J. Phys. II France
Volume 3, Numéro 8, August 1993
Page(s) 1171 - 1177
DOI: 10.1051/jp2:1993189
J. Phys. II France 3 (1993) 1171-1177

Remarks on the dynamics of random copolymers

J.P. Bouchaud and M.E. Cates

TCM Group, Cavendish Laboratory, Madingley Road, Cambrdige CB3 0HE, U.K.

(Received 7 May 1993, accepted 15 June 1993)

We discuss the dynamics of random AB copolymers, and show that a glassy, quasi-frozen phase is reached as soon as $\chi_{\rm AB}\sqrt{\frac{N}{N_{\rm e}^{1/2}}}\simeq 1$ (where N is the number of monomers, $N_{\rm e}$ the entanglement length and $\chi_{\rm AB}$ the Flory interaction parameter). This criterion is satisfied for much smaller $\chi_{\rm AB}$ than the value for which segregation occurs: $\chi_{\rm AB} \simeq 1$. The relaxation time of weakly disordered chains is furthermore found to take the empirical form $N^{3+\mu}$, where $\mu$ can reach significant values for certain choices of $\chi_{\rm AB}$ and the fraction of B-monomers.

64.60C - 05.40

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