Synthesis of polymers having tetraphenyldiaminobiphenyl units for a host polymer of photorefractive composite

Acrylate type of monomer having tetraphenyldiaminobiphenyl (TPD) unit was prepared and was homo- and copolymerized with n-butyl acrylate using AIBN as an initiator. Electrochemical property of synthesized polymers was evaluated with cyclic voltammetry. All polymers exhibited the irreversible oxidation peak at 1.1 V in the initial cycle due to the oxidative coupling of TPD unit and two pairs of reversible oxidation and reduction peaks were observed in the subsequent cycles. Drift mobilities of synthesized polymers were in the range of 10(-5) cm(2)/V s at applied field of 1.6 x 10(5) V/cm and were 100 times higher than th at of PVK. Photorefractivity of polymers doped with 4-(N,N-diethylamino)-beta-nitrostyrene (nonlinear chromophore) and fullerene (C-60, charge generator) was investigated with two-beam coupling (2BC) technique. A 100-mu m thick composite film showed gains of 9 and 40 cm(-1) at an external electric fields of 50 and 70 V/mu m, respectively. The phase shift between the index grating and interference pattern was 43 degrees at an external electric field of 50 V/mu m.