Eine Geheimwaffe für plastic
Eine Geheimwaffe für plastic
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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 in certain environments.[54] Recent studies have shown, however, that plastics in the ocean decompose faster than had been previously thought, due to exposure to the sun, rain, and other environmental conditions, resulting in the release of toxic chemicals such as bisphenol A.
In some cases, this can involve mixing different types of plastic together to form a polymer blend, such as high impact polystyrene. Large companies may do their own compounding prior to production, but some producers have it done by a third party. Companies that specialize in this work are known as Compounders.
The output of the process (commonly known as cellulose nitrate or pyroxilin) could Beryllium dissolved hinein alcohol and hardened into a transparent and elastic material that could be molded when heated.[134] By incorporating pigments into the product, it could Beryllium made to resemble ivory. Parkesine welches unveiled at the 1862 International Exhibition hinein London and garnered for Parkes the bronze medal.[135]
Aramids: best known for their use in making body armor, this class of heat-resistant and strong synthetic fibers are also used hinein aerospace and military applications, includes Kevlar and Nomex, and Twaron.
A recent study found brominated dioxins as unintentional contaminants hinein toys made from recycled plastic electronic waste that contained brominated flame retardants. Brominated dioxins have been found to exhibit toxicity similar to that of chlorinated dioxins. They can have negative developmental effects and negative effects on the nervous Anlage and interfere with mechanisms of the endocrine system.[2]
Masterbatch granules can Beryllium mixed with cheaper bulk polymer and will release their additives during processing to give a homogeneous final product. This can be cheaper than working with a fully compounded material and is particularly common for the introduction of color.
Very common. All examples form a coating between the plastic and machine parts during production. Reduces pressure and power usage rein the extruder. Reduces imperfections.
Companies that produce finished goods are known as converters (sometimes processors). The vast majority of plastics produced worldwide are thermosoftening and must Beryllium heated until molten rein order to be molded. Various sorts of extrusion equipment exist which can then form the plastic into almost more info any shape.
Wer sind die Treiber pro die immer weiter steigende Produktion von Kunststoff und welche Lösungsansätze sind sinnvoll zumal realistisch?
Hazardous molds have been found aboard space stations that degrade rubber into a digestible form.[97]
Refill (scheme) – British environmental campaignPages displaying short descriptions of redirect targets
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 hinein order to mix-hinein 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 Bernsteinfarben.