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CN-122012020-A - Aldehyde-free cellulose composite bio-based rubber adhesive and preparation method thereof

CN122012020ACN 122012020 ACN122012020 ACN 122012020ACN-122012020-A

Abstract

The invention discloses an aldehyde-free cellulose composite bio-based rubber adhesive and a preparation method thereof, wherein the raw material components comprise, by weight, 30-50 parts of composite tackifying resin, 10-20 parts of modified nano microcrystalline cellulose, 5-15 parts of dibutyl itaconate-levulinate copolymer, 1-5 parts of vulcanization active auxiliary agent, 0.5-3 parts of bio-based antioxidant, 30-60 parts of mixed solvent of D-limonene and ethyl acetate, the composite tackifying resin is prepared by reacting dehydroabietic acid rosin resin, epoxidized cardanol and a bio-based cross-linking agent, the bio-based cross-linking agent is furfural, the modified nano microcrystalline cellulose is prepared by esterifying and modifying dodecyl succinic anhydride, and the invention solves the performance bottlenecks of low adhesive strength, poor water resistance, easy aging, easy frosting and the like commonly existing in the bio-based adhesive.

Inventors

  • LANG XUDONG
  • HU LIXIN

Assignees

  • 江苏国立化工科技有限公司

Dates

Publication Date
20260512
Application Date
20260303

Claims (10)

  1. 1. The formaldehyde-free cellulose composite bio-based rubber adhesive is characterized by comprising the following raw material components in parts by weight: 30-50 parts of composite tackifying resin; 10-20 parts of modified nano microcrystalline cellulose; 5-15 parts of dibutyl itaconate-levulinate copolymer; 1-5 parts of vulcanization active auxiliary agent; 0.5-3 parts of biological antioxidant; 30-60 parts of a mixed solvent of D-limonene and ethyl acetate; The composite tackifying resin is prepared by reacting dehydroabietic acid type rosin resin, epoxidized cardanol and a bio-based cross-linking agent, wherein the bio-based cross-linking agent is furfural, and the modified nano microcrystalline cellulose is prepared by esterifying and modifying dodecyl succinic anhydride.
  2. 2. The formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 1, wherein in the composite tackifying resin, the weight ratio of dehydroabietic acid type rosin resin, epoxidized cardanol and bio-based crosslinking agent is 1-2:1:0.05-0.1, the reaction of the dehydroabietic acid type rosin resin, the epoxidized cardanol and the bio-based crosslinking agent is carried out in a microwave reactor, and a catalyst is added in the reaction process, wherein the catalyst is p-toluenesulfonic acid, the addition amount of the catalyst is 0.1-0.3% of the total mass of the dehydroabietic acid type rosin resin, the epoxidized cardanol and furfural, the microwave power is 300-500W, the reaction temperature is 140-160 ℃, and the reaction time is 1-2 h.
  3. 3. The formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 1, wherein the preparation method of the modified nano microcrystalline cellulose is characterized in that microcrystalline cellulose is mixed with water according to the mass ratio of 1:10-15, cellulase accounting for 0.5-1% of the mass of the microcrystalline cellulose is added, and enzymolysis treatment is carried out at the microwave power of 200-400W and the temperature of 50-60 ℃ for 30-60 min; heating the system to 85-95 ℃ after the enzymolysis reaction is finished, preserving heat for 15-20 min, inactivating cellulase at high temperature, cooling to room temperature, separating cellulose solid by filtration and centrifugation, fully washing with deionized water until the pH is neutral, drying to constant weight at 60-80 ℃ to obtain pretreated microcrystalline cellulose, dispersing the pretreated microcrystalline cellulose into anhydrous pyridine, wherein the mass ratio of the microcrystalline cellulose to the anhydrous pyridine is 1:5-10, heating to 60-90 ℃, dropwise adding dodecyl succinic anhydride under stirring, the weight ratio of the microcrystalline cellulose to the dodecyl succinic anhydride is 1:0.3-0.6, reacting at constant temperature for 1-3 h, decompressing and distilling to remove pyridine after the reaction is finished, redispersing the obtained solid product in the deionized water, carrying out nanocrystallization treatment at 800-1200 bar pressure by using a high-pressure homogenizer, circulating for 5-10 times to obtain stable nano cellulose aqueous dispersion, and carrying out spray drying to obtain powdery modified nano cellulose.
  4. 4. The method for preparing the formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 3, wherein the spray drying has an inlet temperature of 150-180 ℃, an outlet temperature of 70-90 ℃, a feeding rate of 5-10 mL/min and an atomization pressure of 0.3-0.5 MPa.
  5. 5. The formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 1, wherein the molar ratio of dibutyl itaconate structural units to levulinate structural units in the dibutyl itaconate-levulinate copolymer is 1:0.5-2, and the copolymer has a number average molecular weight of 3000-8000.
  6. 6. The formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 1, wherein the vulcanization coagent is a compound of zinc oxide, stearic acid and tetrabenzyl thiuram disulfide, the weight ratio of the zinc oxide, the stearic acid and the tetrabenzyl thiuram disulfide is 2-3:1:0.5, the bio-based antioxidant is a compound of tea polyphenol, vitamin E and hydroxypropylated lignin, and the weight ratio of the zinc oxide, the stearic acid and the tetrabenzyl thiuram disulfide is 1-2:1-2:0.5-1.
  7. 7. The formaldehyde-free cellulose composite bio-based rubber adhesive according to claim 1, wherein the volume ratio of D-limonene to ethyl acetate in the mixed solvent of D-limonene and ethyl acetate is 1:1-3.
  8. 8. A method for preparing the formaldehyde-free cellulose composite bio-based rubber adhesive according to any one of claims 1 to 7, comprising the steps of: s1, crushing the composite tackifying resin to a particle size of 1-5 mm for later use; s2, premixing: Adding a mixed solvent of D-limonene and ethyl acetate with a formula amount of half into a dissolution kettle, sequentially adding composite tackifying resin, dibutyl itaconate-levulinate copolymer, vulcanization active auxiliary agent and biological antioxidant under stirring, stirring and dissolving at 40-60 ℃ for 0.5-1 h to obtain a uniform component A, pre-mixing modified nano microcrystalline cellulose with the rest half of the mixed solvent of D-limonene and ethyl acetate, performing auxiliary dispersion for 5-10 min by using a microwave reactor at 200-300W, and performing ultrasonic dispersion for 10-20 min by using an ultrasonic cell grinder at a frequency of 25-35kHz and a power of 500-800W to obtain a uniform component B dispersion; S3, preparing a finished product: Slowly adding the dispersion liquid of the component B obtained in the step S2 into the component A at the rotating speed of a high-speed dispersing machine of 800-1200 rpm, after the addition, increasing the rotating speed to 1500-2000 rpm, continuously dispersing at a high speed of 30-60 min until the system is uniform and stable, and filtering to obtain the formaldehyde-free cellulose composite bio-based rubber adhesive.
  9. 9. The method for preparing an aldehyde-free cellulose composite bio-based rubber adhesive according to claim 8, wherein in S3, the stirring rate when dissolving the a component is controlled to be 300-500 rpm.
  10. 10. The method for preparing an aldehyde-free cellulose composite bio-based rubber adhesive according to claim 8, wherein after S3 is completed, the aldehyde-free cellulose composite bio-based rubber adhesive is subjected to vacuum degassing treatment under the conditions of a vacuum degree of-0.08 to-0.095 MPa and a degassing time of 15 to 30 min.

Description

Aldehyde-free cellulose composite bio-based rubber adhesive and preparation method thereof Technical Field The invention relates to the technical field of rubber adhesive preparation, in particular to an aldehyde-free cellulose composite bio-based rubber adhesive and a preparation method thereof. Background In the field of rubber industry, adhesives are key auxiliary agents for ensuring firm combination of elastic rubber bodies and framework materials such as fibers or metals, and the performances of the adhesives directly influence the structural safety and the service life of composite products such as tires, conveyor belts and the like. Along with the strict global environmental protection regulations and the development of green low carbon, the development of high-performance bio-based rubber adhesives capable of replacing traditional petroleum-based products has become an important direction in industry, and particularly has urgent market demands for new energy automobile industries needing to meet the requirements of low VOC and low peculiar smell. In the prior art, the adhesion between rubber and reinforcing materials is mostly dependent on petroleum-based adhesive systems represented by resorcinol-formaldehyde resin, and the adhesive has good initial adhesive effect, but has the defects of unrenewable raw materials, high emission of volatile organic matters in the production process and possible residual toxic substances such as formaldehyde in finished products. To cope with these problems, research has been turned to developing adhesives from biomass such as natural rubber, vegetable oil, lignin, starch, etc., and improving performance by compounding nanofillers, compounding bio-based aids, etc., in an attempt to enhance environmental compatibility of the product while maintaining the bonding function. However, the existing bio-based bonding technology still faces two key technical challenges that have not been adequately addressed. On one hand, the bio-based component has poor compatibility with a hydrophobic rubber matrix due to high polarity and compact structure, so that the interface binding force is weak, and the sufficient bonding strength and durability are difficult to maintain under the conditions of damp heat aging or dynamic fatigue. On the other hand, the small molecular biology-based adhesive component is easy to migrate and separate out in a rubber system, so that not only is the adhesive active component lost and the performance attenuated, but also a frosting phenomenon is formed on the surface of a product, the appearance and the subsequent processing technology of the product are influenced, and the large-scale application of the product in high-performance rubber products is restricted. Disclosure of Invention The invention provides an aldehyde-free cellulose composite type bio-based rubber adhesive and a preparation method thereof, aiming at the technical problems that the existing bio-based rubber adhesive has low adhesive strength and insufficient durability, and performance attenuation and surface frosting caused by small molecule migration. The invention adopts the technical scheme that the formaldehyde-free cellulose composite bio-based rubber adhesive comprises the following raw material components in parts by weight: 30-50 parts of composite tackifying resin; 10-20 parts of modified nano microcrystalline cellulose; 5-15 parts of dibutyl itaconate-levulinate copolymer; 1-5 parts of vulcanization active auxiliary agent; 0.5-3 parts of biological antioxidant; 30-60 parts of a mixed solvent of D-limonene and ethyl acetate; The composite tackifying resin is prepared by reacting dehydroabietic acid type rosin resin, epoxidized cardanol and a bio-based cross-linking agent, wherein the bio-based cross-linking agent is furfural, and the modified nano microcrystalline cellulose is prepared by esterifying and modifying dodecyl succinic anhydride; The preparation method of the dibutyl itaconate-levulinate copolymer comprises the steps of adding dibutyl itaconate and levulinate monomers according to a molar ratio of 1:0.5-2, taking azobisisobutyronitrile as an initiator, wherein the using amount of the initiator is 0.5-1% of the total mass of the dibutyl itaconate and levulinate monomers, polymerizing 4-6 h at 70-80 ℃, and obtaining the copolymer with the number average molecular weight of 3000-8000 after precipitation and purification. The preparation method has the advantages that the composite tackifying resin is used as an adhesive main body, high initial adhesion and cohesive strength are provided, the modified nano microcrystalline cellulose is used as an enhanced framework, the mechanical property and water resistance of an adhesive layer are obviously improved, the dibutyl itaconate-levulinate copolymer is used as a reactive compatibilizer, the interfacial compatibility of a bio-base component and a rubber matrix is effectively improved, the vulcanization coagent ensures the