1.
Fundamentals of Polymer Engineering
Polymerization Reactions
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Course Code: PE-3107
Credits: 3-0-3
Teacher: Engr. Asra Tariq
Email Id: asra.tariq@ntu.edu.pk

2.
Step Growth Polymerization
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3.
Ring Opening Polymerization
 A ring-opening polymerization (ROP) is another form of chain-
growth polymerization in which the terminal end group of a polymer
chain acts as a reactive centre where further cyclic monomers can be
added by ring-opening and addition of the broken bond. Typical
cyclic monomers that can be polymerized via ROP are di-functional
monomers that carry two different reactive groups like one amine or
alcohol and one carboxylic acid that have undergone a cyclization
reaction. Two examples are caprolactam and caprolactone:
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4.
Ring Opening Polymerization
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5.
Ring Opening Polymerization
 Most monomers that undergo AROP contain polar bonds like ester, amide,
carbonate, urethane, epoxide, and phosphate which polymerize to the
corresponding polyester, polyamide, polycarbonate, polyurethane,
polyepoxide, and polyphosphate.
 Common nucleophilic reagents used for the initiation of AROP usually will
include organometals (e.g. alkyl lithium, alkyl magnesium bromide, alkyl
aluminum, etc.), metal amides, alkoxides, phosphines, amines, alcohols and
water.
 Termination in AROP can be described as chain transfer reactions to
monomer that is available.
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6.
Polyaddition Polymerization
 A polymerization reaction that forms polymers via individual
independent addition reactions. Polyaddition occurs as a reaction between
functional groups on molecules with low degrees of polymerization, such as
dimers, trimers and oligomers, to form species of higher molar mass.
 One of the main features of polyaddition reactions is that during the
formation of the polymer does not emit any volatile compounds, as is the
case of polycondensation reactions.
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7.
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8.
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8Polyaddition Polymerization
Polyurethane
Diisocyanate Polyol

9.
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10.
Polycondensation Polymerization
 The polycondensation a process for the production of polymers from
bifunctional and polyfunctional compounds (monomers), accompanied by
the elimination of low-molecular weight by-products (for example, water,
alcohols, and hydrogen halides). A typical example of polycondensation is
the synthesis of complex polyester.
 Polycondensation in which only bifunctional compounds participate leads to
the formation of linear macromolecules and is called
linear polycondensation. If molecules with three or more functional groups
participate in polycondensation, three-dimensional structures are formed
and the process is called three-dimensional polycondensation.
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11.
Polycondensation Polymerization
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