Synthesis and molecular properties of polymers with asymmetrically substituted side dendrons based on L-aspartic acid

Various acrylic polymers in which an aspartic acid fragment with different end groups (the firstgeneration dendron) is attached to the main chain either via the amide group or the 4-aminobenzoic acid residue are studied. The synthesis of monomers and polymers with the asymmetric substitution of the aspartic fragment, in which a long hexadecyl group is situated only at the α-carboxyl group, is described. The molecular, optical, electrooptical, and conformational properties of the polymer containing the long hexadecyl group at the α-carboxyl bond and the hydrolyzed β-ester bond in the aspartic acid fragment are examined in detail. In the range M = (23−508) × 103, the Mark-Kuhn-Houwink equations [η] ∼ M0.53 and D ∼ M−0.53 are obtained for the intrinsic viscosity and diffusion of the polymers under study in octyl alcohol. The length of the statistical Kuhn segment (120 Å), the hydrodynamic diameter of a chain (50 Å), the shear optical coefficient, and the anisotropies of the segment and monomer unit are determined. An analysis of the experimental data shows that the main optical axis of the side hexadecyl chain makes an angle of ∼54.5° with the direction of the main chain.