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CN-122011757-A - Preparation method of nylon rubber-plastic material with high mechanical memory

CN122011757ACN 122011757 ACN122011757 ACN 122011757ACN-122011757-A

Abstract

The invention relates to the technical field of polymer composite materials and discloses a preparation method of a nylon rubber-plastic material with high mechanical memory, which comprises the steps of respectively drying nylon 66 resin with specific viscosity and thermoplastic polyurethane elastomer with specific hardness, carrying out compatibilization and premixing on the nylon 66 resin with specific viscosity, maleic anhydride grafted POE, a composite antioxidant and a beta crystal nylon nucleating agent according to parts by weight, carrying out melt blending on the premix by a double screw extruder, injecting a phenolic resin vulcanizing agent under a set temperature gradient for in-situ dynamic vulcanization, extruding through a high-shear orientation die orifice, sequentially carrying out quenching-slow cooling two-stage cooling on extruded strips, granulating, carrying out hot press molding on the granules into a spline, and carrying out programmed temperature rise and drop treatment under the constraint of a clamp, thereby endowing the material with a temporary shape. The material prepared by the invention has the characteristics of high shape recovery rate, accurate recovery response temperature and excellent mechanical property, and is controllable in process and suitable for industrial production.

Inventors

  • YAO GANG
  • Xing chuang
  • YANG CONGBING
  • HU FEI

Assignees

  • 江苏润泰银科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (9)

  1. 1. A preparation method of a nylon rubber-plastic material with high mechanical memory is characterized by comprising the following steps: S1, respectively drying and pre-treating nylon 66 resin with the characteristic viscosity number of 2.8-3.2dL/g and thermoplastic polyurethane elastomer with the Shore hardness of 75A-90A; S2, weighing 70-75 parts of pretreated nylon 66 resin, 25-30 parts of pretreated thermoplastic polyurethane elastomer, 4-6 parts of maleic anhydride grafted POE, 1.5-2.5 parts of composite antioxidant containing hindered phenol and phosphite ester and 0.3-0.8 part of beta-crystal form nylon nucleating agent for compatibilization and premixing to obtain premix; S3, adding the premix into a double-screw extruder, setting a temperature gradient of 210 ℃ to 225 ℃ to 235 ℃ to 245 ℃ in a third zone to a sixth zone, setting the screw speed to be 380-420r/min, injecting a phenolic resin vulcanizing agent in a fifth zone, and finally extruding through a high-shear orientation die to obtain a strip-shaped extrudate; s4, quenching the strip-shaped extrudate for 30-45 seconds through a cooling water tank at the temperature of 40-45 ℃ in a first temperature zone, slowly cooling for 60-90 seconds through an oil bath at the temperature of 75-80 ℃ in a second temperature zone, and granulating to obtain drum-shaped granules; s5, performing hot press molding on the drum-shaped particles to obtain standard sample bars, and performing programmed heating and cooling under the constraint of a clamp to obtain a finished product material with a preset temporary shape.
  2. 2. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1, which is characterized in that: The step of respectively carrying out drying pretreatment on nylon 66 resin with the intrinsic viscosity of 2.8-3.2dL/g and thermoplastic polyurethane elastomer with the Shore hardness of 75A-90A comprises the following steps: Placing the nylon 66 resin with the intrinsic viscosity of 2.8-3.2dL/g into vacuum drying equipment, and drying for 6-8 hours at the temperature of 100-110 ℃ and the vacuum degree of less than or equal to 0.095 MPa; Placing the thermoplastic polyurethane elastomer with the Shore hardness of 75A-90A in a dehumidifying and drying oven, and circularly treating the thermoplastic polyurethane elastomer with the drying air with the dew point of less than or equal to-40 ℃ for 3-4 hours at the temperature of 80-85 ℃; and respectively transferring the treated nylon 66 resin and the thermoplastic polyurethane elastomer into a closed container filled with dry nitrogen, and cooling to 25-30 ℃ for later use.
  3. 3. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1, which is characterized in that: weighing 70-75 parts of pretreated nylon 66 resin, 25-30 parts of pretreated thermoplastic polyurethane elastomer, 4-6 parts of maleic anhydride grafted POE, 1.5-2.5 parts of composite antioxidant containing hindered phenol and phosphite ester and 0.3-0.8 part of beta-crystal form nylon nucleating agent for compatibilization and premixing according to parts by weight, wherein the step of obtaining premix comprises the following steps: preheating a mixing chamber of a high-speed mixer to 20+/-2 ℃, and continuously introducing cooling water into a jacket of the high-speed mixer; adding 70-75 parts of pretreated nylon 66 resin and 25-30 parts of pretreated thermoplastic polyurethane elastomer into a high-speed mixer, and dry-mixing for 2-3 minutes at the rotating speed of 300-500 r/min; Manually stirring and premixing 4-6 parts of maleic anhydride grafted POE, 1.5-2.5 parts of composite antioxidant containing hindered phenol and phosphite ester and 0.3-0.8 part of beta-crystal nylon nucleating agent at the temperature of 20-25 ℃ for 30-60 seconds to form an auxiliary agent premix; Uniformly adding the auxiliary agent premix into the high-speed mixer, and mixing for 8-12 minutes at the rotating speed of 800-1200r/min, wherein the temperature of materials in the high-speed mixer is controlled below 45 ℃; after the high speed mixing is completed, the rotational speed is reduced to 100-200r/min, mixing is continued for 1-2 minutes, and then the obtained premix is discharged and immediately transferred into a sealed container.
  4. 4. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1, which is characterized in that: The premix is added into a double-screw extruder, a temperature gradient of 210 ℃ to 225 ℃ to 235 ℃ to 245 ℃ is set in a third zone to a sixth zone, the screw rotating speed is set to be 380-420r/min, phenolic resin vulcanizing agent is injected in a fifth zone, and finally the mixture is extruded through a high-shear orientation die, and the step of obtaining a strip-shaped extrudate comprises the following steps: Adding the premix into a double-screw extruder through a main feeding port, and sequentially passing through one to six areas, wherein the method comprises the following steps: Melting and plasticizing at 190-205 ℃ when the premix reaches the first zone to the second zone of the twin-screw extruder; When the melted and plasticized premix reaches the third zone, the fourth zone, the fifth zone and the sixth zone of the double-screw extruder, respectively taking 210 ℃ and 225 ℃ and 235 ℃ and 245 ℃ as temperature gradients, and carrying out homogenization mixing at the screw speed of 380-420 r/min; And stably extruding the oriented melt at the outlet of a high-shear orientation die of the double-screw extruder under the die pressure of 2.5-3.5MPa to form a continuous strip-shaped extrusion.
  5. 5. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1 or 4, which is characterized in that: when the melt-plasticized premix reaches the fifth zone of the twin-screw extruder: Weighing phenolic resin vulcanizing agent accounting for 1.5-2.5% of the mass of the thermoplastic polyurethane elastomer, and injecting the phenolic resin vulcanizing agent into a melt flow in a pulse injection mode through a high-pressure metering pump; controlling the melt pressure of the fifth area to be 4.0-6.0MPa, and carrying out in-situ dynamic vulcanization reaction to obtain micro-crosslinked elastomer particles; Wherein the twin screw extruder is configured with high shear kneading block elements in the fifth zone to subject the melt to high shear in that zone.
  6. 6. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1 or 4, which is characterized in that: The high-shear orientation die of the double-screw extruder is of a parallel slit structure, the slit gap is 0.5-1.0mm, and the length-diameter ratio is 10:1 to 20:1; when the melt flows through the high-shear orientation die, the instantaneous shear rate born at the gap of the slit is more than or equal to 500s < -1 >, so that nylon molecular chains and micro-crosslinked elastomer particles are oriented and arranged along the extrusion direction.
  7. 7. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1, which is characterized in that: Quenching the strip-shaped extrudate for 30-45 seconds through a cooling water tank at the temperature of 40-45 ℃ in a first temperature zone, slowly cooling for 60-90 seconds through an oil bath at the temperature of 75-80 ℃ in a second temperature zone, and granulating to obtain drum-shaped granules, wherein the step of obtaining the drum-shaped granules comprises the following steps of: leading out the strip-shaped extrudate at a constant speed of 5-8m/min through a first pair of traction rollers; Completely immersing the pulled strip-shaped extrudate into a cooling water tank with a first temperature zone of 40-45 ℃ for quenching, and staying for 30-45 seconds; The quenched bar-shaped extrudate is put out, is suspended and conveyed in the room temperature air of 20-30 ℃ for 5-10 seconds, and is then completely immersed into a constant-temperature hot oil bath with a second temperature zone of 75-80 ℃ for slow cooling, and stays for 60-90 seconds; And (3) leading out the slowly cooled strip-shaped extrudate through a second pair of traction rollers, feeding the extrudate into a granulator, cutting the extrudate to obtain drum-shaped granules with the diameter of 2-3mm and the length of 3-4mm, and collecting the drum-shaped granules in a moisture-proof container.
  8. 8. The method for preparing the nylon rubber-plastic material with high mechanical memory according to claim 1, which is characterized in that: the step of hot-press molding the drum-shaped particles to obtain standard sample bars, and performing programmed heating and cooling under the constraint of a clamp to obtain a finished product material with a preset temporary shape comprises the following steps: uniformly laying the drum-shaped particles into a standard spline die, hot-pressing for 8-10 minutes on a hot press at the temperature of 240-245 ℃ and the pressure of 12-15MPa, and then cooling to below 60 ℃ at the speed of 10-15 ℃ per minute, and demoulding to obtain a homogeneous standard spline; The homogeneous standard spline is arranged on a programming fixture, and is integrally moved into an incubator, the temperature in the incubator is uniformly increased to 50+/-1 ℃ at the heating rate of 2-3 ℃ per minute, and the incubator is kept at constant temperature for 15-20 minutes; uniformly reducing the temperature in the incubator from 50+/-1 ℃ to below 20 ℃ at a rate of 1-2 ℃ per minute under the condition of maintaining the constraint of the clamp unchanged; And taking out the programming fixture from the incubator, and unloading to obtain a finished product material.
  9. 9. A high mechanical memory nylon rubber-plastic material prepared by the method of any one of claims 1-8, characterized in that: through a standard thermal mechanical cycle test, the shape recovery rate Rr of the nylon rubber and plastic material with high mechanical memory is more than or equal to 95%, and the recovery response temperature Tr is 45+/-3 ℃.

Description

Preparation method of nylon rubber-plastic material with high mechanical memory Technical Field The invention relates to the technical field of polymer composite materials, in particular to a preparation method of a nylon rubber plastic material with high mechanical memory. Background Along with the rapid development of the fields of intelligent manufacturing, flexible electronics, biomedical treatment and the like, the requirements for high polymer materials with shape memory function are increasingly urgent, and common shape memory materials generally have the problems of insufficient mechanical strength, low recovery precision, difficult accurate regulation and control of response temperature and the like, so that the application of the material in bearing structures or precise occasions is limited. Nylon (polyamide) series resins, especially nylon 66, are regarded as ideal structural material substrates due to their excellent mechanical properties, heat resistance, abrasion resistance and processability, however, nylon 66 is a typical high crystalline polymer whose shape memory behavior is limited by higher glass transition temperature and melting point, resulting in a higher shape recovery temperature and poor controllability of recovery process. Blending nylon with TPU is a common strategy to improve its toughness and introduce shape memory potential, however, nylon 66 is less compatible with TPU, simple blending tends to cause interfacial debonding and memory performance decay of the material during cyclic deformation, and in addition, conventional blended materials lack effective regulation of microscopic phase structure, crystallization behavior and molecular orientation during processing, and stable and efficient shape memory performance is difficult to achieve. At present, the preparation method of the shape memory nylon material with high mechanical property is mainly focused on chemical synthesis of novel copolymer or introduction of expensive functional monomer, and has complex process, high cost and difficulty in considering large-scale processing and forming and performance stability, so that development of a preparation method based on mature commercial raw materials is urgently needed. Disclosure of Invention The invention aims to solve the problems in the prior art and provides a preparation method of a nylon rubber plastic material with high mechanical memory. In order to achieve the purpose, the invention adopts the following technical scheme that the preparation method of the nylon rubber plastic material with high mechanical memory comprises the following steps: S1, respectively drying and pre-treating nylon 66 resin with the characteristic viscosity number of 2.8-3.2dL/g and thermoplastic polyurethane elastomer with the Shore hardness of 75A-90A; S2, weighing 70-75 parts of pretreated nylon 66 resin, 25-30 parts of pretreated thermoplastic polyurethane elastomer, 4-6 parts of maleic anhydride grafted POE, 1.5-2.5 parts of composite antioxidant containing hindered phenol and phosphite ester and 0.3-0.8 part of beta-crystal form nylon nucleating agent for compatibilization and premixing to obtain premix; S3, adding the premix into a double-screw extruder, setting a temperature gradient of 210 ℃ to 225 ℃ to 235 ℃ to 245 ℃ in a third zone to a sixth zone, setting the screw speed to be 380-420r/min, injecting a phenolic resin vulcanizing agent in a fifth zone, and finally extruding through a high-shear orientation die to obtain a strip-shaped extrudate; s4, quenching the strip-shaped extrudate for 30-45 seconds through a cooling water tank at the temperature of 40-45 ℃ in a first temperature zone, slowly cooling for 60-90 seconds through an oil bath at the temperature of 75-80 ℃ in a second temperature zone, and granulating to obtain drum-shaped granules; s5, performing hot press molding on the drum-shaped particles to obtain standard sample bars, and performing programmed heating and cooling under the constraint of a clamp to obtain a finished product material with a preset temporary shape. The technical scheme provided by the invention has the beneficial effects that at least: The nylon rubber plastic material with high shape recovery rate, accurate recovery response temperature and excellent mechanical property is successfully prepared through the cooperation of precise formula design and a full-flow process, and can trigger efficient and stable shape recovery in a normal-temperature environment, so that the applicable temperature window of the shape memory material in the fields of biomedical treatment, intelligent wearing, daily necessities and the like is remarkably widened. The invention creatively introduces the beta-crystal nylon nucleating agent into a nylon 66+TPU blending system, and is matched with a graded cooling process to effectively induce a nylon matrix to form a beta-crystal structure, thereby successfully regulating and controlling the shape recovery temperature of th