Self Repairing Hulls?

[STRIDE]

I have seen "Self Repairing" composite structures using a material called shape memory polymers.

These materials have large strain capability and the ability to return to their original shape when they are heated. So, theoretically, after a serious impact, you could just heat your hull, and restore it to it's original shape. The shape memory polymer resin can be used to create a composite like any other thermoset resin.

Does anyone have any experience with this material?
Or maybe a source for Shape Memory Polymer resin?

That is a joke right?

How would a thermoplast stand the loads of a boat? Except maybe a dhingy or canoe.

Regards
Richard

[Paul B]

Originally Posted by apex1

That is a joke right?

How would a thermoplast stand the loads of a boat? Except maybe a dhingy or canoe.

Regards
Richard

He said thermoset, not thermoplastic.

Regardless, I doubt there is any real application here. If it was easy the auto manufacturers would be making body panels that would simply pop back into shape with the application of a bit of heat after a fender bender.

Originally Posted by Paul B

He said thermoset, not thermoplastic.

And then? It is a thermoplast by nature.
And I understood what he said............

The auto industry btw uses it in exactly the way you describe! For bumper fenders!

[STRIDE]

No joke, Richard.

Veriflex is the only distributed shape memory resin system that I could find in the US. The Ultimate Tensile Strength of the neat resin [Veriflex E2] is around 11,000 psi. Compare that to West System 105/205 with a UTS of 7,846 psi.

Problem is, CRG, the distributor of Veriflex, no longer sells it.
Also, what do you mean by Thermoplast?
Thermoplastic? It is not a thermoplastic.

Originally Posted by STRIDE

No joke, Richard.

Veriflex is the only distributed shape memory resin system that I could find in the US. The Ultimate Tensile Strength of the neat resin [Veriflex E2] is around 11,000 psi. Compare that to West System 105/205 with a UTS of 7,846 psi.

Problem is, CRG, the distributor of Veriflex, no longer sells it.
Also, what do you mean by Thermoplast?
Thermoplastic? It is not a thermoplastic.

Oh, sorry, have forgotten in English it is in fact called thermoplastic. (the rest of the world says thermoplast)

And of course it is a TP polymer you are referring to. (try wiki on that)

UTS is not all in boatbuilding you know, and this West formulation not the ultimate competitor.

Regards
Richard

[Paul B]

Originally Posted by apex1

And then? It is a thermoplast by nature.
And I understood what he said............

You did? Hmmm....

Thermoset resins are not thermoplastic by nature. Once set by temperature a thermoset will not transition back to a "plastic" consistency when subjected to heat. It will char and burn.

Originally Posted by Paul B

You did? Hmmm....

Thermoset resins are not thermoplastic by nature.

They are! Or how do you bring them into shape? By layup like poly or epoxy resin? No by temperature.

Once "set" of course they are a different creature. But by nature they are thermoplastic polymere.

And insufficient for boatbuilding btw.

this may help....
http://en.wikipedia.org/wiki/Shape_memory_polymer

Regards
Richard

[Paul B]

Originally Posted by apex1

They are! Or how do you bring them into shape? By layup like poly or epoxy resin? No by temperature.
Regards
Richard

Theremosets are by definition set by temperature. That includes Poly and Epoxy resins. I'm sure you've heard the term exotherm.

[Doug Lord]

I built carbon/epoxy models for many years. One small model had the hull and deck bonded while they were still in the mold(s). Once, after a cold front had passed I pulled the little boat and the hull was distorted a lot-low pressure on the inside and high pressure on the outside(?). I thought it was junk. Then I drilled a hole in the deck and the thing popped out but the hull was still distorted. Since I had nothing to lose I took a heat gun to the hull skin and it popped out the rest of the way with absolutely no damage whatsoever.
I was amazed...
I drilled a hole in the deck mold in way of the hatch so it would never happen again....

Originally Posted by Paul B

I'm sure you've heard the term exotherm.

vague.........

I am only for 35 years in Business now.

[Paul B]

Originally Posted by apex1

vague.........

I am only for 35 years in Business now.

Yet you still claim thermosets are thermoplastic ny nature...

Originally Posted by STRIDE

So, theoretically, after a serious impact, you could just heat your hull,

...that was clear?

No UV or electric trigger, just heat. Right?

Then polystyrene and poly butadiene, polyurethanes, polyethylene terephthalate, polynorbornene.... are the common materials in question.

And these are??

[STRIDE]

Originally Posted by apex1

Then polystyrene and poly butadiene, polyurethanes, polyethylene terephthalate, polynorbornene.... are the common materials in question.

And these are??

Thermoplastics, I suppose.
My approach to polymer chemistry has always been from the manufacturing perspective. In manufacturing discourse, a thermoplastic is a material that comes already solid [ie: casting pellets/thermoforming sheets] and a thermoset would be a material that is liquid. Thermoplastics are melted. Thermosets are cured.
At least that is how I see it.

Doug: That is very interesting. Partially cured resins have been shown to have shape memory properties, and it is always cool to see a practical application.

[Doug Lord]

Originally Posted by STRIDE

Thermoplastics, I suppose.
My approach to polymer chemistry has always been from the manufacturing perspective. In manufacturing discourse, a thermoplastic is a material that comes already solid [ie: casting pellets/thermoforming sheets] and a thermoset would be a material that is liquid. Thermoplastics are melted. Thermosets are cured.
At least that is how I see it.

Doug: That is very interesting. Partially cured resins have been shown to have shape memory properties, and it is always cool to see a practical application.

---------------------------------
I hadn't considered that, thanks. The laminate was done 24 hours before I pulled it so it definitely wasn't fully cured.....