An electro-optic waveguide device comprising an electro-optic polymer core and at least one crosslinked polymer clad, wherein the crosslinked polymer clad is comprised of a first constitutional unit derived from a compound having the formula wherein, m=0-6; n−0-1; q=1-3; y=0-3; Ar1 is an aryl or heteroaryl group; and independently at each occurrence p=0-1; R is an alkyl, heteroalkyl, aryl, or heteroaryl group; Ar2 is an aryl or heteroaryl group; and X is a crosslinkable group. The R group may be an alkyl or heteroalkyl group with at least 6 atoms in a straight chain. In some embodiments, the R group is an alkoxy capped oligoalkylene group. Other embodiments include a polymer comprising a first constitutional unit derived from a compound having the formula described above.