Crosslinked poly(norbornene-dicarboximide)s as electro-optic chromophore hosts

Abstract A series of crosslinked poly(norbornene-dicarboximide)s have been prepared by ring opening metathesis polymerization. Increasing quantities of a bifunctional norbornene-dicarboximide crosslinker was doped into a high T g cyclohexyl-substituted norbornene-dicarboximide monomer before polymerization. The wt% of the crosslinker was increased from 0.00 to 4.40 wt%, after which the polymers became gelated. Polymer molecular weights increased drastically from 23,500 to 2,135,000 g/mol, the polydispersities increased from 1.18 to 73.47 and the viscosities increased from 5.27 to 538.7 mPa·s as the wt% of the crosslinker was increased. The trans : cis vinylene ratio remained constant at 1:0.18 as well as the T g and T d with average values of 210 °C and 392 °C being measured. Five of the crosslinked polymers and the reference homopolymer were utilized as hosts for the high activity tert -butyldiphenylsilyl substituted FTC chromophore guest. The polymer host containing 1.96 wt% crosslinker was found to have a maximum r 33 of 78 pm/V when polled at 150 °C with an electric field strength of 100 V/μm. The r 33 increased linearly from 63 to 78 pm/V as the wt% of the crosslinker was increased from 0.00  to 1.96 wt%. The thermal and temporal stability was found to increase slightly with the 0.00 wt% polymer exhibiting a stability of 77%, while the 1.96 wt% polymer exhibited a stability of 79% when both were heated to 85 °C and aged for 500 h in air.