DIP IN G''(OMEGA) OF POLYMER MELTS AND SEMIDILUTE SOLUTIONS Academic Article uri icon

abstract

  • ((ArJ2) 31 ((A1n) 2)'/2b (LeL)'/2b (t/? R) 1'4 (1) where Le is the entanglement length and b is the segment (or persistence) length. A similar effect has been suggested for the stress relaxation f~ nction.~,~ According to the reptation idea, stress is relaxed when the chain ends pass (for the first time) through an entanglement point. It follows that the stress relaxation function Gbrth (t)(with the plateau modulus normalized to unity) obeys4p5 where a and d are numerical constants resulting from the first-passage-time nature of this anomalous diffusion problem9 a N 0.508. At further shorter times, times shorter than the entanglement time Te, stress relaxes by free Rouse motion. In “living” polymer systems one has to consider another time scale, the lifetime of an average chain Tb. 5, 7 This is the average time for a chain to keep its integrity before breaking into two chains or combining …

publication date

  • January 1, 1994