polypropylene polymers in the formation of dielectric thin films in capacitors that
show significantly higher energy and power densities.
Keywords Block copolymer Á Capacitor Á Crosslinked polypropylene Á Energy
storage Á Functional polyolefin Á Graft copolymer Á Hydroxylated polypropylene Á
Metallocene Á Reactive chain transfer agent Á Reactive comonomer
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
2 New Functionalization Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
2.1 Polyolefins with Side Chain Functional Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
2.2 Polyolefins with a Chain-End Functional Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
3 Polyolefin Block and Graft Copolymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
4 Functional PP Capacitors for Energy Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
5 Conclusions . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . 273
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
1 Introduction
Since the discovery of high-density polyethylene (HDPE) and polypropylene (PP)
in the early 1950s, the functionalization of polyolefins [1, 2] has been a scientifically challenging and industrially important area of study. The continuing interest is
driven by an impetus to improve on the poor interactive properties of polyolefins
and apply them to higher value products, especially polymer blends and composites
for which adhesion and compatibility with other materials are paramount. Despite
significant research efforts [3, 4] in the past decades (since the beginning of the
Ziegler–Natta era in the 1950s), both direct and post-polymerization approaches
have yielded limited success.
Direct polymerization could be an ideal process [5–8] if the copolymerization of
α-olefin (ethylene, propylene, etc.) with functional monomers was as effective and
straightforward as the corresponding homopolymerization reaction. Unfortunately,
some fundamental chemical difficulties, namely catalyst poisoning, are difficult to
overcome and have prevented serious consideration of the direct process for
commercial applications. The small number of catalytic (cationic) sites tend to
form complexes with non-bonded electron pairs on N, O, and X (halides) of
functional monomers, preferring to react with the π-electrons of the double
bonds. The result is the deactivation of the active polymerization sites due to side
reactions or the formation of stable complexes between catalysts and functional
groups, thus inhibiting polymerization. Two general approaches are (1) protecting
sensitive functional groups from the poisoning catalyst [9] and (2) employing late
transition metal catalysts that are less oxophilic and more stable to heteroatoms
[10–12]. So far, most experimental results show a significant decrease in catalyst
234
T.C.M. Chung
show significantly higher energy and power densities.
Keywords Block copolymer Á Capacitor Á Crosslinked polypropylene Á Energy
storage Á Functional polyolefin Á Graft copolymer Á Hydroxylated polypropylene Á
Metallocene Á Reactive chain transfer agent Á Reactive comonomer
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
2 New Functionalization Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
2.1 Polyolefins with Side Chain Functional Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
2.2 Polyolefins with a Chain-End Functional Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
3 Polyolefin Block and Graft Copolymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
4 Functional PP Capacitors for Energy Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
5 Conclusions . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . 273
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
1 Introduction
Since the discovery of high-density polyethylene (HDPE) and polypropylene (PP)
in the early 1950s, the functionalization of polyolefins [1, 2] has been a scientifically challenging and industrially important area of study. The continuing interest is
driven by an impetus to improve on the poor interactive properties of polyolefins
and apply them to higher value products, especially polymer blends and composites
for which adhesion and compatibility with other materials are paramount. Despite
significant research efforts [3, 4] in the past decades (since the beginning of the
Ziegler–Natta era in the 1950s), both direct and post-polymerization approaches
have yielded limited success.
Direct polymerization could be an ideal process [5–8] if the copolymerization of
α-olefin (ethylene, propylene, etc.) with functional monomers was as effective and
straightforward as the corresponding homopolymerization reaction. Unfortunately,
some fundamental chemical difficulties, namely catalyst poisoning, are difficult to
overcome and have prevented serious consideration of the direct process for
commercial applications. The small number of catalytic (cationic) sites tend to
form complexes with non-bonded electron pairs on N, O, and X (halides) of
functional monomers, preferring to react with the π-electrons of the double
bonds. The result is the deactivation of the active polymerization sites due to side
reactions or the formation of stable complexes between catalysts and functional
groups, thus inhibiting polymerization. Two general approaches are (1) protecting
sensitive functional groups from the poisoning catalyst [9] and (2) employing late
transition metal catalysts that are less oxophilic and more stable to heteroatoms
[10–12]. So far, most experimental results show a significant decrease in catalyst
234
T.C.M. Chung