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The structure and properties of the H-bonded liquid crystalline (LC) polymer grafted onto fluorocarbon polymer substrate were studied by the FTIR spectroscopy technique. The grafted LC polymer brush was prepared via “grafting from” polymerization of 4-(6-acryloyloxyhexyloxy)benzoic acid initiated from the surface of UV-irradiated FEP substrate. The orientation under the uniaxial mechanical stress and the temperature behavior of LC brush stabilized by H-bonds were studied. Substantial changes of the structure and orientation of the LC brush were observed upon increase in temperature. The grafting of the LC layer provides the reversible destruction and restoration of the macroscopic orientation. In contrast to the homopolymer, the orientation behavior of grafted H-bonded LC layer is controlled by the fluorocarbon substrate.

The orientation behavior of liquid crystal networks having the Sm CA structure stabilized by H-bonds has been studied. The mesogenic groups formed by hydrogen bonds generate a layered structure of the polymer. The hydrogen bonds are responsible for the elastic properties of the liquid crystal polymer network and the mechanism of its plastic flow above the threshold strain. The mechanical response is interpreted in terms of the mechanism of breaking and reconnecting H-bonds under stress. The local sliding of layers is possible if H-bonds are temporarily disconnected and then reconnected again to restore the LC structure. The anisotropy of the mechanical properties of the H-bonded polymer materials is observed in the monodomain LC networks.

Hydrolysis of polyacrylonitrile (PAN) was carried out in 65% HNO3 at 21 °C. The composition and structure of hydrolyzed samples (HPAN) were determined using ¹³C NMR spectrometry. The HPAN are multiblock copolymers containing acrylonitrile (A) and acrylamide (B) units. A set of individual rate constants for the reaction of central A units in AAA, AAB + BAA, and BAB triads, k0, k1, and k2, respectively, describes fairly well both the reaction kinetics and the HPAN distribution of units. Thus, the accelerating effect of neighboring groups (k0:k1:k2 = 1:18:36) is the principal, if not exclusive, factor determining the peculiarities of the acidic PAN hydrolysis. Less than 3% of acrylamide groups are involved in cyclization (formation of glutarimide cycles) under the hydrolysis conditions used, so that cyclization may be neglected in the analysis of the hydrolysis kinetics and the HPAN structure within the framework of the neighbor effect.