{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T11:09:58Z","timestamp":1791457798418,"version":"4.3.4"},"reference-count":32,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2012,9,12]],"date-time":"2012-09-12T00:00:00Z","timestamp":1347408000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A structural study of epoxidized natural rubber (ENR-50) and its cyclic dithiocarbonate derivative was carried out using NMR spectroscopy techniques. The overlapping 1H-NMR signals of ENR-50 at \u03b4 1.56, 1.68\u20131.70, 2.06, 2.15\u20132.17 ppm were successfully assigned. In this work, the 13C-NMR chemical shift assignments of ENR-50 were consistent to the previously reported work. A cyclic dithiocarbonate derivative of ENR-50 was synthesized from the reaction of purified ENR-50 with carbon disulfide (CS2), in the presence of 4-dimethylaminopyridine (DMAP) as catalyst at reflux temperature. The cyclic dithiocarbonate formation involved the epoxide ring opening of the ENR-50. This was followed by insertion of the C\u2013S moiety of CS2 at the oxygen attached to the quaternary carbon and methine carbon of epoxidized isoprene unit, respectively. The bands due to the C=S and C\u2013O were clearly observed in the FTIR spectrum while the 1H-NMR spectrum of the derivative revealed the peak attributed to the methylene protons had split. The 13C-NMR spectrum of the derivative further indicates two new carbon peaks arising from the &gt;C=S and quaternary carbon of cyclic dithiocarbonate. All other 1H- and 13C-NMR chemical shifts of the derivative remain unchanged with respect to the ENR-50.<\/jats:p>","DOI":"10.3390\/molecules170910974","type":"journal-article","created":{"date-parts":[[2012,9,12]],"date-time":"2012-09-12T12:11:41Z","timestamp":1347451901000},"page":"10974-10993","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":53,"title":["A Structural Study of Epoxidized Natural Rubber (ENR-50) and Its Cyclic Dithiocarbonate Derivative Using NMR Spectroscopy Techniques"],"prefix":"10.3390","volume":"17","author":[{"given":"Rosniza","family":"Hamzah","sequence":"first","affiliation":[{"name":"Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamad Abu","family":"Bakar","sequence":"additional","affiliation":[{"name":"Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melati","family":"Khairuddean","sequence":"additional","affiliation":[{"name":"Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Issam Ahmed","family":"Mohammed","sequence":"additional","affiliation":[{"name":"School of Industrial Technology, Universiti Sains Malaysia, Penang 11800, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rohana","family":"Adnan","sequence":"additional","affiliation":[{"name":"Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2012,9,12]]},"reference":[{"key":"ref_1","first-page":"87","article-title":"Epoxidized Natural Rubber","volume":"Volume 4","author":"Gelling","year":"1987","journal-title":"Development of Rubber Technology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"86","DOI":"10.5254\/1.3536060","article-title":"Modification of Natural Rubber with Peracetic Acid","volume":"58","author":"Gelling","year":"1985","journal-title":"Rubber Chem. 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