Questions tagged [differential-scanning-calorimetry]

This tag should be applied to questions regarding the theory and application of differential scanning calorimetry (DSC).

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Weird jumps in DSC measurements between scans

I have multiple DSC measurements with multiple up- and down-scans and some of the time, seemingly at random, the inflection points will show massive jumps in the heat flow. I have no idea where they ...
J.Doe's user avatar
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Endothermic peak in DSC

I have an endothermic peak, with no mass loss and no change in (organic) crystal structure (monitored by vt-pxrd). What can cause such effect? Also, excluding the options of impurities or instrumental ...
tps475's user avatar
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3 votes
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How to use DSC to differentiate first and second order phase transition?

The DSC trace below was recorded for a thermotropic calamitic liquid crystal. The heating rate was 5 $^\text{o}$C min$^{-1}$; a heating scan is followed by a cooling scan. Based on the previously ...
TheLearner's user avatar
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1 vote
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How Does Differential Scanning Calorimetry (DSC) Differentiate Between Exothermic and Endothermic Changes?

In DSC, heat flux difference between sample and reference is measured as function of temperature while temperature of sample and reference are maintained the same. DSC is often used for polymer ...
Dario Mirić's user avatar
2 votes
0 answers
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Why is there no exothermic crystallization peak visible during cooling of PLA and no endothermic melting peak visible during a second heating of PLA?

I am doing lab research on DSC measurement (Heat-cool-heat) for understanding melting characteristics of polymers (PLA, PA6 and PE). During cooling i saw exothermic peak and during second heating i ...
Roshan Timsina's user avatar
2 votes
0 answers
78 views

Why would the first Tg be higher than a rescan Tg of an epoxy by DSC? [closed]

I have some small cured epoxy shafts I am cutting segments out of for checking Tg by DSC. First scan gave a Tg of 118 °C, follow on was 109 °C. Scans were repeated on a new sample of the shaft with ...
erdiede's user avatar
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2 votes
1 answer
449 views

Does alumina become transparent at high temperatures?

Consider a normal opaque alumina crucible. I've heard that they become transparent at higher temperatures and therefore, are not appropriate for high precision DSC (caloric) measurements. The reason ...
user65662's user avatar
1 vote
2 answers
302 views

Assigning labels and answering questions using given DSC graph

I'm currently working through past exam papers in preparation for my upcoming Inorganic Chemistry exam and I got to this question. We really haven't looked at DSC graphs, so I'm not completely sure ...
Lenard Carroll's user avatar
1 vote
0 answers
213 views

Correctness of DSC curve for polyamid or polyester

I did a DSC on a part of an alternator car belt. We already found out that it should by a polyester or a polyamid. But then we got the following DSC curve: How is it possible that the glass ...
Ayoub Rossi's user avatar
2 votes
1 answer
494 views

DSC Metal hysteresis (melt/cryst)

So we were analyzing Polymers using DSC and calibrated the system using Indium. I expected it to be a single transition only as Indium only has 1 known crystal structure and as I never worked with DSC ...
Justanotherchemist's user avatar
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Is Polymorphism accompanied with an energy change?

Differential Scanning Colorimetry (DSC) is a technique used to identify Polymorphism by revealing two melting points of a pure crystalline structure. DSC shows a peak associated with the formation ...
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