Membrane Gas Separation

3 
Addition - type Polynorbornene with 
Si( CH
3
 ) 
3
Side Groups: Detailed Study 
of Gas Permeation, Free Volume and 
Thermodynamic Properties
Yuri Yampolskii 
a
, Ludmila Starannikova 
a
, Nikolai Belov 
a
, Maria Gringolts 
a
, 
Eugene Finkelshtein 
a
and Victor Shantarovich 
b


a
A. V. Topchiev Institute of Petrochemical Synthesis, Moscow, Russia
b
N. N. Semenov Institute of Chemical Physics, Moscow, Russia
3.1
Introduction 
Norbornene and its numerous derivatives are an unusual case in polymer and membrane 
science: by selecting different catalysts for the polymerization process, materials with 
entirely different structures can be prepared. The norbornene bicyclic molecule is strongly 
strained, so ring opening metathesis polymerization (ROMP) is signifi cantly favoured by 
thermodynamic factors. Because of this, numerous cyclolinear structures of ROMP poly-
mers were prepared in the presence of the catalysts such as WCl 
6
, RuCl 
3
, Re 
2
O 
7
/Al 
2
O 
3
or 
Grubbs Ru complexes and characterized during the last decades [1 – 6] . These polymers 
include as side groups the following substituents: SiMe 
3
, CN, Et, Bu, Cl, F, CF 
3
, OC 
3
F 
7
, 
etc., have modest permeability ( P (O 
2
) = 2 – 100 Barrer) and behave like conventional glassy 
polymers. 
Meanwhile, norbornene being a bicyclic olefi n can be polymerized also via an addition 
scheme with opening of the double bonds. This reaction proceeds in the presence of 
Ni or Pd catalysts and results in polymers with entirely different structures and, hence, 
different properties (Scheme 3.1 ).

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44
Membrane Gas Separation
Several authors reported the transport properties of the addition - type polynorbornenes 
bearing such alkyl substituents as CH 
3
, n - C 
4
H 
9
, n - C 
10
H 
21
[7 – 10] . These polymers are 
distinguished by very rigid structure ( T
g
at about 300 ° C or higher) and permeability coef-
fi cients P (O 
2
) in the range 20 – 90 Barrer, so not a big difference is observed in comparison 
with ROMP polynorbornenes studied. However, much higher permeability was reported 
for the product of addition 
- 
type polymerization of trimethylsilylnorbornene
[11,12] 
(Structure 3.1 ). 
This amorphous glassy polymer has the permeability coeffi cients P (O 
2
) in the range 
800 – 1000 Barrer (for different samples) [12,13] . Such behaviour is in line with well -
documented effects of the introduction of bulky Si(CH 
3
) 
3
group into various main chains; 
however, the effect here, bearing in mind very rigid structure of the backbone chain, is 
much larger (Table 3.1 ).
In this article we shall give a survey of the transport parameters, thermodynamic prop-
erties and free volume of addition - type poly(trimethylsilylnorbornene) (PTMSN).
metathesis
polymerization
n
n
n
addition
polymerization
Scheme 3.1
SiMe
3
n
Structure 3.1
Table 3.1  Effects of introduction of Si(CH 
3
 ) 
3
groups in various main chains 
Polymer type
a
P (O 
2
), Barrer
Ref.
PS
2.9
[14]
SiMe 
3
- PS
56
[15]
PNB (ROMP)
2.6
[16]
SiMe 
3
- PNB (ROMP)
20.9
[17]
APN
6.9
[12]
SiMe 
3
- APN
840
[12]
a
PS, polystyrene; SiMe 
3
- PS, poly( p - trimethylsilylstyrene); PNB, polynorbornene; SiMe 
3
- PNB: ROMP 
poly(trimethylsilylnorbornene); APN addition - type polynorbornene, SiMe 
3
- PNB addition - type poly
(trimethylsilylnorbornene) .

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Addition-type Polynorbornene with Si(CH
3
)
3
 Side Groups
45