Billon, N.; Castellani, R.; Bouvard, J.-L.; Rival, G. Viscoelastic Properties of Polypropylene during Crystallization and Melting: Experimental and Phenomenological Modeling. Polymers2023, 15, 3846.
Billon, N.; Castellani, R.; Bouvard, J.-L.; Rival, G. Viscoelastic Properties of Polypropylene during Crystallization and Melting: Experimental and Phenomenological Modeling. Polymers 2023, 15, 3846.
Billon, N.; Castellani, R.; Bouvard, J.-L.; Rival, G. Viscoelastic Properties of Polypropylene during Crystallization and Melting: Experimental and Phenomenological Modeling. Polymers2023, 15, 3846.
Billon, N.; Castellani, R.; Bouvard, J.-L.; Rival, G. Viscoelastic Properties of Polypropylene during Crystallization and Melting: Experimental and Phenomenological Modeling. Polymers 2023, 15, 3846.
Abstract
This paper deals with the viscoelastic behavior during crystallization and melting of semicrystalline polymers with the aim of later modeling the residual stresses after processing in case where crystallization occurs in quasi static conditions (in additive manufacturing for example). Despite of an abundant literature on polymer crystallization, the current state of scientific knowledge does not yet allow ab initio modeling. Therefore, an alternative and pragmatic way has been explored to propose a first approximation of the impact of crystallization and melting on the storage and the loss moduli during crystallization-melting-crystallization cycle. An experimental approach, combining DSC, optical microscopy and oscillatory shear rheology was used to define macroscopic parameters related to the microstructure. These parameters have been integrated into a phenomenological model. Isothermal measurements were used to describe the general framework, and crystallization at a constant cooling rate was used to evaluate the feasibility of a general approach. It can be concluded that relying solely on the crystalline fraction is inadequate to model the rheology. Instead accounting for the microstructure at the spherulitic level could be more useful. Additionally, the results obtained from the experiments help to enhance our understanding of the correlations between crystallization kinetics and its mechanical effects.
Keywords
Crystallization; Rheology; Viscoelasticity
Subject
Chemistry and Materials Science, Polymers and Plastics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
