[thr33k]

Hi all,

I really need some help to find a material that has a density of 0.78 +- 0.03 and is a solid at room temperature. The closest I've been able to find is Polymethylpentene, does anybody know of a better match? Thanks,

James

[Stepan]

you can make a composite material of any density by blending any polymer with hollow glass micro capsules (3M makes them)

[thr33k]

Ah thanks for that, I'll look into those!

[typhoon2028]

what about a foam?

[Enthalpy]

People develop very porous molecules for hydrogen storage. Hugely lighter than your figure. They're hollow, but at molecular scale. Making them less light would be easy.

Aerogels as well are extremely light, due to porosity at a very small scale.

Or you have alkali metals, but with serious drawbacks...

[Enthalpy]

Wood of course, provided it fits your other requirements.

By choosing the proper species, you can get any density between <160kg/m³ (Balsa) and >1400kg/m³ (African blackwood).

Some varnish maybe?

[typhoon2028]

polypropylene foam
polyethylene foam
polyurethane foam