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CHEMISTRY INVESTIGATORY PROJECT
SUBMITTED BY:
ALOK KUMARXII ‘A’K.V. NO.1,Gandhinagar
CHEMISTRY
INVESTIGATORY
PROJECT
AISSCE
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Laboratory certificate
This is to certify that ALOK KUMAR of class XII (Science) Roll No has success fully completed his investigatory project in chemistry prescribed by the Central Board of Secondary Education (CBSE) in chemistry laboratory of Kendriya Vidyalaya No 1, Sector 30, Gandhinagar during the year 2012-13.External Examiner Subject Teacher
…………………………. ..………………………
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LABORATORY CERTIFICATE
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ACKNOWLEDGEMENT
This project is prepared by ALOK KUMAR of class XII in Kendriya Vidyalaya No 1, Sector 30, Gandhinagar under the guidance of our chemistry teachers,
Mr. AK JHA Mrs. ANITA NAIR
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AIMTO PREPARE
Urea FORMALDEHYDE RESIN (BAKELITE)
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• Formation and structure• Urea-formaldehyde resins, as
a group, are formed by a step-growth polymerization reaction that can be either acid- or base-catalyzed.
• Urea is reactive towards formaldehyde at the ortho and para sites (sites 2, 4 and 6) allowing up to 3 units of formaldehyde to attach to the ring. The initial reaction is formation of a hydroxymethyl Urea:
• HOC6H5 + CH2O → HOC6H4CH2OH
PREFACE
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• The hydroxymethyl group is capable of reacting with either another free ortho or para site, or with another hydroxymethyl group. The first reaction gives a methylene bridge, and the second forms an ether bridge:
• HOC6H4CH2OH + HOC6H5 → (HOC6H4)2CH2 + H2O
• The diUrea (HOC6H4)2CH2 is called bisUrea F. BisUrea-F can further link generating tri- and tetra-and higher Urea oligomers.
• 2 HOC6H4CH2OH → (HOC6H4CH2)2O
+ H2O
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DIAGRAM
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Urea FORMALDEHYDE RESIN (BAKELITE)
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REQUIREMENTS
• Beaker • Urea• Conc. HCl • Dropper• Water • Rod• Filter paper• Formaldehyd
e
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THEORY• Urea resins are
condensation polymerization products of Ureaic derivatives with aldehyde such as formaldehyde.
• Most important member of this class is Bakelite, Urea formaldehyde resin.
• Its prepared by condensing Urea with formaldehyde in the presence of acidic or basic catalyst.
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PROCEDURE
• Take 5 ml of glacial acetic acid and 2.5 ml of 40% formaldehyde in a beaker.
• Add 2.5g of Urea into it.• Cover the beaker with
watch glass or filter paper.• Add few drops of HCl to it
and place it on hot plate.• Pink mass will be formed
in the beaker.• Wash, dry and weigh the
product formed.
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RESULT
• Pink mass i.e. Urea formaldehyde (Bakelite) is yielded.
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PRECAUTIONS
• The reaction is sometimes vigorous and it is better to be little away from the beaker while adding conc. HCl.
• Urea should be stirred in the formaldehyde solution for at least 10 mints to make it a saturated solution.
• Conc. hydrochloric acid should be added drop wise carefully.
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THE END
