Civil Engineering Reference
In-Depth Information
Heat-aging
S3
Schedule
Temp.
Days
T
g
Oils
Polymer
Strength Elongation
loss
**
(%)
loss
***
(%)
(kNm
-1
)
(°C)
(°C)
(%)
22*
0
-46
52.5
11.4
307
100
1
-45
51.8
10.8
314
100
7
-42
51.9
11.3
297
100
28
-44
51.6
10.6
270
130
1
-46
52.8
9.3
273
130
7
-45
52.4
9.8
227
130
28
-44
51.8
9.7
159
(c)
* Unheated control sample.
** Percent based on the integrated area of peak between 200 and 400°C (not
available for S1 or S3).
*** Percent based on the integrated area of peak between 400 and 550°C. In the case
of S1 and S3, the area most probably includes both oil and polymer loss.
The fact that no significant changes were observed on the materials
characterized by thermoanalytical techniques in earlier sudies,
[31]-[34][36]
did not mean that the techniques were not suitable. Changes were not
observed because the materials studied were not affected by the exposure
conditions. Therefore, no changes would be observed regardless of the
technique used for characterizing changes. The study carried out by Paroli,
et al.,
is a clear example. They used three different techniques, TG,
DMA,
[38]
and tensile testing. All show that out of three materials, two
performed well after exposure whereas the other did not stand the exposure.
The applicability of thermoanalytical techniques for characteriz-
ing roof membrane materials was supported by studies carried out in the
early 90s.
[39]-[46]
In 1993, Paroli, et al.,
[47]
also published the results of a
study on the effects of accelerated heat aging on three poly(vinyl chloride)
(PVC) roofing membranes using TG, DMA, and tensile testing. The results
