Poster De Conférence Année : 2022

Strain-induced crystallization in natural rubber: is there time-strain superposition?

Résumé

Stretching polymer chains promotes crystallization. This idea, rationalized by Flory as early as 1947, is one basic concept in polymer physics and is relevant in a vast majority of polymer manufacturing processes. In natural rubber (NR), strain-induced crystallization (SIC) is a key feature which underlies its exceptional performances as an elastomer material. In many, if not most, practical situations, the behavior is actually controlled by the kinetics of SIC. In particular, understanding crystallization kinetics is essential for explaining the hysteretic behavior observed in dynamic conditions. In this talk we shall show that, under the strong assumption that, in crosslinked materials, SIC is mainly driven by nucleation processes, an explicit kinetic equation can be established to describe the evolution of the crystallinity index. This is based on the dependence of the nucleation rate on the overstretching of the amorphous phase. Indeed, while in thermal polymer crystallization the driving force is the overcooling, in SIC it is the overstretching. According to a lever rule, in contrast to thermal crystallization in which the overcooling may be controlled, overstretching relaxes as crystallization proceeds, which makes the kinetic equation a little bit more complex. It follows that a general time-strain superposition principle cannot be rigorously established for the general time evolution of the crystallinity index at various initial overstretching values

Fichier non déposé

Dates et versions

hal-04926987 , version 1 (03-02-2025)

Identifiants

  • HAL Id : hal-04926987 , version 1

Citer

Paul Sotta, Pierre‐antoine Albouy. Strain-induced crystallization in natural rubber: is there time-strain superposition?. Deformation, Yield and Fracture in Polymers, Apr 2022, Kerkrade, Netherlands. ⟨hal-04926987⟩
35 Consultations
0 Téléchargements

Partager

  • More