We report on time resolved combined differential scanning calorimetry, small-angle and wide-angle x-ray scattering of hydrogen bonded flexible polymer-surfactant systems. The results show the presence of an order-disorder transition from a homogeneous to a lamellar structure due to dynamic coupling between surfactant and polymer. The homogeneous state exhibits a distinct small-angle x-ray scattering peak due to characteristic comb copolymerlike fluctuations. The peak position is strongly dependent on temperature and on the amount of surfactant material. ͓S1063-651X͑96͒11712-8͔

Dynamic mechanical spectroscopy (DMS) is used to further investigate the recently observed order−disorder transition (ODT) in comblike block copolymers obtained by hydrogen bonding between poly(4-vinylpyridine) and pentadecylphenol (P4VP−PDP x ). For stoichiometric amounts of pyridine and phenol, i.e., x = 1.0, the ODT to a lamellar structure occurs at T ≃ 65 °C. The dynamic moduli G‘ and G‘‘ simultaneously show a crossover from a liquidlike behavior (G‘ ∼ ω1.5 and G‘‘ ∼ ω) to a response intermediate between a Newtonian fluid and a solid (G‘ ≈ G‘‘ ∼ ω1/2). The behavior above T ODT differs slightly from a homopolymer melt (G‘ ∼ ω2.0) due to composition fluctuations, whereas the behavior below T ODT is characteristic for quenched block copolymer lamellar phases with local uniaxial order and global isotropy. Near room temperature, a transition to solid behavior (G ∼ ω0) takes place due to crystallization of the alkyl side chains. Larger amounts of PDP lower the T ODT temperature, and for x = 2.0 the transition to solid response occurs directly from the disordered state. Small and wide angle X-ray scattering (SAXS and WAXS) experiments and differential scanning calorimetry (DSC) corroborate these findings. Furthermore, SAXS and WAXS demonstrate that the low-temperature state of P4VP−PDP2.0 is not stable and indicate that ultimately macrophase separation into a pure crystalline PDP phase and a microphase separated P4VP−PDP phase occurs.

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