Is solid PU waterproof?

[bafometto81]

Dear all,

solid polyurethane used as infill material for field joint coating is waterproof?

thanks,

rgds

NB

 

[gr2vessels]

The solid polyurethane is 100% impermeable after setting / hardening.
refer also to

http://www.geocities.com/pucoating/faq1.htm

Cheers,
gr2vessels

 

[IRstuff]

Polyurethanes are described as "water resistant" here:

http://www.rlhudson.com/material_profiles/polyurethane.htm

Datasheet:

http://www.amchemproducts.com/techdata_files/purethane_386/386_chemical_prop.htm

http://www.amchemproducts.com/techdata_files/data_sheet_amshield.htm

TTFN

FAQ731-376

 

[rodneybennet]

Let's comment on this. Here it goes:

-It all depends on whether polyester based or aliphatic urethanes are involved.
-Temperature is an important factor, above 50 degrees Celsius and polyester based will definitely give significant problems on the medium term.
-Water has a high relative high solubility in Polurethane (at least when compared to Epoxy, Vinyl Ester, PPS, PEEK etc.) and a moderate diffusion rate. Hence it is permeable, and certainly not the best candidate with this regard.
-Sometimes this product is sold with so called "Moisture Scavangers". This concept very probably does not extend the lifetime in a humid environment of this product / in this configuration.

Here is a thread on polyurethane that may also be of your interest:

http://www.composite-agency.com/messages/3675.html

Good Luck,
Rodney

 

[bafometto81]

Thanks Everybody!

Nicolò