In order to synthesize cyanic RAFT agents for RAFT polymerization of methyl methacrylate (MMA)

an improved aqueous phase method was developed to prepare di(thiocarbazolyl) disulfide (DTCD) with carbazole as main material and potassium ferrocyanide as oxidant.Compared with the traditional oilphase method

the expected high purity DTCD was obtained in the form of crystal that was precipitated and separated from the aqueous solution.Then

2-cyanoprop-2-yl N-carbazolylcarbodithioate (CYCBD) and 4-cyanovalericacid Ncarbazolylcarbodithioate (CVCBD) were synthesized based on a substitution reaction between DTCD and azobisisbutyronitrile (AIBN) or azobis(cyanovaleric acid) (ACVA).The activities of CYCBD and CVCBD as RAFT agents for the polymerizations of MMA were determined

and the results showed that both of the RAFT agents were of significant activity in the RAFT polymerization of MMA and molecular weight distribution of fluoresence\|labelled poly(methyl methanylate) CPMMA prepared by CYCBD or CVCBD is less than 1.2. The fluorescence characteristics of CYCBD and CVCBD as well as CPMMA prepared by CYCBD or CVCBD were also studied.The results showed that all of them exhibited significant fluorescence in tetrahydrofuran (THF) solution.Moreover

CPMMA prepared by CYCBD or CVCBD possesses obvious fluorescence emission at a wavelength of 358 nm

and there is a good linear relationship between fluorescence intensity and concentration of CPMMA when the concentration of CPMMA in the range of 01～20 μmol/L.In a word

CYCBD and CVCBD as RAFT agents possess good control ability and can be used to synthesize fluorescencelabelled polymers with well-defined structure.