CN107674622B - High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof - Google Patents
High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof Download PDFInfo
- Publication number
- CN107674622B CN107674622B CN201710936735.9A CN201710936735A CN107674622B CN 107674622 B CN107674622 B CN 107674622B CN 201710936735 A CN201710936735 A CN 201710936735A CN 107674622 B CN107674622 B CN 107674622B
- Authority
- CN
- China
- Prior art keywords
- parts
- agent
- component
- water
- planetary stirrer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/44—Amides
- C08G59/46—Amides together with other curing agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/62—Alcohols or phenols
- C08G59/621—Phenols
- C08G59/623—Aminophenols
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/04—Non-macromolecular additives inorganic
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/08—Macromolecular additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/011—Nanostructured additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Inorganic Chemistry (AREA)
- Adhesives Or Adhesive Processes (AREA)
Abstract
The invention discloses a high-performance structural adhesive for a water environment reinforcing project and a preparation method thereof. The structural adhesive consists of A, B components with the mass ratio of 2:1-3: 1. The component A consists of nano-silica graft modified epoxy resin, epoxy active diluent, elastic modifier, water-absorbent resin, defoamer, dispersant, active silica micropowder, cement, calcium sulfate whisker, organic montmorillonite and thixotropic agent; the component B consists of a compound amine curing agent, a curing accelerator, a coupling agent, a defoaming agent, a dispersing agent, active silica micropowder, cement, calcium sulfate whiskers, organic montmorillonite, a thixotropic agent and carbon black. The invention has the advantages of high bonding strength of the interface with water, high mechanical strength, good toughness, strong impact resistance and fatigue resistance, good construction performance and the like, can obviously improve the bonding effect and durability of the structural adhesive in the engineering of reinforcing the environment with water, and is particularly suitable for the adhesive requirement of the engineering of reinforcing and repairing the hydraulic buildings.
Description
Technical Field
The invention belongs to the technical field of chemical building materials, and particularly relates to a high-performance structural adhesive for water environment reinforcing engineering and a preparation method thereof.
Background
The building structure adhesive is used as a core material of a chemical bonding reinforcement technology, and the bonding quality of the building structure adhesive plays an important role in the structure reinforcement effect. The epoxy structural adhesive is widely applied to the field of concrete structure reinforcing engineering by the characteristics of excellent bonding performance, outstanding mechanical property, small curing shrinkage rate, good process performance, good storage stability and the like, and is one of the most important building materials in the structural reinforcing engineering.
The epoxy structural adhesive has good bonding performance in a dry environment, but the bonding performance is obviously reduced in a water environment, and the application requirement of special environmental structure reinforcement engineering cannot be met. In recent years, underwater buildings such as reservoirs, dams, culverts, piers, embankments, port wharfs and the like are reinforced more and more, the engineering inevitably involves bonding on water or wet interfaces, and the high-performance structural adhesive for the water environment reinforcing engineering is required to be more and more, and the performance requirement is higher and more.
Before the invention, a Chinese patent with an application number of 201110224028.X discloses an underwater epoxy structure adhesive, the shear strength of the adhesive measured after the adhesive is cured in an underwater environment is 16.6MPa, the tensile strength of the adhesive is 31.2MPa, the strength index of the adhesive meets the standard requirement of steel adhesive in GB50367-2006 specification for reinforcing a concrete structure, but the standard is not the standard of the underwater structure adhesive, and the shear strength of the adhesive does not meet the standard requirement that the shear strength is more than 19.4MPa in JT/T215-1995 technical requirement of the underwater adhesive and an experimental method, so that the development of a high-performance underwater structure adhesive meeting the standard requirement of JT/T215-1995 technical requirement of the underwater adhesive and the experimental method has important practical significance for reinforcing engineering of the underwater environment with water.
Disclosure of Invention
The invention aims to solve the problem of application of a structural adhesive in a water-borne environment reinforcement project, provides a high-performance structural adhesive and a preparation method thereof, and aims to solve the problem that the traditional structural adhesive has poor bonding performance on a water or moisture interface and cannot meet the application requirement of the hydraulic structure reinforcement project.
The high-performance structural adhesive for the water-borne environment reinforcement engineering is composed of A, B two components in a mass ratio of 2:1-3: 1; and after the component A and the component B are accurately weighed according to the mass ratio, uniformly stirring and mixing to obtain the high-performance structural adhesive for the water-borne environment reinforcement engineering.
The formula of the component A comprises the following components in parts by mass: 60-80 parts of nano-silica graft modified epoxy resin, 0-10 parts of epoxy active diluent, 10-30 parts of elastic modifier, 1-2 parts of water-absorbent resin, 0.1-0.2 part of defoaming agent, 0.1-0.2 part of dispersing agent, 120 parts of active silica powder, 180 parts of cement, 5-10 parts of calcium sulfate whisker, 3-8 parts of organic montmorillonite and 1-4 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 100 parts of compound amine curing agent, 0-4 parts of curing accelerator and 4-7 parts of coupling agent; 0.1-0.2 part of defoaming agent, 0.1-0.2 part of dispersing agent, 180 parts of active silica powder, 5-10 parts of cement, 5-15 parts of calcium sulfate whisker, 3-8 parts of organic montmorillonite, 1-4 parts of thixotropic agent and a proper amount of carbon black.
The nano-silica graft modified epoxy resin in the component A is obtained by grafting hydroxyl groups enriched on the surfaces of nano-silica particles and epoxy groups in an epoxy resin molecular structure through chemical reaction, wherein the particle size of the nano-silica particles is 20-40nm, the epoxy resin is liquid bisphenol F type epoxy resin, and the mass fraction of the nano-silica is 2-4%; the epoxy active diluent is one or a mixture of more of diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether and butanediol diglycidyl ether; the elastic modifier is a liquid polymer with a main chain of a flexible chain segment and an end group of an epoxy group; the water-absorbing resin is a starch grafted acrylate polymerization cross-linked product or an acrylamide-acrylate copolymerization cross-linked product.
The compound amine curing agent in the component B is prepared by compounding a phenolic aldehyde amine curing agent and a polyamide curing agent according to a certain proportion, wherein the phenolic aldehyde amine curing agent is a compound prepared by performing a Mannich reaction on the basis of cardanol, formaldehyde, long-chain aliphatic amine and the like, and the mass fraction of the phenolic aldehyde amine curing agent is 30-70%; the curing accelerator is one of phenol, bisphenol A, resorcinol, DMP-30 and boron trifluoride monoethylamine; the coupling agent is one of vinyl triethoxysilane, KH-550, KH-570, and aniline methyl triethoxysilane.
The defoaming agent in the component A and the component B is BYK-066N; the dispersant is BYK-163; the active silicon micro powder is 400-mesh quasi-spherical silicon micro powder subjected to surface treatment by a silane coupling agent; the cement is ordinary portland cement; the calcium sulfate crystal whisker is an active crystal whisker which is subjected to surface modification by a silane coupling agent and has the average diameter of 1-8 mu m and the average length of 50-200 mu m; the organic montmorillonite is montmorillonite treated by quaternary ammonium salts such as cationic surfactant octadecyl and trimethyl, etc.; the thixotropic agent is hydrophobic fumed silica with the surface treated by organic matters.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 2-3 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 8-10 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 50-60 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 3-5 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 50-60 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-insulating device, the rotating speed of the dispersion disc is set to be 1000-1200rpm, and the temperature is set to be 40-60 ℃;
the premix of the solid raw materials is obtained by preliminarily mixing the solid raw materials before adding the solid raw materials into the planetary stirrer, so that the solid raw materials are uniformly mixed in advance, the mixing and dispersing time in the planetary stirrer is shortened, and the phenomenon that the viscosity of the materials is sharply increased and exceeds the maximum power of the stirrer due to the fact that the thixotropic agent is added into the planetary stirrer at one time is avoided.
And grinding the materials in the planetary stirrer by a three-roller grinder, and then packaging and storing the materials, wherein the grinding times are 2 times.
By adopting the technical scheme, the invention has the following advantages:
1) the inorganic nano material is modified, and the adhesive has high physical strength. According to the invention, the matrix resin is the nano silicon dioxide graft modified epoxy resin, the nano material can be uniformly dispersed in the matrix resin, and the characteristics of high specific surface area, high modulus, nano size effect and the like of inorganic nano silicon dioxide particles are used as a reinforcing material, so that the mechanical strength of the colloidal material can be obviously improved;
2) organic-inorganic composite toughening and good colloid toughness. According to the invention, a composite toughening system of inorganic nano silicon dioxide and an organic elastic modifier is adopted, and an inorganic nano particle toughening mechanism and a rubber elastomer toughening mechanism exist in a colloid when external stress is borne, so that the toughening effect is obvious, and the elastic modulus is not reduced;
3) the hydrophobic structure and the hydrophilic structure have synergistic effect, and the bonding strength of the interface with water is high. The key to water-borne interfacial bonding is how to eliminate the interfacial water film, allowing the adhesive to wet, spread and penetrate at the interface. The invention adopts the following mode to realize the high-efficiency bonding of the interface with water:
(a) adopts a phenolic amine and polyamide compound curing system. The phenolic aldehyde amine curing agent is a compound formed by a Mannich reaction based on cardanol, formaldehyde, long-chain aliphatic amine and the like, the aliphatic long side chain of the phenolic aldehyde amine curing agent endows the curing agent with excellent hydrophobic property, and the hydrophobic effect can ensure that the surrounding moisture does not influence the adhesion effect of surface resin; the polyamide curing agent has better hydrophilic property due to the amido bond contained in the molecular structure, and can ensure better compatibility of the adhesive and an interfacial water film, so that the compound curing system can ensure that the adhesive is effectively bonded on a water-carrying interface, and can also prevent external water from permeating into the bonding interface to further influence the bonding effect and the durability of a bonding structure.
(b) Adding water-absorbing component into the formula system. The water-absorbing materials such as water-absorbing resin and cement are added into the formula system, so that the water in the interface water film can be absorbed by the water-absorbing materials in the system under the condition that the whole epoxy adhesive is hydrophobic and drains water, the adverse effect of the interface water film on the interface bonding is eliminated, and the interface bonding strength is improved.
4) Calcium sulfate whisker and organic montmorillonite are used as functional fillers, and the colloid has strong impact resistance and fatigue resistance. The calcium sulfate whisker is a whisker-shaped single crystal which is similar to a short fiber in shape and much smaller than the short fiber in size, has extremely small diameter and extremely large length-diameter ratio, has a highly ordered atomic arrangement structure, is almost free from defects existing in a common large crystal, and has extremely excellent physicochemical properties and excellent mechanical properties. Compared with commonly applied organic short fibers, the calcium sulfate whisker has better compatibility with various inorganic fillers and better dispersibility, basically has no problem of dispersibility, has better compatibility with an epoxy group after being modified by a coupling agent, and can better exert the fiber reinforcement function.
Montmorillonite is a clay mineral formed by stacking silicate sheets with negative electricity on the surface and with nanometer thickness by virtue of the electrostatic action between layers, and has a unique one-dimensional layered nano structure. The montmorillonite is not favorable for dispersion in epoxy matrix due to lipophobicity of montmorillonite caused by a large amount of inorganic ions between layers, and after organic modification, the hydrophilicity between montmorillonite layers can be changed into lipophilicity, the surface energy of montmorillonite can be reduced, the interlayer spacing of montmorillonite can be increased, and the chain or monomer of polymer can enter between layers, so that the nano composite material can be manufactured, and the impact resistance and fatigue resistance of colloid can be obviously improved.
According to the invention, by utilizing the synergistic effect of the fiber reinforced material and the nano composite material, when the colloid bears external stress, external energy is greatly absorbed in the forms of deformation of a microstructure, interface stripping and the like, so that the impact resistance and the fatigue resistance of the colloid can be remarkably improved.
5) The hydrophobic fumed silica is used as a thixotropic agent, the adhesive has good construction performance, and the adhesive is particularly suitable for construction in a water-carrying environment. The hydrophobic fumed silica serving as the thixotropic agent can obviously improve the hydrophobicity and the water drainage of the adhesive and greatly reduce the adverse effect of external water on the interface bonding and the colloid curing of the adhesive.
Compared with the prior art, the invention has the following advantages:
1) the water-carrying interface has high bonding strength. The invention realizes the high-efficiency bonding of the interface with water by utilizing the synergistic effect of the hydrophobic structure and the hydrophilic structure and adopting two modes of a phenolic amine and polyamide compound curing system and adding a water-absorbing material in the formula.
2) High mechanical strength and toughness. According to the invention, the nano silicon dioxide graft modified epoxy resin is used as a matrix material, and the mechanical strength of the colloidal material can be remarkably improved by utilizing the characteristics of high specific surface area, high modulus, nano size effect and the like of nano silicon dioxide particles; meanwhile, a composite toughening system of inorganic nano silicon dioxide and an organic elastic modifier is adopted, so that an inorganic nano particle toughening mechanism and a rubber elastomer toughening mechanism exist in the colloid at the same time, the toughening effect is obvious, and the elastic modulus is not reduced.
3) Strong impact resistance and fatigue resistance. The invention utilizes the synergistic effect of the fiber reinforced material and the nano composite material to ensure that the colloid can greatly absorb the external energy in the forms of microstructure deformation, interface peeling and the like when bearing the external stress, so the colloid has high impact resistance and fatigue resistance.
4) The construction performance in water environment is good. The invention adopts hydrophobic fumed silica as the thixotropic agent, can obviously improve the hydrophobicity and the water drainage of the adhesive, greatly weakens the adverse effect of external water on the interface bonding and the colloid solidification of the adhesive, and is more suitable for construction glue in a water-carrying environment.
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.
Example 1:
the high-performance structural adhesive for the water-borne environment reinforcement engineering consists of A, B two components in mass ratio: and the component B is 2: 1. The component A and the component B are accurately weighed according to the mass ratio, and then are stirred and mixed uniformly to obtain the invention.
The formula of the component A comprises the following components in parts by mass: 60 parts of nano-silica graft modified epoxy resin, 10 parts of epoxy active diluent, 30 parts of elastic modifier, 1 part of water-absorbent resin, 0.1 part of defoaming agent, 0.1 part of dispersing agent, 120 parts of active silica micropowder, 5 parts of cement, 5 parts of calcium sulfate whisker, 3 parts of organic montmorillonite and 4 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 30 parts of phenolic aldehyde amine curing agent, 70 parts of polyamide curing agent, 4 parts of curing accelerator and 4 parts of coupling agent; 0.1 part of defoaming agent, 0.1 part of dispersing agent, 120 parts of active silica powder, 5 parts of cement, 5 parts of calcium sulfate whisker, 3 parts of organic montmorillonite, 4 parts of thixotropic agent and 0.001 part of carbon black.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 3 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 10 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding the premix into the planetary stirrer for mixing and stirring for 50 minutes in a small amount; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 5 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 50 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, wherein the rotating speed of the dispersion disc is set to be 1000rpm, and the temperature is set to be 40 ℃.
Example 2:
the high-performance structural adhesive for the water-borne environment reinforcement engineering consists of A, B two components in mass ratio: the component B is 3: 1; the component A and the component B are accurately weighed according to the mass ratio, and then are stirred and mixed uniformly to obtain the invention.
The formula of the component A comprises the following components in parts by mass: 80 parts of nano-silica graft modified epoxy resin, 0 part of epoxy active diluent, 10 parts of elastic modifier, 2 parts of water-absorbent resin, 0.2 part of defoaming agent, 0.2 part of dispersing agent, 180 parts of active silica micropowder, 10 parts of cement, 15 parts of calcium sulfate whisker, 8 parts of organic montmorillonite and 1 part of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 70 parts of phenolic aldehyde amine curing agent, 30 parts of polyamide curing agent, 0 part of curing accelerator and 7 parts of coupling agent; 0.2 part of defoaming agent, 0.2 part of dispersing agent, 180 parts of active silica micropowder, 10 parts of cement, 15 parts of calcium sulfate whisker, 8 parts of organic montmorillonite, 1 part of thixotropic agent and a proper amount of carbon black.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 2 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 8 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding the premix into the planetary stirrer for mixing and stirring for 60 minutes in a small amount; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 3 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 60 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, wherein the rotating speed of the dispersion disc is set to be 1200rpm, and the temperature is set to be 60 ℃.
Example 3:
the high-performance structural adhesive for the water-borne environment reinforcement engineering consists of A, B two components in mass ratio: the component B is 3: 1; the component A and the component B are accurately weighed according to the mass ratio, and then are stirred and mixed uniformly to obtain the invention.
The formula of the component A comprises the following components in parts by mass: 70 parts of nano-silica graft modified epoxy resin, 5 parts of epoxy active diluent, 20 parts of elastic modifier, 1.5 parts of water-absorbent resin, 0.15 part of defoaming agent, 0.15 part of dispersing agent, 150 parts of active silica micropowder, 8 parts of cement, 10 parts of calcium sulfate whisker, 5 parts of organic montmorillonite and 2 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 50 parts of phenolic aldehyde amine curing agent, 50 parts of polyamide curing agent, 3 parts of curing accelerator and 5 parts of coupling agent; 0.15 part of defoaming agent, 0.15 part of dispersing agent, 150 parts of active silica micropowder, 8 parts of cement, 10 parts of calcium sulfate whisker, 5 parts of organic montmorillonite, 3 parts of thixotropic agent and a proper amount of carbon black.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 2.5 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 9 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding the premix into the planetary stirrer for mixing and stirring for 55 minutes in a small amount; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 2.5 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 55 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, wherein the rotating speed of the dispersion disc is set to be 1100rpm, and the temperature is set to be 50 ℃.
Example 4:
the high-performance structural adhesive for the water-borne environment reinforcement engineering consists of A, B two components in mass ratio: the component B is 2: 1; the component A and the component B are accurately weighed according to the mass ratio, and then are stirred and mixed uniformly to obtain the invention.
The formula of the component A comprises the following components in parts by mass: 75 parts of nano-silica graft modified epoxy resin, 5 parts of epoxy active diluent, 15 parts of elastic modifier, 1.5 parts of water-absorbent resin, 0.15 part of defoaming agent, 0.15 part of dispersing agent, 120 parts of active silica micropowder, 5 parts of cement, 5 parts of calcium sulfate whisker, 3 parts of organic montmorillonite and 4 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 40 parts of phenolic aldehyde amine curing agent, 60 parts of polyamide curing agent, 3 parts of curing accelerator and 5 parts of coupling agent; 0.15 part of defoaming agent, 0.15 part of dispersing agent, 180 parts of active silica micropowder, 10 parts of cement, 15 parts of calcium sulfate whisker, 8 parts of organic montmorillonite, 1 part of thixotropic agent and a proper amount of carbon black.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 2 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 8 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding the premix into the planetary stirrer for mixing and stirring for 50 minutes in a small amount; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 3 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 60 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, wherein the rotating speed of the dispersion disc is set to be 1200rpm, and the temperature is set to be 60 ℃.
Example 5:
the high-performance structural adhesive for the water-borne environment reinforcement engineering consists of A, B two components in mass ratio: the component B is 3: 1; the component A and the component B are accurately weighed according to the mass ratio, and then are stirred and mixed uniformly to obtain the invention.
The formula of the component A comprises the following components in parts by mass: 65 parts of nano-silica graft modified epoxy resin, 10 parts of epoxy active diluent, 25 parts of elastic modifier, 2 parts of water-absorbent resin, 0.15 part of defoaming agent, 0.15 part of dispersing agent, 180 parts of active silica micropowder, 10 parts of cement, 15 parts of calcium sulfate whisker, 8 parts of organic montmorillonite and 2 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 65 parts of phenolic aldehyde amine curing agent, 35 parts of polyamide curing agent, 1 part of curing accelerator and 5 parts of coupling agent; 0.15 part of defoaming agent, 0.15 part of dispersing agent, 120 parts of active silica powder, 5 parts of cement, 5 parts of calcium sulfate whisker, 3 parts of organic montmorillonite, 4 parts of thixotropic agent and a proper amount of carbon black.
The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering comprises the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 3 minutes; then adding the raw materials such as the elastic modifier, the water-absorbent resin, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 10 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the like into a planetary stirrer in batches, and gradually adding the premix into the planetary stirrer for mixing and stirring for 60 minutes in a small amount; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component A.
2) Preparation of the component B: weighing the raw materials according to the proportion, firstly adding the raw materials such as the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent, the dispersing agent and the like into a planetary stirrer, and stirring and mixing for 3 minutes; then adding the premix of the solid raw materials such as the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent, the carbon black and the like into a planetary stirrer in batches, and gradually adding a small amount of the premix into the planetary stirrer for mixing and stirring for 50 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
The planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, wherein the rotating speed of the dispersion disc is set to be 1200rpm, and the temperature is set to be 60 ℃.
In the above embodiments 1 to 5, the nano silica graft modified epoxy resin is obtained by grafting hydroxyl groups enriched on the surface of nano silica particles and epoxy groups in the molecular structure of the epoxy resin through a chemical reaction, wherein the particle size of the nano silica particles is 20 to 40nm, the epoxy resin is liquid bisphenol F type epoxy resin, and the mass fraction of the nano silica is 3%;
the epoxy reactive diluent is polyethylene glycol diglycidyl ether;
the elastic modifier is a polyurethane elastic modifier QS-P24B, and the Beijing Jindaoshi material has limited technology
Company production; the water-absorbent resin is an acrylamide-acrylate copolymerization crosslinking product;
the phenolic aldehyde amine curing agent is a compound formed by Mannich reaction based on cardanol, formaldehyde, long-chain fatty amine and the like, and is NX-6032 phenolic aldehyde amine curing agent produced by Kadeli company;
the curing accelerator is phenol;
the coupling agent is KH-570;
the defoaming agent is BYK-066N;
the dispersant is BYK-163;
the active silicon micro powder is 400-mesh quasi-spherical silicon micro powder subjected to surface treatment by a silane coupling agent;
the cement is ordinary portland cement;
the calcium sulfate whisker is an active whisker which is subjected to surface modification by a silane coupling agent and has the average diameter of 1-8 mu m and the average length of 50-200 mu m;
the organic montmorillonite is montmorillonite treated by a cationic surfactant octadecyl quaternary ammonium salt;
the thixotropic agent is hydrophobic fumed silica with the surface treated by organic matters.
The premix of the solid raw materials is obtained by preliminarily mixing the solid raw materials before adding the solid raw materials into the planetary stirrer, so that the solid raw materials are uniformly mixed in advance, the mixing and dispersing time in the planetary stirrer is shortened, and the phenomenon that the viscosity of the materials is sharply increased and exceeds the maximum power of the stirrer due to the fact that the thixotropic agent is added into the planetary stirrer at one time is avoided.
And grinding the materials in the planetary stirrer by a three-roller grinder, and then packaging and storing the materials, wherein the grinding times are 2 times.
The performance test structure of the high-performance structural adhesives prepared in examples 1-5 in an in-water environment is as follows:
Claims (5)
1. the high-performance structural adhesive for the water environment reinforcing engineering is characterized by consisting of A, B two components in a mass ratio of 2:1-3: 1; after the component A and the component B are accurately weighed according to the mass ratio, uniformly stirring and mixing to obtain the high-performance structural adhesive for the water-borne environment reinforcement engineering;
the formula of the component A comprises the following components in parts by mass: 60-80 parts of nano-silica graft modified epoxy resin, 0-10 parts of epoxy active diluent, 10-30 parts of elastic modifier, 1-2 parts of water-absorbent resin, 0.1-0.2 part of defoaming agent, 0.1-0.2 part of dispersing agent, 120 parts of active silica powder, 180 parts of cement, 5-10 parts of calcium sulfate whisker, 3-8 parts of organic montmorillonite and 1-4 parts of thixotropic agent;
the formula of the component B comprises the following components in parts by mass: 100 parts of compound amine curing agent, 0-4 parts of curing accelerator and 4-7 parts of coupling agent; 0.1-0.2 part of defoaming agent, 0.1-0.2 part of dispersing agent, 180 parts of active silica powder, 5-10 parts of cement, 5-15 parts of calcium sulfate whisker, 3-8 parts of organic montmorillonite, 1-4 parts of thixotropic agent and 0.001-0.1 part of carbon black;
the nano-silica graft modified epoxy resin in the component A is obtained by grafting hydroxyl groups enriched on the surfaces of nano-silica particles and epoxy groups in an epoxy resin molecular structure through chemical reaction, wherein the particle size of the nano-silica particles is 20-40nm, the epoxy resin is liquid bisphenol F type epoxy resin, and the mass fraction of the nano-silica is 2-4%; the epoxy active diluent is one or a mixture of more of diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether and butanediol diglycidyl ether; the elastic modifier is a liquid polymer with a main chain of a flexible chain segment and an end group of an epoxy group; the water-absorbing resin is a starch grafted acrylate polymerization cross-linked product or an acrylamide-acrylate copolymerization cross-linked product;
the compound amine curing agent in the component B is prepared by compounding a phenolic aldehyde amine curing agent and a polyamide curing agent; wherein the phenolic aldehyde amine curing agent is a compound formed by performing a Mannich reaction on the basis of cardanol, formaldehyde and long-chain fatty amine; the curing accelerator is one of phenol, bisphenol A, resorcinol, DMP-30 and boron trifluoride monoethylamine; the coupling agent is one of vinyl triethoxysilane, KH-550, KH-570, and aniline methyl triethoxysilane;
the defoaming agent in the component A and the component B is BYK-066N; the dispersant is BYK-163; the active silicon micro powder is 400-mesh spherical silicon micro powder subjected to surface treatment by a silane coupling agent; the cement is ordinary portland cement; the calcium sulfate whiskers are active whiskers with the average diameter of 1-8 mu m and the average length of 50-200 mu m after surface modification by a silane coupling agent; the organic montmorillonite is montmorillonite treated by cationic surfactant octadecyl quaternary ammonium salt; the thixotropic agent is hydrophobic fumed silica with the surface treated by organic matters.
2. The high-performance structural adhesive for the water-borne environment reinforcement engineering according to claim 1, wherein the mass fraction of the phenolic aldehyde amine curing agent in the compound amine curing agent is 30-70%.
3. The preparation method of the high-performance structural adhesive for the water-borne environment reinforcement engineering according to claim 1 or 2, which is characterized by comprising the following specific steps:
1) preparation of component A: weighing the raw materials according to the proportion, firstly adding the nano silicon dioxide graft modified epoxy resin and the epoxy active diluent into a planetary stirrer, and stirring and mixing for 2-3 minutes; then adding the elastic modifier, the water-absorbent resin, the defoaming agent and the dispersing agent into a planetary stirrer, and stirring and mixing for 8-10 minutes; then adding the premix of the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite and the thixotropic agent into a planetary stirrer in batches, and mixing and stirring for 50-60 minutes; finally, grinding the materials in the planetary stirrer by a three-roller grinder, and packaging and storing to obtain a component A;
2) preparation of the component B: weighing the raw materials according to the proportion, adding the compound amine curing agent, the curing accelerator, the coupling agent, the defoaming agent and the dispersing agent into a planetary stirrer, and stirring and mixing for 3-5 minutes; then adding the premix of the active silica micropowder, the cement, the calcium sulfate whisker, the organic montmorillonite, the thixotropic agent and the carbon black into a planetary stirrer in batches, and mixing and stirring for 50-60 minutes; and finally, grinding the materials in the planetary stirrer by a three-roll grinder, and packaging and storing to obtain the component B.
4. The method for preparing the high-performance structural adhesive for the water-borne environment reinforcement project according to claim 3, wherein the planetary stirrer is provided with a dispersion disc and a heating and heat-preserving device, the rotation speed of the dispersion disc is set to 1000-1200rpm, and the temperature is set to 40-60 ℃.
5. The method for preparing the high-performance structural adhesive for the water environment reinforcement project according to claim 3, wherein the materials in the planetary stirrer are ground by a three-roll grinder and then packaged and stored, and the grinding times are 2 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710936735.9A CN107674622B (en) | 2017-10-10 | 2017-10-10 | High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710936735.9A CN107674622B (en) | 2017-10-10 | 2017-10-10 | High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107674622A CN107674622A (en) | 2018-02-09 |
| CN107674622B true CN107674622B (en) | 2020-04-24 |
Family
ID=61139525
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710936735.9A Active CN107674622B (en) | 2017-10-10 | 2017-10-10 | High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107674622B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110885410A (en) * | 2018-04-21 | 2020-03-17 | 湖南辰砾新材料有限公司 | Fluorosilicone modified acid and alkali resistant epoxy resin emulsion and preparation method thereof |
| CN108753224B (en) * | 2018-04-26 | 2021-02-26 | 山西省交通科学研究院 | Bridge segment assembling glue and preparation method and construction process thereof |
| CN108609915A (en) * | 2018-04-26 | 2018-10-02 | 山西省交通科学研究院 | A kind of composite concrete material and preparation method thereof |
| CN108546008B (en) * | 2018-04-26 | 2021-03-16 | 山西省交通科学研究院 | Epoxy resin/cement mortar composite concrete material and preparation method thereof |
| CN108559431B (en) * | 2018-04-26 | 2021-03-16 | 山西省交通科技研发有限公司 | Interface adhesive for bonding new and old concrete and preparation method and construction process thereof |
| CN108894074A (en) * | 2018-06-10 | 2018-11-27 | 重庆诚邦路面材料有限公司 | A kind of fine antiskid wearing layer of cement pavement and construction method |
| CN109628038B (en) * | 2018-12-26 | 2021-05-28 | 北京新时代寰宇科技发展有限公司 | Novel modified epoxy resin adhesive for building and preparation method thereof |
| CN111592846A (en) * | 2019-09-12 | 2020-08-28 | 石家庄广科新材料有限公司 | Epoxy adhesive for preparing prefabricated wallboard mold and preparation method thereof |
| CN113845890B (en) * | 2020-06-28 | 2023-05-26 | 中国石油化工股份有限公司 | Borehole wall repairing agent suitable for broken stratum and preparation method and application thereof |
| CN112175557A (en) * | 2020-09-24 | 2021-01-05 | 江苏锋芒复合材料科技集团有限公司 | Adhesive for ultra-wide grinding belt |
| CN114933782B (en) * | 2022-05-07 | 2023-04-11 | 中南大学 | Epoxy resin grouting material and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102391817A (en) * | 2011-08-05 | 2012-03-28 | 苏州市姑苏新型建材有限公司 | Underwater epoxy structure adhesive and preparation method thereof |
-
2017
- 2017-10-10 CN CN201710936735.9A patent/CN107674622B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102391817A (en) * | 2011-08-05 | 2012-03-28 | 苏州市姑苏新型建材有限公司 | Underwater epoxy structure adhesive and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107674622A (en) | 2018-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107674622B (en) | High-performance structural adhesive for water environment reinforcing engineering and preparation method thereof | |
| CN108546008B (en) | Epoxy resin/cement mortar composite concrete material and preparation method thereof | |
| CN108559431B (en) | Interface adhesive for bonding new and old concrete and preparation method and construction process thereof | |
| CN107445545B (en) | High-ductility cement-based composite material for repairing hydraulic concrete structure | |
| CN107840626B (en) | Double-doped grouting material for road surface restoration and preparation method thereof | |
| CN103482904B (en) | A kind of modified epoxy mortar resistant abrasion patching material | |
| CN111423192B (en) | Method for improving deformation capacity of high-ductility concrete | |
| CN1887955A (en) | Green high-strength epoxy grouting material and its prepn | |
| CN103965820B (en) | High strength underwater structure glue and preparation method thereof | |
| CN102504670A (en) | Permeable epoxy resin waterproof coating for concrete | |
| CN112500042A (en) | Elastic-toughness well cementation cement slurry suitable for coal bed gas and preparation method thereof | |
| CN108609915A (en) | A kind of composite concrete material and preparation method thereof | |
| CN111718680A (en) | Interface adhesive for improving bonding force of new and old concrete and preparation method and construction process thereof | |
| CN114031896B (en) | Epoxy resin composition for carbon fiber winding and preparation method thereof | |
| CN107746550B (en) | High-permeability non-shrinkage epoxy grouting material | |
| CN114907802B (en) | Carbon fiber impregnating adhesive for maintaining underwater concrete member and preparation method thereof | |
| CN113897160A (en) | Carbon fiber cloth adhesive for underwater or humid environment reinforcement engineering and preparation method thereof | |
| CN108275913A (en) | A kind of bridge epoxy resin mortar and preparation method thereof | |
| CN111454018A (en) | High-toughness wear-resistant epoxy resin polymer mortar and application method thereof | |
| CN1597775A (en) | Preparation technology for composite of epoxy resin nano silicon dioxide | |
| CN106883733A (en) | A kind of freeze-thawing resistant epoxy protective coating and preparation method thereof | |
| CN116283055A (en) | Epoxy repair material and preparation method and application thereof | |
| CN1250667C (en) | Dynamic structural adhesive for bridge | |
| CN114276077B (en) | Underwater building structure repair material and preparation method and application thereof | |
| CN110922925A (en) | Epoxy resin adhesive for wet surface of concrete |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20221107 Address after: 030032 No.27, Wuluo street, economic and Technological Park, Xiaodian District, Taiyuan City, Shanxi Province Patentee after: Shanxi Transportation Technology Research and Development Co.,Ltd. Address before: 030006 No. 79 Xuefu street, Shanxi, Taiyuan Patentee before: Shanxi Transportation Research Institute |