A Real Unbreakable Comb?
September 3, 2013 3:09 PM Subscribe
Chemists at Duke University have developed a new plastic that becomes stronger with mechanical stress.
The carefully designed molecular structure of the material is what gives it this unusual property. Like all plastics, this one has a backbone composed mostly of carbon. However, the carbon atoms are arranged in a series of triangles extending down in long chains with two bromine atoms at one point. The researchers found that the unique structure of this compound could turn “destructive” energy into “constructive” energy.
Nature Chemistry article abstract (full article behind paywall.)
Maybe this won't happen anymore.
Via
The carefully designed molecular structure of the material is what gives it this unusual property. Like all plastics, this one has a backbone composed mostly of carbon. However, the carbon atoms are arranged in a series of triangles extending down in long chains with two bromine atoms at one point. The researchers found that the unique structure of this compound could turn “destructive” energy into “constructive” energy.
Nature Chemistry article abstract (full article behind paywall.)
Maybe this won't happen anymore.
Via
First thing I thoughts of when I saw this:
That 3D printed gun? Get's better the more you fire it.
Though I could also see non-lethal uses. Soft plastic printer gel, printed, smack on table, hard rigid product after printing. The more you pound on it, the harder it gets.
Though the interesting thing will be the ability to "sculpt" the plastic and hammer it into whatever shape you want.
I think the hardening they describe in medical devices will actually be contrary to the actual usage requirements. You want a plastic artery to remain flexible, not become more rigid (I would think, not a doctor or medical scientist). The best option would be something that doesn't lose cohesion over time through wear and tear, something that repairs weakened bonds but doesn't become more rigid over time, like how muscles repair themselves (through other processes, sure, but still, that's more likely the goal).
posted by daq at 3:20 PM on September 3, 2013 [1 favorite]
That 3D printed gun? Get's better the more you fire it.
Though I could also see non-lethal uses. Soft plastic printer gel, printed, smack on table, hard rigid product after printing. The more you pound on it, the harder it gets.
Though the interesting thing will be the ability to "sculpt" the plastic and hammer it into whatever shape you want.
I think the hardening they describe in medical devices will actually be contrary to the actual usage requirements. You want a plastic artery to remain flexible, not become more rigid (I would think, not a doctor or medical scientist). The best option would be something that doesn't lose cohesion over time through wear and tear, something that repairs weakened bonds but doesn't become more rigid over time, like how muscles repair themselves (through other processes, sure, but still, that's more likely the goal).
posted by daq at 3:20 PM on September 3, 2013 [1 favorite]
Does the paper go into how far this effect goes? presumably the plastic can't become infinitely stronger.
posted by GuyZero at 3:21 PM on September 3, 2013
posted by GuyZero at 3:21 PM on September 3, 2013
I propose they make this stuff into an unbreakable fly swatter. We've busted, like, 3 of those things so far this summer.
daq: "The more you pound on it, the harder it gets."
/does the clint squint
posted by jquinby at 3:21 PM on September 3, 2013 [5 favorites]
daq: "The more you pound on it, the harder it gets."
/does the clint squint
posted by jquinby at 3:21 PM on September 3, 2013 [5 favorites]
That's... really awesome. So we now have something that can be heavily used and will become stronger to a point where it then begins to behave like a normal polymer with a stability X% higher than the original polymer.
I'd love to see how they originally thought this up or if it was one of those happy accidents.
Also, they're starting to crack down on the 'uploaded to post docs unsecure lab website' copies, aren't they?
posted by Slackermagee at 3:23 PM on September 3, 2013
I'd love to see how they originally thought this up or if it was one of those happy accidents.
Also, they're starting to crack down on the 'uploaded to post docs unsecure lab website' copies, aren't they?
posted by Slackermagee at 3:23 PM on September 3, 2013
When I first heard about this I was all excited because it sounded like exactly what we needed to build our ship out of to restart the Earth's magnetic field, but reading into it this sounds like a different sort of thing.
posted by ckape at 3:25 PM on September 3, 2013 [2 favorites]
posted by ckape at 3:25 PM on September 3, 2013 [2 favorites]
Perhaps one day you’ll even have to “season” a new phone by knocking it around a little bit.
Man, the ad copy for that hard-to-reach hard boiled film noir dectective from the 1940s demographic just writes itself.
posted by yoink at 3:26 PM on September 3, 2013 [1 favorite]
Man, the ad copy for that hard-to-reach hard boiled film noir dectective from the 1940s demographic just writes itself.
posted by yoink at 3:26 PM on September 3, 2013 [1 favorite]
Challenge accepted!
posted by rocket88 at 3:27 PM on September 3, 2013 [1 favorite]
posted by rocket88 at 3:27 PM on September 3, 2013 [1 favorite]
Mutant entrepreneur and cravat enthusiast Sebastian Shaw expressed skepticism. "Fools! You are hardly the first* to contemplate escheat of my Black Kingdom! Take you care - attacks on my person only tend to make me stronger!"
[*New Mutants #23, True Believers!]
posted by Iridic at 3:34 PM on September 3, 2013 [7 favorites]
[*New Mutants #23, True Believers!]
posted by Iridic at 3:34 PM on September 3, 2013 [7 favorites]
I don't actually understand the point of this. All they have made is a plastic that gets harder when it is worked. Lots of materials become harder when they are worked - metals, for instance. The typical failure mode of most plastics is fracture after repeated stress, and it sounds as though this would be just as susceptible.
The article itself says "The goal now is to reverse the hardening when stress is removed from the plastic." Yes, that would be a neat trick, and would definitely be worth getting excited about.
posted by Joe in Australia at 3:35 PM on September 3, 2013 [2 favorites]
The article itself says "The goal now is to reverse the hardening when stress is removed from the plastic." Yes, that would be a neat trick, and would definitely be worth getting excited about.
posted by Joe in Australia at 3:35 PM on September 3, 2013 [2 favorites]
They will doubtless blend this with Imipolex G and get a self-erecting plastic tool that gets hard & stays hard.
posted by chavenet at 3:36 PM on September 3, 2013 [1 favorite]
posted by chavenet at 3:36 PM on September 3, 2013 [1 favorite]
What happens when an irresistible force meets an unbreakable comb?
posted by ckape at 3:38 PM on September 3, 2013 [1 favorite]
posted by ckape at 3:38 PM on September 3, 2013 [1 favorite]
I'd love to see how they originally thought this up or if it was one of those happy accidents.
Self-healing materials are pretty hot right now, and this is a very sensible chemistry strategy to get a stress-induced reaction in a polymer. I would bet this work was designed for this goal from the ground up, with very little serendipity involved.
Does the paper go into how far this effect goes? presumably the plastic can't become infinitely stronger.
"Stronger" is one of those ambiguous words, from a purely technical point of view. There are a bunch of ways to think about the strength of a material. What they looked at here is called the elastic modulus: it measures how much a material deforms in response to stress. It corresponds, basically, to the "hardness" of a material. This plastic gets 75 times harder when it's run through an extruder, and continues hardening for at least a week afterwards, ending nearly 150 times harder than when it started.
It probably also becomes more brittle.
posted by mr_roboto at 3:43 PM on September 3, 2013 [6 favorites]
Self-healing materials are pretty hot right now, and this is a very sensible chemistry strategy to get a stress-induced reaction in a polymer. I would bet this work was designed for this goal from the ground up, with very little serendipity involved.
Does the paper go into how far this effect goes? presumably the plastic can't become infinitely stronger.
"Stronger" is one of those ambiguous words, from a purely technical point of view. There are a bunch of ways to think about the strength of a material. What they looked at here is called the elastic modulus: it measures how much a material deforms in response to stress. It corresponds, basically, to the "hardness" of a material. This plastic gets 75 times harder when it's run through an extruder, and continues hardening for at least a week afterwards, ending nearly 150 times harder than when it started.
It probably also becomes more brittle.
posted by mr_roboto at 3:43 PM on September 3, 2013 [6 favorites]
Condoms of this stuff could replace the use of Viagra!
posted by Greg_Ace at 3:51 PM on September 3, 2013 [1 favorite]
posted by Greg_Ace at 3:51 PM on September 3, 2013 [1 favorite]
A couple of quibbles:
1) Increased hardness is not equal to increased "strength", by which I think most engineers would consider to be the yield or ultimate stress of the material.
2) As mentioned, if it becomes more brittle as it increases in hardness (which is usually the case for most materials), your phone will be indestructible until it shatters into a million pieces.
Cool idea with the self-healing fractures, though. Would be a great technology to build into aircraft materials.
posted by backseatpilot at 3:51 PM on September 3, 2013 [3 favorites]
1) Increased hardness is not equal to increased "strength", by which I think most engineers would consider to be the yield or ultimate stress of the material.
2) As mentioned, if it becomes more brittle as it increases in hardness (which is usually the case for most materials), your phone will be indestructible until it shatters into a million pieces.
Cool idea with the self-healing fractures, though. Would be a great technology to build into aircraft materials.
posted by backseatpilot at 3:51 PM on September 3, 2013 [3 favorites]
daq: "First thing I thoughts of when I saw this:
That 3D printed gun? Get's better the more you fire it."
That and cops claiming they were just "breaking in" their new nightsticks.
posted by Hairy Lobster at 4:09 PM on September 3, 2013 [1 favorite]
That 3D printed gun? Get's better the more you fire it."
That and cops claiming they were just "breaking in" their new nightsticks.
posted by Hairy Lobster at 4:09 PM on September 3, 2013 [1 favorite]
There is motorcycle gear stuff out there called D3O armor. It's soft and flexible, but gets hard on impact, then returns to flexible.
This new plastic seems like it gets hard and stays hard. Not sure that's desirable?
(I know: depends on the use/application...haha)
posted by CrowGoat at 4:17 PM on September 3, 2013
This new plastic seems like it gets hard and stays hard. Not sure that's desirable?
(I know: depends on the use/application...haha)
posted by CrowGoat at 4:17 PM on September 3, 2013
So this will get us that space elevator? (Or is that grapheme?)
posted by zardoz at 4:17 PM on September 3, 2013
posted by zardoz at 4:17 PM on September 3, 2013
This is not quite the miracle it might seem. What they have managed to do is mechanically induce cross-linking, which rigidly locks the plastic polymers in place at many points instead of allowing them to slide. This is exactly what happens when we expose many plastics to UV. Yes it makes the plastic harder and there are cases where we deliberately expose plastic to UV to create a "setting" operation. (Some 3D printers work on this principle.) But in most cases it's bad.
Cross-linked plastics become brittle and usually change shape, causing them to crack. It seems very unlikely that this mechanical cross-linking would be uniform so this would be a big problem. I'd consider this more of a novelty than a useful product until someone suggests a real use for it.
Oh, and plastics aren't the only things that cross-link; collagens in your skin do it too, which is why human skin gets tougher and wrinkles as we age.
posted by localroger at 4:22 PM on September 3, 2013 [1 favorite]
Cross-linked plastics become brittle and usually change shape, causing them to crack. It seems very unlikely that this mechanical cross-linking would be uniform so this would be a big problem. I'd consider this more of a novelty than a useful product until someone suggests a real use for it.
Oh, and plastics aren't the only things that cross-link; collagens in your skin do it too, which is why human skin gets tougher and wrinkles as we age.
posted by localroger at 4:22 PM on September 3, 2013 [1 favorite]
In the literature on the metaphysics of dispositional properties, the plastic's sturdiness would be referred to as a "finkish" disposition.
You might analyze dispositional properties as the sorts of properties that object have when certain counterfactuals are true of them: that is, when they would behave certain ways in certain stimulus conditions. Attributing fragility to an object might simply be to say that it would break when struck, for example. But finkish dispositions cause a problem for this analysis: the stimulus conditions are also conditions under which the disposition is gained or lost.
posted by painquale at 4:33 PM on September 3, 2013
You might analyze dispositional properties as the sorts of properties that object have when certain counterfactuals are true of them: that is, when they would behave certain ways in certain stimulus conditions. Attributing fragility to an object might simply be to say that it would break when struck, for example. But finkish dispositions cause a problem for this analysis: the stimulus conditions are also conditions under which the disposition is gained or lost.
posted by painquale at 4:33 PM on September 3, 2013
Finally, something to restrain that meddlesome Mr. Bond!
posted by klangklangston at 4:36 PM on September 3, 2013 [1 favorite]
posted by klangklangston at 4:36 PM on September 3, 2013 [1 favorite]
So the polymer contains these triangular cycloproprane groups. You can think of these as something like wound-up springs. Carbon likes to bond with other carbon atoms at an angle of 109.5°, but in cyclopropane, it's been forced into bonds with an angle of 60°, so the bonds are under strain. When subjected to mechanical stress, these triangular groups start to pop open, freeing up reactive groups that proceed to cross-link with other nearby polymer chains. That means there's definitely a finite capacity of the material to "strengthen", though I would second others in noting that this is a pretty inaccurate term.
posted by dephlogisticated at 4:59 PM on September 3, 2013
posted by dephlogisticated at 4:59 PM on September 3, 2013
> That 3D printed gun? Get's better the more you fire it.
I imagine the last thing you'd want for your gun is a barrel with an unpredictable modulus of elasticity.
posted by ardgedee at 5:15 PM on September 3, 2013
I imagine the last thing you'd want for your gun is a barrel with an unpredictable modulus of elasticity.
posted by ardgedee at 5:15 PM on September 3, 2013
Too late for my receding hairline. Oh, science, how you mock me.
posted by arcticseal at 5:25 PM on September 3, 2013 [1 favorite]
posted by arcticseal at 5:25 PM on September 3, 2013 [1 favorite]
There is strong and there is tough. Lots of people buy into the Larry Niven Known Space meme that something composed of all covalent bonds in nigh-indestructible, but I've yet to meet one who'll put a diamond on top my relatively soft anvil, no matter how much I promise to use only gravity (the weakest of the forces) to accelerate my 8 lb. sledge.
posted by Kid Charlemagne at 5:38 PM on September 3, 2013 [4 favorites]
posted by Kid Charlemagne at 5:38 PM on September 3, 2013 [4 favorites]
Somehow the idea of annealing plastic with a torch doesn't sound too appealing.
posted by Foosnark at 5:41 PM on September 3, 2013
posted by Foosnark at 5:41 PM on September 3, 2013
Anyone interested in this topic is very strong urged to read the extremely readable The New Science of Strong Materials by JE Gordon. Knows his stuff and explains it clearly.
posted by DU at 5:46 PM on September 3, 2013 [3 favorites]
posted by DU at 5:46 PM on September 3, 2013 [3 favorites]
All they have made is a plastic that gets harder when it is worked. Lots of materials become harder when they are worked - metals, for instance.
Scientists Reinvent Metal!
Work hardening doesn't alter the stiffness of a metal (i.e., its resistance to elastic or recoverable deformation), which was shown here to increase by two orders of magnitude.
(And I must point out that the paper's authors---and Nature Chemistry---erred by describing this increase as strengthening. Hardness or strength is strictly an increase in a material's resistance to plastic, or recoverable, deformation. The material undoubtedly also strengthens, but what they demonstrated was stiffening.)
posted by Mapes at 5:51 PM on September 3, 2013 [1 favorite]
Scientists Reinvent Metal!
Work hardening doesn't alter the stiffness of a metal (i.e., its resistance to elastic or recoverable deformation), which was shown here to increase by two orders of magnitude.
(And I must point out that the paper's authors---and Nature Chemistry---erred by describing this increase as strengthening. Hardness or strength is strictly an increase in a material's resistance to plastic, or recoverable, deformation. The material undoubtedly also strengthens, but what they demonstrated was stiffening.)
posted by Mapes at 5:51 PM on September 3, 2013 [1 favorite]
Work hardening doesn't alter the stiffness of a metal (i.e., its resistance to elastic or recoverable deformation)
Actually, that's exactly what work hardening does; you can break off a metal tab by bending it back and forth because work hardening makes the metal so stiff it can no longer bend and it breaks instead.
That's also exactly what this plastic seems to do. The difference though being that there is no way to anneal the plastic back to flexibility once it's hardened.
posted by localroger at 5:53 PM on September 3, 2013
Actually, that's exactly what work hardening does; you can break off a metal tab by bending it back and forth because work hardening makes the metal so stiff it can no longer bend and it breaks instead.
That's also exactly what this plastic seems to do. The difference though being that there is no way to anneal the plastic back to flexibility once it's hardened.
posted by localroger at 5:53 PM on September 3, 2013
Actually, that's exactly what work hardening does; you can break off a metal tab by bending it back and forth because work hardening makes the metal so stiff it can no longer bend and it breaks instead.
No, it is stronger but not stiffer. Work hardening does not alter elastic modulus.
posted by Mapes at 5:58 PM on September 3, 2013
No, it is stronger but not stiffer. Work hardening does not alter elastic modulus.
posted by Mapes at 5:58 PM on September 3, 2013
Work hardening doesn't alter the stiffness of a metal (i.e., its resistance to elastic or recoverable deformation)....
...Hardness or strength is strictly an increase in a material's resistance to plastic, or recoverable, deformation.
You've now used 3 words, "stiffness", "hardness" and "strength" to mean the same thing: "reistance to elastic or recoverable deformation". You also said that this paper was about stiffness but not about hardness or strength. These two statements would seem to be irreconcilable.
posted by DU at 6:00 PM on September 3, 2013
...Hardness or strength is strictly an increase in a material's resistance to plastic, or recoverable, deformation.
You've now used 3 words, "stiffness", "hardness" and "strength" to mean the same thing: "reistance to elastic or recoverable deformation". You also said that this paper was about stiffness but not about hardness or strength. These two statements would seem to be irreconcilable.
posted by DU at 6:00 PM on September 3, 2013
Sorry, that should be "plastic, or nonrecoverable, deformation."
posted by Mapes at 6:02 PM on September 3, 2013
posted by Mapes at 6:02 PM on September 3, 2013
Here, from here, is a neat illustration of the difference between stiffening vs. strengthening during work hardening. The force required to obtain a given additional displacement increases with successive loading, reflecting increased strength and hardness. However, the force-displacement relationship during the initial part of each loading-unloading cycle exhibits essentially the same slope. This slope corresponds to the material's stiffness, which depends in metals only on composition and crystal structure. The interesting thing here is that the researchers moved beyond these boundaries in a polymer system.
posted by Mapes at 6:10 PM on September 3, 2013 [1 favorite]
posted by Mapes at 6:10 PM on September 3, 2013 [1 favorite]
I'm sorry, but that picture is incomprehensible and I've even learned this stuff! If you want to know more, read JE Gordon.
posted by DU at 6:15 PM on September 3, 2013
posted by DU at 6:15 PM on September 3, 2013
One more, slide 3, may look more familiar. But the earlier is also essentially a stress-strain diagram, just plotted as force vs. displacement.
posted by Mapes at 6:19 PM on September 3, 2013
posted by Mapes at 6:19 PM on September 3, 2013
Just what the world needs - more indestructible plastic.
posted by islander at 6:33 PM on September 3, 2013 [1 favorite]
posted by islander at 6:33 PM on September 3, 2013 [1 favorite]
Again, a very crowded field, again, nowhere near the fist to do this, again, meh science journalism.
posted by lalochezia at 6:51 PM on September 3, 2013
posted by lalochezia at 6:51 PM on September 3, 2013
Kid Charlemagne: "There is strong and there is tough. Lots of people buy into the Larry Niven Known Space meme that something composed of all covalent bonds in nigh-indestructible, but I've yet to meet one who'll put a diamond on top my relatively soft anvil, no matter how much I promise to use only gravity (the weakest of the forces) to accelerate my 8 lb. sledge."
What would happen? Would it dent the anvil and sledgehammer or shatter into dust?
posted by double block and bleed at 7:55 PM on September 3, 2013
What would happen? Would it dent the anvil and sledgehammer or shatter into dust?
posted by double block and bleed at 7:55 PM on September 3, 2013
The more you pound on it, the harder it gets.
Huhuhuh.
posted by Sys Rq at 8:05 PM on September 3, 2013
Huhuhuh.
posted by Sys Rq at 8:05 PM on September 3, 2013
so diamonds are very hard... but brittle?
posted by Hoosier Prospector at 8:08 PM on September 3, 2013
posted by Hoosier Prospector at 8:08 PM on September 3, 2013
so diamonds are very hard... but brittle?
Yes, diamonds are very hard, but brittle. I worked for many years in a jewelry production house, I've shoved more diamonds into more gold than most people have ever even looked at in jewelry store windows.
It's entirely easy to crush or shatter a diamond. Push on it the wrong way, it goes snap. Sometimes it turns into powder, most of the time it just snaps into 2 or 3 pieces. It's fascinating -- you can set a diamond in wax and pour plaster around it and melt out the wax and pour molten metal into the hole and end up with a diamond cast into place in a ring or whatnot. But if a hand setting is designed wrong or if your setting tools slips in just the wrong way while you're bending prongs or setting beads, or if the tension of the metal on the stone is off in a way which the stone doesn't like... *poof*
posted by hippybear at 8:26 PM on September 3, 2013 [3 favorites]
Yes, diamonds are very hard, but brittle. I worked for many years in a jewelry production house, I've shoved more diamonds into more gold than most people have ever even looked at in jewelry store windows.
It's entirely easy to crush or shatter a diamond. Push on it the wrong way, it goes snap. Sometimes it turns into powder, most of the time it just snaps into 2 or 3 pieces. It's fascinating -- you can set a diamond in wax and pour plaster around it and melt out the wax and pour molten metal into the hole and end up with a diamond cast into place in a ring or whatnot. But if a hand setting is designed wrong or if your setting tools slips in just the wrong way while you're bending prongs or setting beads, or if the tension of the metal on the stone is off in a way which the stone doesn't like... *poof*
posted by hippybear at 8:26 PM on September 3, 2013 [3 favorites]
I thought products were already encased in this shit. Last time I bought a pack of D batteries it took a pair of garden shears to open them.
posted by mr_crash_davis at 8:35 PM on September 3, 2013 [4 favorites]
posted by mr_crash_davis at 8:35 PM on September 3, 2013 [4 favorites]
"Nanotechnology will take care of all this."
Since when isn't chemistry a nanotechnology?
posted by Kid Charlemagne at 8:39 PM on September 3, 2013
Since when isn't chemistry a nanotechnology?
posted by Kid Charlemagne at 8:39 PM on September 3, 2013
Want this proven false? Let my kids at it. Hell, let most kids at it.
posted by Nanukthedog at 9:09 PM on September 3, 2013
posted by Nanukthedog at 9:09 PM on September 3, 2013
Since when isn't chemistry a nanotechnology?
The dividing line is generally that chemistry applies to bulk phenomena and nanotechnology to individual atoms/molecules or extremely tiny particles.
posted by localroger at 5:41 AM on September 4, 2013
The dividing line is generally that chemistry applies to bulk phenomena and nanotechnology to individual atoms/molecules or extremely tiny particles.
posted by localroger at 5:41 AM on September 4, 2013
I ♥ SCIENCE!
posted by Mental Wimp at 8:36 AM on September 4, 2013
posted by Mental Wimp at 8:36 AM on September 4, 2013
self-erecting tool that gets hard and stays hard.
Was that on purpose?
posted by BrotherCaine at 8:43 AM on September 4, 2013
Was that on purpose?
posted by BrotherCaine at 8:43 AM on September 4, 2013
1.) I want this to be a thing. Like right now. I'm sick of babying my gear, I want everything I own to be ruggedized. Not because I need it, but because I can never tell from moment to moment what I'm going to throw at someone's head in a fit of boredom.
2.) Nothing ispermanent unbreakable in a world where angle grinders exist.
posted by quin at 9:01 AM on September 4, 2013
2.) Nothing is
posted by quin at 9:01 AM on September 4, 2013
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Probably a bad idea to send all that kinetic energy to the innards, which was previously going into deforming the shell. Cheaper to fix the case, maybe, than all the bits and pieces inside.
posted by Blazecock Pileon at 3:19 PM on September 3, 2013 [2 favorites]