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Mechanically strong yet metabolizable plastic breaks down in seawater (www.science.org)
122 points by anigbrowl 21 hours ago | hide | past | web | 95 comments | favorite





> can be water stabilized with hydrophobic coatings

So when they make takeout containers out of this it's going to be coated with... something. I am suspicious of all these coatings they're slapping on compostable food containers these days.


Well, even vegetable oil is hydrophobic, so "something" needn't be too horrible. (Oil would obviously wipe off too easily.)

Apparently soybean wax works well: https://pmc.ncbi.nlm.nih.gov/articles/PMC7435775/

Though not for hot foods. It'll only work up to 50°C.


Or hot climates that reach >50 C

Or simple locked car on a sunny day (maybe not during winter), with dark interior. This can reach >90C over an hour or two.

No car interior has ever reached 90C. Did you mean 90 F?

Overall temperature isn’t 90C but your lunch could be in contact with those temperatures:

https://www.clickorlando.com/news/2019/09/26/heres-how-hot-t...

“In a locked vehicle, a dark dashboard, steering wheel or seat can often reach temperature ranges of 180 - 200 degrees F, which then warms the air trapped inside a vehicle.” 194F is 90C.

And that’s Florida, other parts of the globe have higher outdoor temperatures which result in higher internal temperatures.


Maybe not far off from 90, given you can fry eggs in open air in the sun and for that you need 65.

https://www.youtube.com/watch?v=PhYkUuvDsGA


There's no reason you'd ever worry about that; no one can use any object in such a climate, because they'd die.

People definitely live in places where it gets that hot. (And note that's the air temperature in the shade, not even surface temperatures in sunlight which can get much hotter).

People survive because it's not 50°C all the time in those hot places. And the wet bulb temperature is lower, so sweating works (just about) to regulate body temperature. Mostly air conditioning and shelter, though.



Those links aren't shy about explaining that people exposed to that level of heat die. Here's the first one:

> According to a study recently published in Nature Medicine, more than 60 000 people died because of last year’s summer heatwaves across Europe.

It's not necessary for your home food storage to be able to survive temperatures that you can't. If it happens to the food in your home, it will happen to you too.


There's also shellac.

They specifically mention a coating in the abstract, parylene C.

I am suspicious of the food in the takeout containers.

Perhaps some sort of food-grade wax? Although then you've got to worry about hot foods...

My aunt got me a big wooden bowl in college and I was poor so I ate popcorn out of it. I noticed the popcorn tasted weird for quite some time. I finally put two and two together when the coating had all come off the bottom. The hot popcorn and oil had been removing the God knows what shiny finish and I had been eating it. :(

laughs in PFAS

The sooner the cost of plastics actually reflect their true cost to society (which is basically infinite if they cause genetic damage), the sooner we get viable replacements.

Interesting that this is a thermoplastic - my first question is how it performs as a 3D printer filament?

> Plastics that can metabolize in oceans are highly sought for a sustainable future.

Really? I think that putting more nutrients in the water is almost as bad as having plastics floating around. The Baltic sea for example, have dead zones caused by agricultural runoff.

Surely, the best would be to not put more stuff in the water?


it is certainly good to not put more stuff in the water. i would suggest it is even better not to make stuff that shouldn't go in the water. but apparently a lot has already been made and there's constantly more of it in the water, and it looks like nobody is stopping

so if some major fraction of present production of that shit that shouldn't go in the water can be eliminated, and satisfied by an alternative that is not a persistent accumulating poison, i'll take it


Depends on what you put in, how much, and where.

I do not think moderate quantities of nutrients are a problem, and very likely has benefits.


The natural input of "nutrients" to the ocean is vast, compared to the natural input of modern artificial plastics.

Well yeah but good luck with that.

We've heard the "biodegradable" greenwashing scam of plastic technology advances over and over again. Maybe we shouldn't be seeking continued use of toxic petrochemical processes and should instead change our storage and packaging materials to be less hazardous and more reusable, because many other options already exist.

It's very easy to say "why don't we just stop using toxic petrochemicals," but very hard to do in practice. For a sustainability advancement to be considered a success, it has to actually replace something. To replace something, it:

- has to be affordable, or people will refuse to buy it. The general public cares more for its wallet than the environment.

- has to be at least as performant as what it's replacing, or people won't want to change. The general public is not going to buy an inferior product in the name of sustainability.

- has to be more environmentally friendly than what preceeded it, or it has no benefit.

If you can find a more environmentally friendly material that is able to replace plastic, achieve its physical properties, at the same cost, then patent it and you will be very wealthy. And will have outplayed the billions (probably a lowball) being dumped into this by governments, universities, and private companies around the world.

Also, the reason most of these articles hype their own work up is because the name of the game in academia is grant money. If a funding agency doesn't think your work is impactful, they'll give it to someone who is. That's why articles rarely describe their incremental work as just being incremental.


I would be interested to know the cost of more sustainable packaging at economies of scale. Almost all plastic-based packaging emerged after 1950, yet even before then, there was a need to package mass consumer goods on a large scale.

I also believe plastic and PFAS coatings are used in packaging largely because they are assumed to be the only suitable materials. However, in earlier times, there were many clever and cost-effective solutions.


Population of the world in 1950 was 2.5 billion. The population of the world has over tripled. This world put a lot of scaling pressure on everything.

I didn't think plastics are used because they are considered the only submittable suitable material, but they are definitely the cheapest and easiest to use. You cannot injection mold wood to be the exact shape and size with a snug fit for something you are packaging.


The fraction of the world's population regularly consuming manufactured and packaged goods is also increasing. That increases discarded plastics and other materials.

About a decade ago I tracked down the somewhat provocative claim that contemporary New Yorkers (city, not state) produced less refuse, by mass, than those of the 1930s. My first thoughts were that total packaging weight and waste food might account for this, older packaging materials being more ecologically-friendly, but generally more massive: wood, glass, metal, etc., and refrigeration and food preservation less developed.

Good guesses, but wrong as it happens.

The culprit was coal ash, on the order of 40% of all rubbish by weight. It had been > 80% in 1900.

Building heat was supplied by boilers running on coal. That left a large quantity of fly ash as residue. As heating switched to natural gas and cogeneration steam from the 1950s through the 1960s, coal use was largely eliminated.

Former generations of New Yorkers would often refer to receptacles as ash cans, and they were traditionally made of galvanized steel, both useful when contents might contain glowing coals. As trash evolved to colder refuse, plastic bins or bags could be substituted. "[T]he New York City Sanitation Department began encouraging the use of plastic garbage bags in 1969." (<https://archive.nytimes.com/cityroom.blogs.nytimes.com/2007/...>)

Net non-coal refuse has increased, but the total, at least as of a decade ago, was still below the early-20th-century high point. Much of the current total however is plastics, and in particular disposable diapers.

I'd had additional sources on this at one point though I can't locate them presently.

This paper discusses composition and confirms the 40% & 80% figures above:

"How New York City Residents Diminished Trash", Paul E Waggoner and Jesse H. Ausubel, The Connecticut Agricultural Experiment Station, New Haven andRockefeller University, New York. October 2003.

<https://phe.rockefeller.edu/wp-content/uploads/2019/09/NYTra...>

The NYT article above also confirms "ash cans".


It doesn't have to be cheap, It just has to be made cheaper artificially with globally enforced taxes.

The number one economic role of government is mitigating externalities that arise from free trade, often through the restraint of that trade.


globally enforced taxes

Why not just pass a law requiring everyone to be good?


Congrats you just made everyone subject to those taxes artificially worse off. People aren't stupid and can see what you did. You will be voted out of office next term. If you're going to artificially adjust prices it's got to go the other way where you subsidize the behavior you want. It worked with lightbulbs.

Or perhaps everyone is actually better of if negative externalities are taxed.

Or perhaps everyone is worse off because some well connected lobbyist got the government to mandate their more expensive, less effective product.

You made a change which caused consumer prices to go up, folks are already struggling financially it doesn't matter if it's for a good reason.

This is the "I know you're struggling but the economy is actually doing great" but applied to environmentalism.


> The general public cares more for its wallet than the environment.

More or less, yes, but I think it deserves more nuance. Most of the general public is stuck trying to make ends meet, and regard the environment as a problem to be solved by their government and rich corporations.

If you take away their plastic bags and straws, they will make do.


You seem to believe plastic containers are used due to being a more affordable and technically superior solution. That’s a common mistake.

The true reason it’s so cheap and available, is subsidies. $7 trillion as of 2023, to be exact.

Without subsidies, using a non-renewable, expensive to harvest resource, to produce single-use plastic would be an absolutely irrational decision.

https://www.imf.org/en/Blogs/Articles/2023/08/24/fossil-fuel...


You'd want to factor in externalities as well, both on the extraction side (fossil fuels are phenomenally under-priced, likely by a factor of millions), and disposal (environmental impacts of discarded plastics and pollution during manufacture).

This bogus number comes from putting a value on the supposed environmental cost, but that is not what subsidy means in the economic sense. We already established that if we somehow could globally settle on a price for externalities, alternatives would be competitive, but they would still be intrinsically more expensive.

Except it isn't a "bogus number". Fossil fuel subsidies are real.

>"It’s not just the US: according to the International Energy Agency, fossil fuel handouts hit a global high of $1 trillion in 2022 – the same year Big Oil pulled in a record $4 trillion of income."

https://www.budget.senate.gov/chairman/newsroom/press/sen-wh...

I say give the subsidies to environmentally friendly producers instead, that don't use fossil fuels as the base material for producing packaging products. $1 trillion in one year is just an unfathomable amount of money to give away to corporations that are already making record profits far above the $1 trillion they already get.


That will be 5 $ more per butterstick, for the logistics of reusable porcelain butter packages.. which have to be collected, washed and shipped. Which makes it a rich people feel good status-symbol luxury, sadly.

Your sticks of butter come wrapped in plastic?

I don't think I've ever seen anything other than wax paper or foil, with only tubs of butter, rather than sticks, in plastic.


Up until earlier this year, many "grease proof" papers (e.g. butter wrappers) were PFAS.

PFAS aren't plastics.

And removing them clearly didn't increase the price of sticks of butter by $5.


A lot of plastic containers use fluorine-treated plastic [1], resulting in the creation of PFAS. The fluorine is used to strengthen the plastic and make it less permeable.

> Since EPA released its investigation, we have learned the disturbing fact that the fluorination of plastic is commonly used to treat hundreds of millions of polyethylene and polypropylene containers each year ranging from packaged food and consumer products that individuals buy to larger containers used by retailers such as restaurants to even larger drums used by manufacturers to store and transport fluids.

[1] https://blogs.edf.org/health/2021/07/07/beyond-paper-pfas/


A lot of "butter" spreads are sold in plastic tubs.

Butter used to be packaged in wax paper, which was (then) biodegradable. The plastic packaging is about branding and shipping, not cost.

It still is.

Well maybe not at Whole Foods, I've never been in one, but at Walmart it's four wax-paper wrapped sticks in a cardboard box.


Do you know that it’s waxed paper, and not plasticized paper? Genuine question, since I imagine “wax” paper is either plasticized or using petroleum-based waxes.

Not arguing the general point, for which I agree, but isn't butter commonly sold in aluminum foil wrappers?

Or you know, supermarkets would purchase 50kg blocks of butter and fraction it, clients would then be responsible for bringing their own reusable containers.

You’d still have to pay the employee who’d be responsible for cutting and weighing the butter for each customer, and taking payment for the butter (or however else that would work). Or build a machine that does it. Not sure how the cost for that would work out, or the machine’s ecological footprint in comparison.

Plus all of the food hygiene and logistical implications of handling products in bulk, multiplied by the 30,000 different products in a typical supermarket.

I don't know about the US, but in my country butter is packaged in waxed paper, which is fully biodegradable.


It wouldn’t be that different from how a lot of cheese is being handled where I live. Except they currently put the cuts into plastic wrappings (which are “sealed” by the price sticker) instead of customer-provided containers. On the other hand, for fruits we already do use nets brought by the customer, and the weighing happens at the checkout.

>multiplied by the 30,000 different products in a typical supermarket

It's almost like we're going to have to reduce our consumption or something. Maybe we don't need 200 different kinds of cereal and 300 different kinds of coffee available every single day.


My local supermarket chains already do that. It's called the Deli Counter. The cost is not a big deal.

No one will actually do that, except the few weirdos who think that it's a good idea.

Remember: "Reusable" containers also have an environmental cost. Each container will be used, on average, X times. Then it will break, or otherwise end its useful life, and end up in a landfill too.

Don't assume that a "reusable" container is better for the environment: My house is full of free, pristine, reusable water bottles that are gifts, souvenirs, ect. My kids go through about 2 reusable water bottles a year, each.


I’ve had the same steel water bottle for over 10 years. Just because you don’t reuse things well doesn’t mean it’s impossible.

I stress the word "free" here. Most of them were gifts.

See https://news.ycombinator.com/item?id=42214319


What were the inputs like to manufacture the steel container?

I mean, of course it's not perfect. But isn't 2 water bottles in a land fill orders of magnitude better than 300? Isn't the reduction of bulk trash the point? Why would the fact that a glass container can break make it not still a better alternative to 50 plastic ones?

> But isn't 2 water bottles in a land fill orders of magnitude better than 300?

I think you're making a lot more assumptions than you think:

For example, glass vs glass: My single-use glass container may be recyclable, but the fancy glass reusable one isn't.

Aluminum: Aluminum cans are highly recyclable. Is your metal reusable water bottle recyclable?

Plastic: Ooooh, I won't go there.


Butter is, perhaps, a bit sticky for that, but my local co-op has various bulk grains and flour and beans and such that customers can bring their own containers for.

This. There seems to be one of these announcements every so often, and i havent seen any of them used at scale, or making any kind of dent in the status quo.



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