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Improved mechanical properties of NR/EPDM blends by controlling the migration of curative and filler via reactive processing technique
- Source :
- Journal of applied polymer science, 111(4), 2035-2043. Wiley
- Publication Year :
- 2009
- Publisher :
- Wiley, 2009.
-
Abstract
- Simple blending of natural rubber/ethylene–propylene–diene rubber (NR/EPDM) generally results in inferior mechanical properties because of curative migration and their differences for filler affinity. In this work, the 70/30 and 50/50 NR/EPDM blends prepared by reactive processing techniques were investigated and compared with the simple, nonreactive blends. The reactive blend compounds were prepared by preheating EPDM, containing all curatives to a predetermined time related to their scorch time prior to blending with NR. For the 70/30 gum blends, four types of accelerators were studied: 2,2-mercaptobenzothiazole (MBT), 2,2-dithiobis- (benzothiazole) (MBTS), N-cyclohexyl-2-benzothiazolesulfenamide (CBS), and N-tert-butyl-2-benzothiazolesulfenamide (TBBS). When compared with the simple blends, the reactive blends cured with CBS and MBTS showed a clearly improved tensile strength whereas the increase of tensile strength in the blends cured with TBBS and MBT was marginal. However, a dramatic improvement of ultimate tensile properties in the reactive 50/50 NR/EPDM blends cured with TBBS was observed when compared with the simple blend. For the N-550-filled blends at the blend ratios of 70/30 and 50/50, the reactive-filled blends prepared under the optimized preheating times demonstrated superior tensile strength and elongation at break over the simple blends. The improved crosslink and/or filler distribution between the two rubber phases in the reactive blends accounts for such improvement in their mechanical properties. This is shown in the scanning electron micrographs of the tensile fractured surfaces of the reactive blends, which indicate a more homogeneous blend. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
- Subjects :
- Materials science
Polymers and Plastics
EPDM rubber
Scanning electron microscope
Vulcanization
General Chemistry
Carbon black
METIS-265150
Surfaces, Coatings and Films
law.invention
Natural rubber
law
visual_art
Ultimate tensile strength
Materials Chemistry
visual_art.visual_art_medium
Polymer blend
Composite material
Elongation
Subjects
Details
- ISSN :
- 10974628 and 00218995
- Volume :
- 111
- Database :
- OpenAIRE
- Journal :
- Journal of Applied Polymer Science
- Accession number :
- edsair.doi.dedup.....4b31c9038e06c7c42259cd3143b32d09