2,5-Dibromo-1,4-(dihydroxymethyl)benzene was used as initiator in ring-opening polymerization of e-caprolactone in the presence of stannous octoate (Sn(oCt)(2)) catalyst. The resulting poly(epsilon-caprolactone) (PCL) macromonomer, with a central 2,5-dibromo-1,4-diphenylene group, was used in combination with 1,4-dibromo-2,5-dimethylbenzene for a Suzuki coupling in the presence of Pd(PPh3)(4) as catalyst or using the system NiCl2/bpy/PPh3/Zn for a Yamamoto-type polymerization. The poly(p-phenylenes) (PPP) obtained, with PCL side chains, have solubility properties similar to those of the starting macromonomer, ie soluble in common organic solvents at room temperature. The new polymers were characterized by H-1 and C-13 NMR and UV spectroscopy and also by GPC measurements. The thermal behaviour of the precursor PCL macromonomer and the final poly(p-phenylene)-graft-poly(epsilon-caprolactone) copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry analyses and compared. (C) 2004 Society of Chemical Industry.