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New lightweight material is stronger than steel

news.mit.edu

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Re: New lightweight material is stronger than steel

#71

Post by SAI_Peregrinus »

Scene_Cast2 wrote: post #61

Just a heads up - strength is not a single metric. There is tensile (pulling), compression, and shear (sliding) strength. There's also Young's modulus (how much something stretches), fatigue limits (steel can work perpetually with deformations under a certain threshold). There's also specific strength (strength per kg) vs strength per volume and strength per dollar. Steel also comes in lots of different flavors, with…

Also those metrics can vary with direction. For steel they're usually pretty uniform, but this new substance forms "2D sheets" so it's likely strength will be highly directional. Maximum tensile and compressive strength are likely to be 90° apart.

Re: New lightweight material is stronger than steel

#72

Post by exo-pla-net »

Scene_Cast2 wrote: post #61

Just a heads up - strength is not a single metric. There is tensile (pulling), compression, and shear (sliding) strength. There's also Young's modulus (how much something stretches), fatigue limits (steel can work perpetually with deformations under a certain threshold). There's also specific strength (strength per kg) vs strength per volume and strength per dollar. Steel also comes in lots of different flavors, with…

> The researchers found that the new material’s elastic modulus — a measure of how much force it takes to deform a material — is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.

Re: New lightweight material is stronger than steel

#73

Post by jimmytucson »

Scene_Cast2 wrote: post #61

Just a heads up - strength is not a single metric. There is tensile (pulling), compression, and shear (sliding) strength. There's also Young's modulus (how much something stretches), fatigue limits (steel can work perpetually with deformations under a certain threshold). There's also specific strength (strength per kg) vs strength per volume and strength per dollar. Steel also comes in lots of different flavors, with…

I’ve often heard that spider silk is stronger per kg (or is it per m^3?) than steel. Are they talking about pulling, compressing, sliding, or all of the above?

Re: New lightweight material is stronger than steel

#74

Post by cellis »

adrian_b wrote: post #70
montjoy wrote: post #2

> and can be easily manufactured in large quantities That seems promising. I have a couple of concerns - Can it be recycled? - How are new materials like this tested for toxicity?

It is quite certain that a 2-dimensional polymer cannot be recycled like metal, glass or a thermoplastic material, i.e. by remelting or by plastic deformation at high temperatures, because a 2-dimensional polymer cannot be deformed without breaking covalent bonds and it cannot flow in a liquid state. So this new material might behave like the existing cured polymeric resins, e.g. epoxy resins, which form a 3-dimensio…

Your answer illustrates why, after all these years, HN is still one of the best places to lurk. As someone who forgot most of what he learned in HS chemistry, and didn’t take any collegiate courses, what material would you recommend to learn about this stuff?

Re: New lightweight material is stronger than steel

#75

Post by holoduke »

Scene_Cast2 wrote: post #61

Just a heads up - strength is not a single metric. There is tensile (pulling), compression, and shear (sliding) strength. There's also Young's modulus (how much something stretches), fatigue limits (steel can work perpetually with deformations under a certain threshold). There's also specific strength (strength per kg) vs strength per volume and strength per dollar. Steel also comes in lots of different flavors, with…

Exactly. We also have temperature and chemical resistance. Very important in most applications and for example an interesting discussion between rubber and polyurethane compounds.

Re: New lightweight material is stronger than steel

#76

Post by adrian_b »

mgas wrote: post #43
montjoy wrote: post #2

> and can be easily manufactured in large quantities That seems promising. I have a couple of concerns - Can it be recycled? - How are new materials like this tested for toxicity?

I agree with concerns about recyclability. I would also raise concerns about the renewability and/or toxicity of the base materials. If they are petroleum-based, this feels like a losing proposition.

Unfortunately the recyclability and the lack of toxicity are contradictory, they cannot be satisfied simultaneously for this kind of materials.

As long as the 2-dimensional polymeric sheets do not decompose, they will not be toxic, as they cannot enter a living cell (in the form of fine dust they could cause the same problems as any mineral dust, e.g. respiratory damage through purely mechanical action).

However if they do not decompose, they can be recycled only by burning.

If they can be decomposed into monomers by heat, light or chemicals, then the monomer can be recycled. However in that case some spontaneous decomposition will also occur in old objects made of the 2-dimensional polymer and the released monomer molecules would cause toxicity problems.

So only one of these 2 features must be chosen and optimized.

Re: New lightweight material is stronger than steel

#77

Post by cbg0 »

throwaway4aday wrote: post #29
ngngngng wrote: post #25

The article touches on potential to use instead of steel, perhaps even in buildings. But I imagine its heat tolerance would likely kill any chances of that, no?

It's potentially a thermoset plastic in which case it should be able to resist somewhat high temperatures (maybe 300C). So not fireproof but not terrible either.

As a comparison, various types of insulation are rated for 60/90 minutes at 1000 degrees Celsius, while some types of brick are rated for 180 minutes. If this material can't sustain similar temperatures, it's unlikely it will be used in construction.

Re: New lightweight material is stronger than steel

#78

Post by NAR8789 »

> Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.

Anyone else get immediately sidetracked by how metal the name "Carbon P. Dubbs" is? (and how unexpectedly apropos it is to chemical engineering?)

https://digging-history.com/2016/01/18/tombstone-tuesday-car...

Apparently his full name was "Carbon Petroleum Dubbs" and the relation to chemical engineering isn't really coincidental.

Re: New lightweight material is stronger than steel

#80

Post by TylerE »

jimmytucson wrote: post #73
Scene_Cast2 wrote: post #61

Just a heads up - strength is not a single metric. There is tensile (pulling), compression, and shear (sliding) strength. There's also Young's modulus (how much something stretches), fatigue limits (steel can work perpetually with deformations under a certain threshold). There's also specific strength (strength per kg) vs strength per volume and strength per dollar. Steel also comes in lots of different flavors, with…

I’ve often heard that spider silk is stronger per kg (or is it per m^3?) than steel. Are they talking about pulling, compressing, sliding, or all of the above?

Plenty of things are stronger than steel on a per pound basis.

For instance, many aluminum alloys have about 60-80% the tensile strength of steel, but only 1/3rd the weight.

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