I do not believe there is a transition temperature for that, I think the only way to change the structure from one to the other is to do a remelt. You can get spherulites by cooling a melt without a temperature gradient or by adding nucleation sites. By the way spherulites are mostly crystalline.
Well I do believe the first step an amorphous texture which you can obtained as you quench the melt , then chrystalite are formed , then the aggregate are formed with boundary, and in between the boundary , there is an amorphous site which is susceptible to oxidation then the spherulite area
By me at 7:58am. Since my answer was there is no transition temperature the temperature value is null.
I am not sure if you are familiar with polypropylene, but thanks for the reply. But for your information an amorphous film produced on a surface with time it will convert itself into spherulitic texture .
I am somewhat familiar with polypropylene. That's nice but your question was not about a transition from an amorphous state. Is that now what your question is? I am not a mind reader.
I don't care about proper (whatever that is suppose to mean) a clear question would be helpful. It now sounds like you are asking what the devitrification temperature is for amorphous polypropylene. Is that your question?
It is getting confusing . Let me put it this way Melt 160 C -- Chrystlite ( small Christal formation ) --- Spherulite formation 100 C. you have three stages