Chemistry Reference
In-Depth Information
alternative to conventional thermoplastic polymers (petrochemical origin),
such as polyolefins and polyesters.
4
Biopolymers have been widely used in the packaging industry as substi-
tutes for conventional plastic packages. According to these authors, biopo-
lymers can be classified into:
d
n
2
r
4
n
g
|
8
(i) Polymers derived from biomass, with or without modification
(starch).
(ii) Polymers produced by microrganisms in their natural state or gen-
etically modified (PHA, polyhydroxyalkanoates).
(iii) Polymers produced with bio-intermediate participation. These bio-
intermediates are produced from renewable sources, such as PLA
(poly lactic acid).
There is not an international consensus about the content of bio-based
polymer required to qualify the product as a bioplastic yet. The percentage of
renewable carbon source that has been debated is between 25 and 40%.
4
One of the most versatile bioplastics is PLA, a type of polyester obtained by
lactic acid polymerization, resulting from sugar fermentation. Besides its
use in disposable packaging (Ingeo) that is already in use by several com-
panies (Coca-Cola, McDonald's), it is also used as pillow filling and in
comforters (NatureWorks), in film and paper coating (BASF) and it is also in
use in the automotive (Hyundai) and electronic industries (Samsung).
Polymers synthesized by microorganisms directly, such as poly-
hydroxyalkanoates (PHAs) and poly-hydroxybutyrate (PHB), are entering the
food packaging market slowly. Due to their biocompatibility, they have also
found important applications in the field of medicine (Biopol produced by
Monsanto is made of a copolymer composed of PHB).
It is worth noting that biopolymers made from sugar represent a prom-
ising business; once they are produced using clean technology, the process
will aid in preserving the environment, and it is able to be integrated into the
existing production process in plants. Due to the sugarcane production
cycle, plant devices are traditionally idle for at least half a year.
5
.
9.2 Literature Review
The international oil price rise, geopolitical instability in important oil
production regions and the global need to develop technologies with low
greenhouse gas emissions have all pointed to the real possibility of ex-
ploiting raw materials such as renewable feedstocks for intermediate bio-
synthesis and final chemical products. According to Silva et al.,
6
the
experience of using ethanol as fuel and the incentive for biodiesel pro-
duction are factual examples of using renewable raw materials to replace
those derived from petroleum. Besides the energy supply needs, the second
largest petroleum demand is for its use as raw material for polymer
production.
Search WWH ::
Custom Search