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CN-121991520-A - Activated phosphogypsum-polyurethane composite modified asphalt and ultrasonic synergistic preparation method thereof

CN121991520ACN 121991520 ACN121991520 ACN 121991520ACN-121991520-A

Abstract

The invention discloses activated phosphogypsum-polyurethane composite modified asphalt and an ultrasonic collaborative preparation method thereof, belonging to the technical field of new materials for road engineering. The modified asphalt takes matrix asphalt as a substrate, and comprises two-component polyurethane, phosphogypsum subjected to three-step activation treatment, a coupling agent and nano SiO 2 , wherein the activated phosphogypsum is subjected to water washing, 500-600 ℃ calcination and silane coupling agent grafting pretreatment, so that the compatibility with an organic phase is effectively improved, the preparation method adopts an ultrasonic and high-speed shearing synergistic process, the components are uniformly dispersed and fully crosslinked with the polyurethane, and the synergism of nano SiO 2 is combined, so that the high-low temperature performance, the ageing resistance and the interface binding force of the modified asphalt are remarkably improved. The invention solves the core pain points of uneven phosphogypsum dispersion, insufficient polyurethane crosslinking and poor compatibility in the prior art, realizes the resource utilization, has strong process operability and meets the highway construction requirements.

Inventors

  • XUE JINSHUN
  • CHEN XIAO
  • ZHAO WEI
  • LIU QILIANG
  • ZHAO LIXIANG
  • WANG YUANYUAN
  • ZHOU FEI
  • YANG JIANHUA

Assignees

  • 湖北文理学院
  • 河北交规院瑞志交通技术咨询有限公司
  • 湖北文理学院理工学院

Dates

Publication Date
20260508
Application Date
20260313

Claims (9)

  1. 1. The activated phosphogypsum-polyurethane composite modified asphalt is characterized by comprising, by mass, 100 parts of matrix asphalt, 3-5 parts of double-component polyurethane material (wherein 2-4 parts of component A and 1-2 parts of component B) and 0.3-0.6 part of coupling agent, and 0.1-0.3 part of nano SiO 2 , wherein the activated phosphogypsum is phosphogypsum powder obtained by three pretreatment steps of water washing, calcination and silane coupling agent grafting, the calcination temperature is 500-600 ℃, the calcination time is 1-2 h, and the grafting amount of the silane coupling agent is 0.5-1.0% of the mass of the phosphogypsum.
  2. 2. The activated phosphogypsum-polyurethane composite modified asphalt according to claim 1, wherein the two-component polyurethane A component is isocyanate, the B component is polyol, and the mass ratio of the A component to the B component is 2-4:1.
  3. 3. The activated phosphogypsum-polyurethane composite modified asphalt according to claim 1, wherein the coupling agent is a silane coupling agent, preferably gamma-aminopropyl triethoxysilane.
  4. 4. The activated phosphogypsum-polyurethane composite modified asphalt according to claim 1, wherein the particle size of the nano SiO 2 is 10-50 nm, and the purity is more than or equal to 99%.
  5. 5. The activated phosphogypsum-polyurethane composite modified asphalt according to claim 1, wherein the particle size of the activated phosphogypsum is 0.01-0.1 mm, and the matrix asphalt is 70# matrix asphalt.
  6. 6. An ultrasonic collaborative preparation method for preparing the activated phosphogypsum-polyurethane composite modified asphalt according to any one of claims 1-5, which is characterized by comprising the following steps: Step 1), taking all components according to parts by weight, wherein the activated phosphogypsum is obtained by pretreatment of washing original phosphogypsum with water to remove soluble impurities, drying, placing in a muffle furnace at 500-600 ℃ for calcination for 1-2 h, cooling to room temperature, crushing to 0.01-0.1 mm of particle size, adding a silane coupling agent, and stirring for 30-40min at 80-90 ℃ to complete grafting modification; Step 2), preheating matrix asphalt to 120-140 ℃ for melting, adding a polyurethane A component, shearing for 5min at 1500-2500 rpm, simultaneously performing ultrasonic dispersion for 3min by matching with 20-30 kHz, and keeping the temperature at 120-140 ℃ to obtain a mixture A; Step 3), adding a polyurethane B component into the mixture A, shearing for 5min at 1500-2500 rpm, simultaneously performing ultrasonic dispersion for 3min by matching with 20-30 kHz, and keeping the temperature at 120-140 ℃ to obtain a mixture B; Step 4), adding activated phosphogypsum into the mixture B, shearing for 5min at 1500-2500 rpm, simultaneously performing ultrasonic dispersion for 3min by matching with 20-30 kHz, and keeping the temperature at 120-140 ℃ to obtain a mixture C; step 5), adding a coupling agent into the mixture C, shearing for 5min at 1500-2500 rpm, simultaneously carrying out ultrasonic dispersion for 3min by matching with 20-30 kHz, and keeping the temperature at 120-140 ℃ to obtain a mixture D; Step 6), adding nano SiO 2 into the mixture D, shearing for 5min at 1500-2500 rpm, simultaneously performing ultrasonic dispersion for 3min by matching with 20-30 kHz, and keeping the temperature at 120-140 ℃ to obtain a mixture E; step 7), integrally shearing the mixture E at 1500-2500 rpm for 0.5-1.5 h, maintaining the temperature at 120-140 ℃, and performing 20-30 kHz ultrasonic dispersion for 10-15 min after shearing; And 8) placing the product obtained in the step 7) in an oven at 110-130 ℃ for curing for 20-40 min to obtain the activated phosphogypsum-polyurethane composite modified asphalt.
  7. 7. The ultrasonic collaborative preparation method according to claim 6, wherein in the step 1), the usage amount of the silane coupling agent is 0.5-1.0% of the mass of phosphogypsum.
  8. 8. The ultrasonic collaborative preparation method according to claim 6, wherein in step 2) to step 6), shearing and ultrasonic dispersion are performed synchronously, the temperature is stabilized at 120-140 ℃, and the temperature fluctuation is not more than + -5 ℃.
  9. 9. The method according to claim 6, wherein in step 7), the whole shearing process adopts a uniform shearing mode, and the ultrasonic dispersion adopts intermittent ultrasonic, and the ultrasonic dispersion is suspended for 1min every 5min.

Description

Activated phosphogypsum-polyurethane composite modified asphalt and ultrasonic synergistic preparation method thereof Technical Field The invention belongs to the technical field of new materials for road engineering, and particularly relates to activated phosphogypsum-polyurethane composite modified asphalt and an ultrasonic collaborative preparation method thereof. Background The asphalt mixture is a core material for road pavement, and with the rapid increase of traffic volume and frequent extreme climate, higher requirements are put on the high-low temperature performance, durability and ageing resistance of asphalt. At present, polymer and industrial solid waste composite modified asphalt is an important direction for improving material performance and realizing solid waste recycling, wherein polyurethane is widely applied due to excellent low-temperature toughness, phosphogypsum is used as a large amount of industrial byproducts in phosphoric acid production, annual yield is high, treatment cost is high, asphalt high-temperature stability can be improved by using the modified phosphogypsum as a modifier, and key technical pain points still exist in the synergistic modification of the modified phosphogypsum and the industrial solid waste composite modified asphalt. In the prior art, as disclosed in the academic paper published in PLOS ONE 2025 (DOI 10.1371/journ al. Fine. 0327312), the modified asphalt is prepared from phosphogypsum which is not subjected to special activation treatment, has low surface activity, poor compatibility with polyurethane and matrix asphalt, easy interfacial peeling and performance attenuation after long-term high-temperature use, and the like. Another prior patent CN202311128808.3 (publication No. CN117049857 a) discloses a PU/cement composite modified phosphogypsum asphalt concrete, the core technical route of which is a PU prepolymer+cement+phosphogypsum system, which is used for solving the water-resistant and freezing-resistant problems of the asphalt concrete, and the core pain points of uneven dispersion, poor interface combination and insufficient polyurethane crosslinking of the phosphogypsum cannot be solved without involving the compatibility optimization technology of polyurethane and phosphogypsum or adopting an ultrasonic collaborative preparation technology. In addition, the technical scheme of carrying out three-step activation pretreatment and combining ultrasonic and high-speed shearing synergistic process on phosphogypsum and improving compatibility and ageing resistance by adding nano SiO 2 is not found in the prior art. At present, the present invention greatly promotes the utilization of industrial solid waste resources and the development of green low carbon, the Guangzhou area is taken as a basic building core area, the demand for new materials of high-performance roads is urgent, and the present invention aims at the pain point of the prior art, and realizes the high-efficiency utilization of solid waste and the breakthrough of asphalt performance. Disclosure of Invention Object of the invention The invention aims to overcome the technical defects of asphalt performance attenuation and insufficient high-low temperature cooperative lifting caused by poor compatibility, uneven dispersion and insufficient polyurethane crosslinking of phosphogypsum, polyurethane and matrix asphalt in the prior art, and provides an activated phosphogypsum-polyurethane composite modified asphalt and an ultrasonic cooperative preparation method thereof. According to the method, through triple innovations of phosphogypsum activation modification, ultrasonic and high-speed shearing cooperation and functional component addition, the high-efficiency compatibility of phosphogypsum, polyurethane and matrix asphalt is realized, the high-low temperature performance, durability and ageing resistance of the modified asphalt are improved, meanwhile, the high-value recycling of phosphogypsum is realized, the green low-carbon development concept is met, and the construction requirements of high-grade roads are met. (II) technical scheme In order to achieve the above purpose, the present invention adopts the following technical scheme: The activated phosphogypsum-polyurethane composite modified asphalt comprises, by mass, 100 parts of matrix asphalt, 3-5 parts of double-component polyurethane materials (2-4 parts of component A and 1-2 parts of component B), 0.3-0.6 part of coupling agent and 0.1-0.3 part of nano SiO 2, wherein the activated phosphogypsum is phosphogypsum powder obtained by three pretreatment steps of water washing, calcining and silane coupling agent grafting, the calcining temperature is 500-600 ℃, the calcining time is 1-2 h, and the grafting amount of the silane coupling agent is 0.5-1.0% of the phosphogypsum. Preferably, the two-component polyurethane A component is isocyanate, the B component is polyol, and the mass ratio of the A component to the B component is 2-