A Monte Carlo study of polymer network dynamics

Junction fluctuations in a polymer network are investigated by using the Monte Carlo method. In our calculation, a modified bond-fluctuation model is adopted. In our model, the kuhnian bond lengths are set to vary between 2 and 4, which is different from the lengths between 2 and √10 of the standard model. It is found that the average fluctuations of junctions i and j may be expressed in the form ofΔRi2/r20=a(φ−1)+b(φ=3, 4, 5, 6)〈ΔRiΔRj〉/r20=a′(φ−1)+b′(φ=3, 4, 5, 6)where a=0.83, b=−0.076, a′=0.06, b′= 0.0075, and 〈r2〉0 is the mean-square end-to-end distance of two adjacent junction points and φ is the junction functionality. Comparisons with the Cayley tree model are also made. Our method uses real, rather than phantom, chains, and this method can be used to investigate the dynamics of polymer network chains.