After the First World War, improvements in chemical technology led to an explosion of new forms of plastics.
Thermoplastics can be remelted and reused, and thermoset plastics can be ground up and used as filler, though the purity of the material tends to degrade with each reuse cycle.
Among the earliest examples in the wave of new plastics were "polystyrene" (PS) and "polyvinyl chloride" (PVC), developed by IG Farben of Germany.
American consumers enthusiastically adopted the endless range of colorful, cheap, and durable plastic gimmicks being produced for new suburban home life.
Some researchers have genetically engineered bacteria that synthesize a completely biodegradable plastic, but this material is expensive at present.
By the 1990s, plastic recycling programs became common in the United States and elsewhere.
Nylon continues to be an important plastic, and not just for fabrics.
When such plastic materials are dumped into landfills, they can become "mummified" and persist for decades even if they are intended to be biodegradable.
The vast majority of plastics are composed of polymers in which the backbone is made of carbon atoms, with or without oxygen, nitrogen, chlorine, or sulfur atoms.
The term plastic is applied to a wide range of synthetic and semi-synthetic products, and a few naturally occurring materials as well.
Plastics have become an indispensable part of our modern technological society.
Polytheism (from the Greek: polus, many, and theos, god) refers to belief in, or worship of, multiple gods or deities.
Using such approaches, plastics can be designed with immense variation in properties such as heat tolerance, hardness, and resiliency.
To assist recycling of disposable items, the Plastic Bottle Institute of the Society of the Plastics Industry devised a now-familiar scheme to mark plastic bottles by plastic type.
Some alternatives being considered are: graphite, fiberglass, carbon fiber, graphene, carbon nanotubes, diamond, aerogel, carbon nanofoam, cellulose soybean plastic (bioplastic), and other carbon-based, non-petroleum materials.
The biggest problem with plastics recycling is that the sorting of plastic waste is difficult and labor intensive.
The cause of the increase is the sharply rising cost of petroleum, the raw material that is chemically altered to form commercial plastics.
Another plastic that was critical to the war effort was "synthetic rubber," which was produced in a variety of forms.
New manufacturing processes were developed to churn out plastic products in vast quantities.
General Electric introduced "lexan," a high-impact "polycarbonate" plastic, in the 1970s.
Cheaper, less brittle plastics have largely replaced phenolic plastics, but they are still used in applications requiring its insulating and heat-resistant properties.
PET is less permeable than other low-cost plastics and so is useful for making bottles for carbonated drinks (because carbonation tends to attack other plastics) and acidic drinks such as fruit or vegetable juices.
When the Bakelite patent expired in 1927, the Catalin Corporation acquired the patent and began manufacturing Catalin plastic using a different process that allowed a wider range of coloring.
The most promising alternatives to plastic are graphene, carbon nanotube, and carbon nanofoam.
Another important plastic, "polyethylene" (PE, sometimes known as "polythene"), was discovered in 1933 by Reginald Gibson and Eric Fawcett at the British industrial giant, Imperial Chemical Industries (ICI).
Possessing many properties superior to those of rayon, it is produced from "biomass" feedstocks, and the manufacturing process is extraordinarily clean by the standards of plastics production.
Currently, the percentage of plastics recycled in the United States is very small—somewhere around 5 percent.
The limitations of celluloid led to the next major advance known as "phenolic" or "phenol-formaldehyde" plastics.
The disadvantage of biodegradable plastics is that the carbon that is locked up in them is released into the atmosphere as the greenhouse gas carbon dioxide when they degrade.
The American Plastics Council spends about 20 million U.S. dollars per year on advertising campaigns that attempt to convince more members of the public to recycle.
Other classification systems include thermoplastic versus thermoset, elastomers, and engineering plastics.
Some plastics of commercial interest have a backbone of silicon.
Additional plastics emerged in the pre-World War II period, though some did not come into widespread use until after the war.
To help solve these problems, plastic recycling programs have been instituted in many countries.
After the war, the new plastics that had been developed entered the consumer mainstream in a flood.
In 2004, the higher price of plastic drove a number of plastic-toy manufacturers out of business.
Plastics fall in a larger category of materials known as polymers.
Recycling certain types of plastics can be unprofitable as well.
Given their adaptability, general uniformity of composition, and lightweight, plastics are being used for numerous products, including those used in homes, schools, offices, factories, recreational facilities, and means of transportation and communication.
Another prominent material in 1950s homes was "Formica®," a durable and attractive plastic laminate that was used to surface furniture and cabinetry.
Research has been done on biodegradable plastics that break down with exposure to sunlight.
The name plastic is derived from the fact that many of these materials have the property of plasticity—that is, they can be shaped in different forms, including various boards, films, and fibers.
Composites using epoxy as a matrix include glass-reinforced plastic, where the structural element is glass fiber, and "carbon-epoxy composites," in which the structural element is carbon fiber.
Some are many times stronger than plastic but crack if made thin like cellophane.
Starch can be mixed with plastic to allow it to degrade more easily, but it still does not lead to complete breakdown of the plastic.
Epoxies are a class of thermoset plastic that form cross-links and "cure" when a catalyzing agent, or "hardener," is added.
The real star of the plastics industry in the 1930s was "polyamide" (PA), far better known by its trade name, "nylon."
Hyatt was something of an industrial genius who understood what could be done with such a shapeable (or "plastic") material.
Conventional "thermoplastics" can be molded and then melted again, but thermoset plastics form bonds between polymers strands when "cured," creating a tangled matrix that cannot be undone without destroying the plastic.
To customize the properties of a plastic, chemists may add molecular groups that "hang" from the backbone of each polymer chain.
Scientists are currently seeking cheaper alternatives to plastic.
Glass bottles and aluminum cans. In states with bottle bills, you can redeem many of the cans and bottles you buy for cash, usually 5-10 cents a bottle. You pay the deposit when you buy the product, so redeeming these empties is a great way to recycle, while putting a little change back in your pocket.Apr 5, 2012