is 30 s, and the cooling time is 20-30 s; a modified polypropylene HPPM square power corrugated pipe is obtained.

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