report components in the blends ABS-PC

[campp]

Hello everyone,

I want to know if the analysis DSC can give the approximatives informations about the ratio of composants in the blends ABS-PC. I used Δcp PC pure (about 0.29J/gK in literature) and Δcp PC blend (about 0.10J/gK in analysis) and I acquired a report ABS/PC=2/1. I don't know if this calculation is correct and if the results could be considered.
Also I know that the PC glass transition temperature is lowered by about 3°C due to interaction with the ABS (145°C drops to 142°C). It is normal, but when the Tg decreases much more, with about 8°C? What happened? The PC was degraded during the injection?

Thank you.

 

[Demon3]

DSC is definitely not the right tool. For one thing the specific heat capacity (volumetric) for just about every solid is the same. That's been measured for hundreds of substances and published. I've tabulated values myself. Tg is not good either as different ABS will interact differently with PC. For example, the surfactants used to make ABS will plasticize the PC.

Much better to use FTIR.

Chris DeArmitt - PhD FRSC

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http://www.phantomplastics.com

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[CoryPad]

Yes, measuring Absorbance in FTIR and using Beer's Law will allow concentration determination.