urea formaldehyde

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Urea Formaldehyde Urea Formaldehyde Abdul Haseeb Abdul Haseeb E13-318 E13-318 5 5 th th Semester Semester Metallurgy and Materials Metallurgy and Materials Engineering Engineering

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Page 1: Urea formaldehyde

Urea FormaldehydeUrea Formaldehyde

Abdul HaseebAbdul HaseebE13-318E13-318

55thth Semester SemesterMetallurgy and Materials EngineeringMetallurgy and Materials Engineering

Page 2: Urea formaldehyde

IntroductionIntroduction

UF is an “amino resin” or “amine-formaldehyde” class of UF is an “amino resin” or “amine-formaldehyde” class of thermoset adhesive. thermoset adhesive. Binding property.Binding property.Good adhesion, high curing rate and low cost.Good adhesion, high curing rate and low cost.Brittleness.Brittleness.Urea and Formaldehyde are usually in different mole Urea and Formaldehyde are usually in different mole ratios.ratios.

Repeating unit of UFRepeating unit of UF

Page 3: Urea formaldehyde

Polymerization methodPolymerization method

Mild alkali(pH>7)

pH is used to control reaction rate. Occurs slowly pH is used to control reaction rate. Occurs slowly under slightly basic conditions.under slightly basic conditions.Production of the intermediates is monitored and Production of the intermediates is monitored and controlled by viscosity.controlled by viscosity.

Reference: Reference: Materials and Design: The art and science of material by Michael F. Ashby, Kara Jhonsons,

Page 4: Urea formaldehyde

UF Condensation ReactionUF Condensation Reaction

Result: Cured network (cross-linked) molecular structure

Condensation may be linear or cross-linked

Page 5: Urea formaldehyde

Physical properties, Uses and limitationsPhysical properties, Uses and limitations

Density 1500 Kg/mDensity 1500 Kg/m33..Tensile strength 48-78 MNmTensile strength 48-78 MNm-2 -2 ..Compressive strength 70-110 Compressive strength 70-110 MNmMNm-2 .-2 .

Better electrical properties.Better electrical properties.Scratch free.Scratch free.Get effected by sunlight.Get effected by sunlight.

Reference: Fundamentals of material science by R.K.RajpootReference: Fundamentals of material science by R.K.Rajpoot

These are the uses of UF:These are the uses of UF:Glues for plywoodGlues for plywoodCellulose and foam products.Cellulose and foam products.PaintsPaints..

Surface coatings.Surface coatings.Adhesives.Adhesives.Plugs, switches, buttons etc.Plugs, switches, buttons etc.

These are the limitations of UF:These are the limitations of UF:Formaldehyde emission.Formaldehyde emission.Poor water resistance.Poor water resistance.

Page 6: Urea formaldehyde

Self healing coatings containing dual active agent Self healing coatings containing dual active agent loaded urea formaldehyde (UF) microcapsulesloaded urea formaldehyde (UF) microcapsules

T. Siva, S. SathiyanarayananT. Siva, S. Sathiyanarayanan

Linseed oil, mercaptobenzothiazole (MBT), urea, formaldehyde, Linseed oil, mercaptobenzothiazole (MBT), urea, formaldehyde, Ammonium chloride.Ammonium chloride.UF has high degradation temperature 710°C as compared to UF has high degradation temperature 710°C as compared to UFLO/MBT which has 622°C. UFLO/MBT which has 622°C. From the Soxhlet apparatus they have estimated that the core content of From the Soxhlet apparatus they have estimated that the core content of microcapsules is 78% UF. Inhibitor loaded Linseed oil has the ability to microcapsules is 78% UF. Inhibitor loaded Linseed oil has the ability to dry by oxidation with atmospheric oxygen and hence seals the crack in dry by oxidation with atmospheric oxygen and hence seals the crack in the coating.the coating.

Reference: Sciencedirect.comReference: Sciencedirect.com

Page 7: Urea formaldehyde

Tensile shear strength of wood bonded with urea formaldehyde Tensile shear strength of wood bonded with urea formaldehyde with different amounts of microfibrillated cellulose with different amounts of microfibrillated cellulose

Jin Heon KwonJin Heon Kwon , , Seung-Hwan Lee,Seung-Hwan Lee, Nadir Ayrilmis, Tae Hyung HanNadir Ayrilmis, Tae Hyung Han

Plant fibers, which are abundant renewable resources, exhibit high Plant fibers, which are abundant renewable resources, exhibit high specific strength and stiffness, and industrial use of plant fibers as specific strength and stiffness, and industrial use of plant fibers as fillers in composites have attracted much interest.fillers in composites have attracted much interest.Cross-linked network Cross-linked network

between the MFCs and thebetween the MFCs and the UF molecules was UF molecules was produced.produced.

Excess amount of fillers Excess amount of fillers reduces tensile strength.reduces tensile strength.

Reference: Science Direct.comReference: Science Direct.com

Page 8: Urea formaldehyde

Conclusion:Conclusion:By all this we can conclude that due to the variety of synthesis By all this we can conclude that due to the variety of synthesis and good properties, this material is of so much importance in and good properties, this material is of so much importance in industrial usage as well as in research workindustrial usage as well as in research work.