CHEMICAL ENGINEERING TRANSACTIONS VOL. 78, 2020 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Jeng Shiun Lim, Nor Alafiza Yunus, Jiří Jaromír Klemeš Copyright © 2020, AIDIC Servizi S.r.l. ISBN 978-88-95608-76-1; ISSN 2283-9216 The Characterization of Hydroxyl Terminated Epoxidized Natural Rubber (HTENR) via Oxidation Degradation Method Siti Maizatul Farhain Salehuddin a , Norfhairna Baharulrazi a, *, Siti Hajjar Che Man a , Wan Khairuddin Wan Ali b , Nurul Hayati Yusof c a Department of Bioprocess and Polymer Engineering, School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Malaysia b Department of Aeronautics, Automotive and Ocean, School of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Malaysia c Malaysian Rubber Board (MRB), 47000, Sungai Buloh, Selangor norfhairna@utm.my The degradation of epoxidized natural rubber (ENR-50) and liquid epoxidized natural rubber (LENR) was done via oxidative degradation method for the production of hydroxyl terminated epoxidized natural rubber (HTENR) and hydroxyl terminated liquid epoxidized natural rubber (HTLENR) has been analysed. Cobalt (II) acetylacetonate (CAA) were used as an oxidizing agent for chain scission reaction at temperature 60 °C in the presence of ethanol. The reaction temperature was fixed at 60 °C meanwhile reaction time and the amount of CAA were varied according to the reaction formulation. The HTENR and HTLENR obtained have been characterized using Gel Permeation Chromatography (GPC), Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR). GPC were used to determine the molecular weight before and after the oxidative degradation of respected HTENR and HTLENR were compared with ENR-50 and LENR. The lowest Mn and Mw of HTLENR that were obtained from the oxidative degradation method were found to be 5,163 g/mol and 58,087 g/mol. The appearances of OH end groups were verified by FTIR and NMR analyses to validate the position of each OH functional groups. FTIR analysis confirmed that HTENR and HTLENR contained OH group with the appearance of a broad peak around 3,400 cm -1 to 3,550 cm -1 after the reaction. The presence of OH end groups was verified by NMR analysis with the appearance at 3.39 ppm and 3.66 ppm, corresponding to methylene proton adjacent to hydroxyl group in HOCH2CH2CH2 and methane proton adjacent to OH group in CH2CH2CH(OH)CH3. 1. Introduction Degradation of polymeric materials are of wide interest to research scientists as they often produce new materials that cannot be prepared or are costly to prepare by means of conventional polymerization reactions. These methods are also used to improve the properties of some commercial polymers or to introduce specific reactive intermediates on the polymer chains for further modification. The degradation of the polymers in solution is advantageous as it provides better heat transfer rates and degradation in a single phase. The oxidative degradation of the polymer in solution usually occurs by random chain scission of the polymer chains. Amongst the degradation methods, photo and oxidative degradations are widely reported. Phinyocheep et al. (2005) studied on chemical degradation of epoxidized natural rubber (ENR) was prepared from the epoxidation of natural rubber in latex phase using performic acid generated in situ by the reaction of hydrogen peroxide and formic acid. As well as, Chaikumpollert et al. (2009) investigated the low temperature degradation and characterization of natural rubber which was performed with potassium persulfate (K2S2O8). According to the degradation mechanism, the introduction of the carbonyl and formly groups at both terminated were appeared due to the oxidative degradation of rubber. Recently, Baharulrazi (2015) reported on the synthesis and characterization of hydroxyl terminated epoxidized natural rubber as a binder for solid rocket propellant. Oxidative degradation of deproteinized natural rubber (DPNR) by CAA in the presence of ethanol yielded the lowest molecular weight compared to other alcohols employed. Epoxidized natural rubber DOI: 10.3303/CET2078026 Paper Received: 14/04/2019; Revised: 19/08/2019; Accepted: 16/09/2019 Please cite this article as: Salehuddin S.M.F., Baharulrazi N., Che Man S.H., Wan Ali W.K., Yusof N.H., 2020, The Characterization of Hydroxyl Terminated Epoxidized Natural Rubber (HTENR) via Oxidation Degradation Method, Chemical Engineering Transactions, 78, 151-156 DOI:10.3303/CET2078026 151