High-strength pp-r glass fiber reinforced pipe and preparation method thereof

Abstract

The application relates to the technical field of plastic pipes, and discloses a high-strength PP-R glass fiber reinforced pipe and a preparation method thereof. The high-strength PP-R glass fiber reinforced pipe comprises the following components in parts by weight: 80-90 parts of random copolymerized polypropylene, 2-10 parts of glass fiber, 5-12 parts of composite metal oxide, 8-10 parts of a toughening agent, 0.5-1 part of an organic nucleating agent and 1-2 parts of an antioxidant. The preparation method of the composite metal oxide comprises the following steps: firstly mixing a metal nitrate solution and an organic acid, secondly mixing the mixture by adding an ionic liquid, performing a self-propagating combustion reaction, washing, drying and obtaining the composite metal oxide. Through the technical scheme, the problem of high longitudinal shrinkage of the PP-R glass fiber reinforced pipe in the related art is solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of plastic pipes, in particular to a high-strength PP-R glass fiber reinforced pipe and a preparation method thereof. BACKGROUND

[0002] Polypropylene random copolymer (PP-R) glass fiber reinforced pipes are widely used in cold and hot water pipeline systems. The PP-R material is reinforced by adding glass fibers, which improves the rigidity and strength of the pipe material, enabling it to withstand greater pressure and external force. However, the current PP-R glass fiber reinforced pipe still has the problem of high longitudinal shrinkage.

[0003] High longitudinal shrinkage can cause a series of serious consequences. During pipeline installation, high longitudinal shrinkage causes the pipe size to change during installation, making it difficult to accurately butt joint, reducing the sealing of the connection, and easily causing leakage, affecting the normal operation of the entire pipeline system. In the long-term use process, due to the temperature change of the cold and hot water pipeline, the internal stress caused by longitudinal shrinkage will continuously act on the pipe material, which may cause deformation, cracking and other problems of the pipe material over time, thereby reducing the service life of the pipe material.

[0004] Therefore, it is necessary to develop a PP-R glass fiber reinforced pipe with low longitudinal shrinkage. SUMMARY

[0005] The application provides a high-strength PP-R glass fiber reinforced pipe and a preparation method thereof, which solves the problem of high longitudinal shrinkage of the PP-R glass fiber reinforced pipe in the related art.

[0006] The technical scheme of the application is as follows:

[0007] The application provides a high-strength PP-R glass fiber reinforced pipe, which comprises the following components by weight: 80-90 parts of random copolymer polypropylene, 2-10 parts of glass fiber, 5-12 parts of composite metal oxide, 8-10 parts of toughening agent, 0.5-1 part of organic nucleating agent, and 1-2 parts of antioxidant.

[0008] The preparation method of the composite metal oxide comprises the following steps:

[0009] The metal nitrate solution and the organic acid are first mixed, and then mixed with an ionic liquid, followed by a self-propagating combustion reaction, washing, and drying to obtain the composite metal oxide.

[0010] As a further technical scheme, the raw material of the metal nitrate solution comprises metal nitrate and water in a mass-volume ratio of 1g:2-4mL.

[0011] The organic acid comprises one or both of citric acid and glycine, and is preferably glycine.

[0012] The ionic liquid comprises 1-ethyl-3-methylimidazolium dicyanamide.

[0013] In the component of the high-strength PP-R glass fiber reinforced pipe, the organic acid includes citric acid, glycine and the like, which is used as a fuel for preparing the composite metal oxide by the solution combustion method, is complexed with metal ions, effectively controls the dispersion of the metal ions in the combustion process, and promotes the formation of uniform and fine composite metal oxide particles.

[0014] As a further technical solution, the metal nitrate comprises one or both of cobalt nitrate and zinc nitrate.

[0015] As a further technical solution, when the metal nitrate comprises cobalt nitrate and zinc nitrate, the mass ratio of the cobalt nitrate to the zinc nitrate is 4:1~4.

[0016] In the component of the high-strength PP-R glass fiber reinforced pipe, the metal nitrate uses cobalt nitrate and zinc nitrate as the precursors of the metal oxide, compared with using single cobalt nitrate or zinc nitrate, the cobalt nitrate and the zinc nitrate together as the precursors of the metal oxide reduce the longitudinal shrinkage of the PP-R glass fiber reinforced pipe, and especially when the mass ratio of the cobalt nitrate to the zinc nitrate is 4:1~4, the impact strength of the PP-R glass fiber reinforced pipe is also improved.

[0017] As a further technical solution, the mass ratio of the metal nitrate to the organic acid is 3:0.6~0.8;

[0018] The mass ratio of the metal nitrate to the ionic liquid is 5:1~2.

[0019] As a further technical solution, the stirring speed in the first mixing is 300~500rpm, and the stirring time is 5~8min;

[0020] The stirring speed in the second mixing is 200~400rpm, and the stirring time is 4~6min.

[0021] As a further technical solution, the random copolymerized polypropylene comprises one or more of random copolymerized polypropylene PA14D, random copolymerized polypropylene 4220, and random copolymerized polypropylene 200P.

[0022] As a further technical solution, the organic nucleating agent comprises one or both of nucleating agent TMB-5 and nucleating agent BT-5.

[0023] When the organic nucleating agent is nucleating agent TMB-5, it belongs to a beta crystal nucleating agent, can induce the random copolymerized polypropylene to mainly form beta crystals in the crystallization process, and ensures the mechanical properties and stability of the PP-R glass fiber reinforced pipe;

[0024] When the organic nucleating agent is nucleating agent BT-5, it can accelerate the crystallization rate of the random copolymerized polypropylene, so that the random copolymerized polypropylene molecular chain is orderly arranged to form crystals in a shorter time, the crystallization rate is accelerated, the size change caused by the slow crystallization at room temperature is avoided, and the size stability of the PP-R glass fiber reinforced pipe can be ensured.

[0025] As a further technical solution, the organic nucleating agent comprises nucleating agent TMB-5 and nucleating agent BT-5 in a mass ratio of 1:1.

[0026] The antioxidant comprises one or more of a hindered phenolic antioxidant, an amine antioxidant, and a phosphite antioxidant.

[0027] The random copolymerized polypropylene as the base material of the high-strength PP-R glass fiber reinforced pipe has a large number of tertiary carbon atoms in the molecular structure, and the hydrogen atoms on the tertiary carbon atoms are relatively active and are easy to be taken away under the action of heat, light, oxygen, and mechanical stress in the processing process, and are prone to oxidative degradation. Therefore, the addition of the antioxidant inhibits or delays the oxidation process of the random copolymerized polypropylene, and ensures the performance stability and service life of the PP-R glass fiber reinforced pipe.

[0028] The hindered phenolic antioxidant may be, for example, antioxidant 1010, antioxidant 1076, antioxidant 264, etc.; the amine antioxidant may be, for example, antioxidant 6PPD, etc.; and the phosphite antioxidant may be, for example, antioxidant 168, antioxidant 626, antioxidant TPP, etc.

[0029] As a further technical solution, the toughening agent comprises a polyolefin elastomer.

[0030] As a further technical solution, the polyolefin elastomer comprises one or more of DF610, DF710, and DF740.

[0031] As a further technical solution, the diameter of the glass fiber is 5-12 microns, for example, 5 microns, 10 microns, 11 microns, or 12 microns, and is preferably 10 microns.

[0032] As a further technical solution, the length of the glass fiber is 0.5-1.5 mm, for example, 0.5 mm, 1 mm, or 1.5 mm, and is preferably 1.5 mm.

[0033] As a further technical solution, the particle size of the composite metal oxide is 30-40 nm, for example, it can be 30 nm, 35 nm, 40 nm, and preferably 30 nm.

[0034] The application also provides a preparation method of the high-strength PP-R glass fiber reinforced pipe.

[0035] The components of the high-strength PP-R glass fiber reinforced pipe are mixed, dried, extruded into a pipe blank, and cooled and shaped to obtain the high-strength PP-R glass fiber reinforced pipe.

[0036] The working principle and advantages of the application are as follows:

[0037] In the application, the composite metal oxide prepared by self-propagating combustion reaction of metal nitrate solution, organic acid and ionic liquid is added to the PP-R glass fiber reinforced pipe, which significantly reduces the longitudinal shrinkage rate of the PP-R glass fiber reinforced pipe. In the prior art, metal oxide is often directly added to the PP-R glass fiber reinforced pipe. In the application, metal nitrate solution is used as the precursor of metal oxide, organic acid is used as fuel, and ionic liquid is used as nitrogen source and carbon source to prepare nitrogen-carbon composite metal oxide through self-propagating combustion reaction. The atomic interaction of nitrogen and carbon atoms enhances the stability of the metal oxide. After being added to the PP-R glass fiber reinforced pipe, the metal oxide is uniformly distributed in the matrix of the PP-R glass fiber reinforced pipe as a heterogeneous nucleation point, which can effectively limit the thermal motion of PPR molecular chains and inhibit the shrinkage trend caused by temperature changes. At the same time, the nitrogen-carbon composite metal oxide has better dispersibility, avoiding the problem of local shrinkage difference caused by easy agglomeration of ordinary metal oxide in the matrix of the PP-R glass fiber reinforced pipe. Therefore, by adding the composite metal oxide prepared by self-propagating combustion reaction of metal nitrate solution, organic acid and ionic liquid to the PP-R glass fiber reinforced pipe, the dispersibility and stability of the metal oxide are improved, the longitudinal shrinkage rate of the PP-R glass fiber reinforced pipe is significantly reduced, and the shape and size of the pipe are better maintained, reducing the problems of loose pipe connection and leakage caused by longitudinal shrinkage. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0039] In the following examples and comparative examples, the ionic liquid is 1-ethyl-3-methylimidazolium dicyanamide with a purity of 98%.

[0040] Example 1

[0041] The high-strength PP-R glass fiber reinforced pipe comprises the following components by weight: random copolymerized polypropylene (model PA14D) 80 parts, glass fiber (diameter 12 μm, length 1.5 mm) 2 parts, composite metal oxide 5 parts, polyolefin elastomer (POE, polyolefin thermoplastic elastomer DF610) 8 parts, nucleating agent TMB-5 0.5 parts, antioxidant 168 1 part;

[0042] The preparation method of the composite metal oxide comprises the following steps:

[0043] Zinc nitrate hexahydrate and water are mixed at a mass-volume ratio of 1 g:2 mL to obtain a zinc nitrate hexahydrate solution;

[0044] The zinc nitrate hexahydrate solution and glycine are mixed at a stirring speed of 300 rpm for 8 min, the ionic liquid is added and mixed at a stirring speed of 200 rpm for 6 min, then the gel is concentrated by heating, the gel is continuously expanded by heating, and then a self-propagating combustion reaction is spontaneously performed for 60 s, and then washing, drying, and crushing are performed to obtain the composite metal oxide with a particle size of 35 nm; wherein the mass ratio of zinc nitrate hexahydrate to glycine is 3:0.6, and the mass ratio of zinc nitrate hexahydrate to ionic liquid is 5:1;

[0045] The preparation method of the high-strength PP-R glass fiber reinforced pipe comprises the following steps:

[0046] The components of the high-strength PP-R glass fiber reinforced pipe are mixed, dried at 80°C for 20 min, extruded into a pipe blank, drawn into a vacuum spray water tank for vacuum cooling and shaping, then cooled again in the vacuum spray water tank, drawn out, lettered and coded, and cut to obtain the high-strength PP-R glass fiber reinforced pipe with an average outer diameter of 40.2 mm and a wall thickness of 5.6 mm.

[0047] Example 2

[0048] The high-strength PP-R glass fiber reinforced pipe comprises the following components by weight: random copolymerized polypropylene (model PA14D) 90 parts, glass fiber (diameter 5 μm, length 0.5 mm) 10 parts, composite metal oxide 12 parts, polyolefin elastomer (POE, polyolefin thermoplastic elastomer DF710) 9 parts, nucleating agent TMB-5 1 part, antioxidant 1010 1 part, antioxidant 168 1 part;

[0049] The preparation method of the composite metal oxide comprises the following steps:

[0050] Zinc nitrate hexahydrate and water are mixed in a mass-volume ratio of 1 g:4 mL to obtain a zinc nitrate hexahydrate solution;

[0051] The zinc nitrate hexahydrate solution and citric acid are mixed at a stirring speed of 500 rpm for 5 min, the ionic liquid is added and mixed at a stirring speed of 400 rpm for 4 min, the gel is concentrated by heating, the gel is expanded by continuous heating and then spontaneously undergoes a self-propagating combustion reaction for 60 s, and then the gel is washed, dried, and crushed to obtain a composite metal oxide with a particle size of 40 nm; wherein the mass ratio of zinc nitrate hexahydrate to citric acid is 3:0.8, and the mass ratio of zinc nitrate hexahydrate to ionic liquid is 5:2;

[0052] The preparation method of the high-strength PP-R glass fiber reinforced pipe comprises the following steps:

[0053] The components of the high-strength PP-R glass fiber reinforced pipe are mixed, dried at 80℃ for 30 min, extruded into a pipe blank, drawn into a vacuum spray water tank for vacuum cooling and shaping, then cooled again in the vacuum spray water tank, drawn out, lettered and coded, and cut to obtain a high-strength PP-R glass fiber reinforced pipe with an average outer diameter of 40.3 mm and a wall thickness of 5.7 mm.

[0054] Example 3

[0055] The high-strength PP-R glass fiber reinforced pipe comprises the following components by weight: random copolymerized polypropylene (model PA14D) 60 parts, random copolymerized polypropylene (model 200P) 25 parts, glass fiber (diameter 10 μm, length 1.5 mm) 6 parts, composite metal oxide 8 parts, polyolefin elastomer (POE, polyolefin thermoplastic elastomer DF610) 10 parts, nucleating agent TMB-5 0.4 parts, nucleating agent BT-5 0.4 parts, and antioxidant 1010 1.5 parts.

[0056] The preparation method of the composite metal oxide comprises the following steps:

[0057] Cobalt nitrate hexahydrate and water are mixed in a mass-volume ratio of 1 g:3 mL to obtain a cobalt nitrate hexahydrate solution;

[0058] The cobalt nitrate hexahydrate solution and glycine are mixed at a stirring speed of 400 rpm for 6 min, the ionic liquid is added and mixed at a stirring speed of 300 rpm for 5 min, the gel is concentrated by heating, the gel is expanded by continuous heating and then spontaneously undergoes a self-propagating combustion reaction for 60 s, and then the gel is washed, dried, and crushed to obtain a composite metal oxide with a particle size of 30 nm; wherein the mass ratio of cobalt nitrate hexahydrate to glycine is 3:0.7, and the mass ratio of cobalt nitrate hexahydrate to ionic liquid is 5:1.5.

[0059] The preparation method of the high-strength PP-R glass fiber reinforced pipe comprises the following steps:

[0060] The components of the high-strength PP-R glass fiber reinforced pipe are mixed, dried at 80 DEG C for 30 min, extruded into a pipe blank, drawn into a vacuum spray water tank for vacuum cooling and shaping, then cooled again in the vacuum spray water tank, drawn out, sprayed with characters, coded, cut, and the high-strength PP-R glass fiber reinforced pipe with an average outer diameter of 40.3 mm and a wall thickness of 5.6 mm is obtained.

[0061] Example 4

[0062] The difference between this embodiment and example 3 is only that the cobalt nitrate hexahydrate is replaced by zinc nitrate hexahydrate, that is, the preparation method of the composite metal oxide comprises the following steps:

[0063] The zinc nitrate hexahydrate and water are mixed in a mass-volume ratio of 1g:3mL to obtain a zinc nitrate hexahydrate solution;

[0064] The zinc nitrate hexahydrate solution and glycine are mixed at a stirring speed of 400 rpm for 6 min, the ionic liquid is added and mixed at a stirring speed of 300 rpm for 5 min, then the gel is concentrated by heating, the gel is continuously expanded by heating, and then the self-propagating combustion reaction is spontaneously carried out for 60 s, washed, dried, and crushed to obtain the composite metal oxide with a particle size of 30 nm; wherein the mass ratio of the zinc nitrate hexahydrate to the glycine is 3:0.7, and the mass ratio of the zinc nitrate hexahydrate to the ionic liquid is 5:1.5.

[0065] Example 5

[0066] The difference between this embodiment and example 3 is only that the preparation method of the composite metal oxide comprises the following steps:

[0067] The metal nitrate and water are mixed in a mass-volume ratio of 1g:3mL to obtain a metal nitrate solution;

[0068] The metal nitrate solution and glycine are mixed at a stirring speed of 400 rpm for 6 min, the ionic liquid is added and mixed at a stirring speed of 300 rpm for 5 min, then the gel is concentrated by heating, the gel is continuously expanded by heating, and then the self-propagating combustion reaction is spontaneously carried out for 60 s, washed, dried, and crushed to obtain the composite metal oxide with a particle size of 30 nm; wherein the mass ratio of the metal nitrate to the glycine is 3:0.7, and the mass ratio of the metal nitrate to the ionic liquid is 5:1.5; the metal nitrate is cobalt nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 5:1.

[0069] Example 6

[0070] The difference between this example and Example 5 is only that the metal nitrate is cobalt nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 4:5.

[0071] Example 7

[0072] The difference between this example and Example 5 is only that the metal nitrate is cobalt nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 1:1.

[0073] Example 8

[0074] The difference between this example and Example 5 is only that the metal nitrate is cobalt nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 4:1.

[0075] Comparative Example 1

[0076] The difference between this comparative example and Example 3 is only that the composite metal oxide is replaced by cobalt oxide with a particle size of 30 nm.

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 3 is only that the composite metal oxide is not prepared by adding an ionic liquid.

[0079] Experimental Example 1

[0080] The high-strength PP-R glass-reinforced pipes prepared in Examples 1-8 and Comparative Examples 1-2 were tested for longitudinal shrinkage according to the standard GB / T 18742.2-2017 "Polypropylene piping systems for hot and cold water systems - Part 2: Pipes", using Method B - Oven test, with test conditions of 135±2℃, 1h, and the results are shown in Table 1 below.

[0081] Table 1 Performance test results

[0082]

[0083] Compared with Comparative Examples 1-2, the PP-R glass-reinforced pipes prepared in Examples 1-8 have lower longitudinal shrinkage, indicating that the use of a metal nitrate solution as a precursor of metal oxide, an organic acid as fuel, and an ionic liquid as a nitrogen source and carbon source to prepare a nitrogen-carbon composite metal oxide through a self-propagating combustion reaction significantly reduces the longitudinal shrinkage of the PP-R glass-reinforced pipe.

[0084] Experimental Example 2

[0085] The high-strength PP-R glass-reinforced pipes prepared in Examples 5-8 were tested for notched Charpy impact strength according to the standard GB / T 1043.1-2008 "Determination of impact properties of plastics - Part 1: non instrumented impact test", with a test temperature of 0℃ and a notch type of A-type notch, and the results are shown in Table 2 below.

[0086] Table 2 Performance test results

[0087]

[0088] Compared with examples 5~6, the simply supported beam notched impact strength of the PP-R glass fiber reinforced pipe prepared in examples 7~8 is higher, which indicates that when the composite metal oxide is prepared, the metal nitrate adopts cobalt nitrate and zinc nitrate as the precursor of the metal oxide, and the mass ratio of the cobalt nitrate and the zinc nitrate is 4:1~4, thereby improving the impact strength of the PP-R glass fiber reinforced pipe.

[0089] Experimental example 3

[0090] The high-strength PP-R glass fiber reinforced pipe prepared in example 3 is tested according to the standard GB / T 18742.2-2017 'Polypropylene piping systems for cold and hot water Part 2: pipes', and the results are shown in the following table 3.

[0091] Table 3 Performance test results

[0092]

[0093] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-strength PP-R glass fiber reinforced pipe, characterized in that, The components include the following weight parts: 80-90 parts of random copolymerized polypropylene, 2-10 parts of glass fiber, 5-12 parts of composite metal oxide, 8-10 parts of toughening agent, 0.5-1 part of organic nucleating agent, and 1-2 parts of antioxidant; The preparation method of the composite metal oxide comprises the following steps: The metal nitrate solution and the organic acid are mixed for the first time, and then the ionic liquid is added for the second time, and then a self-propagating combustion reaction is carried out, and then washing and drying are carried out to obtain the composite metal oxide; The raw material of the metal nitrate solution comprises metal nitrate and water in a mass-volume ratio of 1g:2-4mL; The organic acid comprises one or both of citric acid and glycine; The ionic liquid comprises 1-ethyl-3-methylimidazolium dicyanamide; The metal nitrate comprises one or both of cobalt nitrate and zinc nitrate; The mass ratio of the metal nitrate to the organic acid is 3:0.6-0.8; The mass ratio of the metal nitrate to the ionic liquid is 5:1-2.

2. The high-strength PP-R glass fiber reinforced pipe according to claim 1, characterized in that, When the metal nitrate comprises cobalt nitrate and zinc nitrate, the mass ratio of the cobalt nitrate to the zinc nitrate is 4:1-4.

3. The high-strength PP-R glass fiber reinforced pipe according to claim 1, characterized in that, The stirring speed in the first mixing is 300-500rpm, and the stirring time is 5-8min; The stirring speed in the second mixing is 200-400rpm, and the stirring time is 4-6min.

4. The high-strength PP-R glass fiber reinforced pipe according to claim 1, characterized in that, The random copolymerized polypropylene comprises one or more of random copolymerized polypropylene PA14D, random copolymerized polypropylene 4220, and random copolymerized polypropylene 200P.

5. The high-strength PP-R glass fiber reinforced pipe according to claim 1, characterized in that, The organic nucleating agent comprises one or both of nucleating agent TMB-5 and nucleating agent BT-5; The antioxidant comprises one or more of hindered phenolic antioxidant, amine antioxidant, and phosphite antioxidant; The toughening agent comprises polyolefin elastomer.

6. The high-strength PP-R glass fiber reinforced pipe according to claim 1, characterized in that, The diameter of the glass fiber is 5-12μm, and the length is 0.5-1.5mm; and the particle size of the composite metal oxide is 30-40nm.

7. A method for preparing a high-strength PP-R glass fiber reinforced pipe, used for preparing the high-strength PP-R glass fiber reinforced pipe according to any one of claims 1-6, characterized in that, The method comprises the following steps: The components of the high-strength PP-R glass fiber reinforced pipe are mixed, dried, extruded into a pipe blank, and cooled and shaped to obtain the high-strength PP-R glass fiber reinforced pipe.

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