Low-temperature-resistant modified PPR (polypropylene random copolymer) and preparation process thereof

Abstract

The invention belongs to the technical field of PPR pipes, and particularly relates to low-temperature-resistant modified PPR which comprises the following raw material components in parts by weight: 80-100 parts of a modified PPR matrix, 0.5-3 parts of an antioxidant, 1-5 parts of a silane coupling agent, 10-20 parts of filler and 10-15 parts of a diluent. The modified PPR material prepared by the invention has excellent low temperature resistance and flame retardance.

Description

Technical Field

[0001] The invention belongs to the technical field of PPR pipes, and in particular relates to a low-temperature resistant modified PPR and a preparation process thereof. Background Art

[0002] Polypropylene random copolymer (PPR for short) is a new type of plastic pipe product first developed and used in Europe. It is a third-generation polypropylene product. Under heating and pressurizing conditions, propylene monomer and a small amount of olefin monomer are randomly copolymerized by the catalytic action of a catalyst. Due to the random introduction of ethylene molecules, the arrangement and distribution of methyl groups on the tertiary carbon in the polymer molecular chain will be completely disrupted, thereby hindering the formation of the polymer crystalline state structure, resulting in changes in the physical properties, mechanical properties and crystallization properties of random copolymer polypropylene.

[0003] PPR has attracted more and more attention due to its excellent comprehensive performance. It has a wide range of applications, mainly in industrial fields such as pipes, packaging bags, automotive components, and furniture. PPR materials have good heat resistance and compressive strength, and good high-temperature creep performance. Compared with other plastics, it has great advantages in environmental protection, recyclability, and the complexity of processing technology. However, due to the low notched impact strength of PPR, especially its brittleness is particularly prominent at low temperatures (below 0°C) or high strain rates, the impact performance and other aspects are far from meeting the various technical requirements in the industrial field, which limits its application scope to a certain extent. Therefore, effectively improving the low-temperature impact resistance of PPR materials has become a key technical issue that needs to be solved urgently.

[0004] In addition, although PPR is a general-purpose thermoplastic resin and is widely used in all aspects of production and life due to its excellent comprehensive properties, PPR is a flammable material, which greatly limits its further application. Therefore, how to improve the flame retardant properties of PPR materials is also a key technical issue that needs to be solved urgently.

[0005] Based on this, there is an urgent need to develop a modified PPR material that has both low temperature resistance and flame retardant properties. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a low temperature resistant modified PPR and a preparation process thereof. In order to achieve the above object, the present invention adopts the following technical scheme: A low temperature resistant modified PPR, comprising the following raw materials in parts by weight: Modified PPR matrix 80~100 parts 0.5~3 parts of antioxidant Silane coupling agent 1~5 parts Filler 10~20 parts 10~15 parts of diluent The preparation method of the modified PPR matrix is: 50-80 parts of PPR matrix and 80-100 parts of acetone are added into a reactor, and then 3-5 parts of modifier and 1-3 parts of initiator are added, mixed in a high-speed mixer for 10-20 minutes, and extruded through a twin-screw extruder to obtain a modified PPR matrix; The structure of the modifier is: .

[0007] In some embodiments, the antioxidant is one or more of antioxidant 1010 , antioxidant 168 , and antioxidant 1076 .

[0008] In some embodiments, the coupling agent is selected from one or more of KH-550, KH-560, KH-570, KH-792, KH-791, and DL-602.

[0009] In some embodiments, the diluent is selected from one or more of ethylene glycol ethyl acetate, n-butyl glycidyl ether, diglycidyl ether, and 1,4-butanediol diglycidyl ether.

[0010] In some embodiments, the filler is one or more of glass powder, mica powder, quartz powder and asbestos powder.

[0011] In some embodiments, the initiator is selected from one or more of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, and tert-butylperoxycarbonate isopropyl ester.

[0012] In some embodiments, the preparation process of the low temperature resistant modified PPR comprises the following steps: The modified PPR matrix, antioxidant, silane coupling agent, filler and diluent are uniformly mixed according to the above weight parts to obtain a mixture; the above mixture is added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets; the pellets are placed in an oven for drying for later use; the dried pellets are injection molded on an injection molding machine to obtain low-temperature resistant modified PPR.

[0013] In some embodiments, the extrusion process parameters are: extrusion temperatures are 190° C., 195° C., 200° C., 205° C., and 215° C., respectively, and the main engine speed is 200 r / min.

[0014] In some embodiments, the injection molding process parameters are as follows: injection temperatures are 230°C, 225°C, 220°C, 215°C, and 210°C, respectively; and injection pressures are 55 MPa in zone one, 50 MPa in zone two, 45 MPa in zone three, and 40 MPa in zone four.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The modified PPR material prepared by the present invention has excellent low temperature resistance and flame retardant properties. On the one hand, the modifier of the present invention has a novel structure, and a siloxane flexible chain is introduced into its molecular structure, which can introduce soft and twistable fragments into the PPR material, thereby improving the low temperature resistance of the material; on the other hand, the modifier also introduces a triazine flame retardant group, which has an excellent flame retardant effect, so that the limiting oxygen index of the PPR material reaches 36.8, and the flame retardant grade of the horizontal and vertical combustion test reaches V-0. DETAILED DESCRIPTION

[0016] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0017] When the embodiments give numerical ranges, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those generally understood by those of ordinary skill in the art to which the present invention belongs.

[0018] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention are obtained through conventional commercial channels.

[0019] Preparation Example 1 Preparation of Modifier Step 1: Preparation of intermediate compound C ;

[0020] Compound B (0.1 mol), compound A (0.12 mol), triethylamine (0.2 mol) and acetone (300 ml) were added to a three-necked flask. The mixture was stirred in a water bath at 0°C for 4 hours. After the reaction, the precipitate was filtered and washed with acetone for several times. The solid was dried in an oven at 80°C for 12 hours to obtain the intermediate compound C as a white solid with a yield of 83.1%.

[0021] LC-MS (ESI): [M+H]+ =396.1.

[0022] Step 2: Preparation of Modifier ;

[0023] Under nitrogen environment, the intermediate compound C (0.1 mol), allyl zinc chloride (0.25 mol), and Pd(PPh3)4 (0.01 mol) were added to the reactor, and then deoxygenated THF (500 mL) was added, and the temperature was raised to 50°C and stirred for 2 hours. After the reaction, the mixture was filtered, and the filtrate was washed with deionized water 3 times (300 mLx3). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a crude product. The crude product was separated and purified by column chromatography to obtain a modifier compound with a yield of 90.2% and an HPLC purity of 99.4%.

[0024] LC-MS (ESI): [M+H] + =408.2.

[0025] 1 H-NMR (500 MHz, CDCl3): δ(ppm): 5.41-5.35(m,2H), 5.11-5.03(m,4H), 3.61(s,9H), 3.50-3.42 (m,4H), 3.35-3.22 (m,8H), 2.30-2.21 (m,2H), 1.52-1.41(m,2H), 0.58-0.50(m,2H).

[0026] Preparation Example 2 Preparation of Modified PPR Matrix 80 parts of PPR matrix (RP2400, Korea Petrochemical Corporation) and 100 parts of acetone were added to the reactor, and then 5 parts of the modifier obtained in Preparation Example 1 and 1 part of the initiator 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane were added, mixed in a high-speed mixer for 10 minutes, and finally extruded through a twin-screw extruder to obtain a modified PPR matrix. The extrusion process of the twin-screw extruder is: 175°C in zone 1, 180°C in zone 2, 185°C in zone 3, 190°C in zone 4, 200°C in zone 5, die head temperature of 205°C, feeding frequency of 40Hz, and screw speed of 200rpm.

[0027] Example 1 A low temperature resistant modified PPR material, comprising the following raw materials in parts by weight: Modified PPR matrix 100 copies Antioxidant 1010 1 part Coupling agent KH-560 3 parts Filler mica powder 10 parts Diluent diglycidyl ether 15 parts The preparation method of the above-mentioned low temperature resistant modified PPR material is: The modified PPR matrix, antioxidant, silane coupling agent, filler and diluent are uniformly mixed according to the above weight parts to obtain a mixed material; The above mixture was added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets. The extrusion process parameters were: extrusion temperature 190°C, 195°C, 200°C, 205°C, 215°C, main engine speed 200 r / min; the pellets were dried in a 90°C oven for 3 h for use. The dried pellets were injection molded on an injection molding machine to obtain a standard specimen of low-temperature resistant modified PPR material. The injection molding process parameters were: injection molding temperature 230°C, 225°C, 220°C, 215°C, 210°C, injection molding pressure 55 MPa in zone 1, 50 MPa in zone 2, 45 MPa in zone 3, and 40 MPa in zone 4.

[0028] Example 2 A low temperature resistant modified PPR material, comprising the following raw materials in parts by weight: Modified PPR matrix 90 parts Antioxidant 1076 2 parts Coupling agent KH-570 2 parts Filler quartz powder 20 parts Diluent n-butyl glycidyl ether 15 parts The preparation method of the above-mentioned low temperature resistant modified PPR material is: The modified PPR matrix, antioxidant, silane coupling agent, filler and diluent are uniformly mixed according to the above weight parts to obtain a mixed material; The above mixture was added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets. The extrusion process parameters were: extrusion temperature 190°C, 195°C, 200°C, 205°C, 215°C, main engine speed 200 r / min; the pellets were dried in a 90°C oven for 3 h for use. The dried pellets were injection molded on an injection molding machine to obtain a standard specimen of low-temperature resistant modified PPR material. The injection molding process parameters were: injection molding temperature 230°C, 225°C, 220°C, 215°C, 210°C, injection molding pressure 55 MPa in zone 1, 50 MPa in zone 2, 45 MPa in zone 3, and 40 MPa in zone 4.

[0029] Example 3 A low temperature resistant modified PPR material, comprising the following raw materials in parts by weight: Modified PPR matrix 80 parts Antioxidant 1010 1 part Coupling agent DL-602 2 parts Filler quartz powder 15 parts Diluent 1,4-butanediol diglycidyl ether 10 parts The preparation method of the above-mentioned low temperature resistant modified PPR material is: The modified PPR matrix, antioxidant, silane coupling agent, filler and diluent are uniformly mixed according to the above weight parts to obtain a mixed material; The above mixture was added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets. The extrusion process parameters were: extrusion temperature 190°C, 195°C, 200°C, 205°C, 215°C, main engine speed 200 r / min; the pellets were dried in a 90°C oven for 3 h for use. The dried pellets were injection molded on an injection molding machine to obtain a standard specimen of low-temperature resistant modified PPR material. The injection molding process parameters were: injection molding temperature 230°C, 225°C, 220°C, 215°C, 210°C, injection molding pressure 55 MPa in zone 1, 50 MPa in zone 2, 45 MPa in zone 3, and 40 MPa in zone 4.

[0030] Comparative Example 1 On the basis of Example 1, the modified PPR substrate was replaced with an unmodified PPR substrate (RP2400, Korea Petrochemical Corporation), and the specific method was as follows: A low temperature resistant modified PPR material, comprising the following raw materials in parts by weight: PPR substrate 100 copies Antioxidant 1010 1 part Coupling agent KH-560 3 parts Filler mica powder 10 parts Diluent diglycidyl ether 15 parts The preparation method of the above-mentioned low temperature resistant modified PPR material is: The PPR matrix, antioxidant, silane coupling agent, filler and diluent are mixed uniformly according to the above weight parts to obtain a mixed material; The above mixture was added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets. The extrusion process parameters were: extrusion temperature 190°C, 195°C, 200°C, 205°C, 215°C, main engine speed 200 r / min; the pellets were dried in a 90°C oven for 3 h for use. The dried pellets were injection molded on an injection molding machine to obtain a standard specimen of low-temperature resistant modified PPR material. The injection molding process parameters were: injection molding temperature 230°C, 225°C, 220°C, 215°C, 210°C, injection molding pressure 55 MPa in zone 1, 50 MPa in zone 2, 45 MPa in zone 3, and 40 MPa in zone 4.

[0031] Performance Testing In order to better reflect the performance of the low-temperature resistant modified PPR material of the present application, the low-temperature resistance and flame retardancy of the PPR materials prepared in Examples 1 to 3 and Comparative Example 1 were tested, and the test method was as follows: 1) Tensile strength test: the test standard is ISO527 / 2-93; 2) Low temperature notched impact strength test: the test standard is ISO180-93; 3) Limiting oxygen index (LOI) test: the test standard is GB / T 2406.2-2009; 4) Vertical burning UL-94 test: The test standard is GB / T2408-2008.

[0032] The results are shown in Table 1.

[0033] Table 1 Performance test results

[0034] It can be seen from the data in Table 1 that the modified PPR material prepared by the present invention has excellent low temperature resistance and flame retardant properties. The main reason is that, on the one hand, the modifier of the present invention introduces a siloxane flexible chain, which can introduce soft and twistable fragments into the PPR material, thereby improving the low temperature resistance of the material; on the other hand, the modifier of the present invention introduces a triazine flame retardant group, which has an excellent flame retardant effect, so that the limiting oxygen index of the PPR material reaches 36.8%, and the flame retardant grade of the horizontal and vertical combustion test reaches V-0.

[0035] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A low temperature resistant modified PPR, characterized by: Including the following ingredients: Modified PPR matrix 80~100 parts 0.5~3 parts of antioxidant Silane coupling agent 1~5 parts Filler 10~20 parts 10~15 parts of diluent The preparation method of the modified PPR matrix is: 50-80 parts of PPR matrix and 80-100 parts of acetone are added into a reactor, and then 3-5 parts of modifier and 1-3 parts of initiator are added, mixed in a high-speed mixer for 10-20 minutes, and extruded through a twin-screw extruder to obtain a modified PPR matrix; The structure of the modifier is: .

2. The low temperature resistant modified PPR according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1010 , antioxidant 168 , and antioxidant 1076 .

3. The low temperature resistant modified PPR according to claim 1, characterized in that: The coupling agent is selected from one or more of KH-550, KH-560, KH-570, KH-792, KH-791 and DL-602.

4. The low temperature resistant modified PPR according to claim 1, characterized in that: The diluent is selected from one or more of ethylene glycol ethyl acetate, n-butyl glycidyl ether, diglycidyl ether, and 1,4-butanediol diglycidyl ether.

5. The low temperature resistant modified PPR according to claim 1, characterized in that: The filler is one or more of glass powder, mica powder, quartz powder and asbestos powder.

6. The low temperature resistant modified PPR according to claim 1, characterized in that: The initiator is selected from one or more of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester and tert-butylperoxycarbonate isopropyl ester.

7. The preparation process of the low temperature resistant modified PPR according to any one of claims 1 to 6, characterized in that: The following steps are involved: The modified PPR matrix, antioxidant, silane coupling agent, filler and diluent are uniformly mixed according to the above weight parts to obtain a mixture; the above mixture is added to a twin-screw extruder for melt extrusion, water cooling, and granulation to obtain pellets; the pellets are placed in an oven for drying for later use; the dried pellets are injection molded on an injection molding machine to obtain low-temperature resistant modified PPR.

8. The preparation process according to claim 7, characterized in that: The extrusion process parameters are as follows: extrusion temperatures are 190°C, 195°C, 200°C, 205°C, and 215°C, and the main engine speed is 200 r / min.

9. The preparation process according to claim 7, characterized in that: The injection molding process parameters are as follows: injection temperatures are 230°C, 225°C, 220°C, 215°C, and 210°C respectively; injection pressures are 55 MPa in zone one, 50 MPa in zone two, 45 MPa in zone three, and 40 MPa in zone four.

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