A new type of plastic made from corn starch could solve some of the material's most egregious crimes

Plastic or Plastic? A new type of plastic could solve some of the environmental issues typical plastic causes. Stephanie Chan

On the heels of our reporting about Canada's probable move to ban BPA plastics comes a story about researchers working at Missouri University of Science and Technology to develop hybrid plastics that would biodegrade in landfills within four months. As our editor Nicole Dyer pointed out in a comment to the BPA post, the larger and more important issue facing plastics is their propensity to stick around forever. As we pointed out in our article about the waste gyre in the Pacific Ocean, plastics will eventually photodegrade into microscopic bits, but those polymer molecules will forever be inorganic toxins. The Missouri S&T scientists are working to change that by focusing their attention on a biodegradable polyester.

Polylactic acid is a polyester derived from corn starch which decomposes and mineralizes into water and carbon dioxide when composted. It's already being used in some brands of compostable "plastic" bags. The team is working to blend the acid with other bio- and oil-based polymers to find the right kinds of resins for commercial use. They're also looking at repurposing waste materials resulting from biodiesel refinement—anything that can be culled from renewable sources. Whether this is a long-term solution remains to be seen.

Via PhysOrg

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10 Comments

it could use farm crops such as corn or wheat and raise the price of food and sugar supplements .

Another crap idea from some hippies that can't look 2 feet into the future. Why don't we just start building everything out of things people eat, like rice or some other staple food? Yay for hunger! Yay for deforestation!

They can be made out of any kind of starch. My company is also making biodegradable bags out of ground limestone.

Adam R Sweet, Director of Operations
TwoTree International, LLC
http://www.twotreellc.com

Good one keep em common:YAY...Good shopping
Matthew T. Gossar

i dont understand why so many people seem to think that the more we use food products for non food related purposes (biofule, etc) the less food the world will have to eat? Last time i checked, not every ounce of freeland has been converted into farmland people. its called supply and demand....sure if we only had X ammount of food to use this might be an issue...but guess what? once there is more demand or a need, something magical will happen! More people will go into farming, more land will be converted to farmland, more food will be grown. Obviously its a bit more complex then that, but still, thats the gist of it.

I think it's great that people want to make the move into a more 'environmetaly concious' lifestyle, but there can be drawbacks... I think sublumjack1 makes a great point- more demand, more supply. But everything is working on a ratio, not a straight scale. If there are more people being born exponentially we need to consider the fact that more land will be used for housing and businesses, not just farming. (not to mention all the food required for the newborns.) There is only so much land on our earth that is exploitable for farming, and quite frankly people will NEVER stop having children... (even in China.) There needs to be a balance somewhere... REUSE for SUSTAINABILITY, lets not try to figure out how to use more resources, lets just make it durable enough to last for MANY uses. Car companies- make designer totes that come with the car in a glove box, no more people forgetting their bag at home! Just a thought...

Once again, self-proclaimed "environmentalists" prescribe a "cure" that makes everything far, far worse.

Here's what an article in Britain's (very left-wing) "The Guardian" newspaper says:

"The substitutes can increase emissions of greenhouse gases on landfill sites, some need high temperatures to decompose and others cannot be recycled in Britain.

Many of the bioplastics are also contributing to the global food crisis by taking over large areas of land previously used to grow crops for human consumption."

More here:
http://www.guardian.co.uk/environment/2008/apr/26/waste.pollution

I like the limestone idea for bags and we have to make sure the environment is safe for right now. Also, some people seem to think that there is unlimited land so the demand and deforestation can increase. To a point it can increase, but then the animal world falls out of kilter. The industries just need to be careful when they increase and not think about the ALL POWERFUL DOLLAR. The corn starch bags would make corn farmers richer, but make other people who use corn products poorer.

The plastic bag thing is rift with issues - there are so many 'altenatives' out there that it is hard to know exactly what the impact might be.

It is undoubtedly the case that replacing disposable oil based plastic bags with disposable starch based bags would put pressure on food production. However, there are bags on the market that avoid these issues, for example by utilising non-food quality streams (such as substandard or brownfield corn, or my personal favorite, potato starch from the peel as a waste product from chip and crisp factories).

There is a lot of very poor marketing from companies trying to push plastic bags as degradable/biodegradable and these do cause problems, as the guardian article tundraesa quotes points out, but the increasingly widely accepted standard is compostable not biodegradable - to European Standard EN13432 or US Standard ASTM D6400.

More to the point, however, is that shops that go 'plastic bag free' (that will usually offer a compostable bag alternatve for a nominal charge) tend to see a drop in usage of between 90 - 95 % (this bears out on my local highstreet which is in the process of going plastic bag free). Reduce, Reuse, Recycle - it is in that order for a reason!

I truly don't understand how one can label anyone interested in improving and preserving our environment as a 'crazy liberal' or 'hippie.'

The point of the article is that we don't have to use petroleum based products in order to enjoy the conveniences that plastics provide. Any sort of starch will do to construct biodegradable bags. Corn is just an example. Personally, I'm not a big fan of using food grade materials to make things for other uses..ethanol or bags. Grasses or even potato peels(as another user pointed out) would work as well.

Also, anything decomposing emits some heat, that's unavoidable. And yes, they do put out greenhouse gases while decomposing. However, the alternative of countless tons of plastics degrading into microscopic toxins affecting all life on earth(including humans as it goes up the food chain) seems to be a bad alternative. And manufacturing plastics from fossil fuels isn't exactly an emissions free process...to say the least.

As for the land issue, there is only so much arable land and we need to preserve some of it in it's natural state for our own health, if nothing else. Forested land regulates our weather, cleans our air and purifies our water. So, no, we can't just convert it all into farmland, we have to use our resources wisely and conserve.

Human population is a huge problem. No, people won't stop having children, but they are having less in most developed nations. Europe's population is actually declining. If the world population doesn't slow and descend at some point we *will* run out of resources and that would be very ugly. If everyone currently on the planet lived and consumed like an American...we'd need a few more planets. Not saying I don't enjoy and appreciate my standard of living, but we might want to think about the numbers a little more.



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