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WorksheetsGlass Transition Temperature
Total questions: 15
Worksheet time: 4mins
Crystalline polymers are isotropic
True
False
Crystalline polymers exhibit both melt temperature and transition temperature
True
False
According to the free volume theory movements other than atomic level vibrations possible at temperatures
Below Tg
Equal to Tg
Above Tg
None
Identify the factor(s) affecting Tg:
Molecular Weight
Chemical cross-linking
Polar groups
All of these
In order to increase the sliding of polymer chains past each one should
Add dopants
Add plasticizers
Heat the polymer
None
Increase in moisture content leads to
Increase in Tg
No effect on Tg
Decrease in Tg
Cannot comment
If the transition temperature of a crystalline material is T1 and that of an amorphous material is T2, considering other factors being same, then
T1 > T2
T1 < T2
T1 = T2
Cannot comment
DSC stands for
Differential scanning calorimetry
Dynamic scanning calorimetry
Dynamic scaling calorimetry
Differential scaling calorimetry
Important application(s) of Glass transition temperature
Heat engines
Food processing
Electrochemistry
All of these
The temperature-time curve of DSC analysis is generally
Increasing exponentially
Decreasing linearly
Increasing linearly
None of these
In the experiment demonstrated, the sample heat will consume _________ compared to the reference pan.
More heat
Less heat
Equal heat
Negligible heat
Which is a method to determine transition temperature
Thermomechanical Analysis (TMA)
Dynamic Mechanical Analysis (DMA)
Differential Scanning Calorimetry (DSC)
All of these
In the experiment demonstrated, we have to subtracted the heat of the crystallization from the total heat given off because
H` should be negative
We want to determine how much of the polymer was already crystalline
H` should be positive
None of these
A sample of polymer(sample mass = 2gm) gave a result of H` = 8J. Determine the percentage crystallinity of the sample, given that the specific heat of melting of the sample is 10 J/gm.
20%
40%
80%
50%
When do you think offline classes could resume for us?
Tomorrow
Next semester
Never
