ADHESIVES
1. Glues of Animal Origin
Properties
Methods of Manufacture
Commercial Grades and Specifications
Methods of Analysis
Sampling
Procedure
Identification
Physical Measurements
Determination of Other Constituents
2. Fish Glues
Introduction
Manufacturing Process
Properties
Applications & Formulations
Rubber-to-Steel
Strawboard-to-Steel
Rubber-or Cork-to-Plywood
Paper-to-Steel
Straight Line Gluing
3. Animal Glues
Introduction
Chemical Composition
Manufacture of Animal Glues
Properties
Liquid Animal Glues
Formulation & Applications
Methods of Application
4. Casein Glues and Adhesives
Introduction
Properties
Casein Blend Glues
Lime free Casein Adhesives
Applications
Casein Adhesives for Bonding Paper
Casein Adhesive for Binding Dissimilar Materials
5. Blood Albumen Glues
Introduction
Solubility Categories
Properties
Blood-Soybean Flour Combinations
Mold Resistance
Application
6. Amino Resin Adhesives
Introduction
Manufacturing Technology
Urea Adhesive for Plywood
Urea Adhesive for Particle Board
Spray Dried Melamine-formaldehyde Resins
Foundry Resin
Aniline-Formaldehyde Resin
Ø Represents benzene ring
Sulfonamide-Formaldehyde Resins
Applications
Adhesives for Hardwood Plywood
Sand Core Binder
Water Proof Corrugated Board
Compounding and Formulation
7. Cyanoacrylate Adhesives
Introduction
Bonding with Cyanoacrylates
Adhesive Properties
Applications
8. Epoxy Resin Adhesives
Introduction
Chemistry
Epoxy Novolac Resins
Flexible Epoxy Resins
Epoxidized Olefins
Speciality Epoxy Resins & Derivatives
Epoxy Esters of Rosin
Epoxy Esters of Styrenated Rosin
Epoxy Esters of Disproportionated Rosin
Epoxy Novolac Esters
Epoxy Ester of Maleopimaric Acid
Compounding
Curing Agents
Diluents
Modifiers
Flexibilizers
Fillers
Accelerators
Speciality Additives
Manufacture of Adhesives
9. Phenolic Resin Adhesives
Introduction
Resole resin
Novalac Resins
Manufacture
Applications and Formulations
Contact Adhesives
Adhesive Compounding
Nitrile/Phenolic Contact Adhesives
Structural Adhesives
Vinyl/Phenolic
Epoxy/Phenolic
Hot Melt Adhesives
Hot Melt Vinyl Film to Wood Laminating Adhesives
Pressure Sensitive Adhesives (PSA)
10. Polychloroprene Resin Adhesives
Introduction
Types of Polychloroprene
Applications and Formulations
Applications
11. Polyester Resin Adhesives
Introduction
Linear Polycarbonates
Polymerized Oils
Alkyd Resins
Unsaturated Polyester Adhesives
Adhesives for Flexible Printed Circuit
Allyl Ester Adhesives
12. Polyethyleneimine in Adhesives
Introduction
Applications
General Adhesives
Tie Coat Adhesives
13. Polysulfide Sealants and Adhesives
Introduction
Polysulfide Sealants
Chemistry
Compounding
Curing Agent
Retarder
Reinforcement
Adhesion Additives
Primers
Improved Heat Resistance
Applications
Adhesives from Polysulfide Liquid Polymer
Epoxy Resin Reactions
14. Resorcinolic Adhesives
Introduction
Resorcinol-Phenol Formaldehyde Resins
Modified Resorcinol Resins
Aspects of Adhesion Mechanism
Formulation of Glue Mixtures
Laminating
15. Ethylene Copolymer Hot Melt Adhesives
Introduction
Crystallinity
Compatibility
Pressure Sensitive Tack
Hot Melt Adhesive Formulating
Book Binding Adhesives
Carton and Case Sealing Adhesives
Carpet Application
Shoe Adhesives
Pressure Sensitive Adhesives (PSA)
Furniture Adhesives
16. Furan Resin Adhesives
Introduction
17. Isocyanate Adhesives
Introduction
Advantages of Isocyanate Adhesives
Disadvantages of Isocyanates
Applications
Types and uses of Isocyanate based Adhesive System
18. Lignin Adhesives
Introduction
Formulations
19. Polyamide Adhesives
Introduction
Class I: Thermoset Adhesives Containing Liquid Polyamide Curing Adhesives
Class II: Nylon-Epoxy Resins
Class III: Thermoplastic Hot Melt Polyamide Adhesives
Class IV: Thermoplastic-Thermoset Adhesives
20. Polyimide Adhesives
Introduction
Adhesive and Bonding Technology
Foam System
21. Rosin Adhesives
Introduction
Applications
Formulations
Solvent Adhesives
Emulsion Adhesives
Hot Melt Adhesives
Methods of manufacture
22. Silicone Adhesives and Sealants
Introduction
Chemistry
Oxime silane
Properties
Rheological Characteristics
Thermal Stability
Weathering Characteristics
Adhesion Characteristics
Applications
Industrial
Construction
23. Tannin Adhesives
Introduction
Formulation
24. Terpene Based Adhesives
Introduction
Chemistry
Beta-pinene resins
Dipentene resins
Alpha-pinene resins
Physical characteristics of resins
Pressure sensitive adhesives
Hot melt adhesives
Analytical methods
Commercial resins and their uses
Commercial production
Applications in pressure sensitive adhesives
Applications in hot melt adhesives
25. Starch Adhesives
Introduction
Unmodified Starches
High Strength Adhesive
Cheap Diluted Adhesive
Non-weather Proof Corrugated Board Adhesive
Water Resistant Corrugated Paper Box Adhesive
Final Mixture
Acid Modified or Thin Boiling Starch Adhesive
Oxidised Starch Adhesives
Dextrin Based Adhesives
Properties
26. Acrylic Adhesives and Sealants
Polymerization
Solution Polymerization
Properties of the product
Emulsion polymerization
Properties of the dispersion
Properties
Formulations and Applications
Adhesives to paper coated with PVDC
Delayed tack adhesive
Adhesives for Laminating
Laminating Plasticized PVC film to textiles
Laminating PVC film to particle board
Laminating plasticized PVC film to split leather
High temperature &pressure lamination
Flocking Adhesives
Building Adhesives
Adhesives for plasticized PVC floor tiles
Adhesives for ceramic tiles
Pressure-Sensitive Adhesives
Flame Resistant & Pressure Sensitive Adhesive
Acrylic Sealants
Aqueous Acrylic Sealants
Solvent-Based Acrylic Sealants
27. Pressure Sensitive Adhesives
Adhesive Strip for Antomotive Trim
Eva-Trialkyl Cyanurate Copolymer Adhesive
Carboxylate Polymer Based Adhesives
Fumaric Diester Vinyl Acetate Polymer
28. Hot melt Adhesives
Introduction
Advantages
Disadvantage
Formulations
Ethylene-vinyl Acetate
Amorphous polypropylene and Petroleum Resin
Isopropenyltoluene Copolymers as Tackifiers
Chlorinated Polyphenyl, Chlorinated
Polyisoprene and Nitroso Compound
Carpet Backing Formulation
Other Polyolefin Compositions
Amorphous Polyolefin and Styrene Butadiene
Block Copolymers
-Methylstyrene Tert Butyl Styreneolefin terpolymers
Alkoxystyrene-Acrylonitrile, Copolymers
Boric Acid as Viscosity Stabiliser in Ethylene-
Propylene Adhesives
Thermoplastic Polymer and Chelate of Aminoacetic
Acid
Coal Tar Pitch and Ethylene-Acrylic-Acid Copolymer
Water-Moistenable Vinyl Pyrrolidone-Vinylacetate
Product
RESINS
1. Alkyd Resins
Introduction
Classification
Synthesis
Etherification
Addition reactions of unsaturated monobasic
fatty acids
Addition reactions with other unsaturated alkyd ingredients
Reactions during coating formation with drying
alkyds
Reactions during coating formation in alkyd blends
Raw materials
Manufacture
Health and Safety
Quality Control and Specifications
Analysis
Calculations
Uses
Use of Alkyds in Trade-Sales Finishes
Methods of Analysis
Determination of Composition
Chemical Methods
Determination of Properties and Impurities
2. Acrylic Modified Alkyd Resins
Traffic paints
Industrial applications
Conclusion
3. Alkyd-Amino Combinations Based on Neem Oil
Aim of present investigation
Uses of oils in surface coatings
Neem oil
Alkyd resins
Amino resins
Experiments & Results
Preparation of alkyd resin
Alkyd resin preparation
Preparation of amino resin
Testing of performances of resin samples
Discussion
Analysis of neem oil
Preparation of alkyd from neem oil
Preparation of urea formaldehyde resin
Preparation of thiourea formaldehyde resin
Preparation of various samples (mixtures)
Performances of various resin samples
Scratch hardness
Conclusion
4. Amino Resins
Introduction
Raw materials
Chemistry of resin formation
Typical resin formulations and techniques
Urea formaldehyde resins
High solids urea-formaldehyde adhesive resin
Protective coating resin with high mineral spirits
tolerance
Methylated urea formaldehyde textile resins
Urea-formaldehyde particle board adhesive
Melamine-formaldehyde resins
Butylated melamine protective coating resin
Chlorine resistant melamine resin
Trimethoxymethyl melamine
Hexamethoxymethyl melamine
Melamine resin molding powder
Melamine resin acid colloid
Control of the extent of the reaction
Free formaldehyde estimation
Viscosity tests
Solubility tests
Cure tests
Urea versus melamine resins
Package stability
Competitive product analysis
Chemical modification for water soluble products
Chemical modification for oil soluble products
Ethyleneurea
Methylated uron textile resins
Uron resins
Glyoxal resins
Miscellaneous resins
Amino resins in the paper industry
Formulations for regular and HE colloids
Toxcity
Methods of Analysis
Competitive Product Analysis
5. Carbohydrate Modified Phenol-formaldehyde
Resins
Introduction
Research on Carbohydrate Modified Resins
Carbohydrate-Modified Base-Catalyzed PF resins
Bonding Veneer Panels
Bonding Flakeboard Panels
Carbohydrate-Modified PF Resins Cured at
Neutral Conditions
Bonding Veneer Panels
Color of Bondline
Conclusions
6. Epoxy Resins
Introduction
Synthesis of Resin Intermediates
Cycloaliphatic epoxies
Epoxidized polyolefins
Epoxidised oils and fatty acid esters
Aliphatic-cycloaliphatic glycidyl type resins
Epoxy novolac resins
Resins from phenols other than bisphenol A
Resins from aliphatic polyols
Resins from long chain acids
Fluorinated epoxy resins
Epoxy resins from methylepichlorohydrin
Miscellaneous epoxy resins
Epoxy esters
Water borne epoxy resins and derivatives
Diluents and modifiers
Epoxide reactions and curing mechanisms
Curing of epoxy esters
7. Hydrocarbon Resins
Types of Hydrocarbon Resins
Raw Materials
Properties of Hydrocarbon Resins
Methods of Manufacture
Commercial Resin Types and Specifications
Methods of Analysis
Analysis of Raw Materials
Determination of Chemical Properties
Determination of Physical Properties
8. Polyurethane Resins
Chemistry
Raw materials
Isocyanates
Tolylene diisocyanate (TDI)
4,4' diphenylmethane diisocyanate (MDI)
Hexamethylene diisocyanate (HDI)
Other diisocyanates used in coating systems
Hydroxy component
Hazards of isocyanates
Classification of polyurethanes
Urethane oils and urethane alkyds
Moisture-cured urethanes
Drying time
Catalysts
Solvents
Pigmentation
Additives
Film properties and uses
Typical formulations
Manufacture
Blocked isocyanate systems
Two-component catalyst-cured polyurethanes
Two-component polyol type polyurethanes
9. Phenolic Resins
The Chemistry of Phenolic Resins
The Structure of Phenolic Resins
Formation of phenol alcohols
Formation of methylene bridges
Formation of dibenzyl ethers
Formation of quinone methides
Raw Materials
Phenols
Aldehydes
Hexamethylenetetramine (HMTA)
Fillers for Phenolic Moulding Powders
Types of filler
Thermal Degradation
Modified and Thermal-resistance Resins
Etherification reactions
Esterification reactions
Heavy metal modified resins
Chemical Resistance
Resistance to microorganism
Oil Soluble Phenolic Resins
Composite Wood Material
Moulding Compounds
Heat and sound insulation materials
Industrial laminates and paper impregnation
Coatings
Foundry resins
Phenolic resin as ion-exchange resin
Abrasive materials
Friction materials
Phenolic resin in rubbers and adhesives

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Methylene bridges arise also from dibenzyl ether struc­tures by elimination of one mole of formaldehyde. This reac­tion takes place at about 130-200°C, depending upon the sub­stitution in the phenol ring. The methylene linkage is consi­derably more stable than the methylene ether bridge and is not cleaved by hydrogen bromide. The methylene bridge undoubt­edly plays a major role in the structure of phenolic resins and is encountered in practically all phenol-formaldehyde resins.

Formation of dibenzyl ethers

At about 160°C, phenol alcohols eliminate one mole of water intermolecularly by condensation of two methylol groups, thus forming dibenzyl ethers. The existence of these methylene ether bridges can readily be proved by means of hydrogen bromide, which cleaves the dibenzyl ether to yield crystalline bromides.

The limited stability of the dibenzyl ethers can be demon­strated not only by their ready conversion to methylene bridge compounds but also by their disproportionation to yield phe­nol aldehydes and methyl phenols. The same reaction pro­ducts can be accounted for by assuming the intermediate for­mation of quinone methides.

Formation of quinone methides

At temperatures ranging from 170-220°C, o-and p-quinone methides (o- and p-methylene quinones) are formed by in­tramolecular splitting off of water from phenol alcohols and their bis (hydroxybenzyl) ether. While in the case of substi­tuted phenols monomeric quinone methides can be isolated, the quinone methides derived from phenol itself are usually obtained in the form of the dimer and the trimer. The dimers from o- and p-quinone methides are shown below:

The role and the importance of the methylene quinones in resin formation remain open to speculation, but the fact exists that these intermediates can undergo a series of trans­formations which account fairly well for the appearance of a number of products in phenolic resins.

Raw Materials

Phenolic resins are produced by the reaction of phenols with aldehydes. The simplest representatives of these types of compounds, phenol and formaldehyde, are by far the most important. As an average, considering all applications, the production of 1 tonne of phenolic resin requires approximately 440 kg phenol (containing about 10% cresols and xylenols) and 220 kg formaldehyde as well as solvents, additives and water.

Phenols

Phenols are a family of aromatic compounds with the hy­droxyl group bonded directly to the aromatic nucleus. They differ from alcohols in that they behave like weak acids and dissolve readily in aqueous sodium hydroxide, but are in­soluble in aqueous sodium carbonate. Phenols are colourless solids with the exception of some liquid alkylphenols. The most important phenols are listed in Table 1.

Cashew nut shell liquid (CNSL)

An important phenolic compound from natural sources is cashew nut shell liquid (CNSL). This liquid from the shells of cashew nuts, which grow mainly in Southern India, has become a useful raw material in the manufacture of special phenolic resins to be used for coating, laminating, and brake lining resin formulations.

Those resins possess outstanding resistance to the soften­ing action of mineral oils and high resistance to acids and alkalies. The CNSL, when obtained by a special heat treat­ment which includes decarboxylation, contains a mixture of mono- and diphenols with an unsaturated C15 side chain in the meta position, there by exhibiting high reactivity towards formaldehyde.

Table 1. Some Phenols Used in Phenolic Resins

Name
Phenol	Hydroxybenzene
o-Cresol	1-Methyl-2-hydroxybenzene
m-Cresol	1-Methyl-3-hydroxybenzene
p-Cresol	I-Methyl-4-hydroxybenzene
p-tert. Butylphenol	1-Tert.butyl-4-hydroxybenzene
p-tert. Octylphenol	1-Tert.octyl-4-hydroxybenzene
p-Nonylphenol	1-Nonyl-4-hydroxybenzene
2,3-Xylenol	1,2-Dimethyl-3-hydroxybenzene
2,4-Xylenol	1,3-Dimethyl-4-hydroxybenzene
2,5-Xylenol	1,4-Dimethyl-2-hydroxybenzene
2,6-Xylenol	1,3-Dimethyl-2-hydroxybenzene
3,1-Xylenol	1,2-Dimethyl-4-hydroxybenzene
3,4-Xylenol	1,3-Dimethyl-5-hydroxybenzene
Resorcinol	1,3-Dihydroxybenzene
Bisphenol-A	2,2-bis (4-hydroxyphenyl) propane

Aldehydes

Formaldehyde is the almost exclusively used carbonyl com­ponent for the synthesis of technically relevant phenolic re­sins. Special resins can also be produced with other alde­hydes, for example acetaldehyde, furfural or glyoxal, but have not achieved greater technical importance. Ketones are very seldom used.

Paraformaldehyde is a white, solid, low molecular polycondensation product of methylene glycol with the charac­teristic odour of formaldehyde. The degree of polymerisa­tion ranges between 10 and 100. Types of paraformaldehyde common in the trade contain approximately 1-6.5% of water. The preparation of paraformaldehyde is performed by distil­lation of 30-37% aqueous formaldehyde solution. Accord­ing to the conditions (temperature, time, pressure) different types of paraformaldehyde are obtained. Paraformaldehyde is only very seldom used for resin production because of its high price compared with aqueous formaldehyde solutions and because of problems associated with the exothermal heat evolution. Paraformaldehyde and an acid catalyst may be used to cure novolak resins. However, the odour and high formal­dehyde loss make it unattractive. Products obtained are of poorer quality than when HMTA is used.

On the other hand, paraformaldehyde is used almost ex­clusively to crosslink resorcinol prepolymers, e.g. in cold setting structural wood adhesives. Lower curing temperatures are adequate because of the higher reactivity of resorcinol, thus formaldehyde evolution is greatly reduced. The reacti­vity of paraformaldehyde depends on the degree of polymeri­sation. A fairly accurate reactivity test method is the resorci­nol test. This test indicates the period of time in minutes in which an alkaline resorcinol/paraformaldehyde mixture up to 60ºC due to the “condensation” reaction.

Trioxane and cyclic formals

Trioxane, a cyclic low molecular weight derivatives of formaldehyde or methylene glycol, is a colourless solid (MP 62-64°C, BP l15°C) and can be prepared by the heating of paraformaldehyde or a formaldehyde solution (60-65%) in the presence of 2% of sulfuric acid. Trioxane can be used as formaldehyde spending and curing agent for phenolic resins.

Cyclic formals: 1,3-dioxolane, 4-phenyl-l, 3-dioxolane and 4-methyl-l,3-dioxolane have been recommended to cure novolaks and because and of their solvent action, for low-pressure laminating resins with reduced viscosity.

Hexamethylenetetramine (HMTA)

HMTA, used almost exclusively for cross-linking of novolak resins, is prepared from formaldehyde and ammo­nia.

6CH2O + 4NH3 (CH2)6 N3 + 6H2O

The reaction is reversible. HMTA is split at elevated tem­peratures, generally above 115°C, depending on the medium. In aqueous solution, HMTA is easily hydrolysed. HMTA is often used as catalyst in the resole formation reaction instead of ammonia, yielding equivalent results.

HMTA is highly soluble in water, relatively easy to dis­solve in chloroform, and less soluble in methanol or ethanol. The aqueous solution shows a weak alkaline action with a pH range between 7-10. Finely ground HMTA tends to cause dust explosion.

Furfural

Furfural, sometimes, called furfurol, is a colourless liquid with chemical properties similar to benzaldehyde. Commer­cial production starts with residues of annual plants like maize cobs, bagasse or rice hulls. These naturally occurring pen­tosans are hydrolysed by diluted sulfuric acid to furfural which is then isolated by steam distillation. With alkaline catalysts the first step in the reaction with phenol is similar to than of formaldehyde, yielding 2-(o- or p-hydroxyphenyl)-furfuryl alcohol.

The further reaction mechanism is not estabilished. Furane ring scission and reaction with another phenol nucleus may occur leading to relative wide internuclear distance.

Also the double bond may be involved in the polymerisa­tion reaction and leads to instability under acidic conditions. The phenol-furfural resins shows enhanced flexibility, low melt viscosity and a low viscosity index. Furfural is used in combination with formaldehyde for the preparation of resins for grinding and friction materials. Phenol -furfural resins may be prepared by continuous addition (30 min.) of furfural to a phenol melt at 135°C and refluxing for 3.5 hour. Similarly mixed formaldehyde-furfural resins can be prepared.

An important derivative of furfural is furfuryl alcohol. It is obtained from furfural by hydrogenation. Furfuryl alcohol/ PF resin blends and acidic catalysts are used in the foundry industry for the no-bake and hot-box core-making process and for the preparation of acid resistant cements. Furfuryl alcohol is also used for the production of furnace resins.

Other aldehydes

The higher aldehydes react with phenol at considerably lower rates. Acidic catalysts are preferred e.g. for the prepa­ration of certain binuclear antioxidants. A base catalysed re­action is not practical with acetaldehyde or higher aldehydes since they undergo rapid aldol condensation and self­-resinification reactions.

Novolak resin are prepared under strong acidic conditions, generally in a water-free system, by continuous aldehyde addition to the phenol melt. The preferred mol ratio phenol/ aldehyde is between 1:0.8 to 1:1.3. Only acetaldehyde and butyraldehydes are, however, of limited commercial impor­tance, i.e. for rubber modification and antioxidants. The chemical structure of acetaldehyde novolak resins. corre­sponds to these obtained by the reaction of acetylene and phenol with cyclohexylamine as catalyst.

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