Sains Malaysiana 46(3)(2017): 485–491

http://dx.doi.org/10.17576/jsm-2017-4603-17

Epoxidation and Hydroxylation of Liquid Natural Rubber

(Pengepoksidaan dan Penghidroksilan Getah Asli Cecair)

NUR HANIS ADILA AZHAR¹, HAMIZAH MD RASID¹ & SITI FAIRUS M. YUSOFF^1,2*

¹School of Chemical Sciences and Food Technology, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

²Polymer Research Center (PORCE), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

Received: 24 June 2016/Accepted: 15 August 2016

ABSTRACT

Liquid natural rubber (LNR) was functionalized into liquid epoxidized natural rubber (LENR) and hydroxylated LNR (LNR-OH) via oxidation using a Na₂WO₄/CH₃COOH/H₂O₂ catalytic system. Microstructures of LNR and functionalized LNRs were characterized using Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies. The effect of CH₃COOH, H₂O₂, Na₂WO₄, reaction time and temperature on epoxy content were investigated. LNR-OH was obtained when oxidation reaction was conducted at a longer reaction time, higher temperature or excess amount of catalyst. Thermogravimetric analysis (TGA) reported the thermal behavior of functionalized LNRs. Molecular weight and polydispersity index (PDI) were determined using gel permeation chromatography (GPC).

Keywords: Diols; epoxidation; hydroxylated; liquid natural rubber; oxidation

ABSTRAK

Getah asli cecair (LNR) telah diperfungsikan kepada getah asli cecair terepoksida (LENR) dan getah asli cecair terhidroksil (LNR-OH) melalui tindak balas pengoksidaan menggunakan sistem pemangkinan Na₂WO₄/CH₃COOH/H₂O₂. Mikrostruktur LNR dan LNR diperfungsi dicirikan menggunakan spektroskopi Fourier transformasi inframerah (FTIR) dan resonans magnet nukleus (NMR). Kesan CH₃COOH, H₂O₂, Na₂WO₄, masa dan suhu tindak balas ke atas kandungan epoksi dikaji. LNR-OH diperoleh apabila tindak balas pengoksidaan dijalankan pada masa yang lebih panjang, suhu yang lebih tinggi atau lebihan amaun pemangkin. Analisis termogravimetri (TGA) melaporkan sifat terma LNR yang terfungsi. Berat molekul dan indeks kepoliserakan (PDI) ditentukan melalui kromatografi penelapan gel (GPC).

Kata kunci: Diol; getah asli cecair; pengepoksidaan; pengoksidaan; terhidroksil

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*Corresponding author; email: sitifairus@ukm.edu.my