Probably you will hv to find softening temp. I don't think there are any complete amorphous polymers except highly crosslinked systems or thermosets. You can crystallize thermoplastic polymers by annealing so that some amount of crystallinity will be imparted then take a DSC and the processing temp should be near or above to the  melting temp based on mol wt.

Patro

For most commercial polymers you will find indication in the datasheet. In amorphous polymers you can find or measure the Tg, glass transition temperature. If nothing else is available, you can perform thermomechanical or DMA tests. If you have a Brabender plastograph or something similar, you can test the processability visually.

Thanks

You can try to access to the thermal properties of the amorphous polymer by using a differential scanning calorimetry (DSC) to observe accurately the glass transition (Tg) or as previously mentioned by DMA analysis.

Regards,

As mentioned above DSC or DMA analysis are the way to find the glass transition temperature (Tg ). If you use DSC, you must run the analysis first heating the sample at 10 °C / min upto the desire temperature, then cooling it at the same temperature rate to the lowest possible (it will be determine by the nature of your polymer), and then heating it again. I recommend you to use a modulated DSC to find out the Tg in the Reversible Heat Flux vs Temperature chart. If you don't have access to these techniques you can estimate (Tg) or melting temperature (Tm) more accurate as processing temperature, if you know the general chemical structure of your polymer. The reference is "Properties of Polymers" van Krevelen and te Nijenhuis, Elsevier, chapters 4 and 6. Good Luck!

Thanks

A simple note: For melt mixing technique, the researcher must be sure that the 2 polymers will interact positively with a compatibilizer & that both of them will melt to near completion without degradation. Most of what we call amorphous polymers are not 100% disordered & one can look up their melting points (for the ordered domain) from references. If not found, then the researcher ought to investigate, through experiments on small amounts, what are the best conditions that give the desirable product. 

Measure Tg and  melt mix  at  10 - 20oC  above the Tg temperature

Hemda,

In melt mixing technique amorphous polymers are mainly processed above their glass transition temperature while the crystalline polymers are processed above their melt temperature. 

Thanks

put a temperature meter in the reactors

test it By DSC