Adhesive liquid‐crystalline polymers

Abstract

The synthesis and characterization of liquid-crystalline polymers with possible good adhesive properties is reported. These polymers are prepared by alternating copolymerization of maleic anhydride and mesogenic alkenes. The spacer length m is varied (m = 2,3,4,6, 8 and 9) and methoxybiphenyl is used as the mesogenic group. The glass transition temperature decreases and the isotropization temperature increases with spacer length. Depending on the spacer length and temperature, Sg and SA,, mesophases can be observed. After annealing, spin-coated films of these polymers show very regular layered structures with a layer spacing similar to that in the bulk.

Thermotropic behavior of side-chain liquid-crystalline copolymers from maleic anhydride and mesogen-containing methacrylates

“…The mesomorphic behavior of poly(MA-co-methacrylate)s is different from that of polymethacrylates 8,13) and poly(MA-alt-1-alkene)s 16,17) . Although all polymers show a decrease of T g with spacer length, only the poly(MAalt-1-alkene)s show an increase in T i with spacer length.…”

“…The synthesis and phase behavior of copolymers containing methoxybiphenyl mesogens will be described. The mesomorphic properties are compared to those of previously described poly(MA-alt-1-alkene)s 16,17) and those of polymethacrylates containing similar mesogens 8,13) . The influence of spacer length and MA content on transition temperatures is studied.…”

“…In a previous study, it was shown that maleic anhydride (MA) copolymerizes with mesogenic 1-alkenes yielding SCLCPs with adhesive properties 16,17) . On polar substrates, thin films may be obtained from SCLCPs with MA moieties that form lamellar structures upon annealing 18) and show autophobicity 19) .…”

Highly ordered side-chain liquid-crystalline polymers from maleic anhydride and swallow-tailed 1-alkenes having two mesogens

“…[1,2] These polymers contain methoxybiphenyl mesogens and exhibit smectic mesophases over a temperature range up to 66 8C. SCLCPs with hexyl or longer spacers exhibit a hexatic smectic B and an interdigitated smectic A mesophase.…”

“…Previous studies have already shown that SCLCPs with MA moieties exhibit very interesting physical behavior. [2,11,12] Spincoated films of these polymers on silicon oxide show lamellar ordering upon annealing above the glass transition temperature (T g ). [2,11] In addition, these polymers adhere well on silicon oxide surfaces and exhibit autophobicity.…”