Biomedical Engineering Reference
In-Depth Information
9
Bacterial Cellulose and Its Polymeric
Nanocomposites
Marie-Pierre G. Laborie
9.1
Introduction
In the last decade, a great deal of materials development has involved bacterial cellulose
(BC) as reinforcement for both thermosetting and thermoplastic polymers, synthetic or
bio-based polymers. Due to the network and nanoscale structure of bacterial cellulose
fibers, the reinforcement of polymers with BC leads to nanocomposites with unique
morphologies and properties.
A common challenge in developing nanocomposites is to finely disperse the nanoscale
reinforcement into the matrix such that homogeneous nanocomposites with optimum per-
formance can be achieved. To circumvent this challenge with BC nanocomposites, sev-
eral manufacturing approaches have been taken. In a first approach, reactive monomers
or oligomers are polymerized in situ, i.e. within a BC mat, resulting in an interpenetrat-
ing network or at least a well dispersed nanocomposite. Such an approach has been taken
with phenolic, acrylic and epoxy resins yielding applications as optoelectronic devices
as well as biomaterials and membranes. A second approach that has been most com-
monly used with thermoplastic polymers consists of solvent casting BC and a polymer
solution into solid shapes. With this second approach, BC has been incorporated into
various bio-based polymers including cellulose acetate butyrate (CAB), xylans, starch
and proteins but also with synthetic polymers such as poly(vinyl alcohol) (PVA). Finally,
biomimetic approaches, in which the growth medium of BC is augmented with host poly-
mers allowing for the in vitro assembly of the components, have paved the way for the
development of nanocomposites with unique morphologies and properties. In particular
a wide range of BC/hemicelluloses or BC/lignin nanocomposites have been developed
with this approach with a view to shedding light on the biosynthesis, morphology and
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