TY  - JOUR
AU  - Stajčić, Ivana
AU  - Veljković, Filip
AU  - Petrović, Miloš
AU  - Veličković, Suzana
AU  - Radojević, Vesna
AU  - Vlahović, Branislav
AU  - Stajčić, Aleksandar
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7112
AB  - High performance polymers with bio-based modifiers are promising materials in terms of
applications and environmental impact. In this work, raw acacia honey was used as a bio-modifier
for epoxy resin, as a rich source of functional groups. The addition of honey resulted in the formation
of highly stable structures that were observed in scanning electron microscopy images as separate
phases at the fracture surface, which were involved in the toughening of the resin. Structural changes
were investigated, revealing the formation of a new aldehyde carbonyl group. Thermal analysis
confirmed the formation of products that were stable up to 600 ◦C, with a glass transition temperature
of 228 ◦C. An energy-controlled impact test was performed to compare the absorbed impact energy of
bio-modified epoxy containing different amounts of honey with unmodified epoxy resin. The results
showed that bio-modified epoxy resin with 3 wt% of acacia honey could withstand several impacts
with full recovery, while unmodified epoxy resin broke at first impact. The absorbed energy at first
impact was 2.5 times higher for bio-modified epoxy resin than it was for unmodified epoxy resin.
In this manner, by using simple preparation and a raw material that is abundant in nature, a novel
epoxy with high thermal and impact resistance was obtained, opening a path for further research in
this field.
PB  - MDPI
T2  - Polymers
T1  - Impact- and Thermal-Resistant Epoxy Resin Toughened with Acacia Honey
VL  - 15
IS  - 10
SP  - 2261
DO  - 10.3390/polym15102261
ER  - 

@article{
author = "Stajčić, Ivana and Veljković, Filip and Petrović, Miloš and Veličković, Suzana and Radojević, Vesna and Vlahović, Branislav and Stajčić, Aleksandar",
year = "2023",
abstract = "High performance polymers with bio-based modifiers are promising materials in terms of
applications and environmental impact. In this work, raw acacia honey was used as a bio-modifier
for epoxy resin, as a rich source of functional groups. The addition of honey resulted in the formation
of highly stable structures that were observed in scanning electron microscopy images as separate
phases at the fracture surface, which were involved in the toughening of the resin. Structural changes
were investigated, revealing the formation of a new aldehyde carbonyl group. Thermal analysis
confirmed the formation of products that were stable up to 600 ◦C, with a glass transition temperature
of 228 ◦C. An energy-controlled impact test was performed to compare the absorbed impact energy of
bio-modified epoxy containing different amounts of honey with unmodified epoxy resin. The results
showed that bio-modified epoxy resin with 3 wt% of acacia honey could withstand several impacts
with full recovery, while unmodified epoxy resin broke at first impact. The absorbed energy at first
impact was 2.5 times higher for bio-modified epoxy resin than it was for unmodified epoxy resin.
In this manner, by using simple preparation and a raw material that is abundant in nature, a novel
epoxy with high thermal and impact resistance was obtained, opening a path for further research in
this field.",
publisher = "MDPI",
journal = "Polymers",
title = "Impact- and Thermal-Resistant Epoxy Resin Toughened with Acacia Honey",
volume = "15",
number = "10",
pages = "2261",
doi = "10.3390/polym15102261"
}

Stajčić, I., Veljković, F., Petrović, M., Veličković, S., Radojević, V., Vlahović, B.,& Stajčić, A.. (2023). Impact- and Thermal-Resistant Epoxy Resin Toughened with Acacia Honey. in Polymers
MDPI., 15(10), 2261.
https://doi.org/10.3390/polym15102261

Stajčić I, Veljković F, Petrović M, Veličković S, Radojević V, Vlahović B, Stajčić A. Impact- and Thermal-Resistant Epoxy Resin Toughened with Acacia Honey. in Polymers. 2023;15(10):2261.
doi:10.3390/polym15102261 .

Stajčić, Ivana, Veljković, Filip, Petrović, Miloš, Veličković, Suzana, Radojević, Vesna, Vlahović, Branislav, Stajčić, Aleksandar, "Impact- and Thermal-Resistant Epoxy Resin Toughened with Acacia Honey" in Polymers, 15, no. 10 (2023):2261,
https://doi.org/10.3390/polym15102261 . .

TY  - JOUR
AU  - Radović, Ivana
AU  - Stajčić, Aleksandar
AU  - Radisavljević, Andjela
AU  - Veljković, Filip
AU  - Čebela, Maria
AU  - Mitić, Vojislav V.
AU  - Radojević, Vesna
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3676
AB  - Nowadays, there is a very high importance of composite research and variety of their applications in the modern world. In that sense, we researched hollow glass capillaries filled with dissolved Grubbs catalyst (GC) and dicyclopentadiene (DCPD) were incorporated into a fiber-reinforced epoxy with the aim of improving the flow of healing agents to the crack site. The morphological investigation of the crack site was performed using field emission scanning electron microscopy (FESEM), showing the difference between the samples depending on the used solvent. The software analysis of sample photographs has been performed by calculating the fractured/ healed surface area of the samples, revealing that approximately 20% of the volume was affected by the impact. Fourier transform infrared spectroscopy (FTIR) revealed that poly (dicyclopentadiene) (PDCPD) formed at the healed interface. However, the FTIR investigation of catalyst stability in different solvents showed structural changes in GC and partial deactivation. The mechanical tests of the samples showed that a recovery of 60% after 24 h at room temperature could be achieved through the use of a solvent and very low concentration of GC. The performed research results are a good base to develop the model for predicting the processes and morphology, with the goal to design the final mechanical and in the future, thermal, properties in advance. This opens a new direction for future research in the field of composite healing.
PB  - Elsevier
T2  - Materials Chemistry and Physics
T1  - Solvent effects on structural changes in self-healing epoxy composites
VL  - 256
SP  - 123761
DO  - 10.1016/j.matchemphys.2020.123761
ER  - 

@article{
author = "Radović, Ivana and Stajčić, Aleksandar and Radisavljević, Andjela and Veljković, Filip and Čebela, Maria and Mitić, Vojislav V. and Radojević, Vesna",
year = "2020",
abstract = "Nowadays, there is a very high importance of composite research and variety of their applications in the modern world. In that sense, we researched hollow glass capillaries filled with dissolved Grubbs catalyst (GC) and dicyclopentadiene (DCPD) were incorporated into a fiber-reinforced epoxy with the aim of improving the flow of healing agents to the crack site. The morphological investigation of the crack site was performed using field emission scanning electron microscopy (FESEM), showing the difference between the samples depending on the used solvent. The software analysis of sample photographs has been performed by calculating the fractured/ healed surface area of the samples, revealing that approximately 20% of the volume was affected by the impact. Fourier transform infrared spectroscopy (FTIR) revealed that poly (dicyclopentadiene) (PDCPD) formed at the healed interface. However, the FTIR investigation of catalyst stability in different solvents showed structural changes in GC and partial deactivation. The mechanical tests of the samples showed that a recovery of 60% after 24 h at room temperature could be achieved through the use of a solvent and very low concentration of GC. The performed research results are a good base to develop the model for predicting the processes and morphology, with the goal to design the final mechanical and in the future, thermal, properties in advance. This opens a new direction for future research in the field of composite healing.",
publisher = "Elsevier",
journal = "Materials Chemistry and Physics",
title = "Solvent effects on structural changes in self-healing epoxy composites",
volume = "256",
pages = "123761",
doi = "10.1016/j.matchemphys.2020.123761"
}

Radović, I., Stajčić, A., Radisavljević, A., Veljković, F., Čebela, M., Mitić, V. V.,& Radojević, V.. (2020). Solvent effects on structural changes in self-healing epoxy composites. in Materials Chemistry and Physics
Elsevier., 256, 123761.
https://doi.org/10.1016/j.matchemphys.2020.123761

Radović I, Stajčić A, Radisavljević A, Veljković F, Čebela M, Mitić VV, Radojević V. Solvent effects on structural changes in self-healing epoxy composites. in Materials Chemistry and Physics. 2020;256:123761.
doi:10.1016/j.matchemphys.2020.123761 .

Radović, Ivana, Stajčić, Aleksandar, Radisavljević, Andjela, Veljković, Filip, Čebela, Maria, Mitić, Vojislav V., Radojević, Vesna, "Solvent effects on structural changes in self-healing epoxy composites" in Materials Chemistry and Physics, 256 (2020):123761,
https://doi.org/10.1016/j.matchemphys.2020.123761 . .