New low molecular weight organic materials with a strong tendency towards glass formation and glass temperatures above room temperature were synthesized. These materials consist of twin molecules where two bulky groups, i.e. carbazole (Ca), 3,6-dibromocarbazole (DBrCa), 2,3-benzocarbazole (BC), 1,2-benzo-3,4-dihydrocarbazole (BCDH), phenothiazine (Ph), 1,8-naphthalic acid anhydride (NI), and pyrene-l-aldehyde (PY) have been linked by flexible or semiflexible aliphatic or aromatic central units. Their structure-glass temperature relationship and some relations between thermodynamic parameters and amorphous properties are discussed.
Molecular Design of Novel Main-Chain Biscarbazolyl Polymers for Nonlinear Optics
A series of alpha,omega-bis[(3-formyl)carbazolyl]alkane monomers have been prepared and copolymerized with bis(cyanoacetate) to provide novel accordion-type carbazole main-chain polymers. These main-chain polymers are soluble in common organic solvents, and have glass transition temperatures in the range of 94-117 degrees C and molecular weight 25000-72000.