Outcomes 2018
Outcomes 2019
Increasing the mass percentage of coupling agent (high density polyethylene-HDPE) and variation of processing temperature
The mass percentage of HDPE was increased by 5%, up to 20%, and the most relevant results of the mechanical strength of rubber composites, HDPE and increased percentage of photovoltaic silicon (Si-PV) waste are presented in the tables below.
Table 7 Optimized mechanical properties of composite materials with high Si-PV content
|
Rubber [% mas] |
HDPE [% mas] |
Si-PV [% mas] |
RTR [MPa] |
E [MPa] |
At [%] |
RC [MPa] |
Ri [kJ/m2] |
Cod |
|
T=190 0C, t=30 min |
||||||||
|
50 |
15 |
35 |
2,32 |
19,26 |
30,30 |
209,04 |
60,70 |
A2 |
|
45 |
40 |
2,00 |
12,95 |
21,95 |
203,05 |
36,40 |
A3 |
|
|
45 |
20 |
35 |
2,65 |
24,77 |
20,60 |
210,40 |
44,70 |
D2 |
|
40 |
40 |
2,48 |
30,23 |
12,65 |
193,03 |
36,10 |
D3 |
|
|
T=200 0C, t=30 min |
||||||||
|
50 |
15 |
35 |
2,26 |
20,91 |
26,5 |
167,57 |
58,48 |
B2 |
|
45 |
40 |
2,14 |
19,07 |
19,41 |
206,85 |
40,16 |
B3 |
|
|
45 |
20 |
35 |
2,76 |
18,54 |
22,34 |
201,97 |
48,54 |
E2 |
|
40 |
40 |
2,86 |
33,94 |
21,6 |
198,55 |
36,05 |
E3 |
|
|
T=210 0C, t=30 min |
||||||||
|
50 |
15 |
35 |
2,40 |
14,12 |
34,5 |
204,72 |
50,51 |
C2 |
|
45 |
40 |
2,25 |
19,72 |
27,1 |
201,89 |
42,97 |
C3 |
|
|
45 |
20 |
35 |
2,76 |
28,98 |
20,45 |
206,30 |
41,86 |
F2 |
|
40 |
40 |
2,82 |
25,65 |
25,7 |
211,29 |
51,28 |
F3 |
|
Analyzing the results in table above it is observed that A3 and B3 reached the formulated RT <RT.
Outcomes 2020
Activities Report 2020
Testing the stability/durability in aggressive media: temperature, humidity, saline and under UV radiations, simulating the accelerated outdoor ageing
The selected samples after water and surfactant immersion, passing the stability criterion (ΔΊ), will be further exposed in simulated outdoor aggressive environments (temperature, saline, humidity and under UV radiations) for assessing the stability criteria in outdoor conditions. The composites stability to humidity (0…90 %) and saline environment will be evaluated by their exposure in the climatic chamber from our research laboratory; the NaCl solution will be of 3.5 % to simulate the seaside conditions. The temperature variation will range between: -15…40 0C; UV-A stability to aging will be tested in a home-made photocatalytic reactor.
Exposure of composite materials to UV radiation under laboratory conditions
The mechanical characteristics of composites exposed to UV radiation are represented compared to those recorded before UV exposure in Figs. 7
It can be seen that for most compositions the values of mechanical properties measured before and after exposure to UV radiation are comparable. These are confirming the interface stability to UV radiation action.
FTIR analysis of composites exposed to UV radiation
FTIR analysis was used to investigate the stability / strength of the interfaces developed in the new composite material obtained from rubber waste, HDPE and high Si-PV content after exposure to UV radiation. The FTIR spectra of composites D2, E3 and F3 before and after exposure to UV radiation are shown in Figs. 7.
The following were observed:
- The FTIR bands recorded at 2910 and 2845 cm-1 assigned to the groups –CH, -CH2, CH = CH2 (rubber, HDPE) and the stretching vibration of –CH from EVA, common to the three specimens were recorded both before and after the exposure of the composites to UV radiation at approximately the same values of the wave number;
- The band associated with the C-O-C group of the vinyl component of EVA (ethylene vinyl acetate, present in the Si-PV module) is recorded at approximately the same value of the wave number in the case of specimen E3 - 1022, 66 and 1022, 41 cm-1, before and after exposure to UV radiation; and in the case of F3 - 1012, 1 and 1013.4 before and respectively after UV irradiation, Fig. 7;
- The associated Si-O band is found at the same wavelength around 850 cm-1, both in the case of the unexposed specimen and for the exposed to UV radiation, confirming the interfacial adhesion of the E3 and F3 composites investigated with the technique FTIR analysis;
- the band associated with the Si-O- (R) group of UV irradiated specimens was recorded at approximately the same wavelength as in the case of non-irradiated specimens, which indicated a good resistance of specimens to UV radiation, due to the high degree of interfacial adhesion between components composite (rubber, Si-PV and HDPE).
Fig. 8 Imagini SEM ale epruvetelor C2, D2 si F2 dupa expunerea la radiatii UV
The SEM images of the UV irradiated composites are confirming the strong hybrid interfaces developed between the Si-PV module powder, rubber and HDPE wastes.
Table 11. Recommending the Composite compositions for outdoor applications
