Liau, W. B.W. B.LiauCheng, K. C.K. C.ChengLiauWB2008-12-312018-06-282008-12-312018-06-28199800323861http://ntur.lib.ntu.edu.tw//handle/246246/95559https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032210097&doi=10.1016%2fS0032-3861%2898%2900036-6&partnerID=40&md5=4736720c94fd27683d0a8fe0a8e54fb8The isochronal mechanical relaxation spectra of lightly cross-linked natural rubbers were measured at frequency 1 Hz. The results were analysed using the empirical Havriliak-Negami (HN) equation. The HN equation fitted the relaxation spectra very well. The fitting parameters, α and β, obtained from the data fitting were used to interpret the relation between molecular motions and structure of polymers based on the model proposed by Schönhals and Schlosser. In the high-frequency region of relaxation spectra, the values of αβ were increased with increasing sulphur content. According to the model proposed by Schönhals and Schlosser, it means that the molecular motions are related to the local intramolecular interactions and are mainly influenced by the formation of heterocyclic groups along the chain. However, in the low-frequency region of relaxation spectra, the values of α were not affected by increasing sulphur content. According to the model proposed by Schönhals and Schlosser, the molecular motions in this region are related to the intermolecular interactions. They are not influenced by the level of cross-linking due to the very low level of cross-link.application/pdf587933 bytesapplication/pdfen-USDynamic mechanical relaxation; Havriliak-Negami equation; Molecular motionCrosslinking; Curve fitting; Mathematical models; Molecular dynamics; Molecular structure; Relaxation processes; Sulfur compounds; Havriliak-Negami equation; Schonhals-Schlosser model; Rubberjournal article2-s2.0-0032210097http://ntur.lib.ntu.edu.tw/bitstream/246246/95559/1/02.pdf