About the elongation at break of unfilled natural rubber elastomers. (15th April 2019)

• Record Type: Journal Article
• Authors: Grasland, François; Chazeau, Laurent; Chenal, Jean-Marc; Caillard, Julien; Schach, Regis
• Is Part Of: Polymer. Volume 169(2019)
• Page Start: 195
• Page End: 206
• Publication Date: 2019-04-15
• Subjects: Elastomer -- Rupture properties -- Microstructure -- Strain-induced crystallization -- Network heterogeneities; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.02.032
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: This paper presents the characterization of the mechanical properties, of the ability to crystallize thermally or under strain, and of the Elastically Active Chains (EAC) network of Natural Rubber elastomer, whose EAC average density and length distribution were modified by thermo-oxidative ageing. EAC length distribution is not a critical parameter for λ b r e a k in elastomers which do not crystallize (as far as the quantity of free and dangling chains stays negligible, which is the case in this study). However, it becomes important in crystallizable materials, since it controls the chains quantity which can be stretched enough to crystallize. When this quantity is large enough, the material can be stretched up to λ c, and the crystallization process will enable to increase both λ b r e a k and σ b r e a k . Conversely when it is too low, λ b r e a k is seemingly mainly governed by the average EAC density and a power law then links both quantities. Graphical abstract: Image 1 Highlights: EAC length distribution controls the quantity of chains that crystallize with λ. When large enough, SIC can occur and improves stretch at break. When too small, stretch at break is mainly governed by the average EAC density. A power law then links both quantities with a −0.75 exponent.