urea formaldehyde

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  • Urea FormaldehydeAbdul HaseebE13-3185th SemesterMetallurgy and Materials Engineering

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

    Repeating unit of UF

  • Polymerization methodMild alkali(pH>7)pH is used to control reaction rate. Occurs slowly under slightly basic conditions.Production of the intermediates is monitored and controlled by viscosity.

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

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

  • UF Condensation Reaction

    Result: Cured network (cross-linked) molecular structureCondensation may be linear or cross-linked

  • Physical properties, Uses and limitationsDensity 1500 Kg/m3.Tensile strength 48-78 MNm-2 .Compressive strength 70-110 MNm-2 .Better electrical properties.Scratch free.Get effected by sunlight.

    Reference: Fundamentals of material science by R.K.RajpootThese are the uses of UF:Glues for plywoodCellulose and foam products.Paints.Surface coatings.Adhesives.Plugs, switches, buttons etc.

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

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

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

    Reference: Sciencedirect.com

    Reference: Sciencedirect.com

  • Tensile shear strength of wood bonded with urea formaldehyde with different amounts of microbrillated cellulose Jin Heon Kwon , Seung-Hwan Lee, Nadir Ayrilmis, Tae Hyung HanPlant bers, which are abundant renewable resources, exhibit high specic strength and stiffness, and industrial use of plant bers as llers in composites have attracted much interest.Cross-linked network

    between the MFCs and the UF molecules was produced.Excess amount of fillers

    reduces tensile strength. Reference: Science Direct.com

    Reference: Science Direct.com

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

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