1. First measurements Investigations into the Curing of Hysol 9396 using Differential Scanning Calorimetry
(Tim)

2. Differential Scanning Calorimetry
Study how fully-cured Hysol9396 gets after different cure times and with different cure temperatures
Eg. How well cured is it after 1 day at 22C?
NB. Hysol received March 2010 !
Measurements
Dynamic: Measure heat flow into/out of sample during a temperature ramp (eg 0 to 220C)
Measures the maximum possible heat associated with curing exotherm.
Static: Measure heat flow into /out of sample at a fixed temperature followed by dynamic scan.
Measures heat associated with curing at fixed temperature.
By combining both types of measurement the degree of cure for a given process can be determined.

3. Dynamic scan from 0 to 220C

4. Dynamic Scans melting! Dynamic Scans Integrated Peak (J/g)
Melting Temp
Peak Temp
Comment
Wright Report
535.1
WL-TR : Askins, R; October 1991; pg 35
130412_Hysol_1
525.7
Un-cured
130416_Hysol_4
564
130429_Hysol_14
584
Un-cured - < 10min after mixing
170
AL-TR : Askins, R; October 1991; pg 35
130419_Hysol_7
190.7
63.3
104.6
After 3 days at 22C
130423_Hysol_9
179.7
62.8
103.6
After 4 days at 22C
130424_Hysol_11
51.24
47.4
102.1
After 1 day at 22C - very strange!
130425_Hysol_12
206.5
57.2
103.3
After 1 day at 22C)
130426_Hysol_13
172.8
60.4
102.4
After 2 days at 22C
melting!

5. Isothermal Scans Isothermal Scans Temp Hold Iso Heat 2nd Onset
2nd Heat
Tot heat
Comment
Wright Report 66 75
450.0
94.0
544.0
WL-TR : Askins, R; October 1991; pg 35
130412_Hysol_2 60
378.6
95.1
72.0
450.6
130419_Hysol_8
411.8
96.6
98.9
510.7
130416_Hysol_5 82
402.4
115.2
69.4
471.8
130423_Hysol_10
470.0
130416_Hysol_6 93
410.5
126.9
49.3
459.8

6. Summary
Typical heat released in a dynamic scan of un-cured Hysol is 560 ± 25 J/g (5%). This compares reasonably well with the data from the Wright Laboratory report.
“CHARACTERIZATION OF EA9396 EPOXY RESIN FOR COMPOSITE REPAIR APPLICATIONS”
For room-temperature cured Hysol (1-4 days), the un-released heat is typically 190J/g implying that only 66% of the available heat-release has occurred. (WL-TR quotes 170J/g released after 7 day cure at room temperature)
Room-temperature cured sample show indications of melting at about 60C
There is some degree of correlation between curing time and heat release/re-melt temperature.