Chemical structures and uses of some common plastics Around 70% of global production is concentrated rein 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 discovery of polyethylene terephthalate is credited to employees of the Calico Printers' Association rein the UK rein 1941; it welches licensed to DuPont for the US and ICI otherwise, and as one of the few plastics appropriate as a replacement for glass hinein many circumstances, resulting hinein widespread use for bottles hinein Europe.
Additives may Beryllium weakly bound to the polymers or react hinein the polymer matrix. Although additives are blended into plastic they remain chemically distinct from it, and can gradually leach back out during weit verbreitet use, when in landfills, or following improper disposal in the environment.[36] Additives may also degrade to form other toxic molecules. Plastic fragmentation into microplastics and nanoplastics can allow chemical additives to move hinein the environment far from the point of use.
Rein 2023, plasticosis, a new disease caused solely by plastics, was discovered hinein seabirds. The birds identified as having the disease have scarred digestive tracts from ingesting plastic waste.
Household items made of various types of plastics Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to Beryllium molded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has Leuchtdiode to their widespread use.
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 click here order to Beryllium molded. Various sorts of extrusion equipment exist which can then form the plastic into almost any shape.
Light activated resin – resin that cures when exposed to light of appropriate wavelengthsPages displaying wikidata descriptions as a fallback
The success and dominance of plastics starting rein the early 20th century has caused widespread environmental problems,[3] due to their slow decomposition Satz hinein natural ecosystems. Most plastic produced has not been reused, or is incapable of reuse, either being captured hinein landfills or persisting in the environment as plastic pollution and microplastics.
There are differing estimates of how much plastic waste has been produced rein the belastung century. By one estimate, one billion tons of plastic waste have been discarded since the 1950s.
Silicones (polysiloxanes): heat-resistant resins used mainly as sealants but also used for high-temperature cooking utensils and as a base resin for industrial paints
Also much of the energy used rein plastic production is not sustainable energy, for example high temperature from burning fossil gas. However plastics can limit some methane emissions, for example packaging to reduce food waste.[127]
Plastic pollution can be found rein all the world's major water bodies, for example, creating garbage patches in all of the world's oceans and contaminating terrestrial ecosystems. Of all the plastic discarded so far, some 14% has been incinerated and less than 10% has been recycled.[2]
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-rein the additives.
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 materials, such as corn or cotton derivatives.[1]
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.