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There are vast examples and applications of biodegradable polymers. Bio-based packaging materials have been introduced as a green alternative in the past decades, among which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost.
An example of a compostable polymer is PLA film under 20μm thick: films which are thicker than that do not qualify as compostable, even though they are "biodegradable". [14] In Europe there is a home composting standard and associated logo that enables consumers to identify and dispose of packaging in their compost heap.
A plastic is considered biodegradable if it can degrade into water, carbon dioxide, and biomass in a given time frame (dependent on different standards). Thus, the terms are not synonymous. Not all bioplastics are biodegradable. [44] An example of a non-biodegradable bioplastic is bio-based PET. PET is a petrochemical plastic, derived from ...
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 ...
Bioplastics can be made from proteins from different sources. For example, wheat gluten and casein show promising properties as a raw material for different biodegradable polymers. [41] Additionally, soy protein is being considered as another source of bioplastic. Soy proteins have been used in plastic production for over one hundred years.
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.
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.
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).