[xchcui]

Hi.

The midsoles of my"new"shoes which were kept  a long time in a storage,begin to crumbled.The midsole are,probably,made of polyurethane.
After browsing around the web,i understood that this problem is common
and it happens when the shoes are kept in storage for a long time,while the moisture in the air cause to the polyurethane connections to break and crumbled.
In all the web sites that i was,i have noticed that there is no fix to that problem,besides to replace the midsole to a new one(which is not  so economic and for most it is impossible to find the right midsole).
So,is it really impossible to fix that crumbled midsoles?
Isn't it possible,maybe,to inject to it some kind of material that will revive
the polyurethane?
Thanks.

[P]

I am pretty certain there isn't a fix....   but throwing ideas around - if you could 'partially' dissolve them with some solvent so they soften you might find that the bits that would have crumbled apart stick together now as they re-coalesce in the sticky solvent when it dries....  probably not, but they might. lol. Squeezing them and re-moulding them back together when they are 'softened' might help too.  This is probably wishful thinking though. 

[wildfyr]

Sorry, there is no fix. You can't undo the loss in mechanical properties caused by oxidation and hydrolysis. Even if the form looks the same, they won't perform.

[billnotgatez]

I wonder if an treating the shoes with something prior to storage  might prevent the degradation.
For instance, there are treatments that prevent or slow dry rot in tires.

[xchcui]

Thanks for all the replies.
Wildfyr,i would like to mention,that i am not expecting to
make the midsole flexible again.
It,probably,will become stiff and won't be proper for running etc.But i don't care,since my intention is only to make the crumble process to stop.
One of the ideas that P suggested was close to what i was thinking and it to inject some kind of solvent with syringe into several parts in the midsole,that will be absorbed and
make the crumbled polyurethane stick together.
Can you have any idea which solvent/material may do that?
BTW,treating the shoes with something prior to storage,as billnotgatez,suggested,could be a better solution,but it is too late for those shoes.

[P]

Maybe dipping them into a low viscosity rubber solution and wiping off the excess will bind them back together for a bit.  I don't think injecting areas will do it though. This might end up being more expensive than buying a new pair of cheapy shoes though.

[xchcui]

Maybe dipping them into a low viscosity rubber solution and wiping off the excess will bind them back together for a bit.  ...

What do you mean "low viscosity rubber solution"?
Is this rubber solution made for shoe repair?
Is the rubber solution made from polyurethane ?
May you give me a link for that product?
I am familiar with shoe-goo(which,btw,can't solve this issue)and with contact cement/adhesive,but not with the rubber solution.

[xchcui]

May you explain what was your intention when you said:
rubber solution?
I made a searching in the web for "rubber solution"and
it gives me the standard contact cement results.
May you explain your intention?

[xchcui]

May someone else give more details and explain what was P intention when he said"...dipping them into a low viscosity rubber solution..."?
I mean:what does the rubber solution refer to?contact cement?
What kind of rubber solution:latex based?neoprene based?polyurethane based?...

Thanks.

[P]

May you explain what was your intention when you said:
rubber solution?

You can get rubber solutions which are rubbers in a solvent solution that you can spray or paint onto things...  they come in a wide range of products   - none of which would really be suitable for your shoe repair. I said 'low viscosity' to mean that maybe you could let it down with further solvent to make it more runny so it gets into all the cracks when you dip it. I was thinking that the solvent would evaporate leaving the rubber in the cracks of your crumbling PU soles - binding them back together. Any polymer dissolved into a solvent could work....  it would also depend upon how resistant your soles were to the solvent used. It isn't as straight forward as it sounds..  and probably wont work.

How much did these shoes cost?  I would guess it would be cheaper to buy new ones..  and as others have said - it probably wont work anyway. Sorry. :-(

[xchcui]

Okay i understand.
But it is very annoying to throw a very new shoes,
while i just used them 1-2 times.
The outsoles are new,the upper are new,only the polyurethane midsoles crumbled.
It doesn't really matter what was their price.
The issue here is that it is very sad (and annoying)
to throw a new shoes,while i didn't have the chance to enjoy them,even though they were kept at proper
conditions.With normal shoes,it should not have happened.Next time i will need to check carefully the material of the shoes.
Thanks for your help.

[P]

It doesn't really matter what was their price.
The issue here is that it is very sad (and annoying)
to throw a new shoes,while i didn't have the chance to enjoy them,even though they were kept at proper
conditions.

Sorry we couldn't help. Count your blessings though - there are people in the world with greater problems than crumbly shoes.  If that is a source of great sadness for you then maybe look at it in a bit of perspective with respect to the poor of the world and be happy with what you have. :-)  Look on the bright side and turn it into a positive - at least now you can go shopping for some NEW shoes and you can enjoy them instead. :-)

All the best.

P.