dimethanooctahydronaphthalene (DMON), or trimethanododecahydroanthracene
(TMDA) [98, 132–144] or by terpolymerization (for an attempt at terpolymerization
of ethene, norbornene and styrene see [143]).
Copolymerizations of ethene with bicyclic olefins, such as 2,5-norbornadiene
and 5-vinyl-2-norbornene, have been investigated with metallocene catalysts. The
secondary groups do not interfere with metallocene copolymerizations, and postpolymerization functionalization makes it possible to synthesize functionalized
polyolefins [133–135].
DCPD is a very promising and attractive monomer because it contains two
double bonds and both norbornene and cyclopentene units. If only one of the two
double bonds is selectively copolymerized with ethene, it is possible to
functionalize the remaining double bond (for a review on functionalization of
C–C double bonds, see [136]). Nevertheless, the copolymerization of ethene with
DCPD has not been extensively studied [137] because of the possibility of
crosslinking reactions [137]. Hou [140] achieved alternating ethene–DCPD copolymerization in a controlled fashion over a wide range of temperatures (0–70
C) by
using [Sc(η
5 -C 5 Me 4 SiMe 3 )(CH 2 SiMe 3 )2(THF)]/Ph 3 C][B(C 6 F 5 ) 4 ]. The highest catalytic activity was achieved at 50
C with a DCPD incorporation of ca. 44 mol%
with T g values between 101 and 125
C. Only the norbornene double bond was
selectively copolymerized. Novel ethene–DCPD–styrene terpolymers, which are
difficult to prepare with other catalyst systems, have also been achieved with
excellent selectivity and activity.
Kaminsky copolymerized higher condensed cyclic olefin comonomers such as
DMON or TMDA using metallocene catalysts [38, 98]. Low activities in DMONethene copolymerization and low incorporation were observed because of the
increasing monomer bulk. Although the reactivity ratio for norbornene is similar
to that of propene, reactivity ratios for DMON and TMDA are comparable to those
of 1-butene and 1-hexene.
Recently, Lee and coworkers [141, 144] introduced the copolymerization of
ethene with a regioselective partially hydrogenated tricyclopentadiene (HTCPD) by
using [8-(η
5
–C 5 Me 4 )-2-Me(C 9 H 8 N)-κN]TiMe 2 (C 9 H 10 NH ¼ 1,2,3,4-tetrahydroquinoline) (IV-6) activated with (Ph 3 C)
+
[B(C 6 F 5 ) 4 ]
À . A nearly alternating copolymer
with a HTCPD content of 45 mol% was obtained with a satisfactory activity of
4.7 Â 10
6 g/(mol Ti h) and a T g value of 177
C, significantly higher than that of E–N
copolymer at the same cycloolefin content. Tensile stress–strain curves showed more
ductile properties than a high-T g E–N copolymer with similar T g .
Very recently, effective copolymerization of ethene and exo-1,4,4a,9,9a,10hexahydro-9,10(1
0 ,2
0 )-benzeno-l,4-methanoanthracene (HBMN) by CGC catalyst
activated with Al(iBu) 3 /[Ph 3 C][B(C 6 F 5 ) 4 ] has been obtained [145]. EÀHBMN
copolymers show alternating EÀHBMN sequences, high molecular weight, and
T g up to 207
C at comonomer incorporation of 30.4 mol%. The tensile test indicates
that these copolymers are more flexible than EÀN copolymers and other previously
reported COC even at a higher T g level.
136
L. Boggioni and I. Tritto
(TMDA) [98, 132–144] or by terpolymerization (for an attempt at terpolymerization
of ethene, norbornene and styrene see [143]).
Copolymerizations of ethene with bicyclic olefins, such as 2,5-norbornadiene
and 5-vinyl-2-norbornene, have been investigated with metallocene catalysts. The
secondary groups do not interfere with metallocene copolymerizations, and postpolymerization functionalization makes it possible to synthesize functionalized
polyolefins [133–135].
DCPD is a very promising and attractive monomer because it contains two
double bonds and both norbornene and cyclopentene units. If only one of the two
double bonds is selectively copolymerized with ethene, it is possible to
functionalize the remaining double bond (for a review on functionalization of
C–C double bonds, see [136]). Nevertheless, the copolymerization of ethene with
DCPD has not been extensively studied [137] because of the possibility of
crosslinking reactions [137]. Hou [140] achieved alternating ethene–DCPD copolymerization in a controlled fashion over a wide range of temperatures (0–70
C) by
using [Sc(η
5 -C 5 Me 4 SiMe 3 )(CH 2 SiMe 3 )2(THF)]/Ph 3 C][B(C 6 F 5 ) 4 ]. The highest catalytic activity was achieved at 50
C with a DCPD incorporation of ca. 44 mol%
with T g values between 101 and 125
C. Only the norbornene double bond was
selectively copolymerized. Novel ethene–DCPD–styrene terpolymers, which are
difficult to prepare with other catalyst systems, have also been achieved with
excellent selectivity and activity.
Kaminsky copolymerized higher condensed cyclic olefin comonomers such as
DMON or TMDA using metallocene catalysts [38, 98]. Low activities in DMONethene copolymerization and low incorporation were observed because of the
increasing monomer bulk. Although the reactivity ratio for norbornene is similar
to that of propene, reactivity ratios for DMON and TMDA are comparable to those
of 1-butene and 1-hexene.
Recently, Lee and coworkers [141, 144] introduced the copolymerization of
ethene with a regioselective partially hydrogenated tricyclopentadiene (HTCPD) by
using [8-(η
5
–C 5 Me 4 )-2-Me(C 9 H 8 N)-κN]TiMe 2 (C 9 H 10 NH ¼ 1,2,3,4-tetrahydroquinoline) (IV-6) activated with (Ph 3 C)
+
[B(C 6 F 5 ) 4 ]
À . A nearly alternating copolymer
with a HTCPD content of 45 mol% was obtained with a satisfactory activity of
4.7 Â 10
6 g/(mol Ti h) and a T g value of 177
C, significantly higher than that of E–N
copolymer at the same cycloolefin content. Tensile stress–strain curves showed more
ductile properties than a high-T g E–N copolymer with similar T g .
Very recently, effective copolymerization of ethene and exo-1,4,4a,9,9a,10hexahydro-9,10(1
0 ,2
0 )-benzeno-l,4-methanoanthracene (HBMN) by CGC catalyst
activated with Al(iBu) 3 /[Ph 3 C][B(C 6 F 5 ) 4 ] has been obtained [145]. EÀHBMN
copolymers show alternating EÀHBMN sequences, high molecular weight, and
T g up to 207
C at comonomer incorporation of 30.4 mol%. The tensile test indicates
that these copolymers are more flexible than EÀN copolymers and other previously
reported COC even at a higher T g level.
136
L. Boggioni and I. Tritto