NOMATEN HYBRID-SEMINAR June 30: Advanced ^1H Time-Domain NMR for Rubber Characterization

Over the past few decades, proton time-domain NMR experiments performed on low-field spectrometers have demonstrated their potential applicability to rubber science and technology. This feasible and versatile experimental approach enables us to obtain molecular-level information on the dynamics and structure of rubber samples, with the aim of improving our understanding of structure-property relationships for a rational design and development of rubber materials.

In this contribution, we review some fundamental aspects of the relationship between the NMR observable and the molecular order parameter of macromolecules, and its link with the rubber network structure and dynamics. It provides the opportunity to obtain a quantitative and comprehensive characterization of dangling chain ends, number of cross-links and their spatial distribution, as well as their effect on the rubber dynamics. Consequently, this experimental approach has provided novel insights into different fundamental areas of rubber science and technology, such as rubber dynamics, vulcanization, ageing and recycling.

Finally, we present some new insights into the field of rubber reinforcement. This complex phenomenon is based on molecular arguments, such as the rubber network structure, the filler-rubber and filler-filler interactions as well as the amplification factors, although quantifying them is still a complex challenge. To address this issue, a pioneering experimental methodology has been developed to characterize the rubber-filler interface at the nanoscale by combining 1H Multiple-Quantum NMR, equilibrium swelling and mechanical experiments, hence establishing a common physical framework between the three approaches and developing a novel combined analysis protocol.