How hydrogen bonds influence the slow crack growth resistance of polyamide 12

Mario Messiha, Andreas Frank, Florian Arbeiter, Gerald Pinter

Research output: Contribution to journalArticleResearchpeer-review


Slow Crack Growth (SCG) is considered to be the most critical failure mode for a variety of long-term applications. A key element within this research was to examine the SCG behaviour of polyamide 12 (PA12). Because hydrogen (H) bonds are well-known to affect the mechanical properties of plastics, such as PA12, special focus was put on their influences during quasi-brittle fracture. Therefore, the total fracture energy Gf of PA12 was divided into a pure chain disentanglement fracture energy, driven by creep processes during SCG (Gdis,f), and the additional energy needed to dissociate effective H-bonds that are actively resisting SCG (GH,f) within PA12. In that context, Gf was calculated from the experimentally measured activation energy for SCG via Cracked Round Bar (CRB) tests at different temperatures and the subsequent use of a time-temperature superposition. Subsequently, GH,f, was estimated with the aid of a modified Sequential Debonding Fracture (SDF) model. Subtracting GH,f from Gf, the remaining energy could be classified as Gdis,f and was calculated for different amounts of effective H-bonds. It was demonstrated for the selected material, that GH,f would become the dominating source of energy which has to be overcome, if at least 45% of all H-bonds crossing the crack plane engage in the fracture process and follow a sequential debonding mechanism.
Original languageEnglish
Article number124437
Number of pages10
Issue number17 January
Early online date7 Dec 2021
Publication statusPublished - 17 Jan 2022

Bibliographical note

Funding Information:
The research work of this paper was performed at the Polymer Competence Center Leoben GmbH (PCCL, Austria) within the framework of the K1 COMET-program (Grant Nr.: 879785), which is funded by the Federal Ministry for Transport, Innovation and Technology (Austria) and Federal Ministry for Economy, Family and Youth (Austria) with contributions by Evonik Operations GmbH (Germany) and the Montanuniversitaet Leoben (Austria) . The PCCL is funded by the Austrian Government and the State Governments of Styria and Upper Austria .
Publisher Copyright:
© 2021 The Authors


  • Cyclic cracked round bar test
  • Hydrogen bonds
  • Micro-deformation mechanisms
  • Polyamides
  • Slow crack growth

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