Synthesis of a water soluble, monosubstituted C60 polymeric derivative and its photoconductive properties

Atom transfer radical polymerization (ATRP) catalyzed by N,N',N',N,N-pentamethyldiethylenetriamine (PMDETA)/CuBr was performed to synthesize poly(tert-butyl acrylate) with predictable molecular weight, low polydispersities, and well-defined bromine end groups. The bromine end groups have been substituted by azides. Then C-60 end-capped poly(tert-butyl acrylate) was synthesized by the reaction Of C-60 with PtBA-N-3 in DMF. GPC measurement showed that C-60 was chemically bonded to the end chain of poly(tert-butyl acrylate); i.e., the final products (PtBA-C-60) were monosubstituted. H-1 NMR, FTIR, and UV-vis measurements confirmed that the water-soluble, monosubstituted C-60 derivatives of poly(acrylic acid) (PAA-C-60) have been obtained by hydrolysis of PtBA-C-60. The photoconductivities of PtBA-C-60 and PAA-C-60 were measured by photoinduced xerographic discharge technique. Experimental results showed that C-60 bonded in the polymers is the headstream of the photoconductivity, and an increase of the C-60 content in C-60 polymeric derivatives could improve the photoconductivity dramatically. The microstructures of CGL are very important for the photoconductive properties, and perfect hole-transport channels in the CGL will improve the photoconductivity notably.