Table 3.
Types of carbonaceous nano fillers, preparative methods adopted and morphology of NR nanocomposites.
| Rubber | Filler | Method of Preparation | Morphology | Ref. |
|---|---|---|---|---|
| NBR/PA6 | Functionalized SWCNT | Melt mixing process in internal mixer | TEM: homogenous dispersion of SWNT in the PA6 phase | [91] |
| NBR/PVC blends | SWCNT | Brabender internal mixer | TEM: Fine dispersion of functionalized SWNTs (1.5 phr) is observed NBR/PVC. | [92] |
| NBR | CNT | Lab mixing | — | [93] |
| HNBR | CNT | Roll and mixing solvent methods | TEM: The modified CNTs disperse very well in HNBR when the ultrasonic pre-dispersing technique is utilized to prepare composites. | [94] |
| NBR | MWCNT | Two roll mill | TEM: Dry mixing process is quite effective to disperse and distribute CNTs in NBR. | [95] |
| NBR | MWCNT | Two roll mill | TEM: MWCNT (6 phr)/NBR vulcanizates show enhanced dispersion of filler by increased mixing time. | [96] |
| NBR | MWCNT, CB, conductive CB | Two roll mill | — | [97] |
| HNBR | MWCNT | Two roll mill method | SEM: Fine dispersion of MWCNT (20 phr) in NBR. | [99] |
| NBR and HNBR | MWCNT | Melt compounding | TEM/SEM: Exfoliation and intercalation of nanotubes in (H)NBR matrix. | [100] |
| NBR | Expanded graphite | Mechanical blending (microcomposites) and latex compounding technique | SEM: graphite disperses more uniformly with smaller lamellar agglomerates in composites. | [101] |
| NBR | Expanded graphite | Melt mixing | TEM: Nanoscale dispersion of graphite sheets within NBR matrix. | [102] |
| Carboxylic NBR | MWCNT | Solution mixing method | HRTEM: Wrinkled and folded sheets of GNS–HDA in 1 phr and 1.5 phr GNS–HDA filled XNBR composites | [104] |
| NBR | Graphene | Melt mixing | TEM: Composite with 10 vol % graphenes (xg-M-5) in NBR with 20 vol % softener (DOP) showed exfoliation/breakdown of the graphene nanoplatelets. | [106] |
| NBR | Silica/MWCNT | Melt mixing | SEM: Good dispersion of silica and CNT fillers in NBR. | [107] |
| TPPU-XNBR | MWCNT | Laboratory roll mill | TEM: MWCNT (3 wt %) are preferentially distributed in XNBR phase. However, 5 wt % of MWCNTs are present in TPPU phase. | [110] |
| TPU-NBR | MWCNT/ZnAl-LDH, CNF/ZnAl-LDH | Solution intercalation | HRTEM: 0.5 wt % SFCNT-LDH and SFCNF-LDH fillers in the blend matrix consist of uniformly distributed interconnected network. | [112] |
| TPU-NBR | CNF/MgAl-LDH | Solution intercalation | HRTEM: Interconnected hybrid network spread throughout in TPU/NBR/SFCNF-LDH (0.50 wt %). | [113] |
| TPU-NBR | MWCNT-LDH | Solution intercalation | TEM: Fine dispersion of 0.50 wt % SFCNF-LDH hybrid filler is observed in TPU/NBR matrix. | [114] |
| XNBR (75 phr)/SBR(25 phr) | Graphene oxide (GO) | Coagulation/roll mill | TEM: Uniform dispersion of XNBR/SBR/GO blends (GO-0.1 phr, GO-0.3 phr). | [193] |
| SBR/XNBR | GO | Aqueous-phase mixing (GO/SBR) and a small loading of XNBR latex, followed by co-coagulation | AFM: Full exfoliation of GO nanosheets in GO-15 sample. | [194] |
| NBR | Reduced graphene oxide (rGO) | Solution mixing method | TEM: rGO0.1–1 phr) appears to be evenly dispersed in the NBR matrix. | [195] |