Nonlinear time-dependent behavior of rheodictic polymers : a theoretical and experimental investigation

Oseli, Alen (author), Mihelčič, Mohor (author), Šobak, Matic (author), Slemenik Perše, Lidija (author)

The present study examined the nonlinear time-dependent behavior of rheodictic polymers, a class of noncrosslinked materials that exhibit flow. Such behavior was addressed with extended Schapery’s nonlinear viscoelastic model by introducing new physical quantities, i.e., the flow term and corresponding nonlinear shift parameter . While portrays irrecoverable deformation, depicts a nonlinear contribution to flow acceleration. This theory was accompanied by analytical and experimental methodologies for identifying all the parameters in the linear and nonlinear viscoelastic domains. Predictions of long-term time-dependent behavior (in shear) at various stress states show excellent agreement with the experimental data, i.e., within error, obtained for polycarbonate at . Surprisingly, the newly introduced indicates that flow retardation occurs with increasing stress, implying that a highly deformed entangled system hinders molecular reptation/disentanglement. Nevertheless, the proposed extension of Schapery’s nonlinear viscoelastic model not only allows accurate predictions of the nonlinear time-dependent behavior of rheodictic polymers but also enables a detailed outlook on the underlying molecular mechanisms under severe environmental and loading conditions.

• Language: English
• Keywords: rheodictic polymers, nonlinear behavior, time-dependent mechanical properties, creep process, Schapery’s nonlinear model
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.08.2024
• Year: 2024
• Number of pages: 11
• Numbering: Vol. 137 , art. 108535
• PID: 20.500.12556/RUL-159934
• UDC: 620.17:678.7
• ISSN on article: 1873-2348
• DOI: 10.1016/j.polymertesting.2024.108535
• COBISS.SI-ID: 203185923
• Publication date in RUL: 31.07.2024

Record is a part of a journal

• Title: Polymer testing
• Publisher: Elsevier
• ISSN: 1873-2348
• COBISS.SI-ID: 23025669

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: reodiktični polimeri, nelinearno vedenje, časovno odvisne mehanske lastnosti, proces lezenja, Schaperijev nelinearni model