Block copolymers consisting of polystyrene and a block containing long fluorinated side chains are made by two very effective polymer analogous reactions from commercially available polystyrene-b-polybutadiene block copolymers. Since these polymers consist of two mutually immiscible blocks with hydrophobic and very hydrophobic character they form micelles in a wide range of media down to very hydrophobic solvents, e. g. toluene, tetrahydrofurane (TI-IF), peffluorohexane, perfluoro(methylcyclohexane), hexafluorobenzene and 1,1,2-trichlorotrifluoroethane (Freon 113). First indications that our polymers are useful as effective steric stabilizers in such solvents are given by characterization of some polymer dispersions made in these solvents via precipitation polymerization. In the solid state, mesophase formation typical for block copolymers is observed and characterized by quantitative small angle X-ray scattering (SAXS). The surface of such films is controlled by the fluorinated Mock and exhibits an ultra-low surface energy of the order of ysv = 15 mN/m, below that of polytetrafluoroethylene (PTFE) or polydimethylsiloxanes (PDMS). Unlike PTFE, the blocky nature of the presented polymer enables thermoplastic processing and dissolution in standard solvents, which is of practical relevance. Gas-permeability measurements on membranes coated with these copolymers exhibit some interesting selectivities. Acta Polymer., 48, 262-268 Q VCH Verlagsgesellschaft mbH, D-69451 Weinheim 1997

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Block copolymers made of polystyrene and fluorinated blocks represent a new class of polymers with a very strong incompatibility between the two blocks. They exhibit new stable block copolymer mesophases which are not considered in the phase diagrams of diblock copolymers in the strong and super-strong segregation regime. The solid-state structures of two polymers with different compositions are characterized by synchrotron small-angle X-ray scattering and transmission electron microscopy, thus proving the existence of a quadratically perforated layer phase and a 2D phase of sanidically degenerated cylinders.

SUMMARY: Small angle X-ray scattering (SAXS) on films of poly(N-alkylacrylamides) with various chain lengths reveals that these well known polymers exhibit a microphase-separated solid-state structure with liquid crystalline order. Analysis of the phase morphology in dependence on the alkyl side chain length results in the following scenario: For the C 8 and C 10 tail, the microphases are just weakly developed and quantitative analysis of the broad scattering peak reveals an ill-defined structure without sharp phase boundaries. For the C 12 and C 14 derivative, we found a well developed mesophase, which shows a number of scattering peaks and cannot be related to any classical phase morphology. For these two materials, a phase model is developed on the base of a new technique of quantitative evaluation of the X-ray data. Poly(N-hexadecylacrylamide) and poly(N-octadecylacrylamide) exhibit lamellar morphologies with low long range order. Poly(N-octadecylacrylamide) obtained by polymerization instead of polymer reaction exhibits a different phase morphology which resembles the so-called sponge-like phase. The different phase morphologies are also reflected in the thermal behavior where the sponge phase shows a lower melting point and melting enthalpy of the side chains than the lamellar mesophases, regardless of the longer alkyl chains involved in this system.