Question: a differential scanning calorimetry dsc plot for polyetheretherketone peek is...
A differential scanning calorimetry (DSC) plot for polyetheretherketone (PEEK) is shown below.
a) Answer the following questions about this polymer:
i. What occurs at #1?
ii. What occurs at #2?
iii. What occurs at #3?
iv. What is the approximate melting temp?
v. At what temp would you expect the polymer to undergo glass transition?
b) In the spaces below, determine if the DSC peak is endothermic
or exothermic and explain the reason for your answer.
i. Peak #1:
ii. Peak #2:
iii. Peak #3:
c) Explain any predicted changes in the glass transition temperature (Tg) and relative degree of crystallinity for PEEK due to the changes listed below. Also shown below is the PEEK chemical structure for reference.
i. Change both of the ether linkages to ketone linkages.
ii. Change ether linkages to 2-carbon linkages (e.g., phenyl – C – C – phenyl).
iii. Rapidly cool/quench the PEEK polymer from its melted state to its glassy state.