Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation
Abstract
Stress relaxation at room and elevated temperatures of high density (HDPE) and linear low-density polyethylene (LLDPE) has been investigated. Viscoelastic parameters (elasticity moduli and viscosity coefficients) of amorphous and crystal fraction at temperatures 18, 40, 60, 80 and 100 degreesC are determined by using two-process model for stress relaxation of polyethylene. The results show that amorphous viscosities of both polyethylene types clearly satisfy the Arrhenius dependence on temperature. Therefore, in the amorphous fraction of examined polyethylenes at elevated temperatures, there is a process with temperature independent activation energy. The estimated activation energies DeltaH approximate to 62.5 kJ/mol for LLDPE and DeltaH approximate to 59 kJ/mol for HDPE of that process are compared with activation energies determined from the time temperature superposition of experimental relaxation curves and with literature data.
Keywords:
amorphous fraction / crystal fraction / stress relaxation / viscoelasticSource:
Materials Science Forum, 2000, 352, 195-200Note:
- Trends in Advanced Materials and Processes, 3rd Yugoslov-Materials-Research-Society Conference, Sep 20-24, 1999, Herceg Novi, Yugoslavia
DOI: 10.4028/www.scientific.net/MSF.352.195
ISSN: 0255-5476
WoS: 000168448800029
Scopus: 2-s2.0-0342903239
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Institution/Community
VinčaTY - JOUR AU - Đoković, Vladimir AU - Dramićanin, Miroslav AU - Kostoski, Dušan AU - Dudić, Duško PY - 2000 UR - https://vinar.vin.bg.ac.rs/handle/123456789/6308 AB - Stress relaxation at room and elevated temperatures of high density (HDPE) and linear low-density polyethylene (LLDPE) has been investigated. Viscoelastic parameters (elasticity moduli and viscosity coefficients) of amorphous and crystal fraction at temperatures 18, 40, 60, 80 and 100 degreesC are determined by using two-process model for stress relaxation of polyethylene. The results show that amorphous viscosities of both polyethylene types clearly satisfy the Arrhenius dependence on temperature. Therefore, in the amorphous fraction of examined polyethylenes at elevated temperatures, there is a process with temperature independent activation energy. The estimated activation energies DeltaH approximate to 62.5 kJ/mol for LLDPE and DeltaH approximate to 59 kJ/mol for HDPE of that process are compared with activation energies determined from the time temperature superposition of experimental relaxation curves and with literature data. T2 - Materials Science Forum T1 - Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation VL - 352 SP - 195 EP - 200 DO - 10.4028/www.scientific.net/MSF.352.195 ER -
@article{ author = "Đoković, Vladimir and Dramićanin, Miroslav and Kostoski, Dušan and Dudić, Duško", year = "2000", abstract = "Stress relaxation at room and elevated temperatures of high density (HDPE) and linear low-density polyethylene (LLDPE) has been investigated. Viscoelastic parameters (elasticity moduli and viscosity coefficients) of amorphous and crystal fraction at temperatures 18, 40, 60, 80 and 100 degreesC are determined by using two-process model for stress relaxation of polyethylene. The results show that amorphous viscosities of both polyethylene types clearly satisfy the Arrhenius dependence on temperature. Therefore, in the amorphous fraction of examined polyethylenes at elevated temperatures, there is a process with temperature independent activation energy. The estimated activation energies DeltaH approximate to 62.5 kJ/mol for LLDPE and DeltaH approximate to 59 kJ/mol for HDPE of that process are compared with activation energies determined from the time temperature superposition of experimental relaxation curves and with literature data.", journal = "Materials Science Forum", title = "Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation", volume = "352", pages = "195-200", doi = "10.4028/www.scientific.net/MSF.352.195" }
Đoković, V., Dramićanin, M., Kostoski, D.,& Dudić, D.. (2000). Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation. in Materials Science Forum, 352, 195-200. https://doi.org/10.4028/www.scientific.net/MSF.352.195
Đoković V, Dramićanin M, Kostoski D, Dudić D. Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation. in Materials Science Forum. 2000;352:195-200. doi:10.4028/www.scientific.net/MSF.352.195 .
Đoković, Vladimir, Dramićanin, Miroslav, Kostoski, Dušan, Dudić, Duško, "Viscoelastic properties of polyethylene at elevated temperatures on the basis of two-process model for stress relaxation" in Materials Science Forum, 352 (2000):195-200, https://doi.org/10.4028/www.scientific.net/MSF.352.195 . .