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More sustainable epoxy thanks to phosphorus
Somewhat unrelated: If you use epoxy for repairs, particularly of plastics (though I just used some for a wood repair), get yourself some fiberglass tape/fabric to use with it. Sometimes I'll lay the tape over the repair, sometimes I'll cut it up into little fragments and mix it directly in the epoxy (depending on if the epoxy is the bulk of the repair, like filling in a hole, or if I'm trying to repair a crack.

Also, if you are repairing plastic, consider "hot staples". A friend of mine just educated me on that 6 months ago, and I'm using them all the time, a starter kit costs around $50 though. This is a good, quick demo of them: https://youtube.com/shorts/43TDecNqTco?si=xsDJ3n7KMjpg8NVw

I do the "hot staples" trick but I just use wire scraps and a soldering iron
  • ajb
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Interesting. Of course, it's at least safe if you have a good temperature control. I'm guessing you use single core wire? What kind of tip do you use?
I mostly use the square pins from SIL headers, bent into an appropriate shape. I use a pointed tip but I don't think it matters much, as long as it can transfer heat into the pin.

I most recently used this to repair a snapped headband on some sony headphones. I'd previously tried to superglue it, but the glue eventually came undone - but my "staples" are still going strong.

OT: It's difficult for me with my imperfect vision to read this web page because of inadequate contrast between body-text and background. Firefox dev tools measures a 3.52 contrast ratio — WCAG guidelines recommend 7:1 (AAA rating) or 4.5:1 (AA rating). However, viewing the page in reader mode seems to work as a solution.
What specifically are you measuring and what are the colors?

I'm seeing #555 on #fff for the body text, and while I'd prefer a darker and thicker font that comes out to WCAG 7.46:1 and APCA 85.9

There are two recycling mechanisms:

> After use, the material can simply be ground into powder and pressed into a new shape while heated, causing the bonds to rearrange themselves. This is known as thermomechanical recycling.

> it can also be chemically dissolved

I wonder whether either of these opens up any practical durability issues for this variety of epoxy.

This is covered in the article.

> We have carried out ten [thermomechanical] recycling cycles, and the epoxy has not lost any significant mechanical strength in the process

Chemical dissolving is only needed for carbon fiber composite. 90% of the resin was cited to be recoverable in this process.

I saw that passage, which addresses that durability doesn't degrade through recycling cycles. But what I was curious about was whether this epoxy is more susceptible to weakening when exposed to heat in working environments, perhaps at lower threshold temperatures than common epoxy. Similarly, I wondered whether there were any chemicals which are commonly encountered in working environments which could serve as dissolving agents and damage this epoxy.
I don’t know of any recycled polymer that doesn’t have at least somewhat compromised durability. Doesn’t mean it’s useless though
It appears we got a relevant XKCD just in time: https://xkcd.com/3194/
This looks like recycling fetishism. It's perfectly fine to burn such materials, if they were obtained from non-fossil sources to start with, so there would be no net CO2 addition to the atmosphere.
“The raw materials for epoxy resin production are today largely petroleum derived, although some plant derived sources are now becoming commercially available (e.g. plant derived glycerol used to make epichlorohydrin).”

- https://en.wikipedia.org/wiki/Epoxy

if they were obtained from non-fossil sources - but they weren’t, and the industry hasn’t switched and may never switch to plant based.

Also, what you said isn’t necessarily true even with plant based resins. What is the carbon cost of producing new resin vs recycling old?

There’s more to the impact of a material than the carbon stored inside it.

Yes, we were all duped by the recycling industry. No that doesn’t make all attempts at recycling a lie.

> Also, what you said isn’t necessarily true even with plant based resins. What is the carbon cost of producing new resin vs recycling old?

In the post-fossil fuel age, where is the net carbon supposed to be coming from? Unless we're using limestone, it's from the air, so there can't be net emission.

In the not-yet post-fossil fuel age, what matters is displacing fossil fuels as quickly as possible, not the relatively very minor amount of carbon embodied in the renewable energy machinery.

we are having an existential marine crisis due to the millions of tons of essentialy non recyclable "plastic" bieng dumped in our oceans, a fully recyclable alternative is worth trillions over the long haul. The switch will happen when a viable alternative is discovered, and a material that has inherent value will be a key requirement. If this new epoxy is a true engineered material that is suitable for say, vacume infusion molding of things like wind turbine blades,and smaller ships, and injection molding of buckets and computer chasis etc, etc , then it will become universal for those things.
> existential marine crisis

I think you're being overly hysterical there. Plastics in the ocean are certainly not ideal, but "existential"?

the known consequences of polluting the the entire base of the planets food web isn't existential? "scientists", politicians, beurocrats, lawyers, and the mega wealthy have kept moving the agread upon limits to environmental exploitation, with zero sign that they have any other intent, than to take more³ what you are missing is that no one will ask for permission, to fix that.
I had hoped the use of the word was based on some actual specific world-ending effect I didn't know about, so I could learn something new and important. But apparently it's just untethered anxiety.
We’ve literally been dumping nuclear and chemical waste in the oceans for 100 years now?

It isn’t good, but it isn’t any different than usual either.

  • wiml
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The amount of plastic going into the ocean is increasing rapidly, especially in the last 15 years or so. It is different from (say) 50 years ago.

Also you might have noticed that a lot of sea life is scarcer than it used to be.

An adjacent design validation question on a green chip factory and product design:

Will Phytic acid in Lignin-Vitrimer encase burning CNT carbon nanotubes in a phosphorous char cage, this preventing health hazards and combustion?

This says "phosphorous epoxy".

FR4 silicon PCBs are N-doped and P-doped.

This is a presser (disguised as a science piece) from the company behind this; take it all with a grain of salt.

Also, epoxy already contains harmful endocrine disruptors, adding forever chemicals like those found in almost all flame retardants is just adding fuel to the fire (pun not intended).

  • s0rce
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While this is just a press release its about the academic paper, which is open access https://www.sciencedirect.com/science/article/pii/S138589472...

It doesnt seem like any of the authors are making this commercially currently

They're looking for commercial partners though.
EMPA is not a company, it’s a Swiss government agency. Maybe you should apply the grain of salt to your own priors too…
Thanks for the correction but they're tooting their own horn either way.
  • s0rce
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Yes, this is very common for academic publications, particularly when there could be broad interest. For example, here is the press release from the first publication of my PhD https://web.archive.org/web/20110115053058/https://www.north...
when I hear of industrial uses of phosphorus my ears prick up since phosphorus is a key limiting factor for life.

A world where this actually became industrially very successful combined with a lack of recycling could potentially add large new sink for phosphorus.

In general, be careful when creating a process which locks meaningful amount of phosphorus out of the biosphere.

When a general study was made back in the 1970s of the limits of substitutability and recyclability of mineral resources, it was found phosphorus likely dictates the minimum amount of mining needed in steady state. It occurs at an average concentration of about 0.1% in the continental crust.

I worry just a bit about this in reference to LFP batteries.

I think that was a core plot point of a series of books by Niven I think. Humans are on a planet that has almost no phosphorus or maybe potassium in it's biosphere. Humans have to take it artificially by sprinkling a special salt on every meal. But it's very limited and expensive and so a significant part of the population are mentally handicapped to lesser or greater degrees, generation after generaion.

Ah, Destiny's Road, and it was Potassium.

"...dooming humanity to a slow mental extinction."

Great.

There was also Black Destroyer by a.e. Van vogt, where the cat-like creature specifically ate phosphorus: https://scifi.stackexchange.com/questions/153274
Star Trek episode 2 the creature removes all your salt. There are a lot of examples of a creature extracting all of something like that but these are kind of a different idea.

The potassium one is particularly horrible to think about because it's insideous. The problem removes your very ability to respond to the problem. The entire race just gradually devolving back to stupid, especially if it was from the result of our own actions consuming it all for some industrial or consumer purpose. And before that happens, for untold generations there would be rich people who could afford their kids to grow up with enough and perpetuate the permanent ruling class, and a permanent poverty class that physically can not ever escape or compete regardless of their attitude or effort.

  • s0rce
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I can't imagine this approaches how much is used in agriculture for fertilizer.