Chemistry investigatory project

CHEMISTRY INVESTIGATORY PROJECT

SUBMITTED BY:ALOK KUMARXII ‘A’K.V. NO.1,Gandhinagar

CHEMISTRYINVESTIGATO

RYPROJECT

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

PHENOL FORMALDEHYDE RESIN

(BAKELITE)


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• Formation and structure• Phenol-formaldehyde resins,

as a group, are formed by a step-growth polymerization reaction that can be either acid- or base-catalyzed.

• Phenol 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 phenol:

• HOC6H5 + CH2O → HOC6H4CH2OH

PREFACE

http://en.wikipedia.org/wiki/Step-growth_polymerization

http://en.wikipedia.org/wiki/Acid

http://en.wikipedia.org/wiki/Base_(chemistry)

http://en.wikipedia.org/wiki/Arene_substitution_patterns

http://en.wikipedia.org/wiki/Arene_substitution_patterns


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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 diphenol (HOC6H4)2CH2 is called bisphenol F. Bisphenol-F can further link generating tri- and tetra-and higher phenol oligomers.

• 2 HOC6H4CH2OH → (HOC6H4CH2)2O + H2O

http://en.wikipedia.org/wiki/Methylenes

http://en.wikipedia.org/wiki/Ether

http://en.wikipedia.org/wiki/Bisphenol


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DIAGRAM


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PHENOL FORMALDEHYDE RESIN (BAKELITE)


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REQUIREMENTS

• Beaker • Phenol• Conc. HCl • Dropper• Water • Rod• Filter paper• Formaldehyd

e


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THEORY• Phenol resins are

condensation polymerization products of phenolic derivatives with aldehyde such as formaldehyde.

• Most important member of this class is Bakelite, phenol formaldehyde resin.

• Its prepared by condensing phenol 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 phenol 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. phenol 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.

• Phenol 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

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Chemistry investigatory project