An analysis of the cylindical brush of an isolated comb copolymer molecule
consisting of a semiflexible backbone and flexible side chains is presented
. Using the Alexander-de Gennes approximation, we calculate the free energy
of both straight and bent cylindrical brush and the brush persistence leng
th lambda, and show that lambda scales as a function of the side chain leng
th M as lambda proportional to M-2. The discrepancy between the asymptotic
scaling behavior and recent computer simulation results is also discussed.