Author:
S. Abdel Zaher Khlood,Swellem R.H.,A.M. Nawwar Galal,M. Abdelrazek Fathy,H. El-Sabbagh Salwa
Abstract
Purpose
– The purpose of this paper is to study the efficiency of lignin/silica and calcium lignate/calcium silicate as natural antioxidants in styrene-butadiene rubber (SBR) vulcanizates.
Design/methodology/approach
– It has been found that thermal aging data of the aged sample revealed that SBR vulcanizate undergoes crosslink reactions that lead to embrittlement and ultimately failure. Incorporation of lignin/silica or calcium lignate/calcium silicate, however, resulted in significant improvement of the degradation profile of the vulcanizates at 90±1°C. Loss of tensile strength and flexibility during aging of the SBR compounds with 8 phr lignin/silica or calcium lignate/calcium silicate was mild relative to unfilled polymer, indicating a restricted degradation due to the presence of the investigated compounds. The results obtained revealed that the investigated compounds are good antioxidant, and the evaluation was confirmed by physico-mechanical properties of the vulcanizates, FT-IR spectroscopy, transmission (TEM) and scanning (SEM) electron microscope.
Findings
– It was noticed that SBR vulcanizates having 8 phr of lignin/silica or calcium lignate/calcium silicate exhibited the best mechanical properties in comparison with other concentrations (1, 2, 4, 6 and 10 phr). Also, results revealed that the lignin/silica derivatives are efficient antioxidants in SBR vulcanizates compared to vulcanizates containing conventional antioxidants used in rubber industry, namely polymerized 2,2,4-trimethyl-1, 2-dihydroquinoline (TMQ), and N-isopropyl-N'-phenyl-P-phenylenediamine (IPPD).
Research limitations/implications
– All these results indicated that lignin/silica and calcium lignate/calcium silicate in SBR had good heat resistance and aging resistance, calcium lignate/calcium silicate has an application limitation as not all vulcanizates need to use CaCO3/calcium salts.
Practical implications
– Lignin is usually seen as a waste product of pulp and paper industry and is often used as fuel for the energy balance of the pulping process. It is simple isolation along with silica from rice straw and using it as an antioxidant added further practical utility for this waste.
Originality/value
– The importance of lignin/silica derivatives is arisen from their biodegradability and their ease availability from rice straw black liquor.
Subject
Materials Chemistry,Surfaces, Coatings and Films
Reference27 articles.
1. Abdel-Aziz, M.M.
and
Basfar, A.A.
(2001), “Evaluation of some antioxidants in radiation vulcanized ethylene-propylene diene (EPDM) rubber”, Nuclear Instruments and Methods in Physics Research, Section B, Vol. 185 Nos 1-4, pp. 346-350.
2. Al-Nowaiser, F.M.
(2005), “Evaluation of some diphenylamine derivatives as thermal stabilizers and antifatigue agents in natural rubber vulcanizates”, International Journal of Polymeric Materials, Vol. 54 No. 10, pp. 963-973.
3. ASTM
(2007a), “Determination of cure characteristics for estimating rheometric characteristics”, D2084-07, ASTM, West Conshohocken, PA.
4. ASTM
(2007b), “Determination of physico-mechanical properties”, D412-06, ASTM 624, ASTM, West Conshohocken, PA.
5. ASTM
(2007c), “Determination of thermal oxidative aging”, D3629, ASTM, West Conshohocken, PA.
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