[HN Gopher] More sustainable epoxy thanks to phosphorus
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       More sustainable epoxy thanks to phosphorus
        
       Author : JeanKage
       Score  : 67 points
       Date   : 2026-01-14 10:43 UTC (4 days ago)
        
 (HTM) web link (www.empa.ch)
 (TXT) w3m dump (www.empa.ch)
        
       | pfdietz wrote:
       | 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.
        
         | westurner wrote:
         | 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.
        
         | metalman wrote:
         | 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.
        
           | pfdietz wrote:
           | > existential marine crisis
           | 
           | I think you're being overly hysterical there. Plastics in the
           | ocean are certainly not ideal, but "existential"?
        
             | metalman wrote:
             | 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.
        
         | kennywinker wrote:
         | "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.
        
       | HardCodedBias wrote:
       | 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.
        
         | pfdietz wrote:
         | 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.
        
         | Brian_K_White wrote:
         | 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.
        
           | pretzellogician wrote:
           | There was also Black Destroyer by a.e. Van vogt, where the
           | cat-like creature specifically ate phosphorus:
           | https://scifi.stackexchange.com/questions/153274
        
             | Brian_K_White wrote:
             | 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 wrote:
         | I can't imagine this approaches how much is used in agriculture
         | for fertilizer.
        
       | ComputerGuru wrote:
       | 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 wrote:
         | 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
        
           | LoganDark wrote:
           | They're looking for commercial partners though.
        
         | bootsmann wrote:
         | EMPA is not a company, it's a Swiss government agency. Maybe
         | you should apply the grain of salt to your own priors too...
        
           | ComputerGuru wrote:
           | Thanks for the correction but they're tooting their own horn
           | either way.
        
             | s0rce wrote:
             | 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/201101150
             | 53058/https://www.north...
        
       | rectang wrote:
       | 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.
        
       | rectang wrote:
       | 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.
        
         | hammock wrote:
         | I don't know of any recycled polymer that doesn't have at least
         | somewhat compromised durability. Doesn't mean it's useless
         | though
        
         | vesinisa wrote:
         | 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.
        
           | rectang wrote:
           | 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.
        
       | zahlman wrote:
       | It appears we got a relevant XKCD just in time:
       | https://xkcd.com/3194/
        
       | linsomniac wrote:
       | 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
        
         | Retr0id wrote:
         | I do the "hot staples" trick but I just use wire scraps and a
         | soldering iron
        
           | ajb wrote:
           | 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?
        
             | Retr0id wrote:
             | 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.
        
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