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All polymers are made of repetitive units called monomers. Biopolymers often have a well-defined structure, though this is not a defining characteristic (example: lignocellulose): The exact chemical composition and the sequence in which these units are arranged is called the primary structure, in the case of proteins.
All biodegradable polymers should be stable and durable enough for use in their particular application, but upon disposal they should easily break down. [citation needed] Polymers, specifically biodegradable polymers, have extremely strong carbon backbones that are difficult to break, such that degradation often starts from the end-groups.
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]
Biologically-based polymers, sourced from non-fossil materials, can decompose naturally in the environment, whereas some plastics products made from biodegradable polymers require the assistance of anaerobic digesters or composting units to break down synthetic material during organic recycling processes.
Additives may be weakly bound to the polymers or react in the polymer matrix. Although additives are blended into plastic they remain chemically distinct from it, and can gradually leach back out during normal use, when in landfills, or following improper disposal in the environment. [ 40 ]
Biodegradable bags still strong enough to carry shopping after three years in the ground show that 'biodegradability' isn't all it's cracked up to be. When biodegradable plastic is not ...
The plastic kits and covers are mostly made of synthetic polymers like polythene, and tires are manufactured from polybutadienes. [1] However, due to the environmental issues created by these synthetic polymers which are mostly non-biodegradable and often synthesized from petroleum, alternatives like bioplastics are also being considered. They ...
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 ...