Biodegradability and disposal of polymers
Biodegradability
| Polyesters | Polyamides |
| Chemically inert … and so … | Chemically reactive … and so… |
| CANNOT be hydrolysed and so … | CAN be hydrolysed … and so … |
| Are NOT biodegradable | Are biodegradable |
Methods of disposal or re-use
| Method | Advantages | Disadvantages |
| Landfill | Prevents the release of toxic or environmentally harmful gases. | There is a limited supply of landfill sites and the lack of biodegradability means these will fill up. |
| Combustion | Prevents the build-up in the environment. | Can form C (smoke), CO (poisoness), CO2 and H2O (greenhouse gases). |
| Hydrolysis | Reduces landfill. | Happens very slowly naturally. |
| Recycling | Helps to preserve dwindling supplies of crude oil and the energy wasted in processing it.Unrecycled plastic usually ends up in landfill and so recycling reduces the rate this happens. | Involves collection, sorting, melting, remoulding ALL of which use energy and manpower and is therefore expensive. |
No comments yet.
Leave a Reply
Weird ‘n wonderful from New Scientist- Zoologger: The bird that cares for its rival's chicks February 23, 2012New Zealand's iconic pūkekos often allow other females to lay eggs in their nests, and care for the resulting young. What on earth for?
- Zoologger: Itsy bitsy teeny weeny chameleons February 15, 2012They've got independently rotating eyes, a curiously curly tail, and strangely depressing names. Meet some of the world's tiniest – and cutest – chameleons
- Zoologger: Don't bite - how the zebra got its stripes February 9, 2012An enigma that puzzled Darwin may have been solved – experiments suggest that zebras have stripes to fend off biting insects
- Zoologger: The only males with more brain than females February 2, 2012In one Icelandic lake, male three-spined sticklebacks have much larger brains than females – no other species shows such a big difference between the sexes
- Zoologger: How a blurry-eyed spider pounces on target January 26, 2012The Adanson's house jumper is the first animal found using out-of-focus vision to judge the distance to its victims
- Zoologger: Gecko's amputated tail has life of its own January 19, 2012Faced with a predator, the leopard gecko can jettison its tail – we explain how it keeps moving without a body
- Zoologger: Unique life form is half plant, half animal January 13, 2012A newly discovered single-celled organism isn't an animal, isn't a plant, and isn't even a neat hybrid of the two
- Zoologger: Transgender fish perform reverse sex flip January 6, 2012Boys will be boys… or girls, if it's convenient. From female to male and back again, gender bending means dwarf hawkfish can find a mate in any situation
- 2011 review: The year in Zoologger's extreme beasts December 22, 2011Zoologger is our weekly column highlighting extraordinary animals – and occasionally other organisms – from around the world. Here's our top 10
- Zoologger: My brain's so big it spills into my legs December 14, 2011Little spiders have a big problem – their brains are so big they have literally spilled out of their body cavities and into their legs
- Zoologger: To kill a mockingbird? No, parasitise it December 7, 2011Cowbirds lay their eggs in other birds' nests and often kill their young, so why do mockingbirds let them get away with it?
- Zoologger: Chill out with the world's coldest insect December 1, 2011While cold-shy mammals flee north, the larvae of the Antarctic midge stick it out through the depths of the polar winter
- Zoologger: 'Werewolf birds' hook up by the full moon November 25, 2011Barau's petrel is one of a handful of tropical birds that navigates using the full moon as a kind of Bat-Signal to guide them to their love nests
- Zoologger: Cannibal shrimp shows its romantic side November 17, 2011These small shrimps are no wimps: cannibalistic and willing to fight till death do them part – but only after dark
- Zoologger: The only cross-dressing bird of prey November 9, 2011Some male marsh harriers spend their adult lives mimicking females, apparently to avoid being attacked by other males
- Zoologger: The biggest spider web in the world November 3, 2011A spider less than 2 centimetres long builds webs that span rivers
- Zoologger: Slime killer hagfish feasts in rotten flesh October 27, 2011Despite not having any jaws, hagfish hunt fish, deter predators with slime, and eat rotting corpses from the inside out
- Zoologger: Female monkeys indulge in synchronised sex October 20, 2011In a bid to mate with as many males as possible, female Assamese macaques coordinate when they're willing to have sex
- Zoologger: The toad that's part clone, part love child October 13, 2011Is it a clone, or the result of an amphibian liaison? The Batura toad is both at once
- Zoologger: The first reptile with a true placenta October 6, 2011One African lizard has embryos that implant themselves into the wall of its womb – just as they do in mammals
- Zoologger: The bird that cares for its rival's chicks February 23, 2012
- News from SciAm
- Deadly Duo: Mixing Alcohol and Prescription Drugs Can Result in Addiction or Accidental DeathThe mystery of Whitney Houston's death will not be solved for several weeks, as the Los Angeles County Coroner's Office awaits a full toxicology report. But many experts speculate that the singer's tragic demise involved a deadly cocktail of alcohol and prescription drugs, including Xanax. [More]
- First Horses Shrunk by Warming ClimateThe first horses in North America would not have been able to hold their own in the Triple Crown . At just about 5.6 kilograms the Sifrhippus sandrae hoofed onto the scene some 56 million years ago about the size of a small dog. [More]
- Scary Stuff: Fright Chemical Identified in Injured FishThere's a scene in Pixar's Finding Nemo when Dory, a yellow-finned regal tang, injures herself in a tug-of-war over a snorkel mask. A tiny plume of blood curls away from Dory's face into the water around her, where it is sucked into the nostrils of Bruce, a "vegetarian" shark who immediately recants his no-sushi policy. (Fortunately, […]
- New Family of Limbless Amphibians Discovered in IndiaFrom Nature magazine. [More]
- Dual Interpretations: Milky Way's Outer Fringe of Stars Sparks DisagreementIt's well known that the Milky Way is a spiral galaxy, a swirl of stars in an extended, many-armed disk . But the structure of the galaxy is far from two-dimensional. Above and below those familiar spiral arms is a lesser-known feature, a spherical swarm of stars that makes up a halo around the disk. [More]
- Fossilized, 'Pompeii' Forest Discovered Under AshAbout 300 million years ago, volcanic ash buried a tropical forest located in what is now Inner Mongolia, much like it did the ancient Roman city of Pompeii. [More]
- Alex the Parrot's Posthumous Paper Shows His Mathematical GeniusFrom Nature magazine [More]
- Co-opulation: Sometimes It Takes More Than 2 to Tango [Slide Show]Dawn Higginson thought it was strange when she learned that some diving beetles produce sperm that fuse together at the head like Siamese twins. But when the postdoctoral researcher from the University of Arizona began asking why such conjugate gametes form, things only got even stranger. The sperm of the diving beetle, which gets its name from its ability t […]
- Squid Can Fly to Save EnergySquid can save energy by flying rather than swimming, according to calculations based on high-speed photography. [More]
- Autism Signs Appear in Brains of 6-Month-Old InfantsThe early signs of autism are visible in the brains of 6-month-old infants, a new study finds, suggesting that future treatments could be given at this time, to lessen the impact of the disorder on children. [More]
- Deadly Duo: Mixing Alcohol and Prescription Drugs Can Result in Addiction or Accidental Death
