Nonlinear optically active polymethacrylates with high glass transition temperatures

Abstract

A number of novel nonlinear optically (NLO) active polymethacrylates were prepared from the NLO active methacrylates 2a-d with azobenzene side groups and the bulky comonomer 1-adamantyl methacrylate. The polymers exhibit unusually high glass transition temperatures between 160 "C and 190°C. The copolymerization parameters of the monomer pair 1-adamantyl methacrylate (1)lDisperse red methacrylate 2 b (r, = 1,l t 0,2, r2 = 0,s f 0,2) show that the two monomers are incorporated almost statistically into the polymer chain. Polymers 3a-d are soluble in common organic solvents and excellent films can be obtained by spin coating. After poling in an electric field of 120 V/pm polymer 3b shows a large electrooptic (EO) coefficient (r33) of 25 pm/V at 633 nm. Within two weeks, only a negligible decay of 7% of the EO coefficient was observed at room temperature. On-line monitoring of the second harmonic generation (SHG) at 100 O C showed a fast initial drop (10%) of the SHG signal and subsequently a slow decay of 20% within 10 h. Afterwards, the signal remained almost constant for further 5 h at 100°C. The novel polymers can thus be considered as easy processible NLO materials with a high thermal stability of the chromophore orientation obtained by poling.

Second-order non-linear optical polymers

“…For copolymethacrylates prepared from NLO active methacrylates with azobenzene side groups and the bulky comonomer adamantyl methacrylate (T g 's 160 -190 8C) 49) , a r 33 value of 25 pm/V (measured at 633 nm) was found. Within 2 weeks, only a negligible decay of 7% of the EO effect was observed at room temperature.…”

Thermally stable aliphatic polycarbonate containing bulky carbazole pendants

“…It is well known that side chains have significant influence on the thermal properties of polymers. Eckl et al reported that the T g of polymethacrylates increased from about 100 to 190°C by introducing bulky adamant substitutes onto the side chains 20 . N ‐(2,3‐epoxylpropyl)carbazole is a well known commercial monomer, which can be used for the preparation of photoconductive polymer 21–23.…”

A highly transparent and thermally stable copolymer of 1-adamantyl methacrylate and styrene

“…Eckl et al . reported several copolymers of AdMA with nonlinear optically (NLO) active methacrylates, and Briers et al . also reported NLO active copolymers of AdMA with methylvinyl urethanes .…”

“…For example, Acar et al synthesized poly(1-adamantylmethyl methacrylate) and poly [4-(1-adamantyl)phenyl methacrylate] by free radical polymerization and observed T g for both polymers. 8 Eckl et al reported several copolymers of AdMA with nonlinear optically (NLO) active methacrylates, 9 and Briers et al also reported NLO active copolymers of AdMA with methylvinyl urethanes. 10 In particular, a considerable number of studies have been conducted on copolymers of AdMA or its derivatives as photoresist materials.…”