**5. References**


C. R. Zheng, *Molecular Weight and Distribution of Polymer*, Chemistry Industry Press, Beijing

M. Kroger and H. Voigt, *Macromol. Theory Simul.*, 3, 639(1994).

B. J. Collier, M.Dever and S. Petrovan, *J. Polym. Environment*, 8(3), 151(2000).

(1986).
