Characteristics of Adhesive Materials

Sina Ebnesajjad PhD , Arthur H. Landrock , in Adhesives Engineering science Handbook (Third Edition), 2022

5.56 Vinyl-Phenolic Adhesives

These structural adhesive alloys are also polyvinyl acetals. They may be phenolic-vinyl butyral or phenolic-vinyl formal [8]. "Vinyl" in vinyl-phenolic adhesive is a somewhat misleading term referring either to polyvinyl formal or to polyvinyl butyral. Vinyl phenolics generally take excellent durability, both in water and in other adverse environments. Cure takes identify at 177°C for the polyvinyl formal-phenolic and at 150°C for the polyvinyl butyral-phenolic. These adhesives provide excellent performance, primarily every bit film adhesives. Grades that cure at lower temperatures and pressures yield higher hot strength, college peel force, and take other performance advantages [8,22–24]. Tables five.xi and 5.12 and Section 5.3 provide useful information on these adhesives and their force properties.

Cure conditions for the polyvinyl formal-phenolic film consist of 177°C for 5   min or 150°C for thirty   min at 0.35–3.v   MPa bonding force per unit area. Curing of polyvinyl butyral-phenolic film requires a temperature of 150°C at 0.10–0.20   MPa pressure. Polyvinyl formal-phenolic film, the most mutual form, retains adequate strength when exposed to atmospheric condition, mold growth, salt spray, humidity, and chemical agents such as water, oils, and aromatic fuels. These adhesives more often than not have expert resistance to creep, although temperatures upwards to 90°C produce pitter-patter and softening of some formulations. Fatigue resistance is splendid, with failure generally occurring in the adherends rather than in the adhesive, which has a service temperature range of −sixty°C to 100°C [8].

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Adhesives for Special Adherends

In Adhesives Technology Handbook (Second Edition), 2009

six.ii.8 Magnesium and Magnesium Alloys

Adhesives recommended include epoxies epoxy-phenolics, polyurethanes, silicones, cyanoacrylates, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl-phenolic, nitrile-phenolic, neoprene-phenolic, and nylon-epoxy. A wide diverseness of adhesives can be used for bonding magnesium every bit long every bit proper corrosion protection is maintained in keeping with articulation design and terminate-use requirements. Because of magnesium's sensitivity to moisture and the galvanic couple, water-based adhesives would exist expected to cause problems. Surface grooming should ever exist carried out to ensure that the adhesive itself does not react with the alloy to create a corrosive status. Another important observation is that loftier-modulus adhesives tend to provide lower bond strengths than lower-modulus adhesives. [x]

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Adhesives for Special Adherends

Sina Ebnesajjad , in Handbook of Adhesives and Surface Preparation, 2022

eleven.2.8 Magnesium and Magnesium Alloys

Adhesives recommended include epoxies, epoxy-phenolics, polyurethanes, silicones, cyanoacrylates, polyvinyl acetate, vinyl chloride–vinyl acetate copolymer, vinyl-phenolic, nitrile-phenolic, neoprene-phenolic, and nylon-epoxy. A broad diverseness of adhesives can be used for bonding magnesium as long as proper corrosion protection is maintained in keeping with articulation design and end-employ requirements. Owing to magnesium's sensitivity to moisture and the galvanic couple, water-based adhesives would be expected to crusade bug. Surface preparation should always be carried out in order to ensure that the agglutinative itself does not react with the blend to create a corrosive status. Another important observation is that high-modulus adhesives tend to provide lower bond strengths than do lower-modulus adhesives. ten

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Engineering materials

J. Carvill , in Mechanical Engineer's Data Handbook, 1993

6.sixteen.7 Complementary adhesives and adherents *

Adhesive
Adherends Natural Animal glues Starch Dextrine Casein Elastomers Acrylonitrile butadiene Polychloroprene Polyurethane Silicone safety Polybutadiene Natural rubber Butyl Thermoplastics Cellulose nitrate Polyvinyl alcohol Polyvinyl acetate Polyacrylate Silicone resin Cyanoacrylate Thermosets Phenolic formaldehyde Urea formaldehyde Resorcinol formaldehyde Melamine formaldehyde Polyesters (unsaturated) Epoxy resins Polyamides Phenolic-vinyl formal Phenolic-poly vinylacetal Phenolic nitrile Phenolic epoxy Inorganic Sodium silicate
Metals × × × × × × × × × ×
Drinking glass ceramics × × × × × × × × ×
Wood × × × × × × × × ×
Paper × × × × × × × ×
Leather × × × × ×
Textiles, felt × × × × ×
Elastomers
Polychloroprene ×
(neoprene)
Nitrile × ×
Natural × × × ×
Silicone ×
Butyl × ×
Polyurethane × × ×
Thermoplastics
Polyvinyl chloride × × ×
(flexible)
Polyvinyl chloride × × × ×
(rigid)
Cellulose acetate × × ×
Cellulose nitrate × × ×
Ethyl cellulose × × × ×
Polyethylene (motion-picture show) × × ×
Polyethylene (rigid) × ×
Polypropylene (flick) × × ×
Polypropylene (rigid) × ×
Polycarbonate × ×
Fluorocarbons × × × ×
Polystyrene × × ×
Polyamides (nylon) × × × × ×
Polyformaldehyde × × × ×
(acetals)
Methylpentene × ×
Thermosets
Epoxy × × × ×
Phenolic × × × × ×
Polyester × ×
Melamine × × ×
Polyethylene × × × ×
terephthalate
Diallylphthalate × × ×
Polyimide × ×

Notation: in general, any two adherends may be bonded together if the chart shows that they are uniform with the same adhesive.

*
From Shields, J. Adhesive Bonding, The Design Council.

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Chemical Pumps Metallic and Nonmetallic

Frederic W. Buse , in Centrifugal Pumps (Second Edition), 1992

Thermosetting Polymers

Thermosetting polymers for pump apply are reinforced with fiberglass or carbon fibers. During the molding cycle, these materials undergo a chemical change that is irreversible. The resulting material will non soften or become pliable with heat. They accept iv basic chemistries: polyesters, phenolics, vinyl esters, and epoxies. Each has its ain set of advantages, manufacturing processes, and mechanical and chemical properties. The fibers are either continuous or short fibers and are the key in developing the temperature range and corrosion resistance of the last part. There are many manufacturing processes for thermosets and they are frequently every bit as critical to the final part operation equally the pick of the proper polymer and reinforcement combination. Pinch molding, transfer molding, resin transfer molding, common cold molding, and extrusions are among the most commonly used processes.

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Classification of Adhesives and Compounds

In Adhesives Engineering Handbook (Second Edition), 2009

4.three.7 Society of Manufacturing Engineering science Classification

A Society of Manufacturing Engineers publication [seven] provides a useful, in-depth classification of adhesives, as shown in the following tables. [8]

four.3.seven.1 Chemically Reactive Types

Table four.vii. Catalytic Plural Components—Chemic Cure

Epoxy Polysulfide
Phenolic Polyurethane
Resorcinol-formaldehyde Silicones
Polyester

Table 4.eight. Catalytic Plural Components—Moisture Cure

Silicones Cyanoacrylate
Polyurethane Epoxy (one-container type)
Polysulfides

Table iv.9. Heat-Activated Systems (One-Part, May be Solid Moving picture)

Polybenzimidazole (PBI) Polyvinyl acetates
Polyimide (PI) Vinyl-phenolic
Epoxy Vinyl-epoxies
Nylon Urethanes
Phenolic

4.3.7.two Evaporative or Improvidence Adhesives

Table 4.10. Solvent-Based Systems

Natural rubber Acrylics
Reclaimed safety Miscellaneous
Synthetic rubbers Cellulose esters
Nitrile rubber Asphalt
Neoprene (polychloroprene) Polyamides
Butyl rubber Phenoxy resins
Styrene-butadiene safety Bisphenol-A polycarbonate
Phenolics Polysulfone
Urethanes
Vinyl resins
Polyvinyl acetate
Vinyl-phenolics
Polyvinyl alkyd ethers
Polystyrene

Tabular array 4.11. Water-Based Systems

Natural rubber Miscellaneous adhesives
Reclaimed rubber Synthetic rubber Vinyl resins Natural products (animate being glue, starch, soya, blood gum, casein, cellulose derivatives)
Acrylics Carboxylic-containing copolymers

4.3.7.3 Hot-Melt Adhesives

Table four.12. Hot-Cook Adhesives

Ethylene-vinyl acetate and polyolefin resins
Polyamide (nylon) and polyester resins
Other not melts
Polyester-amides
Thermoplastic elastomers

iv.3.seven.4 Delayed-Tack Adhesives

Table 4.xiii. Delayed-Tack Adhesives

Styrene-butadiene copolymers Polystyrene
Polyvinyl acetate Polyamides

4.three.7.5 Tape and Film Adhesives

Table 4.14. Record and Flick Adhesives

Vinyl-phenolics Elastomer-epoxies (equally nitrile-epoxies)
Epoxy-phenolics Effluvious polymers (PI and PBI)
Nitrile-phenolics
Nylon-epoxies

4.3.vii.6 Pressure-Sensitive Adhesives

Pressure-sensitive adhesives are not discussed in this book.

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Engineering and Technical Guidelines for Painting

Alireza Bahadori Ph.D. , in Essentials of Coating, Painting, and Lining for the Oil, Gas and Petrochemical Industries, 2022

two.19 Electrical Methods

The electrical method of preventing corrosion involves minimizing the menses of corrosion current then that, if negligible electric current flows, negligible corrosion results. Thus, in a corrosion:

I = Eastward / R

where I is the corrosion current, Eastward is the polarized potential difference between local anodes and cathodes, and R is the full electrolyte resistance, which must be much greater than the metal conductor resistance.

Thus, the college the value of R is, the less the value of I is, so by making the electrolytic path of the current of high resistance, the movement of ions is impeded. Paint resins with the highest electrical resistance are catalyzed epoxies, phenolics, vinyls and chlorinated rubbers, each with values in the order of x ohm/cm2.

The addition of coal tar further adds to the resistance, and the addition of extended pigments in the showtime coat such equally talc, red china dirt, mica and atomic number 26 oxide also assists in increasing the resistance. Equally mentioned higher up, the removal of soluble materials on the surface is necessary because their presence will curt circuit the resistance of the paint film so that the value of I increases, possibly to the stage where rusting will occur.

The film thickness is variable and, as the diffusion of water through a paint film is inversely correlated to the moving picture thickness, it volition take longer for moisture to lengthened through a thick motion-picture show than for a sparse film. Similarly, the thicker the coating, the higher the electric resistance, and, for immersed or cached surfaces, the dry motion-picture show thickness of paints needs to be between 250 and 500 μm. An alternative method of electrically preventing corrosion of atomic number 26 is to utilise a metal that is more anodic (i.e., less noble) than iron, such equally zinc. Thus, zinc-rich paint coatings volition protect the steel; as the iron is no longer the anode of the electrical excursion, the zinc metal becomes the anode, and the atomic number 26 will non corrode.

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Introduction to using adhesives in marine and offshore engineering

J.R. Weitzenböck , in Adhesives in Marine Applied science, 2022

1.3.1 Maritime industry

There are a number of actual and potential applications for adhesive bonding in the maritime industry. However, this section will not focus on composite structures onboard ships. Composites are simply mentioned when they are to exist joined past agglutinative bonding. More information about composite applications including sandwich structure is plant in Weitzenböck et al. (2010) or for the sandwich plate organization (SPS) panels in Welch (2005). I of the offset full general reviews of marine applications of adhesive bonding was past Wacker (2000). He reported the bonding of window panes, propeller shafts and FRP pleasance boats. There are some earlier accounts of using adhesives in a marine environment for item applications. Reavey (1981) summarises many years of experience of bonding hovercraft structures successfully, mainly aluminium honeycomb. Fifty-fifty though these structures resemble aircraft structures, they are used in a marine environment. Interestingly, they chose a vinyl phenolic adhesive rather than an epoxy one as used in nigh studies reviewed in this section. A pioneering study past Hashim et al. (1989) proposed the utilize of hot curing epoxy adhesive to attach stiffeners to steel plates for structural ship applications. Results of fatigue and corrosion tests were presented.

Many applications are related to the superstructure of a ship. There are two main thrusts: to repair cracks in aluminium superstructures and to bring together lightweight structures made of composite or aluminium to the steel hull. Allan et al. (1988) report on a inquiry plan to repair aluminium superstructures of Royal Navy warships by using composite patches that are bonded to the aluminium surfaces. They report on a comprehensive design and experimental study. Grabovac and Whittaker (2009) written report on the long-term experience of using carbon-composite patches to repair cracks in an aluminium superstructure of an Australian Navy frigate. They summarise 15 years of experience with this type of repair; non only with the initial application of the composite patches but also in-service harm and wear and its subsequent repair. The authors believe this is a superior repair method for cracks with potential to be recognised as a permanent repair. There are no reports on applying bonded patch repairs to classed ships, such as container ships or oil tankers. However, at that place are considerable activities to repair floating objects, see as well the section on oil and gas applications.

The newspaper by Reichard (1997) reports on a research project to develop composite superstructures for commercial ship application. He presents an innovative bonding process where adhesive record and paste adhesive are combined to class the bonded connection betwixt the composite and steel interfaces. A recent report describes the concept design of a composite superstructure for a roll on–curlicue off ferry (McGeorge et al., 2007). The authors employed risk-based pattern and demonstrated that both structural and fire safe are at to the lowest degree equally proficient as for a conventional superstructure. An important particular of blended superstructures is the joint betwixt the superstructure and the steel deck. Most composite-steel joints are hybrid joints where adhesive bonding is combined with vertical members that limit potential movement in the in-plane management as illustrated in Fig. 1.2. Farther information well-nigh hybrid joining can be found in Weitzenböck and McGeorge (2011). In gild to facilitate more than efficient joining of composite superstructures to steel decks, a recent study looked at the possibilities of surface engineering methods for metal to composite joints in order to improve the immovability of current bonded solutions (Smith and Hutapea, 2007).

1.ii. Hybrid joint concepts for composite superstructures: (a) and (d) glued fork or rail design; (b) and (c) bonded and bolted connection (with kind permission from Springer Scientific discipline+Concern Media: Hybrid adhesive joints, Science and Technology of Commodities-Adhesive Joints, 2022, six, p187, Weitzenböck and McGeorge, Fig. 1).

A methodology for the design and construction of adhesively bonded aluminium superstructures was presented in Judd et al. (1996). In addition, the authors carried out some minor calibration materials tests. Cantrill et al. (2004) designed and constructed a full scale quarter section superstructure. They used a frame construction that was planked with aluminium plates. Both the plates and frame modules were joined by agglutinative bonding.

Adhesive bonding is used in outfitting of ships. Bonding of windows, or direct glazing, has become standard practise on rider ships. The operating feel seems to betoken that there are no problems with adhesive joining (Weitzenböck, 2009). Bonded windows are typically hybrid solutions where bonded joints are secured with additional bolts and metal strips as shown in Fig. 1.3. A give-and-take of the design and approval procedure can exist found in Weitzenböck and McGeorge (2011). Some other documented application on a fast ferry is the apply of agglutinative bonding to attach rider seat mountings to lightweight aluminium decks using adhesive bonding (Anon, 1998).

1.3. Bonded windows on a cruise send. Note the small bolted metal strips where the corners of the window panes run into (with permission from Brombach & Gess).

A meaning application of adhesive bonding is the assembly of the secondary barrier of the membrane type containment systems for LNG carriers (Weitzenböck, 2007). The majority of today's LNG carriers on order have membrane type containment systems. In the past few years there take been cases where the secondary bulwark started to develop leaks. A number of researchers and companies are addressing this problem past developing new or improved processing routes; one example is shown in Kim and Lee (2008)

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Effectiveness of using fibre-reinforced polymer composites for underwater steel pipeline repairs

Md Shamsuddoha , ... Kin-tak Lau , in Blended Structures, 2022

4.4 Electric current codes and practices

The acceptance of fibre-reinforced composites equally alternate of conventional repair materials is indicated through the contempo development of codes and standards. American Society for Testing and Materials (ASTM D2992) [94] specifies a standard practice for designing fibre glass pipe and fittings. However, the about significant advancement to the repair of loftier pressure level and high gamble pipelines is the evolution of the standard past American Society of Mechanical Engineers Pressure Technology Post Construction Committee (ASME PCC-ii:Part 4) [95] which is dedicated to the applicability of composite overwrap repairs to pipelines. Part four of ASME PCC-ii stated, "The composite materials allowed for the Repair System include, but are not limited to, glass, aramid, or carbon fibre reinforcement in a thermoset resin (e.grand., polyester, polyurethane, phenolic, vinyl ester, or epoxy) matrix. Fibres shall be continuous." This code allows whatsoever ASME compliant metallic pipeline to be repaired with a composite overwrap for all the possible repair scenarios of hoop, axial and leak proofing. The code also includes the ASME metal pipe plastic (yielding) philosophy into the repair.

ISO 24817 provides a similar methodology to ASME PCC-two all the same does not allow pipage yielding and therefore is suitable for non-metallic and/or brittle pipes [89]. ASME PCC-2 standard allows the repair of equipment and piping within the scope of ASME Pressure Technology Codes and Standards after it has been placed in service. This standard provides iii designs of repair options for non-leaking pipes. The options are: (i) piping allowable stress i.e. includes allowance for original pipe where yielding of the pipe may or may not be included, (ii) repair laminate allowable strains, i.e. exclude assart of original pipe, and (iii) repair laminate allowable stresses adamant by functioning testing, i.east. design based on long term performance test information. The pipage allowable stress method does not consider the strain hardening of the steel and remaining pipe material does not reach yield and remains elastic throughout functioning. Based on realistic case studies and the calculated values of thickness according to pipe allowable stress method, Alexander [96] concluded that calculated repair thickness was about ii.v times and 5.v times higher than the laminate allowable strain and laminate allowable stress by performance testing, respectively. According to Saeed et al. [97], ASME PCC-2 underestimates the repair layer when internal live pressure exists during the installation and circumferential strain was institute independent of the alive force per unit area. Notwithstanding, Saeed et al. causeless that the substrate pipage carried no farther load after yielding (elastic perfectly plastic) and any further load was just carried past the composite. Thus, consideration of post yield strain hardening in the analysis is one of the shortcomings in the repair of blended repair that require attention and simultaneous studies through numerical analysis and experimental exam data are suggested to attain the closest possible behaviour of the repair.

According to ASME Boiler & Pressure level Vessel Code Section 8 Division 2, 3 analysis methods are bachelor for evaluating protection confronting plastic collapse while analysing pressure vessels [98]. The methods are: (i) Rubberband Stress Analysis Method, (ii) Limit-Load Method and (iii) Elastic–Plastic Stress Assay Method. Rubberband stress analysis method compares the elastic stress analysis results of the structure subjected to certain loading conditions with an associated limiting value. All the same, for components with a complex geometry, limit load or elastic–plastic analysis methods is recommended. Limit-load method determines a lower bound to the limit load of a structure and applies design factors to the limit load such that the onset of gross plastic collapse will not occur [99]. Since limit analysis addresses the failure modes of ductile rupture and the onset of gross plastic deformation of a construction, the strain in the reinforcing blended fabric can be obtained after load has been transferred from the steel carrier structure. However, elastic–plastic stress analysis method considers ultimate stress and perfect plasticity behaviour i.e. non-linear geometry until collapse. This method is more precious than other methods. The inclusion of composite in the repair system introduces more than one stress–strain properties in the model. Numerical analysis is accepted in both limit-load method and elastic–plastic analysis methods for the circuitous geometry and material behaviours. In case of repairing a force per unit area vessel using fibre-composite repair, structural operation of the repair arrangement tin can be analysed with any of the analysis methods. Alexander [21] successfully used limit load analysis to appraise the operation of blended repair for offshore riser.

Usually stress-based design is applied for repair systems. Material nonlinearity is not addressed in these strength and stiffness based analyses where loading is primarily elastic and a safety cistron is introduced to ensure a desired level of confidence. Yet, when load increases and requires a sure amount of textile nonlinearity in the steel (i.e. plasticity) in order to transfer load from the steel to the blended through infill, linear elastic design methods are not useful and may not be adequate every bit they are ofttimes restrictive and conservative.

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