A novel cross-linked pyroelectric polymer with pronounced second-order nonlinear optical properties has been prepared. A multistep synthesis with several selective transformations including a kinetic resolution (transesterification) with the highly enantioselective Candida antarctica lipase B, yielded the monomer 4‘‘-{(R)-(−)-2-[(10-acryloyloxy)decyl]oxy}-3-nitrophenyl 4-{4‘-[(11-acryloyloxy)undecyloxy]phenyl} benzoate A2c which displayed a ferroelectric chiral smectic C phase with large spontaneous polarization (175 nC/cm2). The monomer was poled and subsequently cross-linked by in-situ photopolymerization in the surface-stabilized ferroelectric liquid crystalline state. The cross-linked pyroelectric polymer exhibited an electro-optical coefficient (r 22 − r 12) of 15−35 pm/V.

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A novel method of preparing thermally stable thin films with intrinsic second-order nonlinear optical activity is described. Design and synthesis yielded new ferroelectric bifunctional liquid crystalline acrylate monomer mixtures with a fast electro-optical response in the chiral smectic C (SmC*) phase. The ferroelectric liquid crystalline monomer mixtures were poled and subsequently cross-linked by in-situ photopolymerization in the surface-stabilized ferroelectric liquid crystal state. After cross-linking the polarization is no longer reversible, hence the material is pyroelectric and not ferroelectric. The cross-linked pyroelectric materials displayed a thermally stable nonlinear optical response.

Novel syntheses of bifunctional liquid-crystalline acrylate and methacrylate monomers are described. Thermal and microstructural characterization of the monomers using small-angle X-ray scattering, differential scanning calorimetry, and optical microscopy revealed the presence of smectic A, smectic C, and smectic E phases. Photopolymerization of the bifunctional monomers conducted at different temperatures preserved the monomeric liquid-crystalline structure in the cross-linked polymers. The densely cross-linked polymers showed thermal reversibility. Mixtures of these monomers and chiral monofunctional liquid-crystalline monomers exhibited chiral smectic C mesomorphism that was permanented by photopolymerization and subsequent cross-linking.