TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Disclosed): Preparation of (I) comprises subjecting substituted 1,2,3,4-tetrahydrocarbazole compounds of formula (II) to an oxidation reaction at 140-180 degrees C in the presence of activated carbon and organic solvent, to obtain substituted bicarbazole compounds of formula (III), representative of (I).R3 = R1 or R2.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The composition further comprises a phenylphenoxyalkyl mono(meth)acrylate compound. Preferred Definitions:    photopolymerizable functional group = vinyl, glycidyl, 2-methylgIycidyl group, or (meth)acryloyl group-containing structural site of formula (-(-R3-O-)n-C(=O)-C(R4)=CH2) (M1);    R3 = linear or branched 2-6C alkylene;    R4 = H or methyl; and    n = 0-10.    SPECIFIC COMPOUNDS - 4 Compounds (I) are disclosed i.e. 9,9'-diacryloyl-1,3'-bicarbazole of formula (Ia), 9,9'-divinyl-1,3'-bicarbazole, 9,9'-bis(acryloyloxyethyl)-1,3'-bicarbazole and 1,3'-bicarbazole.    EXAMPLE - 5 g 1,3'-Bicarbazole was suspended in 45.4 g of 3-chloropropionyl chloride, and the resulting reaction mixture was allowed to react at 130 degrees C for 8 hours while hydrogen chloride gas generated was discharged with a nitrogen stream. The reaction mixture was cooled to room temperature, and 200 ml of toluene was added to the reaction mixture to dissolve the reaction product. The resulting solution was washed with water twice, a saturated sodium bicarbonate solution once, and a saturated sodium chloride solution once in that order. The solution was then dried with anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting product was purified to give 9,9'-bis(3-chloropropionyl)-1,3'-bicarbazole. Subsequently, in a 300-ml three-necked flask, 6 g of above obtained 9,9'-bis(3-chloropropionyl)-1,3'-bicarbazole and 0.2 g of 4-methoxyphenol were dissolved in 60 ml of toluene. Next, 2.37 g of triethylamine was added to this solution while stirring, and the reaction solution was allowed to react at 60 degrees C for 4 hours. The reaction solution was cooled to room temperature, and 200 ml of toluene was added to it. The solution was washed with a saturated sodium chloride solution once, 2% hydrochloric acid once, a saturated sodium bicarbonate solution once, and a saturated sodium chloride solution once in that order. The solution was dried with anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure, and the resulting crude product was purified by silica gel column chromatography to give 9,9'-diacryloyl-1,3'-bicarbazole (yield 5.1 g).