10.1 Introduction

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10.1 Introduction
A. Characteristics of step-reaction polymers.  
a. Polymers containing functional group in
backbones   b. Synthesizing dendritic polymers
B. Examples of commercialized step-reaction
polymers.   Note) Table 10.1
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10.2 Step-reaction polymerization---Kinetics
A. Types of monomer   a. AB type
 b. AA and BB type
 c. Three functional group for crosslinked
polymers
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10.2 Step-reaction polymerization---Kinetics
B. Condensation of difunctional monomers.  
a.
 b.
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C. Kinetics of step-polymerization.   a.
Assumption Independence on chain length.  
b. Rate equation and
 Integration
 Combining Carothers equation.
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C. Kinetics of step-polymerization.
 c. Polyesterification self-acid catalyzed
reaction.
Integration
 Combining Carothers equation.
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10. 3 Stoichiometric Imbalance.
A. Chain length control.   a. High molecular
weight.   b. Oligomers for free polymer.   
1) Epoxy oligomer.    2) Unsaturated
polyester.    3) Polyamide
B. Preparing methods for oligomers.  a.
Quenching unsaturated polyester.  b.
Stoichiometric imbalance epoxy resin.  c.
Addition of monofunctional reactant.
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10. 3 Stoichiometric Imbalance.
C. Modification of Carothers equation.  a.
parameter r stoichiometric imbalance.
initial unreacted groups.
unreacted group.
,
Carothers equation.
 if        , then
 if        , then
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10. 4 Molecular weight Distribution
A. Conversion and Nx
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10. 4 Molecular weight Distribution
B. Conversion and Wx
C. Polydispersity index
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10. 5  Network Step Polymerization
A. Greater than two functionality polymers.  
a. Alkyd-type polyester      b.
Phenol-formaldehyde resin     c.
Melamine-formaldehyde resin  
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10. 5  Network Step Polymerization
B. Gelatin High conversion of greater than two
functionality.   a. Gel point onset of
gelatin.         sudden
increase in viscosity.       
 change from liquid to gel.     
  bubbles no longer rising.    
    impossible stirring.
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10. 5  Network Step Polymerization
C. Gel point conversion.
    critical reaction conversion.     
average functionality.
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10. 5  Network Step Polymerization
D. Examples of gel point conversion.
3mol of 1
2mol of 4
Gel point conversion 77 (Experiment)
                      83 (Calculate)
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   10. 6 Step-Reaction Copolymerization.
A. Random copolymers.   112 mixture of
terephthalic acid, isophtahlic acid, ethylene
glycol.
B. Alternating copolymers.   a.
b. Randomization Trans-esterification.
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   10. 6 Step-Reaction Copolymerization.
C. Block copolymer.     Telechelic polymers.
 a.
 b.
 c.
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  10. 7 Step polymerization Techniques.
A. Significant difference between vinyl and
nonvinyl polymerization.   a. Vinyl
polymerization Large enthalpy factor.
                      
   Exotherm reaction.   b. Nonvinyl
polymerization High activation energy.
                    
     Low exotherm.
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  10. 7 Step polymerization Techniques.
B. Step polymerization techniques.   a. Bulk
polymerization.    1) Advantage Free
of contaminants.    2) Disadvantage
High viscosity.   b. Solvent
polymerization.    1) Advantage Lower
viscosity.        
Removing by products by azeotropic distillation.
 2) Disadvantage Solvent removing process.
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  10. 7 Step polymerization Techniques.
 c. Interfacial polymerization.   
 Polymerization at the interface between
immiscible two solvents.     Water Diamine.
    Organic solvent Diacid chloride.   
1) Low temperature polymerization.    2) Rapid
polymerization.    3) Higher molecular weight.
   4) Not necessary stoichiometric balance.
      Schotten-Baumann reaction.
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  10. 7 Step polymerization Techniques.
 d. Phase-transfer catalysis polymerization(PTC).
   1) Phase-transfer catalyst
Benzyltriethylammonium chloride.     
   C6H5CH2N(C2H5)3Cl-    2) Mechanism
Dissolve in water and make ion pair.     
   Move to organic layer.
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10. 8 Dendritic Polymers.
A. Terminology (Since 1980s)     Dendrimer
Dendron like tree.    Starburst polymer. B.
Commercial application.  a. Drug delivery
system Controlled release of agricultural
chemicals  b. Molecular sensors.  c. Rheology
modifiers.
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10. 8 Dendritic Polymers.
C. Characteristics feature.  a. Structure
Three component parts.   1) Core.    2)
Interior dendritic structure.    3) Exterior
surface.   b. Easy control macromolecular
dimension by a repetitive sequence of step.  
c. More soluble than linear polymer high
surface functionality.   d. Low viscosity No
entanglement.   e. Supramolecular assembly
Guest molecules among the interior branches
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10. 8 Dendritic Polymers.
D. Synthsis of dendrimer.  a. Divergent  
 1) Polyamidamine (PAMAM).
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 2)
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10. 8 Dendritic Polymers.
b. Convergent.
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10. 8 Dendritic Polymers.
E. Hyperbranched polymer.   a. Types of
monomer AxB ( x gt 1). F. Nanostructure of
dendrimer.   a. Molecules dimension
1-100nm.   b. Molecules devices Mimicking
nanoscopic biomolecules.
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10. 9 Ring-opening polymerization.
A. Commercially important ring-opening polymers.
  Ring-opening polymers Condensation polymers.
              
 Not polycondensation reaction.
              
 No byproduct.
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B. Mechanism of ring-opening polymerization.  
a. Initiator Ionic or coordination species
(X).    1)
 2)
 b. Initiator XY.    1)
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10. 9 Ring-opening polymerization.
 C. Ring strain Possibility of ring-opening
polymerization.        3 gt 4
gt 8 gt 7 gt 5 gt 6  D. Ring-opening block
copolymerization.      AB, 
AB  , ABA Block copolymer.