J Polym Environ
DOI 10.1007/s10924-010-0258-0
ORIGINAL PAPER
Degradation of Cellulose Acetate-Based Materials: A Review
¨
Juergen Puls • Steven A. Wilson • Dirk Holter
Ó The Author(s) 2010. This article is published with open access at Springerlink.com
Abstract Cellulose acetate polymer is used to make a
variety of consumer products including textiles, plastic
films, and cigarette filters. A review of degradation
mechanisms, and the possible approaches to diminish the
environmental persistence of these materials, will clarify
the current and potential degradation rates of these products after disposal. Various studies have been conducted on
the biodegradability of cellulose acetate, but no review has
been compiled which includes biological, chemical, and
photo chemical degradation mechanisms. Cellulose acetate
is prepared by acetylating cellulose, the most abundant
natural polymer. Cellulose is readily biodegraded by
organisms that utilize cellulase enzymes, but due to the
additional acetyl groups cellulose acetate requires the
presence of esterases for the first step in biodegradation.
Once partial deacetylation has been accomplished either by
enzymes, or by partial chemical hydrolysis, the polymer’s
cellulose backbone is readily biodegraded. Cellulose acetate is photo chemically degraded by UV wavelengths
shorter than 280 nm, but has limited photo degradability in
sunlight due to the lack of chromophores for absorbing
ultraviolet light. Photo degradability can be significantly
J. Puls
vTI Institute of Wood Technology and Wood Biology,
Hamburg, Germany
e-mail: [email protected]
S. A. Wilson (&)
Eastman Chemical Company, Kingsport, TN, USA
e-mail: [email protected]
¨
D. Holter
Rhodia Acetow GmbH, Freiburg, Germany
e-mail: [email protected]
enhanced by the addition of titanium dioxide, which is used
as a whitening agent in many consumer products. Photo
degradation with TiO2 causes surface pitting, thus
increasing a material’s surface area which enhances biodegradation. The combination of both photo and biodegradation allows a synergy that enhances the overall
degradation rate. The physical design of a consumer
product can also facilitate enhanced degradation rate, since
rates are highly influenced by the exposure to environmental conditions. The patent literature contains an abundance of ideas for designing consumer products that are
less persistent in the outdoors environment, and this review
will include insights into enhanced degradability designs.
Keywords Biodegradation Á Photo degradation Á
Disintegration
Introduction
Cellulose acetate (CA) is a modified natural polymer with a
wide range of properties [1, 2]. Although CA can be produced with a range of degrees of substitution (DS), the
most common level is a DS of 2.5 due to good solubility in
common solvents, molecular weights, and melt properties.
These properties facilitate CA’s use in a variety of consumer products including textiles, plastics, films, and cigarette filters that can be discarded and become litter.
Considering that the global production for CA materials
was over 800,000 metric tons per year in 2008 (Table 1),
and many items are disposed of as surface litter or into
composting facilities, it is important to understand the fate
of discarded CA-based products. An increased awareness
of routes of degradation could prove useful to understand
the ultimate environmental impact.
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