Composites of Cysteamine Functionalised Graphene Oxide and Polypropylene

2021 ◽  
Vol 36 (3) ◽  
pp. 297-313
Author(s):  
S. S. Abbas ◽  
T. McNally
Keyword(s):  
Graphene Oxide ◽  
Crystallization Behavior ◽  
Polymer Network ◽  
Filler Loading ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reduced Graphene ◽  
Crystallisation Temperature ◽  
Covalent Bridging ◽  
Rheological Percolation

Abstract Cysteamine functionalised reduced graphene oxide (rGO) was grafted to polypropylene-graft-maleic anhydride (PP-g-MA) and subsequently melt blended with PP. The covalent bridging of rGO to PP-g-MA via the cysteamine molecule and co-crystallization are routes to promoting interfacial interactions between rGO and the PP matrix. A rheological percolation threshold was achieved for a nanofiller loading between 3 wt% and 5 wt%, but none detected for the composites prepared with un-functionalized rGO. At low loadings (0.1 wt%), functionalized rGO is well dispersed in the PP matrix, an interconnecting filler-filler, polymer-filler and polymer-polymer network is formed, resulting in increased tensile toughness (1 500%) and elongation at break (40%) relative to neat PP. Irrespective of whether the rGO was functionalised or not, it had a significant effect on the crystallization behavior of PP, inducing heterogeneous nucleation, increasing the crystallisation temperature (Tm) of PP by up to 10°C and decreasing the crystalline content (Xc) by ∼30% for the highest (5 wt%) filler loading. The growth of the monoclinic a-phase of PP is preferred on addition of functionalised rGO and b crystal growth suppressed.

scholarly journals Boron nitride nanoplatelets as two-dimensional thermal fillers in epoxy composites: new scenarios at very low filler loadings

2020 ◽  
Vol 40 (10) ◽  
pp. 859-867
Author(s):  
Yao Shi ◽  
Genlian Lin ◽  
Xi-Fei Ma ◽  
Xiao Huang ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Boron Nitride ◽  
Filler Content ◽  
Hexagonal Boron Nitride ◽  
Filler Loading ◽  
Epoxy Composites ◽  
General Phenomenon ◽  
Sudden Drop ◽  
Reduced Graphene ◽  
Thermal Conducting

AbstractHexagonal boron nitride (h-BN) nanoplatelets (0.6 μm in diameter and 100 nm in thickness) are introduced into epoxy resin to improve the polymer’s thermal conducting ability. As expected, the thermal conductivities (TCs) of the composites, especially the in-plane TCs, are significantly increased. The in-plane TC of the epoxy composites can reach 1.67 W/mK at only 0.53 wt% loading, indicating h-BN nanopletelets are very effective thermal fillers. However, after carefully studied the correlation of the TC improvement and filler content, a sudden drop of the TC around 0.53 wt% filler loading is observed. Such an unexpected decrease in TC has never been reported and is also found to be consistent with the Tg changes versus filler content. Similar trend is also observed in other 2-D nanofillers, such as graphene oxide, reduced graphene oxide, which may indicate it is a general phenomenon for 2-D nanofillers. SEM results suggest that such sudden drop in TC might be coming from the enrichment of these 2-D nanofillers in localized areas due to their tendency to form more ordered phase above certain concentrations.

Effect of Vulcanization Temperature and Different Fillers on the Properties of Efficiently Vulcanized Natural Rubber

1979 ◽  
Vol 52 (2) ◽  
pp. 263-277 ◽  
Author(s):  
R. Mukhopadyay ◽  
S. K. De
Keyword(s):  
Particle Size ◽  
Natural Rubber ◽  
Crosslinking Density ◽  
Filler Loading ◽  
Zinc Stearate ◽  
Curing Temperature ◽  
Abnormal Behavior ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reinforcing Fillers

Abstract The present work deals with effect of vulcanization temperature on the polymer-filler interaction parameter, vulcanizate structure, and the technical properties of efficiently vulcanized natural rubber stocks in the presence of different fillers. We have used carbon blacks of four different particle sizes (ISAF, HAF, SRF, FT), reinforcing silica, and whiting. In the case of black fillers, as the particle size increases, reversion resistance increases. For all fillers, an increase of curing temperature from 150 to 180°C caused a reduction in strength, modulus, hardness, resilience; and an increase in elongation at break, compression set, and heat build-up. However, the flexing properties and abrasion loss showed improvement at higher curing temperature. Kraus' plots indicate that increase of curing temperature caused reduction in polymer-filler attachment. At both curing temperatures, the activity of fillers follow the order, ISAF > HAF > SRF > FT. Silica showed erratic behavior in that Kraus plots indicate nonreinforcement by the filler. Whiting also behaved abnormally with respect to Kraus plots; at lower filler loading, the system is nonadherent, becoming weakly adherent at higher concentrations. The abnormal behavior of silica-filled compounds has been explained on the basis of a reaction on the silica surface between silanol groups and zinc stearate. Westlinning and Wolff's αF values were found to be independent of curing temperature and characteristic of fillers only (the larger the particle size, the lower is the αF value). The increase in apparent crosslinking density in the case of reinforcing fillers is due to increased υr arising out of increased polymer-filler interaction. Therefore, the sulfur inefficiency parameters (E values) and zinc sulfide efficiency parameters (F values) become less significant in filled vulcanizates.

scholarly journals Non-Isothermal Crystallization Behavior and Thermal Properties of Polyethylene Tuned by Polypropylene and Reinforced with Reduced Graphene Oxide

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1428
Author(s):  
Antimo Graziano ◽  
Otavio Augusto Titton Dias ◽  
Christian Garcia ◽  
Shaffiq Jaffer ◽  
Jimi Tjong ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Thermal Properties ◽  
Reduced Graphene Oxide ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Research Work ◽  
Deformation Resistance ◽  
Reduced Graphene ◽  
Heat Deformation

This research work is the first to report thermal stability, heat deformation resistance, and crystallization behavior of a Polyethylene (PE)-based biphasic polyolefin system reinforced with Reduced Graphene Oxide (RGO), which was obtained through Graphene Oxide (GO) chemical reduction. Polypropylene (PP) represented the polymeric dispersed phase. A strategic PE/PP/RGO manufacturing procedure was employed to thermodynamically localize RGO at the PE/PP interface, as confirmed by Transmission Electron Microscopy (TEM), bringing a uniform micro phase dispersion into the macro phase. In addition, studies of PE non-isothermal crystallization kinetics indicated that the morphology tunable micro phase and the nanolayered RGO promoted a nucleation-controlled PE crystallization, which was supported by Polarized Light Optical Microscopy (PLOM). This, together with fine morphology, justified the remarkable enhancement registered for the ternary system’s thermal stability and heat deformation resistance. Different filler loads were employed, with weight fractions of 2% and 4%. It was observed that the former, being better exfoliated and more homogeneously distributed at the PE/PP interface than the latter, led to a more improved PE crystallization, alongside a greater ternary system’s thermal properties. Moreover, the thermal stability of PE/PP reinforced with 2% of RGO was even higher than that of virgin PP, while their heat deformation resistance values were found to be similar. Therefore, this unique outcome provides industries, such as the energy and automotive sectors, with the opportunity to substitute PP-rich products with those mostly comprised of a cheaper, more abundant, yet performant PE.

scholarly journals Reduced graphene oxide (RGO) enriched polymer network for highly-enhanced electro-optic performance of a liquid crystalline blue phase

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16650-16654 ◽  
Author(s):  
MinSu Kim ◽  
R. K. Mishra ◽  
Ramesh Manda ◽  
G. Murali ◽  
Tae-Hyung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Response Time ◽  
Reduced Graphene Oxide ◽  
Liquid Crystalline ◽  
Polymer Network ◽  
Voltage Response ◽  
Electro Optic ◽  
Reduced Graphene ◽  
Blue Phase

A reduced graphene oxide enriched polymer network enhances the operation voltage, response time, and hysteresis of a liquid crystalline blue phase.

Properties of radiation vulcanised natural rubber latex (RVNRL)–graphene nanocomposites

2018 ◽  
Vol 26 (8-9) ◽  
pp. 461-472
Author(s):  
K Anand ◽  
Siby Varghese ◽  
Thomas Kurian
Keyword(s):  
Graphene Oxide ◽  
Natural Rubber ◽  
Filler Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Graphene Nanocomposites ◽  
Exfoliated Graphene ◽  
Green Route ◽  
Reduced Graphene

Graphene-related materials such as graphene oxide (GO)/exfoliated graphene oxide (XGO) and reduced graphene oxide (RGO) recently achieved much interest in nanocomposite research. In this study, we report the synthesis of RGO by a green route, and its efficacy as a potential filler for radiation-vulcanised natural rubber latex (RVNRL) was explored. The synthesised XGO and RGO suspensions were characterised. The mechanical, morphological and electrical properties of the RVNRL-XGO/RGO nanocomposites were evaluated as a function of filler content. The percolation threshold of the RVNRL-RGO composite was 0.1 wt%. Compared with gum RVNRL, significant improvements in tensile strength and elongation at break were obtained for RVNRL-XGO nanocomposites at 1 wt% XGO loading, indicating increased polymer–filler interaction. The morphological results showed aggregation of filler particles at a concentration of 1.25 wt%.

Heterogeneous iron–nickel compound/RGO composites with tunable microwave absorption frequency and ultralow filler loading

2020 ◽  
Vol 22 (16) ◽  
pp. 8639-8646 ◽  
Author(s):  
Miaomiao Zhang ◽  
Zhiyang Jiang ◽  
Haoxu Si ◽  
Xuefeng Zhang ◽  
Caixia Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Microwave Absorption ◽  
High Efficiency ◽  
Filler Loading ◽  
Nickel Compound ◽  
Absorption Frequency ◽  
Reduced Graphene ◽  
Iron Nickel ◽  
Oxide Composites ◽  
Tunable Absorption

Heterogeneous iron–nickel compound/reduced graphene oxide composites were fabricated to obtain lightweight and high-efficiency microwave absorption materials with tunable absorption frequency.

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