Chemistry Reference
In-Depth Information
anaerobic, oxygen depleted, resulting in a slower degradation rate, and therefore
the intended benefit of biodegradability becomes lost. If disposal of these products
is in aquatic environments, it could cause eutrophication and lead to death of fishes
and other aquatic life. Eutrophication is a process that occurs when there is an
increase in organic matter in an ecosystem that promotes excessive growth of algae
[28]
. As the algae die and decompose it depletes the oxygen available to aquatic
life and causes death of organisms such as fish
[28]
.
Issues other than environmental impact and fossil fuel dependence affect the
feasibility of bioplastics replacing conventional plastics. Factors such as econom-
ics and mechanical properties currently limit growth of the bioplastics industry.
There are a few types of bioplastics that are being produced commercially, mean-
ing that it can be economical to produce bioplastics, but to what extent is
unknown. Bioplastics are in their infancy of technology, whereas conventional
plastics have reached a degree of maturity since being manufactured from the
1920s
[29]
.
PROBLEMS
13-1
Describe briefly the three different routes for making biopolymers.
13-2
Describe the major difference in the molecular structures of starch and
cellulose.
13-3
Explain why certain individuals are allergic to products made of natural
rubber and why such products are not biodegradable.
13-4
Explain why a highly cross-linked natural rubber may not be suitable for
tire applications.
References
[1] E. Richards, Degradable Plastics. Secretariat of the Pacific Regional Environment
Programme. 2009, p. 36.
[2] M. Ramirez-Alvarado, J.W. Kelly, C.M. Dobson, eds. Protein Misfolding Diseases:
Current and Emerging Principles and Therapies. Wiley Series in Protein and Peptide
Science, ed. V.N. Uversky, John Wiley & Sons, 2010
[3] H. Robert Horton (Ed.), Principles of Biochemistry, Prentice Hall, Pearson, 2006.
[4] L.P.B.M Janssen, L. Moscicki, Thermoplastic Starch: A Green Material for Various
Industries, Wiley-VCH, 2009.
[5] M.P. Stevens, Polymer Chemistry: An Introduction, third ed., Oxford, New York,
1999 (551)
[6] Government of Canada, Biopolymers and Bioplastics, 2002.
[7] A. Ciesielski, An Introduction to Rubber Technology, Smithers Rapra Technology,
1999.
[8]
J.G. Smith, Organic Chemistry, vol. 1, McGraw Hill, New York, 2006.
