Characterizing gum natural rubber samples through advanced techniques

• Published in: Journal of applied polymer science 2011-03, Vol.119 (5), p.3058-3071
• Main Authors: Leblanc, Jean L, Pilard, Jean-François, Pianhanuruk, Ekkawit, Campistron, Irene, Buzaré, Jean-Yves
• Format: Article
• Language: English
• Subjects: Aids; Analysis and structure; Applied sciences; Chemical Sciences; Differential scanning calorimetry; Exact sciences and technology; Materials science; microstructure; Mixers; Natural rubber; NMR; Nonlinear dynamics; Nuclear magnetic resonance; Polymer industry, paints, wood; Polymers; Properties and testing; Reproduction; rheology; rubber; Specifications; Technology of polymers; viscoelastic properties
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.33052

Owing to its origin, Natural Rubber exhibits more variation than synthetic polymers. If, over the years, NR specifications have evolved from mere visual inspections towards the more complex Technically Specified Rubber (TSR) schema, industrial practice shows that, even for typical TSR grades, significant variations still exist within each shipment, especially in regard to processability. It follows that mastication is quite systematically needed in industrial operations, without or with processing aids or so-called peptizers. Typical NR compounding operations consume therefore time and mixer capacity, a situation, which obviously calls both better characterization methods of (gum) natural rubber and eventually improved grades. There are nowadays promising new techniques to analyze and characterize polymer materials, some of which are a priori attractive for a better specification of NR grades. One such technique is the so-called Fourier Transform rheometry, a dynamic testing method to investigate both the linear and the non-linear viscoelastic domains of polymer materials. Other are spectroscopic methods like solid Nuclear Magnetic Resonance (NMR), either liquid or solid, whose results might be complemented by Size Exclusion Chromatography with special detection techniques, e.g. SEC-MALS, and Differential Scanning Calorimetry (DSC). The purpose of the work reported here was to investigate a series of gum NR grades using such techniques, with the objectives not only to demonstrate their interest but also to cross-validate their results.