Preparation method and application of modified polypropylene insulated cable material

Abstract

The present invention discloses a preparation method and application of a modified polypropylene insulated cable material, wherein the method comprises: adding an elastomer having a hydroxyl group in a side chain to a silane coupling agent for condensation reaction to obtain a first intermediate material; dispersing 4,4'-stilbene dicarboxylic acid in a first solvent, adding a first catalyst to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a second intermediate material; fully reacting the first intermediate material and the second intermediate material under stirring to obtain a modified elastomer; taking the modified elastomer and dispersing it in a second solvent, adding a second catalyst to activate the carboxyl group in the modified elastomer, and then adding a fatty amine to obtain an alkyl-terminated elastomer; mixing and melting the alkyl-terminated elastomer with homopolymer / copolymer polypropylene to obtain a modified homopolymer / copolymer polypropylene insulated cable material. The method provided by the present application can comprehensively improve the toughness and insulation performance of polypropylene insulated cable materials.

Description

Technical Field

[0001] The invention belongs to the technical field of cable materials, and particularly relates to a preparation method and application of a modified polypropylene insulated cable material. Background Art

[0002] The application range of cables is very wide, involving various fields such as electricity, communications, construction, industry, and transportation. Among them, the power industry has the largest demand for cables.

[0003] At present, cable insulation materials are mostly made of cross-linked polyethylene. Compared with cross-linked polyethylene, polypropylene has the advantages of excellent insulation performance, high temperature resistance, and recyclability. In addition, the extrusion process does not require cross-linking, which can effectively reduce energy consumption. It is considered to be one of the most promising alternative insulation materials for cross-linked polyethylene. However, cables made of polypropylene currently have the disadvantages of strong material rigidity and poor toughness. During the cable manufacturing, transportation, and laying processes, brittle cracking and other problems are prone to occur. In addition, the insulation performance of cables made of polypropylene needs to be further improved.

[0004] Therefore, a method for improving the toughness and insulation of polypropylene materials used to make cables is in urgent need of research. Summary of the Invention

[0005] In view of the shortcomings of the above-mentioned prior art, the present invention provides a preparation method and application of a modified polypropylene insulated cable material, wherein the preparation method can effectively and comprehensively improve the toughness and insulation performance of the polypropylene insulated cable material.

[0006] The first aspect of the present invention provides a method for preparing a modified polypropylene insulated cable material, comprising:

[0007] adding an elastomer having a hydroxyl group on the side chain to a silane coupling agent and stirring until the hydroxyl groups in the elastomer having a hydroxyl group on the side chain complete a condensation reaction to obtain a modified first intermediate material;

[0008] Dispersing 4,4'-stilbene dicarboxylic acid in a first solvent, and then adding a first catalyst to activate the carboxyl groups in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl group-activated second intermediate material;

[0009] adding the first intermediate material to the second intermediate material, and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer;

[0010] The modified elastomer is dispersed in a second solvent, a second catalyst is added to activate the carboxyl groups in the modified elastomer, and a fatty amine is added after the activation of the modified elastomer to obtain an alkyl-terminated elastomer;

[0011] The alkyl-terminated elastomer is mixed and melted with homopolymer / copolymer polypropylene to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

[0012] Optionally, when the alkyl-terminated elastomer is mixed and melted with homo / co-polypropylene to obtain the modified homo / co-polypropylene insulation cable material, the mass ratio of the alkyl-terminated elastomer to the homo / co-polypropylene is 0.2-5:100, and the melting reaction temperature is 180-220°C.

[0013] Optionally, the silane coupling agent includes at least one of a silane coupling agent having an amino group and a methoxy / ethoxy group.

[0014] Optionally, the silane coupling agent having an amino group and a methoxy group / ethoxy group is at least one of silane coupling agent KH550 and silane coupling agent KH792.

[0015] Optionally, the elastomer having a hydroxyl group on a side chain includes at least one of a polyurethane elastomer and a hydroxyl-terminated polycaprolactone.

[0016] Optionally, the first catalyst is at least one of HATU, HBTU and HCTU; the first solvent is dimethyl sulfoxide; the second catalyst is at least one of HATU, HBTU and HCTU, and the second solvent is dimethyl sulfoxide.

[0017] Optionally, the fatty amine is n-octylamine.

[0018] Optionally, after adding the elastomer with hydroxyl groups on the side chains to the silane coupling agent and stirring until the hydroxyl groups in the elastomer with hydroxyl groups on the side chains complete the condensation reaction to obtain the modified first intermediate material, the method further comprises:

[0019] After separating the modified first intermediate material, drying it at 50-70° C. to obtain a dried first intermediate material;

[0020] Accordingly, after adding the first intermediate material to the second intermediate material and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer, the method further includes:

[0021] After the modified elastomer is separated, it is dried at 50-70° C. to obtain a dried modified elastomer.

[0022] Optionally, after adding the first intermediate material to the second intermediate material, stirring is carried out at a temperature of 25-80° C. for 14-24 hours to allow the first intermediate material and the second intermediate material to fully react; and / or

[0023] After the modified elastomer is activated, the fatty amine is added and stirred at a temperature of 25-80° C. for 14-24 hours to allow the modified elastomer and the fatty amine to fully react to obtain an alkyl-terminated elastomer.

[0024] The second aspect of the present invention provides an application of a modified polypropylene insulating cable material in insulating cable materials. The insulating cable material includes the modified polypropylene insulating cable material prepared by the above method.

[0025] The present invention provides a method for preparing a modified polypropylene insulated cable material. The method comprises the following steps: firstly, a condensation reaction is carried out between an elastomer having hydroxyl groups on its side chains and a silane coupling agent to dehydrate the hydroxyl groups in the elastomer having hydroxyl groups on its side chains, thereby enabling the elastomer having hydroxyl groups on its side chains to condense with the silane coupling agent, thereby obtaining a first intermediate material having amino groups; then, the first intermediate material is subjected to a dehydration condensation reaction with 4,4'-stilbene dicarboxylic acid in a second intermediate material to form a peptide bond, thereby activating a certain amount of carboxyl groups in the carboxyl groups contained in the obtained modified elastomer; then, the modified elastomer is subjected to a dehydration condensation reaction with a fatty amine to obtain an alkyl-terminated elastomer containing an elastomer segment and a voltage stabilizer segment; and finally, the alkyl-terminated elastomer is mixed and melted with homopolymer / copolymer polypropylene, thereby improving the toughness and insulation performance of the finally obtained polypropylene cable.

[0026] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or may be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the written description.

[0027] The technical solution of the present invention is further described in detail below through examples. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] The present invention provides a method for preparing a modified polypropylene insulated cable material, comprising the following steps:

[0030] Step 1: adding an elastomer having a hydroxyl group on the side chain to a silane coupling agent and stirring until the hydroxyl groups in the elastomer having a hydroxyl group on the side chain complete the condensation reaction to obtain a modified first intermediate material;

[0031] Step 2: dispersing 4,4'-stilbene dicarboxylic acid in a first solvent, and then adding a first catalyst to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl group-activated second intermediate material;

[0032] Step 3: adding the first intermediate material to the second intermediate material, and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer;

[0033] Step 4: dispersing the modified elastomer in a second solvent, adding a second catalyst to activate the carboxyl groups in the modified elastomer, and adding a fatty amine after the activation of the modified elastomer to obtain an alkyl-terminated elastomer;

[0034] Step 5: Mix and melt the alkyl-terminated elastomer and homo / co-polypropylene to obtain a modified homo / co-polypropylene insulation cable material.

[0035] It should be noted that, in step 1, an elastomer having a hydroxyl group on its side chain is subjected to a condensation reaction with a silane coupling agent to dehydrate the hydroxyl group in the elastomer having a hydroxyl group, thereby completing the condensation of the elastomer having a hydroxyl group and the silane coupling agent, and thereby making the first intermediate material obtained in step 1 a modified intermediate material having an amino group; in step 2, the carboxyl group in 4,4'-stilbene dicarboxylic acid is activated to activate the carboxyl group in the obtained second intermediate material, and thereby making the second intermediate material activated by the carboxyl group react with the modified first intermediate material having an amino group obtained in step 1 in step 3, so that the first intermediate material and 4,4'-stilbene dicarboxylic acid undergo dehydration condensation to form a peptide bond, thereby obtaining a modified elastomer having 4,4'-stilbene dicarboxylic acid; since the modified elastomer having 4,4'-stilbene dicarboxylic acid obtained in step 3 still has certain carboxyl groups, in step 3, In step 4, an alkyl-terminated elastomer is obtained by dehydration condensation of the carboxyl groups with fatty amines. Since the alkyl-terminated elastomer has good compatibility not only with the voltage stabilizer but also with homo / co-polypropylene, the alkyl-terminated elastomer can be uniformly doped into the homo / co-polypropylene. The elastomer chain segments contained in the alkyl-terminated elastomer can effectively improve the toughness of the homo / co-polypropylene doped with the alkyl-terminated elastomer, thereby improving the mechanical properties of the polypropylene cable material containing the homo / co-polypropylene modified with the alkyl-terminated elastomer. At the same time, the voltage stabilizer chain segments contained in the alkyl-terminated elastomer can also prevent the migration of small molecule voltage stabilizers from the homo / co-polypropylene, thereby improving the insulation performance of the polypropylene cable material containing the homo / co-polypropylene modified with the alkyl-terminated elastomer.

[0036] The present application provides a method for preparing a modified polypropylene insulated cable material. First, a condensation reaction is carried out between an elastomer having hydroxyl groups on its side chains and a silane coupling agent to dehydrate the hydroxyl groups in the elastomer having hydroxyl groups on its side chains, and then the elastomer having hydroxyl groups on its side chains is condensed with the silane coupling agent to obtain a first intermediate material having amino groups. The first intermediate material is then subjected to a dehydration condensation reaction with 4,4'-stilbene dicarboxylic acid in a second intermediate material to form a peptide bond, so that a certain amount of carboxyl groups still exist in the second intermediate material after the carboxyl groups contained in the obtained modified elastomer are activated. The modified elastomer is then subjected to a dehydration condensation reaction with a fatty amine to obtain an alkyl-terminated elastomer containing an elastomer segment and a voltage stabilizer segment. Finally, the alkyl-terminated elastomer is mixed and melted with homopolymer / copolymer polypropylene to improve the toughness and insulation properties of the resulting polypropylene cable material.

[0037] In some possible embodiments, when the alkyl-terminated elastomer is mixed and melted with homo / co-polypropylene to obtain a modified homo / co-polypropylene insulation cable material, the mass ratio between the alkyl-terminated elastomer and the homo / co-polypropylene is 0.2-5:100, and the melting reaction temperature is 180-220°C.

[0038] Here, the mass ratio between the alkyl-terminated elastomer and the homopolymer / copolymer polypropylene can be, but is not limited to, any one of 0.2:100, 0.5:100, 1:100, 2:100, 3:100, 4:100, and 5:100; the melt reaction temperature can be any one of 180°C, 190°C, 200°C, 210°C, and 220°C.

[0039] In this embodiment, by selecting the mass ratio between the alkyl-terminated elastomer and the homo / co-polypropylene to be 0.2-5:100 and completing the melt reaction of the alkyl-terminated elastomer and the homo / co-polypropylene at a temperature of 180-220° C., the alkyl-terminated elastomer can be uniformly incorporated into the homo / co-polypropylene, and the modification efficiency of the alkyl-terminated elastomer on the homo / co-polypropylene can be improved.

[0040] In some possible embodiments, the silane coupling agent includes at least one of a silane coupling agent having an amino group and a methoxy group / ethoxy group.

[0041] It should be noted that selecting a silane coupling agent with an amino group and a methoxy / ethoxy group allows the silane coupling agent to contain two different active groups, namely, an amino group and a methoxy / ethoxy group, thereby enabling the silane coupling agent to couple with organic polymers and inorganic fillers to enhance their adhesion.

[0042] In this embodiment, by selecting a silane coupling agent having an amino group and a methoxy group / ethoxy group, the mechanical, electrical, water resistance, and aging resistance of the obtained first intermediate material can be improved based on the amino group and methoxy group / ethoxy group contained in the silane coupling agent having an amino group and a methoxy group / ethoxy group, so that the material properties of the first intermediate material are more suitable for application in cable materials.

[0043] In some possible embodiments, the silane coupling agent having an amino group and a methoxy group / ethoxy group is at least one of silane coupling agent KH550 and silane coupling agent KH792.

[0044] Here, both silane coupling agent KH550 and silane coupling agent KH792 contain two different active groups, namely amino and oxygen groups. Therefore, silane coupling agent KH550 and silane coupling agent KH792 can be used to couple organic polymers and inorganic fillers, enhance their adhesion, and improve the mechanical, electrical, water resistance, and aging resistance of the obtained first intermediate material.

[0045] In some possible embodiments, the elastomer having a hydroxyl group on a side chain includes at least one of a polyurethane elastomer and a hydroxyl-terminated polycaprolactone.

[0046] Here, the elastomer with hydroxyl groups on the side chain is selected as a polyurethane elastomer, which can make the first intermediate material obtained in step 1 have the characteristics of high strength, tear resistance, wear resistance, etc.; the elastomer with hydroxyl groups on the side chain is selected as a terminal hydroxyl polycaprolactone, which can make the first intermediate material obtained in step 1 have the characteristics of high strength, stiffness, wear resistance and insulation.

[0047] In some possible embodiments, the first catalyst is at least one of HATU, HBTU and HCTU; the first solvent is dimethyl sulfoxide; the second catalyst is at least one of HATU, HBTU and HCTU, and the second solvent is dimethyl sulfoxide.

[0048] In some possible embodiments, the fatty amine is n-octylamine.

[0049] Here, the fatty amine is selected as n-octylamine, so that the modified elastomer can react with n-octylamine to obtain an alkyl-terminated elastomer.

[0050] In some possible embodiments, after adding an elastomer having hydroxyl groups on its side chains to a silane coupling agent and stirring until the hydroxyl groups in the elastomer having hydroxyl groups on its side chains complete a condensation reaction to obtain a modified first intermediate material, the process further includes: separating the modified first intermediate material and drying it at 50-70° C. to obtain a dried first intermediate material.

[0051] Here, the liquid in the first intermediate material can be removed by isolating the modified first intermediate material and then drying it at 50-70° C., so that the reaction in step 3 can be carried out without a silane coupling agent.

[0052] It should be noted that the drying temperature of the first intermediate material may be, but is not limited to, any one of 50°C, 55°C, 60°C, 65°C, and 70°C.

[0053] Accordingly, after adding the first intermediate material to the second intermediate material and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer, the method further includes: separating the modified elastomer and drying it at 50-70° C. to obtain a dried modified elastomer.

[0054] Here, the liquid in the modified elastomer can be removed by drying the modified elastomer at 50-70°C after separation.

[0055] It should be noted that the drying temperature of the modified elastomer may be, but is not limited to, any one of 50°C, 55°C, 60°C, 65°C, and 70°C.

[0056] In some possible embodiments, after the first intermediate material is added to the second intermediate material, the mixture is stirred at a temperature of 25-80° C. for 14-24 hours to allow the first intermediate material and the second intermediate material to fully react.

[0057] Here, the reaction temperature of the first intermediate material and the second intermediate material may be, but is not limited to, any one of 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C and 80°C; the stirring time of the first intermediate material and the second intermediate material may be, but is not limited to, any one of 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h and 24h.

[0058] In this embodiment, by setting the reaction temperature of the first intermediate material and the second intermediate material to 25-80° C. and the stirring time to 14-24 h, the first intermediate material and the second intermediate material can fully react to improve the preparation efficiency of the modified elastomer.

[0059] In some possible embodiments, after the modified elastomer is activated, the fatty amine is added and stirred at a temperature of 25-80° C. for 14-24 hours to allow the modified elastomer and the fatty amine to fully react to obtain an alkyl-terminated elastomer.

[0060] Here, the reaction temperature of the modified elastomer and fatty amine after activation can be, but is not limited to, any one of 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C and 80°C; the stirring time of the modified elastomer and fatty amine after activation can be, but is not limited to, any one of 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h and 24h.

[0061] In this embodiment, by setting the reaction temperature of the activated modified elastomer and fatty amine to 25-80°C and the stirring time to 14-24h, the modified elastomer and fatty amine can fully react to improve the preparation efficiency of the alkyl-terminated elastomer.

[0062] The present invention provides an application of a modified polypropylene insulating cable material in insulating cable materials. The insulating cable material includes the modified polypropylene insulating cable material prepared by the above method.

[0063] Since the above method can effectively and comprehensively improve the toughness and insulation performance of the polypropylene insulated cable material, applying the modified polypropylene insulated cable material prepared by the above method to the insulating cable material can effectively improve the toughness and insulation performance of the insulating cable material.

[0064] The following examples illustrate the preparation method of a modified polypropylene insulated cable material provided by the present invention. It should be noted that the methods, reagents, and materials described in the following examples, unless otherwise specified, can all be obtained from commercial channels; and the test methods described, unless otherwise specified, are all conventional methods.

[0065] Example 1

[0066] This embodiment provides a method for preparing a modified polypropylene insulated cable material, comprising the following steps:

[0067] Step 1: Add 10 g of a polyurethane elastomer having a hydroxyl group on the side chain to 300 mL of a silane coupling agent KH550 and stir for 12 h until the hydroxyl groups in the polyurethane elastomer complete the condensation reaction to obtain a modified first intermediate material;

[0068] Step 2: After separating the modified first intermediate material, drying it at 60° C. to obtain a dried first intermediate material;

[0069] Step 3: Disperse 10 g of 4,4'-stilbene dicarboxylic acid in 500 mL of dimethyl sulfoxide, and add HATU to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl-activated second intermediate material;

[0070] Step 4: Add 10 g of the first intermediate material to the second intermediate material obtained in step 3, and stir at 70° C. for 16 h to allow the first intermediate material and the second intermediate material to fully react to obtain a modified elastomer;

[0071] Step 5: After separating the modified elastomer, washing it twice with deionized water and ethanol respectively, and drying it at 60° C. to obtain a dried modified elastomer;

[0072] Step 6: 10 g of the modified elastomer was dispersed in 500 mL of dimethyl sulfoxide, and HATU was added to activate the carboxyl groups in the modified elastomer. After the activation of the modified elastomer was completed, 20 g of n-octylamine was added and stirred at 60° C. for 20 h to fully react the first intermediate material and the second intermediate material to obtain an alkyl-terminated elastomer;

[0073] Step 7: The alkyl-terminated elastomer is mixed with homopolymer / copolymer polypropylene in a mass ratio of 3:100, and melt-treated at 210° C. to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

[0074] Example 2

[0075] This embodiment provides a method for preparing a modified polypropylene insulated cable material, comprising the following steps:

[0076] Step 1: Add 10 g of a polyurethane elastomer having hydroxyl groups on its side chains to 300 mL of a silane coupling agent, KH792, and stir for 12 h until the condensation reaction of the hydroxyl groups in the polyurethane elastomer with hydroxyl groups on its side chains is completed, thereby obtaining a modified first intermediate material;

[0077] Step 2: After separating the modified first intermediate material, drying it at 50° C. to obtain a dried first intermediate material;

[0078] Step 3: Disperse 10 g of 4,4'-stilbene dicarboxylic acid into 500 mL of dimethyl sulfoxide, and then add HATU to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl-activated second intermediate material;

[0079] Step 4: Add 10 g of the first intermediate material to the second intermediate material obtained in step 3, and stir at 25° C. for 16 h to allow the first intermediate material and the second intermediate material to fully react to obtain a modified elastomer;

[0080] Step 5: After separating the modified elastomer, washing it twice with deionized water and ethanol respectively, and drying it in an oven at 65° C. to obtain a dried modified elastomer;

[0081] Step 6: 10 g of the modified elastomer was dispersed in 500 mL of dimethyl sulfoxide, and HATU was added to activate the carboxyl groups in the modified elastomer. After the activation of the modified elastomer was completed, 20 g of n-octylamine was added and stirred at 80° C. for 20 h to fully react the first intermediate material and the second intermediate material to obtain an alkyl-terminated elastomer;

[0082] Step 7: The alkyl-terminated elastomer is mixed with homopolymer / copolymer polypropylene in a mass ratio of 3:100, and melt-treated at 210° C. to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

[0083] Example 3

[0084] This embodiment provides a method for preparing a modified polypropylene insulated cable material, comprising the following steps:

[0085] Step 1: Add 10 g of a polyurethane elastomer having hydroxyl groups on its side chains to 300 mL of a silane coupling agent, KH792, and stir for 14 h until the condensation reaction of the hydroxyl groups in the polyurethane elastomer with hydroxyl groups on its side chains is completed, thereby obtaining a modified first intermediate material;

[0086] Step 2: After separating the modified first intermediate material, drying it at 70° C. to obtain a dried first intermediate material;

[0087] Step 3: Disperse 12 g of 4,4'-stilbene dicarboxylic acid into 500 mL of dimethyl sulfoxide, and then add HCTU to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl-activated second intermediate material;

[0088] Step 4: Add 10 g of the first intermediate material to the second intermediate material, and stir at 80° C. for 16 h to allow the first intermediate material and the second intermediate material to fully react to obtain a modified elastomer;

[0089] Step 5: After separating the modified elastomer, wash it twice with deionized water and ethanol respectively, and dry it in an oven at 70° C. to obtain a dried modified elastomer.

[0090] Step 6: 10 g of the modified elastomer was dispersed in 500 mL of dimethyl sulfoxide, and HACU was added to activate the carboxyl groups in the modified elastomer. After the activation of the modified elastomer was completed, 18 g of n-octylamine was added and stirred at 25° C. for 20 h to allow the first intermediate material and the second intermediate material to fully react to obtain an alkyl-terminated elastomer;

[0091] Step 7: The alkyl-terminated elastomer is mixed with homopolymer / copolymer polypropylene in a mass ratio of 0.5:100, and melt-treated at 190° C. to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

[0092] Example 4

[0093] This embodiment provides a method for preparing a modified polypropylene insulated cable material, comprising the following steps:

[0094] Step 1: Add 10 g of hydroxyl-terminated polycaprolactone to 300 mL of silane coupling agent KH792 and stir for 14 h to complete the condensation reaction of the hydroxyl groups in the polyurethane elastomer with hydroxyl groups on the side chains, thereby obtaining a modified first intermediate material;

[0095] Step 2: After separating the modified first intermediate material, drying it at 65° C. to obtain a dried first intermediate material;

[0096] Step 3: Disperse 12 g of 4,4'-stilbene dicarboxylic acid into 500 mL of dimethyl sulfoxide, and then add HCTU to activate the carboxyl group in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl-activated second intermediate material;

[0097] Step 4: Add 10 g of the first intermediate material to the second intermediate material, and stir at 60° C. for 16 h to allow the first intermediate material and the second intermediate material to fully react to obtain a modified elastomer;

[0098] Step 5: After separating the modified elastomer, wash it twice with deionized water and ethanol respectively, and dry it in an oven at 50° C. to obtain a dried modified elastomer.

[0099] Step 6: 10 g of the modified elastomer was dispersed in 500 mL of dimethyl sulfoxide, and HACU was added to activate the carboxyl groups in the modified elastomer. After the activation of the modified elastomer was completed, 18 g of n-octylamine was added and stirred at 60° C. for 20 h to fully react the first intermediate material and the second intermediate material to obtain an alkyl-terminated elastomer.

[0100] Step 7: The alkyl-terminated elastomer is mixed with homopolymer / copolymer polypropylene in a mass ratio of 2:100, and melt-treated at 180° C. to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

[0101] Comparative Example 1

[0102] This comparative example provides a method for preparing a polypropylene insulated cable material, comprising the following steps: mixing a polyurethane elastomer having a hydroxyl group on its side chain with homopolymer / copolymer polypropylene in a mass ratio of 3:100, and then performing a melt treatment in an internal mixer at 210° C. to obtain a homopolymer / copolymer polypropylene insulated cable material.

[0103] Comparative Example 2

[0104] This comparative example provides a method for preparing a polypropylene insulated cable material, comprising the following steps: mixing a polyurethane elastomer having a hydroxyl group on its side chain, 4,4'-stilbene dicarboxylic acid, and homo / co-polypropylene in a mass ratio of 1.5:1.5:100, and performing a melt treatment in an internal mixer at 210°C to obtain a homo / co-polypropylene insulated cable material.

[0105] Comparative Example 3

[0106] This comparative example provides a method for preparing a polypropylene insulated cable material, comprising the following steps: mixing 4,4'-stilbene dicarboxylic acid and homo / co-polypropylene in a mass ratio of 3:100, and performing a melt treatment in an internal mixer at 210°C to obtain a homo / co-polypropylene insulated cable material.

[0107] The tensile strength of the sample was determined according to the provisions of GB / T 1040.2-2006, the elongation at break of the sample was tested according to the provisions of GB / T 1040-2006, the flexural modulus was tested according to the provisions of GB / T 9341-2008, and the breakdown voltage of the sample was tested according to the provisions of GB / T 1408.1-2016. The insulated cable materials obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were tested, and the test results obtained are shown in Table 1.

[0108] Table 1 Test results of sample performance

[0109]

[0110] It can be seen from the results of the above-mentioned embodiments and comparative examples that the preparation method adopted by the present invention can significantly improve the tensile strength, elongation at break, flexural modulus, and breakdown field strength of the insulating cable material. It can be seen that the preparation method adopted by the present invention can comprehensively improve the toughness and insulation performance of the polypropylene insulating cable material.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a modified polypropylene insulated cable material, characterized in that: include: adding an elastomer with hydroxyl groups on its side chains to a silane coupling agent and stirring until the hydroxyl groups in the elastomer with hydroxyl groups on its side chains complete a condensation reaction, thereby obtaining a modified first intermediate material; the elastomer with hydroxyl groups on its side chains comprises at least one of a polyurethane elastomer and a hydroxyl-terminated polycaprolactone; and the silane coupling agent comprises at least one of an amino group and a methoxy / ethoxy group-containing silane coupling agent; Dispersing 4,4'-stilbene dicarboxylic acid in a first solvent, and then adding a first catalyst to activate the carboxyl groups in the 4,4'-stilbene dicarboxylic acid to obtain a carboxyl group-activated second intermediate material; adding the first intermediate material to the second intermediate material, and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer; The modified elastomer is dispersed in a second solvent, a second catalyst is added to activate the carboxyl groups in the modified elastomer, and a fatty amine is added after the activation of the modified elastomer to obtain an alkyl-terminated elastomer; the fatty amine is n-octylamine; The alkyl-terminated elastomer is mixed and melted with homopolymer / copolymer polypropylene to obtain a modified homopolymer / copolymer polypropylene insulation cable material.

2. The method according to claim 1, characterized in that In the modified homo / co-polypropylene insulated cable material obtained by mixing and melting the alkyl-terminated elastomer and homo / co-polypropylene, the mass ratio of the alkyl-terminated elastomer to the homo / co-polypropylene is 0.2-5:100, and the melting reaction temperature is 180-220°C.

3. The method according to claim 1, characterized in that The silane coupling agent with amino and methoxy / ethoxy groups is at least one of silane coupling agent KH550 and silane coupling agent KH792.

4. The method according to claim 1, wherein The first catalyst is at least one of HATU, HBTU and HCTU; the first solvent is dimethyl sulfoxide; the second catalyst is at least one of HATU, HBTU and HCTU, and the second solvent is dimethyl sulfoxide.

5. The method according to claim 1, wherein After adding the elastomer with hydroxyl groups on the side chains to the silane coupling agent and stirring until the hydroxyl groups in the elastomer with hydroxyl groups on the side chains complete the condensation reaction to obtain the modified first intermediate material, the method further comprises: After separating the modified first intermediate material, drying it at 50-70° C. to obtain a dried first intermediate material; Accordingly, after adding the first intermediate material to the second intermediate material and allowing the first intermediate material and the second intermediate material to fully react under stirring conditions to obtain a modified elastomer, the method further includes: After the modified elastomer is separated, it is dried at 50-70° C. to obtain a dried modified elastomer.

6. The method according to claim 1, characterized in that After adding the first intermediate material to the second intermediate material, stirring at a temperature of 25-80° C. for 14-24 hours to allow the first intermediate material and the second intermediate material to fully react; and / or After the modified elastomer is activated, the fatty amine is added and stirred at a temperature of 25-80° C. for 14-24 hours to allow the modified elastomer and the fatty amine to fully react to obtain an alkyl-terminated elastomer.

7. Application of a modified polypropylene insulated cable material in an insulating cable material, characterized in that: The insulating cable material comprises a modified polypropylene insulating cable material prepared by the method according to any one of claims 1 to 6.

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