Biodegradable plastics are plastics that degrade (break down) upon exposure to sunlight or ultra-violet radiation; water or dampness; bacteria; enzymes; or wind abrasion. Attack by insects, such as waxworms and mealworms, can also Beryllium considered as forms of biodegradation. Aerobic degradation requires that the plastic Beryllium exposed at the surface, whereas anaerobic degradation would Beryllium effective in landfill or composting systems.
The plastic industry includes the global production, compounding, conversion and sale of plastic products. Although the Middle East and Russia produce most of the required petrochemical raw materials, the production of plastic is concentrated hinein the global East and West. The plastic industry comprises a huge number of companies and can be divided into several sectors:
Quickly burning plastics at very high temperatures breaks down many toxic components, such as dioxins and furans. This approach is widely used hinein municipal solid waste incineration. Municipal solid waste incinerators also normally treat the flue gas to decrease pollutants further, which is needed because uncontrolled incineration of plastic produces carcinogenic polychlorinated dibenzo-p-dioxins.
Their biggest single application is rein packaging, with some 146 million tonnes being used this way hinein 2015, equivalent to 36% of global production. Due to their dominance; many of the properties and problems commonly associated with plastics, such as pollution stemming from their poor biodegradability, are ultimately attributable to commodity plastics.
Prior to the Montreal Protocol, CFCs had been commonly used in the manufacture of the plastic polystyrene, the production of which had contributed to depletion of the ozone layer.
Plastics are produced in chemical plants by the polymerization of their starting materials (monomers); which are almost always petrochemical rein nature. Such facilities are normally large and are visually similar to oil refineries, with sprawling pipework running throughout. The large size of these plants allows them to exploit economies of scale.
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 tonlos relatively costly as of 2021.[23]
Additives are chemicals blended into plastics to change their performance or appearance, making it possible to lebensalter the properties of plastics to better suit their intended applications.[31][32] Additives are therefore one of the reasons why plastic is used so widely.
While a finished plastic may Beryllium non-toxic, the monomers used in the manufacture of its parent polymers may Beryllium toxic. Rein some cases, small amounts of those chemicals can remain trapped in the product unless suitable processing is employed.
In 2023, plasticosis, a new disease caused solely by plastics, was discovered rein seabirds. The birds identified as having the disease have scarred digestive tracts from ingesting plastic waste.
Light activated resin – resin that cures when exposed to light more info of appropriate wavelengthsPages displaying wikidata descriptions as a fallback
Self-healing plastic – Substances that can repair themselvesPages displaying short descriptions of redirect targets
Pre-exposure of the plastic to ultraviolet radiation broke chemical bonds and aided biodegradation; the longer the period of UV exposure, the greater the promotion of the degradation.[96]
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 Zusammenstellung bekannter melodien-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 Bernsteinfarben.