Check out these retro videos from Encyclopedia Britannica’s archives. WTFact Britannica shares some of the most bizarre plastic sheet laminator we can find. In these videos, Britannica explains a variety of topics and answers frequently asked questions.
In Demystified, Britannica has all the answers to your burning questions. Britannica is the ultimate student resource for key school subjects like history, government, literature, and more. While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today. Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. We’ve created a new place where questions are at the center of learning. Britannica Presents Earth’s To-Do List for the 21st Century. Learn about the major environmental problems facing our planet and what can be done about them!
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Our editors will review what you’ve submitted and determine whether to revise the article. Conserve Energy Future – What is Plastic Pollution? Polymers Plastic comes in all shapes and sizes, flexible or not, and is made of large molecules called polymers. Read more about the properties of plastic. The term itself is very confusing because there are different types of bioplastics, some biodegradable and some not.
BPA BPA, plastic additives and endocrine-disruptive chemicals are widely added to plastic items we use every day. But with what effects on our health? Recycling codes What do recycling codes and symbols mean and can plastic be recycled? Learn more about the recycling numbers and how much plastic is actually recycled. Toxicity and pathogens Plastic contains and carries pollutants and chemicals found in the environment.
Plastic can also carry disease and bacteria. Functional technology enables a website to remember information that changes the way the website behaves or looks, like your preferred language or the region that you are in. This consent is used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers. This consent helps website owners to understand how visitors interact with websites by collecting and reporting. She has taught science courses at the high school, college, and graduate levels. Plastic is any synthetic or semisynthetic organic polymer.
In other words, while other elements might be present, plastics always include carbon and hydrogen. The polymer used to make plastic is almost always mixed with additives, including colorants, plasticizers, stabilizers, fillers, and reinforcements. These additives affect the chemical composition, chemical properties, and mechanical properties of plastic, as well as its cost. Thermosetting polymers, also known as thermosets, solidify into a permanent shape. They are amorphous and considered to have infinite molecular weight. Thermoplastics, on the other hand, can be heated and remolded over and over again.
Some thermoplastics are amorphous, while some have a partially crystalline structure. The properties of plastics depend on the chemical composition of the subunits, the arrangement of these subunits, and the processing method. All plastics are polymers but not all polymers are plastic. Plastic polymers consist of chains of linked subunits called monomers. If identical monomers are joined, it forms a homopolymer. Different monomers link to form copolymers. Homopolymers and copolymers may be either straight chains or branched chains.
Plastics are usually poor conductors of heat and electricity. Most are insulators with high dielectric strength. Nearly all plastics display elongation when they are stressed that is not recovered after the stress is removed. Plastics tend to be durable, with a slow rate of degradation.
The first completely synthetic plastic was Bakelite, made in 1907 by Leo Baekeland. He also coined the word “plastics. The word “plastic” comes from the Greek word plastikos, which means it can be shaped or molded. Approximately a third of the plastic that is produced is used to make packaging. Another third is used for siding and piping.