TY  - JOUR
AU  - Miličević, Dejan S.
AU  - Mićić, Maja M.
AU  - Stamboliev, G.
AU  - Leskovac, Andreja
AU  - Mitrić, Miodrag
AU  - Suljovrujić, Edin H.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4828
AB  - Different polyolefines (low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and isotactic polypropylene (iPP)) were oriented via solid-state stretching at an elevated temperature. In order to investigate orientation-induced changes in microstructure and crystallinity, optical microscopy (OM), scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) were employed. To quantify the degree of molecular orientation WAXS data were used to calculate Hermans orientation function (f(c)); the results reinforce the morphological picture obtained from OM and SEM confirming Peterlins molecular model of drawing. Furthermore, orientation-induced changes in the crystalline phase, especially in its volume and perfection, were observed by DSC and WAXS. Comparison between these data showed that the biggest change in the degree of crystallinity was achieved during the transformation of the initial lamellar into fibrillar structure. After completion of this transformation further orientation, which occurs through plastic deformation of fibre structure, introduces only minor changes in crystallinity. The overall orientation-induced behaviour hasnt been considerably influenced by the structural differences amongst polyolefins.
T2  - Fibers and Polymers
T1  - Microstructure and Crystallinity of Polyolefins Oriented via Solid-state Stretching at an Elevated Temperature
VL  - 13
IS  - 4
SP  - 466
EP  - 470
DO  - 10.1007/s12221-012-0466-4
ER  - 

@article{
author = "Miličević, Dejan S. and Mićić, Maja M. and Stamboliev, G. and Leskovac, Andreja and Mitrić, Miodrag and Suljovrujić, Edin H.",
year = "2012",
abstract = "Different polyolefines (low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and isotactic polypropylene (iPP)) were oriented via solid-state stretching at an elevated temperature. In order to investigate orientation-induced changes in microstructure and crystallinity, optical microscopy (OM), scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) were employed. To quantify the degree of molecular orientation WAXS data were used to calculate Hermans orientation function (f(c)); the results reinforce the morphological picture obtained from OM and SEM confirming Peterlins molecular model of drawing. Furthermore, orientation-induced changes in the crystalline phase, especially in its volume and perfection, were observed by DSC and WAXS. Comparison between these data showed that the biggest change in the degree of crystallinity was achieved during the transformation of the initial lamellar into fibrillar structure. After completion of this transformation further orientation, which occurs through plastic deformation of fibre structure, introduces only minor changes in crystallinity. The overall orientation-induced behaviour hasnt been considerably influenced by the structural differences amongst polyolefins.",
journal = "Fibers and Polymers",
title = "Microstructure and Crystallinity of Polyolefins Oriented via Solid-state Stretching at an Elevated Temperature",
volume = "13",
number = "4",
pages = "466-470",
doi = "10.1007/s12221-012-0466-4"
}

Miličević, D. S., Mićić, M. M., Stamboliev, G., Leskovac, A., Mitrić, M.,& Suljovrujić, E. H.. (2012). Microstructure and Crystallinity of Polyolefins Oriented via Solid-state Stretching at an Elevated Temperature. in Fibers and Polymers, 13(4), 466-470.
https://doi.org/10.1007/s12221-012-0466-4

Miličević DS, Mićić MM, Stamboliev G, Leskovac A, Mitrić M, Suljovrujić EH. Microstructure and Crystallinity of Polyolefins Oriented via Solid-state Stretching at an Elevated Temperature. in Fibers and Polymers. 2012;13(4):466-470.
doi:10.1007/s12221-012-0466-4 .

Miličević, Dejan S., Mićić, Maja M., Stamboliev, G., Leskovac, Andreja, Mitrić, Miodrag, Suljovrujić, Edin H., "Microstructure and Crystallinity of Polyolefins Oriented via Solid-state Stretching at an Elevated Temperature" in Fibers and Polymers, 13, no. 4 (2012):466-470,
https://doi.org/10.1007/s12221-012-0466-4 . .

TY  - JOUR
AU  - Stamboliev, G.
AU  - Suljovrujić, Edin H.
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3968
AB  - The molecular relaxation behaviour of high density polyethylene (HDPE), exposed to gamma radiation in air to various absorbed doses (up to 700 kGy), has been investigated by dielectric loss (tan delta) analysis. All relaxation zones (gamma, beta and alpha, in order of increasing temperature), between 25 K and the melt temperature, were studied in the frequency range from 1 kHz to 1 MHz. The changes observed in the dielectric relaxation spectra were related to the modifications in the structural and morphological parameters attributed to exposure of the samples to radiation. Radiation-induced changes in the crystal fraction, oxidative degradation and degree of network formation, observed by wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and gel measurements, were well connected with the changes in intensity, position and activation energy of alpha and gamma relaxations. Complete disappearance of the already weak beta relaxation with irradiation is attributed to the more restricted chain segment mobility in the net Structure, but the contribution due to radiation-induced increase in crystallinity should also be taken into account. (C) 2009 Elsevier Ltd. All rights reserved.
T2  - Polymer Degradation and Stability
T1  - A dielectric study of molecular relaxations in irradiated high density polyethylene
VL  - 95
IS  - 4
SP  - 593
EP  - 599
DO  - 10.1016/j.polymdegradstab.2009.12.010
ER  - 

@article{
author = "Stamboliev, G. and Suljovrujić, Edin H.",
year = "2010",
abstract = "The molecular relaxation behaviour of high density polyethylene (HDPE), exposed to gamma radiation in air to various absorbed doses (up to 700 kGy), has been investigated by dielectric loss (tan delta) analysis. All relaxation zones (gamma, beta and alpha, in order of increasing temperature), between 25 K and the melt temperature, were studied in the frequency range from 1 kHz to 1 MHz. The changes observed in the dielectric relaxation spectra were related to the modifications in the structural and morphological parameters attributed to exposure of the samples to radiation. Radiation-induced changes in the crystal fraction, oxidative degradation and degree of network formation, observed by wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and gel measurements, were well connected with the changes in intensity, position and activation energy of alpha and gamma relaxations. Complete disappearance of the already weak beta relaxation with irradiation is attributed to the more restricted chain segment mobility in the net Structure, but the contribution due to radiation-induced increase in crystallinity should also be taken into account. (C) 2009 Elsevier Ltd. All rights reserved.",
journal = "Polymer Degradation and Stability",
title = "A dielectric study of molecular relaxations in irradiated high density polyethylene",
volume = "95",
number = "4",
pages = "593-599",
doi = "10.1016/j.polymdegradstab.2009.12.010"
}

Stamboliev, G.,& Suljovrujić, E. H.. (2010). A dielectric study of molecular relaxations in irradiated high density polyethylene. in Polymer Degradation and Stability, 95(4), 593-599.
https://doi.org/10.1016/j.polymdegradstab.2009.12.010

Stamboliev G, Suljovrujić EH. A dielectric study of molecular relaxations in irradiated high density polyethylene. in Polymer Degradation and Stability. 2010;95(4):593-599.
doi:10.1016/j.polymdegradstab.2009.12.010 .

Stamboliev, G., Suljovrujić, Edin H., "A dielectric study of molecular relaxations in irradiated high density polyethylene" in Polymer Degradation and Stability, 95, no. 4 (2010):593-599,
https://doi.org/10.1016/j.polymdegradstab.2009.12.010 . .

TY  - CONF
AU  - Suljovrujić, Edin
AU  - Stamboliev, G.
AU  - Mitrić, Miodrag
AU  - Leskovac, Andreja
AU  - Miličević, Dejan
AU  - Trifunović, S.
AU  - Mićić, Maja
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11705
PB  - Belgrade : Institute of Technical Sciences of SASA
C3  - YUCOMAT 2008 : 10th Annual Conference YUCOMAT 2008 : programme and the book of abstracts; September 8-12, 2008; Herceg Novi, Montenegro
T1  - Orientation and radiation induced changes in microstructure and crystallinity of isotactic polypropylerne
SP  - 114
SP  - 114
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11705
ER  - 

@conference{
author = "Suljovrujić, Edin and Stamboliev, G. and Mitrić, Miodrag and Leskovac, Andreja and Miličević, Dejan and Trifunović, S. and Mićić, Maja",
year = "2008",
publisher = "Belgrade : Institute of Technical Sciences of SASA",
journal = "YUCOMAT 2008 : 10th Annual Conference YUCOMAT 2008 : programme and the book of abstracts; September 8-12, 2008; Herceg Novi, Montenegro",
title = "Orientation and radiation induced changes in microstructure and crystallinity of isotactic polypropylerne",
pages = "114-114",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11705"
}

Suljovrujić, E., Stamboliev, G., Mitrić, M., Leskovac, A., Miličević, D., Trifunović, S.,& Mićić, M.. (2008). Orientation and radiation induced changes in microstructure and crystallinity of isotactic polypropylerne. in YUCOMAT 2008 : 10th Annual Conference YUCOMAT 2008 : programme and the book of abstracts; September 8-12, 2008; Herceg Novi, Montenegro
Belgrade : Institute of Technical Sciences of SASA., 114.
https://hdl.handle.net/21.15107/rcub_vinar_11705

Suljovrujić E, Stamboliev G, Mitrić M, Leskovac A, Miličević D, Trifunović S, Mićić M. Orientation and radiation induced changes in microstructure and crystallinity of isotactic polypropylerne. in YUCOMAT 2008 : 10th Annual Conference YUCOMAT 2008 : programme and the book of abstracts; September 8-12, 2008; Herceg Novi, Montenegro. 2008;:114.
https://hdl.handle.net/21.15107/rcub_vinar_11705 .

Suljovrujić, Edin, Stamboliev, G., Mitrić, Miodrag, Leskovac, Andreja, Miličević, Dejan, Trifunović, S., Mićić, Maja, "Orientation and radiation induced changes in microstructure and crystallinity of isotactic polypropylerne" in YUCOMAT 2008 : 10th Annual Conference YUCOMAT 2008 : programme and the book of abstracts; September 8-12, 2008; Herceg Novi, Montenegro (2008):114,
https://hdl.handle.net/21.15107/rcub_vinar_11705 .