Network structural dynamics in natural rubber: A comparative study of accelerated storage and natural environment storage

To clarify the evolutionary behavior of the network structure for the natural rubber (NR) during storage, and address the issue of inadequate storage ability in constant viscosity natural rubber (CV rubber) under long time storage, the macrostructure, mesostructure, and microstructure of NR under accelerated and natural environmental storage conditions were systematically analyzed in this work. To eliminate the influence of current preparation methods, the latex-dry mixing method, latex-mixing method, and dry-mixing method were used to prepare CV rubber. The results showed that initial plasticity, macrogel, microgel >1μ , microgel <1μ , and absolute molecular weight were obviously different under two storage conditions. During the accelerated storage, the microgel inside the CV rubber cannot cross-link into macrogel, while the microgel inside the rubber can cross-link into macrogel during natural environment storage. In addition, the sample prepared by latex-mixing method exhibited the most significant effect on the Mooney viscosity, macrogel content, and the absolute molecular weight of CV rubber during natural environmental storage, while the latex-dry mixing method demonstrated the least impact. This work will be conducive to a comprehensive analysis of the impact of storage conditions and mainstream preparation methods on the storage stability for CV rubber, providing a theoretical foundation for achieving stable preparation of CV rubber.