Polyhydroxyalkanoate-based Multiphase Materials - Polyhydroxyalkanoate (PHA) Based Blends, Composites and Nanocomposites - page 133

The use of graphene in a 2, 4, 6% composition in the PHBV led to an
increase in the modulus at break of the PHBV composites. The improvement
in the modulus with an increase in the graphene content was explained to be
the result of the lamellar structures of graphene, which resulted in better
polymer-filler interactions and therefore better stress transfer. The PHA-
graphene composites, like the clay-nanocomposites of PHAs, were also re-
ported to result in a certain level of thermal stability of the PHA. While in the
case of clay nano-composites, the reduced thermal degradation is a result of
reduced permeability of volatile degradation products, in the case of gra-
phene reinforced composites, it was suggested to be the result of donor-
acceptor complexes between graphene and the by-products of nucleophilic
chain scission. 86
''Green nanocomposites'' based on PHAs appear as the next generation of
environmentally-friendly materials and broaden the range of PHAs' appli-
cations by enhancing the polymer properties (ductility, melt viscosity, ther-
mal stability). Thus, more appropriate new macromolecular architectures
and nanoparticle-based systems should allow, in the near future, the limits
of these materials (high crystallinity, brittleness, poor thermal stability) to be
overcome.

d n 2 r 4 n g | 9

6.3 Production and Some Applications

6.3.1 Industrial Production of PHA-based Materials
PHA production is shared between a great number of companies (see
Table 6.2). Worldwide, several dozens of companies are known to be

.

Table 6.2 Main PHA producers.

Pilot/industrial
scale Company Country Trade name PHA

Biomatera Canada Biomatera PHBV Pilot

Biomer Germany Biomer PHB and

copolymers

Pilot

Bio-On Italy Minerv PHA PHB, PHBV Pilot (?)

Kaneka Japan Kaneka PHBHx Pilot/ind. (?)

Meredian US ? Copolymers Pilot, ind. (?)

Metabolix US Copolymers Pilot, ind. (?)

PHB Industrial/
Copersucar

Brazil Biocycle PHB, PHBV Pilot, ind. (?)

PolyFerm Canada Canada VersaMer PHA PHBV and

copolymers

Pilot

Tianan China Enmat PHBV Ind.

Tianjin & DSM China GreenBio Copolymers

based on 3HB
and 4HB

Pilot (?)

Tianzhu China Tianzhu PHBHx Pilot