HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
International audienceThe contribution of entropy change due to stretching of polymer chains in promoting crystal nucleation is theoretically derived for strain-induced crystallization of natural rubber. The results of theoretical calculation are compared with experimental results obtained by fast time-resolved wide-angle X-ray diffraction. Usual values of surface free energies corresponding to chain-folded nuclei lead to theoretical results far from experimental measurements. Because the discrepancy comes from the large activation energy of nucleation even after the stretching of polymer chains, additional contribution of reduced surface free energies due to the formation of bundle-like nuclei was taken into account. This treatment allows to faithfully reproduce experimental results and then to conclude that nuclei formed in natural rubber during stretching are of bundle-like type. Moreover, it reveals that surface energies have a greater effect on the decrease of critical free energy than the change in entropy due to deformation
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.