Continuous and Batch Polymerization of Vinylidene Fluoride in CO2

1
Continuous and Batch Polymerization of Vinylidene
Fluoride in CO2

• Nathan Lechene
• Under the direction of Dr. George Roberts and Dr.
  Lou Wojcinski

2
Project Objectives

• Synthesize poly(vinylidenefluoride) and get the
  number average molecular weight up to 90K grams
  per mole
• Optimize reaction conditions in batch cell
  reactor
• Scale-up reaction to CSTR when optimal conditions
  are achieved

3
Why use fluorinated initiators?

• Prior polymerizations initiated by EPDC resulted
  in lower than desired molecular weights
• Fluorinated initiators show lower decomposition
  temperatures

3
4
Initiator Synthesis

• perfluoro-butyryl peroxide (PBP)

5
Initiator Synthesis

• Initiator is unstable, so the reaction is
  performed from 10 0ºC.
• Initiator is then stored at 70ºC in a dry ice
  chest.
• Decomposition occurs at higher temperatures. This
  decomposition produces the radicals that initiate
  the polymerization reaction.

O
O
O
2
C
F
C
O
C
F
C
O
O
C
C
F
3
7
3
7
3
7
6
Polymerization Reaction
Initiation
Propagation
3
7
2
2
7
Chain Termination

• Termination occurs primarily through the
  combination of two active sites.

8
Reaction Parameters and Environment

• Temperatures range from 30ºC to 50ºC.
• Pressures range from 3000psi to 5000psi.
• Vary initiator (.001-.003M) and monomer
  concentration (2-3M)

9
Batch Cell Reactor
10
Data Collected
11
Data Collected
12
Molecular Wt Distribution
13
Highest Molecular Wts Achieved
14
Scaling-up to the CSTR
15
Scaling-up to the CSTR

• Have not performed any experiments in the CSTR to
  date
• Runs are pending

16
Future Work

• Perform runs in the the CSTR using reaction
  parameters determined by the batch cell reactor
• Analyze the data obtained from the CSTR runs and
  determine if the process is adequate for
  industrial purposes

17
Conclusions

• Batch cell reactions produced high molecular
  weight polymers at 4800psi and lower initiator
  concentrations
• Avg Molecular Wts near 90k g/mol were obtained in
  the batch cell, but remain to be tested in the
  CSTR

18
Acknowledgements

• George Roberts, Lou Wojcinski, Joe DeSimone,
  Manish Saraf, Joe Royer, Sylvain Gerard
• Solvay, Air Products
• NSF Agreement CHE-9876674
• This research was conducted with the support of
  the NSF Green Processing Undergraduate Research
  Program with a grant from the National Science
  Foundation, Award Number, EEC-9912339