Chemistry Reference
In-Depth Information
13.4.2
Biocomposites
A biocomposite is a material composed of two or more distinct constituent mate-
rials (one being naturally derived) which are combined to yield a new material
with improved performance over individual constituent materials. The constituent
materials are the matrix and reinforcing component. The reinforcing component is
the primary load-carrying element, which can be in the form of fibers, whiskers,
particles and flakes
[23]
. The matrix serves to bind the reinforcing components
together and provide mechanical support
[24]
.
A frequently studied biocomposite is natural-fiber-reinforced biopolymer com-
posite. The reinforcing component is natural fiber or cellulose extracts combined
with a bioplastic matrix. The natural fiber adds further strength to the weaker bio-
polymer matrix, allowing for the material to be used in more applications
[25
27]
.
Significant research is being conducted in embedding nanoparticles or particu-
lates such as layered silicates, carbon nanotubes, hydroxyapaptite, cellulose, and
talc into bioplastics
[14]
. The most commonly used in PLA bioplastics is layered
silicate clay, as it has been attributed to a dramatic increase in material properties
such as improved tensile and flexural properties, elevated heat distortion tempera-
ture, enhanced barrier properties, and accelerated biodegradation. Processing
issues associated with these nano-biocomposites are distribution and dispersion of
the reinforcement within the biopolymer
[14]
.
13.5
Future of Bioplastic Products
Bioplastics, bioplastic blends, and biocomposites have the potential to be a green
solution in the future. The potential of these materials is based on their ability to
decrease CO
2
emissions, producing a material which is sustainable without petro-
leum as well as reducing environmental impact after product use. Each of these
aspects will be discussed with the potential of the products as well as the reality.
Bioplastics pose the ability to achieve a near neutral carbon process, closing
the carbon cycle since CO
2
is captured during photosynthesis (making the plant
material as a substrate or feedstock) and released during biodegradation. The total
amount of carbon emissions associated with the energy needed to produce and
dispose of the products should be taken into account. Currently, few processes
have emerged that use less energy in the production process. Researchers are
working on optimizing the efficiency of the processes in order to make bioplastics
a viable alternative in terms of energy consumption.
Bioplastics have the potential to reduce dependence on petroleum-based plas-
tics. The depletion of fossil fuels and the rising cost of petroleum is a growing
concern for long-term sustainability of the plastics industry. Along with the dwin-
dling petroleum supply, the other side of the production cycle, agricultural pro-
ducts, needs to be considered. Depending on the feedstocks required for the
specific bioplastics synthesis, there would be need to be a balance between the
