Accurate description of intrinsic viscosity changes under polymer degradation: Narrow schulz distributions

For the Shulz distributions with weight—polydispersity from 1.4 to 2.0, the following equation is correct: ln [η] = ln [η] 0 − a {ln P 0 + DD − ln[ P F − P 0 ) × exp(−1.2 × DD )]}. Here, P 0 and P F are viscosity–polydispersities of the initial molecular weight distribution (MWD) and the Flory distribution, respectively; a is the Mark–Houwink exponent; and DD = ln( M n 0 / M n ). For more narrow MWDs, the complicated equation is required: ln [η] = ln[η] 0 − a {ln P 0 + DD − ln[ P F − ( P F − P 0 × exp(−0.9 × DD − 0.28 × DD 2 )]}. The inaccuracy of these equations is less than 1.5%. © 1995 John Wiley & Sons, Inc.