Synthesis of AB-type block copolymers containing benzoxazole and anthracene groups by ATRP and fluorescent property

Two functional monomers, methacrylic acid 4-(2-benzoxazol)-benzyl ester (MABE) containing the benzoxazole group and 4-(2-(9-anthryl))-vinyl-styrene (AVS) containing the anthracene group were synthesized by rational design. The MABE was polymerized via atom transfer radical polymerization (ATRP) using ethyl 2-bromoisobutyrate (EBIB) as initiator in CuBr/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) catalyst system; block copolymers poly(MABE-b-AVS) was obtained, which was conducted by using poly(MABE) as macro-initiator, AVS as the second monomer, and CuBr/PMDETA as catalyst. The constitute of two monomers in block copolymers poly(MABE-b-AVS) by ATRP could be adjusted, that is the constitute of the benzoxazole group and the anthracene group could be controlled in AB-type block copolymers. Moreover, the fluorescent properties of homopolymers poly(MABE) and block copolymers poly(MABE-b-AVS) were discussed herein. With the excitation at λex = 330 nm, the fluorescent emission spectrum of poly(MABE) solution showed emission at 375 nm corresponding to the benzoxazole-based part; with the same excitation, the fluorescent emission spectrum of poly(MABE-b-AVS) solution showed a broad peek at 330–600 nm when the monomer AVS to the total monomers mole ratio was 0.31, and the fluorescent emission spectrum of poly(MABE-b-AVS) in film state only showed one peak at 525 nm corresponding to the anthracene-based unit that indicated a complete energy transfer from the benzoxazole group to the anthracene group. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3894–3901, 2007