Side-Chain Liquid Crystalline Poly(meth)acrylates with Bent-Core Mesogens

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Macromolecules

DOI:https://doi.org/10.1021/ma061949u· OSTI ID:930315

Chen, X; Tenneti, K; Li, C; Bai, Y; Wan, X; Fan, X; Zhou, Q; Rong, L; Hsiao, B

We report the design, synthesis, and characterization of side-chain liquid crystalline (LC) poly(meth)acrylates with end-on bent-core liquid crystalline (BCLC) mesogens. Both conventional free radical polymerization and atom transfer radical polymerization have been used to synthesize these liquid crystalline polymers (LCP). The resulting polymers exhibit thermotropic LC behavior. Differential scanning calorimetry, thermopolarized light microscopy, wide-angle X-ray diffraction, and small-angle X-ray scattering were used to characterize the LC structure of both monomers and polymers. The electro-optic (EO) measurement was carried out by applying a triangular wave and measuring the LC EO response. SmCP (Smectic C indicates the LC molecules are tilted with respect to the layer normal; P denotes polar ordering) phases were observed for both monomers and polymers. In LC monomers, typical antiferroelectric switching was observed. In the ground state, SmCP{sub A} (A denotes antiferroelectric) was observed which switched to SmCP{sub F} (F denotes ferroelectric) upon applying an electric field. In the corresponding LCP, a unique bilayer structure was observed, which is different from the reported BCLC bilayer SmCG (G denotes generated) phase. Most of the LCPs did not switch upon applying electric field while weak AF switching was observed in a low molecular weight poly{l_brace}3'-[4-(4-n-dodecyloxybenzoyloxy)benzoyloxy]-4-(12-acryloyloxydodecyloxy)benzoyloxybiphenyl{r_brace} sample.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 930315
• Report Number(s): BNL--81025-2008-JA
• Journal Information: Macromolecules, Journal Name: Macromolecules Vol. 40
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ELECTRICAL PROPERTIES
LIQUID CRYSTALS
MOLECULAR STRUCTURE
MOLECULAR WEIGHT
POLYACRYLATES
SYNTHESIS
national synchrotron light source