Nondestructive testing of defects in adhesive joints

Table 2. Effect of curcumin content on the mechanical properties of EVA-40
Curcumin Tensile strength Elongation at Modulus
content, (wt %) (MPa)
break (%) (MPa)
0 06.73 ± 0.45 1450 ± 567 01.54 ± 0.32
1 11.17 ± 1.58 1130 ± 656 02.50 ± 0.33
2 12.56 ± 3.06 1429 ± 523 03.14 ± 0.64
5 12.58 ± 0.92 1094 ± 544 10.02 ± 1.79
10 15.09 ± 1.59 676 ± 360 26.11 ± 10.87
Figure 1. FTIR spectrum of Curcumin, EVA &
Curcumin loaded (10wt %) EVA40
Figure 3. Tensile Properties of Curcumin-loaded
EVA matrices
WATER ABSORPTION(%)
Tensile Strength (MPa)
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
18
16
14
12
10
8
6
4
2
0
zero
1 week
1 month
EVA ‐ 40 CUR – 5% CUR – 10%
1 week
1 month
3 month
EVA 40 EVA+CUR 5% EVA+CUR 15%
MATERIAL
Figure 5. Water absorption of Curcumin-loaded
EVA matrices
Modulus (GPa)
4
3
2
1
0
-100 -80 -60 -40 -20 0 20 40
Temperature (°C)
EVA CUR 10 (SM) EVA 12 (SM) EVA 18 (SM) EVA 28 (SM)
EVA 40 (SM) EVA CUR 10 (TD) EVA 12 (TD) EVA 18 (TD)
EVA 28 (TD) EVA 40 (TD)
Figure 2. DMA traces of EVA grades and curcumin
loaded (10%) EVA
Water Contact Angle (Degree)
110
100
90
80
70
60
0 5 10 15 20
Curcumin (Wt.%)
Figure 4. Contact Angle measurements of Curcumin
- loaded EVA matrices
Concentration of Curcumin
(μg/ml)
3
2.5
2
1.5
1
0.5
0
7%
10%
15%
Day 1 Day 3 Day 5 Day 7 Day 9 Day 11 Day 13 Day 15
Number of Days
Figure 6. Cumulative elution profile of curcumin
from EVA40 for different loadings
0.8
0.6
0.4
0.2
0.0
5
Tanδ