On the potential of organoclay with respect to conventional fillers (carbon black, silica) for epoxidized natural rubber compatibilized natural rubber vulcanizates

• Published in: Journal of applied polymer science Vol. 94; no. 6; pp. 2438 - 2445
• Main Authors: Teh, P. L., Mohd Ishak, Z. A., Hashim, A. S., Karger-Kocsis, J., Ishiaku, U. S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.12.2004; Wiley
• Subjects: Applied sciences; carbon black; Composites; epoxidized natural rubber; Exact sciences and technology; Forms of application and semi-finished materials; nanocomposites; natural rubber; organoclay; Polymer industry, paints, wood; silica; Technology of polymers; Strengthening; Organic clay; Polymer blends; Carbon black; Montmorillonite; Reinforcing filler; Mechanical properties; Natural rubber; Dispersion reinforced material; Experimental study; Silica; nanocomposites; Composite material; Property formulation relationship; Polymer filler interaction; Vulcanization; Vulcanizate; organoclay; Nanocomposite; Epoxidized natural rubber; Kinetics
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.21188

Onium modified montmorillonite (organoclay) was compounded with natural rubber (NR) in an internal mixer and cured by using a conventional sulfuric system. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) in 10 parts per hundred rubber (phr) was used as a compatibilizer in this study. For comparison purposes, two commercial fillers: carbon black (grade N330) and silica (grade vulcasil‐S) were used. Cure characteristics were carried out on a Monsanto MDR2000 Rheometer. Organoclay filled vulcanizate showed the lowest values of torque maximum, torque minimum, scorch, and cure times. The kinetics of cure reaction showed organoclay could behave as a cocuring agent. The mechanical testing of the vulcanizates involved the determination of tensile and tear properties. The improvement of tensile strength, elongation at break, and tear properties in organoclay filled vulcanizate were significantly higher compared to silica and carbon black filled vulcanizates. In terms of reinforcing efficiency (RE), organoclay exhibited the highest stiffness followed by silica and carbon black filled vulcanizates. Scanning electron microscopy revealed that incorporation of various types of fillers has transformed the failure mechanism of the resulting NR vulcanizates compared to the gum vulcanizates. Dynamic mechanical thermal analysis (DMTA) revealed that the stiffness and molecular relaxation of NR vulcanizates are strongly affected by the filler–rubber interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2438–2445, 2004