Composite modified cable asphalt and preparation method thereof

Abstract

The invention discloses composite modified cable asphalt and a preparation method thereof, and relates to the field of modified asphalt. The composite modified cable asphalt comprises the following raw materials in parts by weight: 100 parts of matrix asphalt, 3-8 parts of polyphosphoric acid, 5-8 parts of an SBS modifier, 20-40 parts of high aromatic oil and 0.2-0.4 part of a stabilizer. Polyphosphoric acid and SBS are subjected to chemical and physical composite modification, so that the degradation phenomenon of SBS in a high-temperature environment is compensated, and the thermal stability of the composite modified cable asphalt is improved; the cold bending experiment at-15 DEG C is qualified, and the high and low temperature performance is excellent; meanwhile, polar functional groups in the polyphosphoric acid improve the adhesion performance of the composite modified cable asphalt. The overall quality of the composite modified cable asphalt is improved; and the application field of a modification process is widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of asphalt modification, and particularly relates to a composite modified cable asphalt and a preparation method thereof. Technical Background

[0002] The traditional cable asphalt production process mainly uses the oxidation process, and a large amount of CO2 will be generated during the production process. The modification process has gradually replaced the oxidation process and become the mainstream process for preparing cable asphalt.

[0003] China University of Petroleum (East China) (2018) publicly disclosed a doctoral dissertation "Research and Development of High-Performance Cable Asphalt Materials". Using conventional polymers to modify matrix asphalt can improve the high and low temperature performance of cable asphalt, but the degradation of polymers in high temperature environments is inevitable. After high-temperature heat storage, the thermal stability of polymer-modified asphalt is greatly reduced. The Chinese patent document with the publication number CN114836050B discloses a submarine cable asphalt and a preparation method thereof, using an SBS modifier and rubber powder to modify matrix asphalt. It can be found that an increase in the polymer content in asphalt will also have a negative impact on the adhesion performance of asphalt. Based on this, it is urgent to improve the thermal stability and adhesion performance of cable asphalt by improving the existing process conditions and raw material ratios. Summary of the Invention

[0004] The purpose of the present invention is to provide a composite modified cable asphalt and a preparation method thereof. The composite modified cable asphalt prepared by this method has high thermal stability and adhesion, and solves the problem of poor thermal stability and adhesion of physically modified cable asphalt.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: On the one hand, the present invention provides a composite modified cable asphalt, which is prepared from the following raw materials in parts by weight: 100 parts of matrix asphalt, 3 - 8 parts of polyphosphoric acid, 5 - 8 parts of SBS modifier, 20 - 40 parts of high-aromatic oil, and 0.2 - 0.4 parts of stabilizer.

[0006] The "prepared from the following raw materials in parts by weight" means that high-aromatic oil and polyphosphoric acid are added to the matrix asphalt for chemical modification, then the SBS modifier is added for shear dispersion, and then the stabilizer is added for heat preservation and development to obtain the composite modified cable asphalt.

[0007] The high-aromatic oil includes any one of rubber oil, furfural extract oil, or reduced fourth-line extract oil.

[0008] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0009] The phosphoric acid content of the polyphosphoric acid described is not less than 105%. The polyphosphoric acid content mainly detects the phosphorus content. Comparing with the reference substance, more phosphorus groups are complexed, resulting in a result exceeding 100%.

[0010] The matrix asphalt described has a penetration of 60 - 80 at 25°C and 0.1 mm. Penetration is an index for measuring the hardness and consistency of a substance and is usually used to evaluate the properties of substances such as grease and asphalt.

[0011] The stabilizer described is sulfur.

[0012] On the other hand, the present invention provides a method for preparing the above - mentioned composite - modified cable asphalt, which includes the following steps: S1. Heat the matrix asphalt to a molten state, add high - aromatic oil and polyphosphoric acid, continue heating, keep stirring at a constant temperature, and carry out chemical modification to obtain PPA - modified asphalt; S2. After cooling the PPA - modified asphalt, add the SBS modifier, keep stirring at a constant temperature, make the SBS modifier fully absorb oil and expand, and carry out shear dispersion to obtain composite - modified asphalt; S3. Cool the obtained composite - modified asphalt, add the stabilizer to the composite - modified asphalt, keep stirring at a constant temperature for development to obtain composite - modified cable asphalt.

[0013] Further, in step S1, the chemical modification temperature is 190 - 210°C, the constant - temperature stirring rate is 400 - 600 rpm, and the time is 8 - 10 h.

[0014] Further, in step S2, the PPA - modified asphalt is cooled to 180 - 185°C, the constant - temperature stirring rate is 400 - 600 rpm, and the time is 0.5 - 1 h; the equipment used for shearing is a high - shear mixing emulsifier, the shear rate is 4000 - 5000 rpm, and the time is 30 - 90 min.

[0015] Further, in step S3, the composite - modified asphalt is cooled to 170 - 175°C, the constant - temperature stirring and development rate is 200 - 400 rpm, and the time is 2 - 4 h.

[0016] In step S1, when heating to 190 - 210°C, if the temperature is too low, the reaction between polyphosphoric acid and asphalt is insufficient; if the temperature is too high, the light components in the asphalt will volatilize excessively. In step 2, the stirring and shearing temperature is 180 - 185°C. If the temperature is too high, SBS will degrade; if the temperature is too low during the stirring process, the SBS modifier will not expand sufficiently, affecting the subsequent shearing process. In step 3, the stirring and development temperature is 170 - 175°C. If the temperature is too high, the asphalt is prone to aging; if the temperature is too low, the stabilizer cannot play its role fully and the SBS modifier cannot develop completely.

[0017] The present invention adopts chemical and physical composite modification. On the one hand, the chemical modification of polyphosphoric acid converts the saturates and aromatics in the matrix asphalt into asphaltenes and resins, making its colloidal structure develop from a sol type to a gel type, improving the anti-deformation ability such as the sag and penetration of the asphalt. At the same time, the high-temperature properties such as the softening point and thermal stability of the asphalt are also improved. On the other hand, polyphosphoric acid makes the SBS sheared more finely, improving its distribution uniformity in the asphalt and promoting the performance of SBS modification. The low-temperature properties such as the cold bending of the asphalt and the high-temperature properties such as the softening point and flash point are improved. In addition, the interaction between polyphosphoric acid and the SBS modifier improves the degradation phenomenon of the SBS modifier and enhances the thermal stability of the composite-modified cable asphalt.

[0018] The addition of polyphosphoric acid enhances the adhesion of the composite-modified cable asphalt with its polar functional groups, enabling the composite-modified cable asphalt to better wrap around the cable armor layer.

[0019] The beneficial effects of the present invention are as follows: The composite-modified cable asphalt product prepared by the present invention has high thermal stability, which is convenient for storage and transportation; it has good adhesion and low-temperature properties and will not fall off or crack in cold winter environments; at the same time, it has a higher softening point and will not drip in high-temperature summer environments. The overall performance of the composite-modified cable asphalt of the present invention meets the technical indicators of the industry standard NB / SH / T0001-2019.

[0020] The present invention adopts a composite modification with the coexistence of chemistry and physics. Polyphosphoric acid reacts with the matrix asphalt and SBS respectively, effectively improving the degradation phenomenon of SBS in high-temperature environments and enhancing the thermal stability of the composite-modified cable asphalt.

[0021] The present invention adopts the synergistic effect of polyphosphoric acid and the SBS modifier. After the addition of polyphosphoric acid, the SBS modifier is more uniformly dispersed in the matrix asphalt and has a better development effect. The modification effect of SBS is exerted more fully, further improving the high- and low-temperature properties of the composite-modified cable asphalt; at the same time, the polar functional groups in polyphosphoric acid improve the adhesion of the composite-modified cable asphalt.

[0022] The present invention adopts the chemical modification of polyphosphoric acid to convert the saturates and aromatics in the matrix asphalt into asphaltenes and resins, changing the internal colloidal structure of the matrix asphalt and improving the anti-deformation ability of the composite-modified cable asphalt.

[0023] The preparation process selected by the present invention is simple, the raw materials are easily available, and the produced composite-modified cable asphalt product has excellent performance and great promotion value. Description of the Drawings

[0024] Figure 1 Fluorescence microscope image of the composite-modified cable asphalt in Comparative Example 1 Figure 2 Fluorescence microscope image of the composite modified cable asphalt in Example 1 Detailed implementation mode

[0025] Hereinafter, embodiments of the technical solution of the present invention will be described in detail. The following embodiments are only examples to explain the technical solution of the present invention, rather than a limitation on the technical solution of the present invention. Example 1

[0026] This example provides a composite modified cable asphalt, which is made from the following raw materials in parts by weight: 100 parts of matrix asphalt, 4 parts of polyphosphoric acid, 7 parts of SBS modifier, 30 parts of high-aromatic oil, and 0.3 parts of stabilizer.

[0027] Among them, the penetration of the matrix asphalt at 0.1 mm at 25 °C is 64.

[0028] The high-aromatic oil is rubber oil.

[0029] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0030] The phosphoric acid content of the polyphosphoric acid is 105%.

[0031] The stabilizer is sulfur.

[0032] This example also provides a preparation method for the above-mentioned composite modified cable asphalt, including the following steps: S1. Heat the matrix asphalt to a molten state, then add the high-aromatic oil and polyphosphoric acid, and then heat to 200 °C, and keep stirring at 500 rpm for 9 h for chemical modification to obtain PPA modified asphalt for standby.

[0033] S2. Cool the PPA modified asphalt to 182 °C, then add a certain amount of SBS modifier, keep stirring at 500 rpm for 1 h to make the SBS modifier fully absorb oil and expand, and then shear at 4500 rpm for 45 min to obtain composite modified asphalt for standby.

[0034] S3. Cool the composite modified asphalt to 172 °C, add the stabilizer to the composite modified asphalt, and keep stirring at 300 rpm for 3 h to prepare the composite modified cable asphalt.

[0035] The composite modified cable asphalt prepared in this example is used for the cable armor layer and is applied in a coating manner. Example 2

[0036] This embodiment provides a composite modified cable asphalt, which is made from the following raw materials in parts by weight: 100 parts of matrix asphalt, 8 parts of polyphosphoric acid, 5 parts of SBS modifier, 20 parts of high aromatic oil, and 0.4 part of stabilizer.

[0037] Among them, the penetration of the matrix asphalt at 25 °C and 0.1 mm is 80.

[0038] The high aromatic oil is furfural extract oil.

[0039] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0040] The phosphoric acid content of the polyphosphoric acid is 110%.

[0041] The stabilizer is sulfur.

[0042] This embodiment also provides a preparation method for the above-mentioned composite modified cable asphalt, which includes the following steps: S1. Heat the matrix asphalt to a molten state, then add the high aromatic oil and polyphosphoric acid, and then heat it for the second time at 210 °C and keep stirring at 400 rpm for 8 h for chemical modification to obtain PPA modified asphalt for standby.

[0043] S2. Cool the PPA modified asphalt to 180 °C, then add a certain amount of SBS modifier, keep stirring at 400 rpm for 0.5 h to make the SBS modifier fully absorb oil and expand, and then shear at 5000 rpm for 30 min to obtain the composite modified asphalt for standby.

[0044] S3. Cool the composite modified asphalt to 175 °C, add the stabilizer to the composite modified asphalt, and keep stirring and developing at 300 rpm for 3 h to prepare the composite modified cable asphalt.

[0045] The composite modified cable asphalt prepared in this embodiment is used for the cable armor layer and is applied in a coating manner. Example 3

[0046] This embodiment provides a composite modified cable asphalt, which is made from the following raw materials in parts by weight: 100 parts of matrix asphalt, 3 parts of polyphosphoric acid, 8 parts of SBS modifier, 40 parts of high aromatic oil, and 0.4 part of stabilizer.

[0047] Among them, the penetration of the matrix asphalt at 25 °C and 0.1 mm is 60.

[0048] The high aromatic oil is the fourth reduced line extract oil.

[0049] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0050] The phosphoric acid content of polyphosphoric acid is 105%.

[0051] The stabilizer described above is sulfur.

[0052] This embodiment also provides a preparation method for the above-mentioned composite modified cable asphalt, including the following steps: S1. Heat the base asphalt to a molten state, then add high-aromatic oil and polyphosphoric acid, and then heat to 190 °C, and keep stirring at 500 rpm for 9 h for chemical modification to obtain PPA modified asphalt for standby.

[0053] S2. After cooling the PPA modified asphalt to 185 °C, add a certain amount of SBS modifier, and keep stirring at 500 rpm for 1 h to make the SBS modifier fully absorb oil and expand, and then shear at 4500 rpm for 45 min to obtain composite modified asphalt for standby.

[0054] S3. Cool the above-mentioned composite modified asphalt to 172 °C, add a stabilizer to the composite modified asphalt, and keep stirring at 400 rpm for 4 h to prepare the composite modified cable asphalt.

[0055] The composite modified cable asphalt prepared in this embodiment is used for the cable armor layer and is applied in a coating manner. Example 4

[0056] This embodiment provides a composite modified cable asphalt, which is made from the following raw materials in parts by weight: 100 parts of base asphalt, 5 parts of polyphosphoric acid, 7 parts of SBS modifier, 30 parts of high-aromatic oil, and 0.3 parts of stabilizer.

[0057] The penetration of the base asphalt at 0.1 mm at 25 °C is 64.

[0058] The high-aromatic oil is rubber oil.

[0059] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0060] The phosphoric acid content of polyphosphoric acid is 105%.

[0061] The stabilizer described above is sulfur.

[0062] This embodiment also provides a preparation method for the above-mentioned composite modified cable asphalt, including the following steps: S1. Heat the base asphalt to a molten state, then add high-aromatic oil and polyphosphoric acid, and then heat to 200 °C, and keep stirring at 500 rpm for 9 h for chemical modification to obtain PPA modified asphalt for standby.

[0063] S2. After cooling the PPA modified asphalt to 182 °C, a certain amount of SBS modifier is added, and it is stirred at 500 rpm for 0.75 h while maintaining the temperature to allow the SBS modifier to fully absorb oil and expand. Subsequently, it is sheared at 4500 rpm for 45 min to obtain the composite modified asphalt, which is reserved for use.

[0064] S3. Cool the obtained composite modified asphalt to 170 °C, add a stabilizer to the composite modified asphalt, and stir it at 300 rpm for 3 h while maintaining the temperature to prepare the composite modified cable asphalt.

[0065] The composite modified cable asphalt prepared in this example is used for the cable armor layer and is applied in a coating manner. Example 5

[0066] This example provides a composite modified cable asphalt, which is made from the following raw materials in parts by weight: 100 parts of matrix asphalt, 7 parts of polyphosphoric acid, 8 parts of SBS modifier, 30 parts of high-aromatic oil, and 0.3 parts of stabilizer.

[0067] Among them, the penetration of the matrix asphalt at 0.1 mm at 25 °C is 64.

[0068] The high-aromatic oil is rubber oil.

[0069] The SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000.

[0070] The phosphoric acid content of the polyphosphoric acid is 105%.

[0071] The stabilizer is sulfur.

[0072] This example also provides a preparation method for the above-mentioned composite modified cable asphalt, which includes the following steps: S1. Heat the matrix asphalt to a molten state, then add high-aromatic oil and polyphosphoric acid, and then heat it to 200 °C and stir it at 600 rpm for 10 h for chemical modification to obtain PPA modified asphalt, which is reserved for use.

[0073] S2. After cooling the PPA modified asphalt to 183 °C, add a certain amount of SBS modifier, and stir it at 600 rpm for 1 h while maintaining the temperature to allow the SBS modifier to fully absorb oil and expand. Subsequently, it is sheared at 4000 rpm for 90 min to obtain the composite modified asphalt, which is reserved for use.

[0074] S3. Cool the obtained composite modified asphalt to 174 °C, add a stabilizer to the composite modified asphalt, and stir it at 200 rpm for 2 h while maintaining the temperature to prepare the composite modified cable asphalt.

[0075] The composite modified cable asphalt prepared in this example is used for the cable armor layer and is applied in a coating manner. Comparative Example 1

[0076] Comparative Example 1 was based on Example 1 with a change in the raw material ratio. The change was that polyphosphoric acid was not added, and the rest of the operations were the same.

[0077] This comparative example provided a composite modified cable asphalt, which was made from the following raw materials in parts by weight: 100 parts of matrix asphalt, 7 parts of SBS modifier, 30 parts of high-aromatic oil, and 0.3 parts of stabilizer.

[0078] Among them, the penetration of the matrix asphalt at 0.1 mm at 25°C was 64.

[0079] The high-aromatic oil was rubber oil.

[0080] The SBS modifier was a styrene-butadiene-styrene block polymer. Further, the SBS modifier had a linear structure and a molecular weight of 110,000.

[0081] The stabilizer was sulfur.

[0082] This comparative example also provided a preparation method for the above-mentioned composite modified cable asphalt, which included the following steps: S1. Heat the matrix asphalt to a molten state, then add the high-aromatic oil, and then heat to 200°C, keep stirring at 500 rpm for 9 h for chemical modification to obtain PPA modified asphalt for standby.

[0083] S2. Cool the PPA modified asphalt to 182°C, then add a certain amount of SBS modifier, keep stirring at 500 rpm for 1 h to make the SBS modifier fully absorb oil and expand, and then perform shearing at 4500 rpm for 45 min to obtain composite modified asphalt for standby.

[0084] S3. Cool the composite modified asphalt to 172°C, add the stabilizer to the composite modified asphalt, keep stirring at 300 rpm for 3 h to prepare the composite modified cable asphalt.

[0085] Test various indexes of the composite modified cable asphalt prepared in Examples 1-5 and Comparative Example 1, and the results are shown in Table 1.

[0086]

[0087] By comparison Figure 1 with Figure 2It was found that, compared with Comparative Example 1, after adding polyphosphoric acid in Example 1, the uniformity of the distribution of SBS in asphalt was significantly improved, and the granular polymer almost disappeared from the image. The polymer formed a network cross-linked structure, indicating that the addition of polyphosphoric acid made the SBS particles disperse more finely, which was beneficial for the polymer to better adsorb the light components in asphalt, thus swelling, cross-linking, forming a network structure, and improving the uniformity of the polymer distribution in asphalt; it well improved the thermal stability and low-temperature properties such as cold bending of the composite modified cable asphalt; at the same time, the synergistic effect of polyphosphoric acid and the SBS modifier made the modification effects of the two play more fully, further improving the high-temperature properties such as the softening point and flash point of the composite modified cable asphalt; in addition, the polar functional groups in polyphosphoric acid also improved the adhesion performance of the composite modified cable asphalt; the overall performance of the composite modified cable asphalt was improved.

[0088] By comparing the data in Table 1, it was found that the various indicators of the composite modified cable asphalt provided in the examples of the present invention met the technical indicators of the industry standard NB / SH / T 0001-2019.

[0089] From the data comparison in Table 1, it can be seen that the cold bending performance of the cable asphalt prepared in Comparative Example 1 was poor, and after heat storage, the performance changed greatly, and its thermal stability data showed a trend opposite to the index requirements, with the softening point decreasing and the penetration increasing. This was because when revising the industry standard NB / SH / T 0001-2019, it was changed according to the oxidation process, without considering the degradation phenomenon of the polymer in the high-temperature environment in the modification process. Therefore, although the experimental data met the requirements of the industry standard NB / SH / T 0001-2019, the performance of the cable asphalt changed greatly.

[0090] On the one hand, the chemical modification of polyphosphoric acid converted the saturates and aromatics in the matrix asphalt into asphaltenes and resins, making its colloidal structure develop from a sol type to a gel type, improving the anti-deformation ability such as the sag and penetration of the asphalt. At the same time, the high-temperature properties such as the softening point and thermal stability of the asphalt were also improved; on the other hand, polyphosphoric acid made the SBS shear more finely, improving its distribution uniformity in asphalt, promoting the play of the SBS modification effect, and improving the low-temperature properties such as cold bending and the high-temperature properties such as the softening point and flash point of the asphalt. In addition, the interaction between polyphosphoric acid and the SBS modifier improved the degradation phenomenon of the SBS modifier and enhanced the thermal stability of the composite modified cable asphalt; and the addition of polyphosphoric acid, with its own polar functional groups, enhanced the adhesion of the composite modified cable asphalt.

[0091] The above embodiments are to further explain the technical solution of the present invention, rather than limiting the technical solution of the present invention. Those of ordinary skill in the art should know that, without departing from the principle of the present invention, some or all of the technologies of the present invention can still be equivalently replaced, and these equivalent replacements should all be covered by the protection scope of the claims of the present invention.

Claims

1. A composite modified cable asphalt, characterized in that: The composite modified cable asphalt is prepared from the following raw materials in parts by weight: 100 parts of base asphalt, 3-8 parts of polyphosphoric acid, 5-8 parts of SBS modifier, 20-40 parts of high aromatic oil, and 0.2-0.4 parts of stabilizer; The raw materials in the following weight proportions are prepared by adding high aromatic oil and polyphosphoric acid to base asphalt for chemical modification, then adding SBS modifier for shear dispersion, and then adding stabilizer for thermal insulation development to obtain composite modified cable asphalt.

2. The composite modified cable asphalt according to claim 1, characterized in that: The base asphalt has a needle penetration of 60-80 at 0.1 mm at 25°C; the high aromatic oil includes any one of rubber oil, furfural extracted oil or reduced four-line extracted oil; the SBS modifier is a linear styrene-butadiene-styrene block polymer with a molecular weight of 110,000; and the stabilizer is sulfur.

3. The composite modified cable asphalt according to claim 1 or 2, characterized in that: The phosphoric acid content of the polyphosphoric acid is not less than 105wt%.

4. The method for preparing the composite modified cable asphalt according to any one of claims 1 or 2, characterized in that: The steps include: S1. The base asphalt is heated to a molten state, high aromatic oil and polyphosphoric acid are added, and heating is continued, and stirring is maintained at a temperature to carry out chemical modification to obtain PPA modified asphalt; S2. After cooling the PPA modified asphalt, add the SBS modifier, keep warm and stir, so that the SBS modifier fully absorbs oil and expands, and shears and disperses to obtain a composite modified asphalt; S3. Cooling the composite modified asphalt, adding a stabilizer to the composite modified asphalt, stirring and developing the composite modified cable asphalt under heat preservation, and obtaining the composite modified cable asphalt.

5. The method for preparing the composite modified cable asphalt according to claim 4, characterized in that: In step S1, the chemical modification temperature is 190-210° C., the heat preservation stirring rate is 400-600 rpm, and the time is 8-10 hours.

6. The method for preparing the composite modified cable asphalt according to claim 4, characterized in that: In step S2, the PPA modified asphalt is cooled to 180-185°C, and the stirring rate is 400-600rpm for 0.5-1h; the shearing equipment is a high shear mixing emulsifier, the shear rate is 4000-5000rpm, and the time is 30-90min.

7. The method for preparing the composite modified cable asphalt according to claim 4, characterized in that: In step S3, the composite modified asphalt is cooled to 170-175°C, and the stirring rate is 200-400rpm for 2-4h.

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