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Molecular weight evaluation of depolymerized poly(ethylene terephthalate) using intrinsic viscosity
Author(s) -
Li Kaixiang,
Song Xiaofang,
Zhang Dong
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.28186
Subject(s) - depolymerization , intrinsic viscosity , viscosity , materials science , molecular mass , molar mass distribution , polymer chemistry , polymer , ethylene , terephthalic acid , inherent viscosity , bottle , chemistry , analytical chemistry (journal) , organic chemistry , composite material , polyester , catalysis , enzyme
A series of poly(ethylene terephthalate) (PET) depolymerization experiments versus time was proceeded under optimal experimental conditions with microwave radiation, in which the temperature was 220°C, the pressure was 200 psi, the microwave power was 260 W, and the ratio of water to PET was 10 : 1. The relative viscosity of the feedstock PET grain and the residual solid products from depolymerization reaction at six different time, respectively, was measured in the solution of 60/40 (w/w) phenol/1,1,2,2‐tetrachloroethane. Then the approximate intrinsic viscosity was calculated from linear and exponential extrapolation of reduced viscosity. Molecular weights were calculated by Mark‐Houwink's equation, with values of K and α taken from the literatures. The results show that the molecular weights fell dramatically with increasing of reaction time, namely the number average molecular weight from 2.57 × 10 4 of the feedstock PET to 372 of the remained solid product at 240 min, and the weight average molecular weight of the samples fell from 3.89 × 10 4 to 408 correspondingly. The intrinsic viscosity decreased greatly with reaction, while the distribution of molecular weight turned to be steady. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008