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Decolorization of colored poly(ethylene terephthalate) bottle flakes using hydrogen peroxide
Author(s) -
Gupta Mohit,
Bandi Suneel A.,
Mehta Sanjay,
Schiraldi David A.
Publication year - 2007
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.27468
Subject(s) - hydrogen peroxide , bottle , potassium permanganate , peroxide , ethylene , nuclear chemistry , materials science , aqueous solution , chemistry , polymer chemistry , organic chemistry , composite material , catalysis
A novel process for the oxidative decolorization of green and blue colored poly(ethylene terephthalate) (PET) bottle flakes, using an aqueous solution of hydrogen peroxide (H 2 O 2 ) has been developed. A strong dependence of H 2 O 2 concentration and temperature on decolorization rate has been found. The decolorized flakes were characterized for color and intrinsic viscosity (IV) values; decolorized flakes exhibit color values similar to those of colorless recycled PET. The IV of peroxide bleached PET flakes indicated a decrease in PET molecular weight, which correlated with the severity of decolorization conditions. Despite decreases in PET IV values, the bleached flake still exhibited useful PET molecular weights. The consumption of H 2 O 2 during the bleaching process was quantified titrating residual peroxide with a standardized potassium permanganate solution. H 2 O 2 consumption rates of 0.3–0.9 g per gram of green PET flake were measured, depending on the specific bleaching conditions used. © 2007 Wiley Periodicals, Inc. JAppl Polym Sci, 2008