4- cyanophenyl-4 - copolymer

Microphase separation does occur at shorter block lengths when the two blocks are highly immiscible, such as with hydrocarbon and fluorocarbon blocks. For example, all of the diblock copolymers of (perfluorooctyl)ethyl vinyl ether and n-[(4 -cyanophenyl-4"-phenoxy)alkyl] vinyl ethers (PRf-PCNVE ) or 2-[(4 -biphe-nyloxy)ethyl]vinyl ether (PRf-PbiPHVE2) listed in Table 16 exhibit the phases characteristic of both of the corresponding homo-... 

If the copolymer is based on monomers whose homopolymers exhibit identical me-sophases, its phase diagram follows ideal solution behavior with a continuous, linear or slightly curved dependence of the transition temperature and enthalpy of at least the highest temperature mesophase on copolymer composition [132, 134,136-140,364]. For example. Fig. 24 a demonstrates that the two structural units ofpoly 3-[(4 -(4"-cya-nophenyl)phenoxy)propyl]vinyl ether -co- 5-[(4 -(4"-cyanophenyl)phenoxy)pentyl] vinyl ether are isomorphic within the nematic mesophase, although they are not iso-... 

Figure 9 Synthesis of 6-[4-(4 -cyanophenyl)phenoxy]hexyl methacrylate/MA-POSS copolymers.

Miscibility studies of the nematic dye-containing copolymers with suitable low molecular weight liquid crystals yield homogeneous nematic mixtures. A binary mixture of 4-cyanophenyl-4-heptylbenzoate and 4-cyanophenyl-4-pentylbenzoate is miscible with the phenylbenzoate-anthraquinone copolymers. 

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