Nicht bekannt, Details Über plastic surgery
Nicht bekannt, Details Über plastic surgery
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Microbial species capable of degrading plastics are known to science, some of which are potentially useful for disposal of certain classes of plastic waste.
Plastics degrade by a variety of processes, the most significant of which is usually photo-oxidation. Their chemical structure determines their fate. Polymers' marine degradation takes much longer as a result of the saline environment and cooling effect of the sea, contributing to the persistence of plastic debris rein certain environments.[54] Recent studies have shown, however, that plastics rein the ocean decompose faster than had been previously thought, due to exposure to the sun, rain, and other environmental conditions, resulting hinein the release of toxic chemicals such as bisphenol A.
Most plastics contain organic polymers.[10] The vast majority of these polymers are formed from chains of carbon atoms, with or without the attachment of oxygen, nitrogen or sulfur atoms. These chains comprise many repeating units formed from monomers. Each polymer chain consists of several thousand repeating units. The backbone is the part of the chain that is on the main path, linking together a large number of repeat units.
A number of additives identified as hazardous to humans and/or the environment are regulated internationally. The Stockholm Convention on Persistent Organic Pollutants (POPs) is a global treaty to protect human health and the environment from chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate rein the fatty tissue of humans and wildlife, and have harmful impacts on human health or on the environment.[2]
A literature study made in 2022 by geologist student Björn Lycke shows that the amount of microplastics rein sediment is increasing worldwide, especially hinein ports and tourist beaches.[82]
Plastics engineering – Engineering field studying polymer materialsPages displaying short descriptions of redirect targets
Some companies produce biodegradable additives to enhance biodegradation. Although starch powder can be added as a filler to allow some plastics to degrade more easily, such treatment does not lead to complete breakdown. Some researchers have genetically engineered bacteria to synthesize completely biodegradable plastics, such as polyhydroxy butyrate (PHB); however, these were lautlos relatively costly as of 2021.[23]
Plasticity also has a technical definition hinein materials science outside the scope of this article referring to the non-reversible change rein form of solid substances.
Plastics typically are made through human industrial systems. Most modern plastics are derived from fossil fuel-based chemicals like natural gas or petroleum; however, recent industrial methods use variants made from renewable website materials, such as corn or cotton derivatives.[1]
Welche person sind die Treiber je die immer längs steigende Produktion von Elaste ansonsten welche Lösungsansätze sind sinnvoll ebenso realistisch?
Hazardous molds have been found aboard space stations that degrade rubber into a digestible form.[97]
Microbial communities isolated from soil samples mixed with starch have been shown to be capable of degrading polypropylene.[92]
Chemical structures and uses of some common plastics Around 70% of global production is concentrated in six major polymer types, the so-called commodity plastics. Unlike most other plastics these can often be identified by their resin identification code (RIC):
The compounding of thermosetting plastic is relatively straightforward; as it remains liquid until it is cured into its final form. For thermosoftening materials, which are used to make the majority of products, it is necessary to melt the plastic rein order to Potpourri-rein the additives.
Because the chemical structure of most plastics renders them durable, they are resistant to many natural degradation processes. Much of this material may persist for centuries or longer, given the demonstrated persistence of structurally similar natural materials such as amber.