Synthesis and Phase Behavior of (Semifluorinated Alkane)‐Based Side‐Chain Liquid Crystalline Copolymers

Abstract

Side-chain liquid crystalline polymer (SCLCP) usually contains a simple and flexible homopolymer as main chain, while its effect on the self-assembly behavior is often ignored. In this work, in order to increase the structural complexity and investigate the interaction between the main chain and mesogens, perfluorinated segments are introduced into the main chain using a photoinduced Step Transfer-Addition & Radical-Termination polymerization method, producing a novel series of SCLCPs containing 4-methoxyphenyl benzoate mesogens, soft hydrocarbon spacers, and a strictly alternating perfluoroalkyl and alkyl backbone. By adjusting the length of spacers or perfluoroalkyl segments, several mesophases with complex chain packing structures are achieved. This design strategy that constructing highly ordered liquid crystalline (LC) structures from SCLCPs with precise chemical structure provides a facile way toward novel LC nanomaterials.

Preparation of fluorinated polyesters by reversible addition–fragmentation chain transfer step-growth polymerization

“…30–34 In this strategy, the C–I bond of the α , ω -diiodoperfluoroalkane was cleaved to generate –CF 2 ˙ and I˙ radicals, which added to the α , ω -unconjugated diene, yielding fluorinated alternating copolymers. With functionalized dienes as the monomers, a series of fluorinated polyolefins, 35,36 polyethers, 37 polyesters, 32,35 and polyether esters 38,39 have been successfully synthesized. Moreover, they also prepared fluorinated block copolymers 40–43 and graft copolymers 44–46 taking advantage of the reactive iodine group on the polymer backbone and terminals.…”

Dependence of micro-structure regularity on the degree of molecular asymmetry in polynorbornene derivatives

“…In their experiments, a bilayer SmC2 phase was formed when m was less than 4, while a highly ordered phase X1 was obtained when m was more than 8 [5]. In addition to the reports cited [6][7][8][9][10][11], our previous work on epoxy [12], poly(L-lactide) (PLLA) [13], and polyurethane (PU) [14,15] also indicates that there is a correlation between the regular morphology of polymers and the length of side chains. However, it is worth noting that for most polymers, changes in regularity of morphology do not always correspond to changes in side chain length.…”

Nitroxide-Mediated Controlled Radical Copolymerization of α-Trifluoromethylstyrenes with Styrenes

“…Semifluorinated polymers include those with a fluoroalkylene in the main chain and those with a fluorine functional group in the polymer side chain. To incorporate fluoroalkylene into the backbone, the use of telechelic functional poly(perfluoroethers) [ 10 ] and leveraging difunctional perfluorinated monomers [ 9 , 11 , 12 ] have been reported. These polymerizations yield fluorine-substituted main chain polymers; however, the polymerization cannot be controlled [ 13 ].…”