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These polymers have the distinct advantage that over time they will break down. Dr. Geoffrey Coates headed research to create catalysts that can not only efficiently create these biodegradable polymers, but the polymers also incorporate the greenhouse gas and global warming contributor, CO 2, and, environmentally present ground-ozone producer ...
Many biodegradable polymers that come from renewable resources (i.e. starch-based, PHA, PLA) also compete with food production, as the primary feedstock is currently corn. For the US to meet its current output of plastics production with BPs, it would require 1.62 square meters per kilogram produced. [70]
Starch: Starch is an inexpensive biodegradable biopolymer and copious in supply. Nanofibers and microfibers can be added to the polymer matrix to increase the mechanical properties of starch improving elasticity and strength. Without the fibers, starch has poor mechanical properties due to its sensitivity to moisture.
Biodegradable polymers are classified into three groups: medical, ecological, and dual application, while in terms of origin they are divided into two groups: natural and synthetic. [18] The Clean Technology Group is exploiting the use of supercritical carbon dioxide , which under high pressure at room temperature is a solvent that can use ...
Once implanted, a biodegradable device should maintain its mechanical properties until it is no longer needed and then be absorbed by the body leaving no trace. The backbone of the polymer is hydrolytically unstable. That is, the polymer is unstable in a water based environment. This is the prevailing mechanism for the polymers degradation.
PHA polymers are thermoplastic, can be processed on conventional processing equipment, and are, depending on their composition, ductile and more or less elastic. [15] They differ in their properties according to their chemical composition (homo-or copolyester, contained hydroxy fatty acids).
Susceptibility to biodegradation is highly dependent on the chemical backbone structure of the polymer, and different bioplastics have different structures, thus it cannot be assumed that bioplastic in the environment will readily disintegrate. Conversely, biodegradable plastics can also be synthesized from fossil fuels. [4] [12]
Biodegradable additives can convert the plastic degradation process to one of biodegradation. Instead of being degraded simply by environmental factors, such as sunlight (photo-oxidation) or heat (thermal degradation), biodegradable additives allow polymers to be degraded by microorganisms and bacteria through direct or indirect attack.