Carbon Nanotube Reinforced Natural Rubber Nanocomposite for Anthropomorphic Prosthetic Foot Purpose

AbstractThis research is motivated by the desire to restore the quality of life to amputees. The study uses multi-walled carbon nanotube (WMCNT) reinforced natural rubber (NR) polymer nanocomposite (PNC) for prosthetic foot application. The compound formulation was carried out in accordance to a modified procedure described by Hemkaew et al. Mixing of the ingredients during vulcanisation was performed according to ASTM D-3182 standard on an open two-roll mill. The various compositions of the nanocomposites (NCs) were cured at a temperature of 150 ± 2 °C and a pressure of 0.2 MPa for 10 minutes in an electrically heated hydraulic press. Mechanical investigation revealed that NR/MWCNT-3 exhibited the highest capacity to withstand tensile and dynamic loading (449.79 MPa). It also showed superior filler distribution and hence improved crystallinity and cross-link. Water absorption test indicated that NR/MWCNT-3 offers optimum dimensional stability at ambient conditions. Moreover, thermogravimetric analysis/differential thermogravimetry (TGA/DTG) showed degradation peaks at 305 °C and 290 °C respectively with temperature range within which the NCs degraded lying between 250 °C and 600 °C. Dynamic mechanical analysis (DMA) revealed that filler incorporation results in higher storage and loss moduli (2000–7500 MPa and 500–1413 MPa respectively). Tan δ curves proved that NR/MWCNT-3 has the highest capacity to dissipate energy through segmental motion. Furthermore, microstructure examination confirmed good filler/matrix adhesion as NR/MWCNT-3 indicated improved interaction; hence higher strength (6.02 MPa) of the NC. Better wear resistance ability can also be reported of the newly developed than existing prosthetic material. It can be deduced that the formulated nanocomposite from MWCNTs for reinforced natural rubber is suitable for the development of the anthropomorphic prosthetic foot.

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A titanium dioxide–carbon nanotube hybrid to simultaneously achieve the mechanical enhancement of natural rubber and its stability under extreme frictional conditions

Materials Advances ◽

10.1039/d0ma00823k ◽

2021 ◽

Vol 2 (7) ◽

pp. 2408-2418

Author(s):

Le Wan ◽

Cong Deng ◽

Ze-Yong Zhao ◽

Hai-Bo Zhao ◽

Yu-Zhong Wang

Keyword(s):

Titanium Dioxide ◽

Carbon Nanotube ◽

Natural Rubber ◽

Titanium Oxide ◽

The Stability

Titanium oxide-carbon nanotube hybrids may efficiently promote the stability of nature rubber under extreme frictional conditions.

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Preparation and characterization of acrylic polymer titania hybrid. A study of organicinorganic interactions in hybrid materials by micro-hardness Vickers

MRS Proceedings ◽

10.1557/proc-726-q6.23 ◽

2002 ◽

Vol 726 ◽

Cited By ~ 1

Author(s):

Van Nhan Nguyen ◽

François Xavier Perrin ◽

Jean-Louis Vernet

Keyword(s):

Mechanical Properties ◽

Large Scale ◽

Sol Gel ◽

Mechanical Analysis ◽

Polymer Chains ◽

Segmental Motion ◽

Acrylic Polymer ◽

Titania Content ◽

Mineral Constituent ◽

Free Films

AbstractMetal-oxide ceramer films have been developed using an acrylic polymer bearing a low amount of methacrylic acid units (ca. 4%mol) as the organic phase with titanium tetrabutoxide as the inorganic sol-gel precursor. The characterisation of free films was realized by various experimental methods. The formation of COOTi bonds prevents large scale phase separation between the organic component and the mineral network. Mechanical properties of the hybrid films have been investigated through dynamic mechanical analysis. The influence of the titania content on the damping peak amplitude suggests that titania is molecularly dispersed in the polymer matrix and that it significantly hinders the segmental motion of the polymer chains. However, the low content in potential carboxylic crosslinking sites explains why the glass transition temperature remains relatively unchanged when titania content increases. Vickers microhardness measurements used in this study allowed us to understand the contribution of the inorganic part (phase TiO2) to the mechanical properties of the polymer. The creep of hybrids has been studied carrying out hardness measurements under various indentation times. The mineral constituent leads to an important increase of the hardness and limits, in a significant way, the creep of polymer.

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A Novel Method of Mechanical Oxidation of CNT for Polymer Nanocomposite Application: Evaluation of Mechanical, Dynamic Mechanical, and Rheological Properties

International Journal of Chemical Engineering ◽

10.1155/2014/623109 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Priyanka Pandey ◽

Smita Mohanty ◽

Sanjay Kumar Nayak

Keyword(s):

Rheological Properties ◽

Load Transfer ◽

Polymer Nanocomposite ◽

Mechanical Analysis ◽

Acid Oxidation ◽

Reinforced Composites ◽

Dynamic Mechanical ◽

Comparative Aspect ◽

Transfer Capability ◽

Novel Method

A new approach of oxidation of carbon nanotubes has been used to oxidize the CNTs. A comparative aspect of the mechanical oxidation and acid oxidation process has been established. FTIR analysis and titration method have shown the higher feasibility of the mechanical oxidation method to oxidize the CNTs. Comparatively less damage to the CNTs has been observed in case of mechanically oxidized as compared to acid oxidized CNTs. The mechanical properties of the nanocomposites reinforced with the acid oxidized CNT (ACNT) and mechanically oxidized CNTs (McCNT) were analyzed and relatively higher properties in the nanocomposites reinforced with McCNT were noticed. The less degree of entanglement in the McCNTs was noticed as compared to ACNTs. The dynamic mechanical analysis of the nanocomposites revealed much improved load transfer capability in the McCNT reinforced composites. Further, the rheological properties of the nanocomposites revealed the higher performance of McCNT reinforced composites.

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EFFECT OF DEVULCANIZATION ON CROSSLINK DENSITY AND CROSSLINK DISTRIBUTION OF CARBON BLACK FILLED NATURAL RUBBER VULCANIZATES

Rubber Chemistry and Technology ◽

10.5254/rct.16.84819 ◽

2016 ◽

Vol 89 (4) ◽

pp. 653-670 ◽

Cited By ~ 4

Author(s):

Anu Mary Joseph ◽

Benny George ◽

Madhusoodanan K. N. ◽

Rosamma Alex

Keyword(s):

Carbon Black ◽

Natural Rubber ◽

Crosslink Density ◽

Morphological Properties ◽

Original Sample ◽

Ambient Conditions ◽

Absolute Value ◽

Roll Mill ◽

Percentage Retention ◽

The Absolute

ABSTRACTCarbon black filled natural rubber (NR) vulcanizates were devulcanized at ambient temperature in a two roll mill. The effect of cure system, that is, conventional vulcanization (CV), semiefficient vulcanization (semi EV), and efficient vulcanization (EV) systems, used for vulcanization of the original sample, on the efficiency of devulcanization was studied. The efficiency of devulcanization expressed as percentage devulcanization of the samples calculated from residual crosslink density measurements was correlated with the sol fraction of the devulcanized samples based on Horikx analysis. Using chemical probe analysis, we determined (i) the crosslink distribution pattern of the original sample, (ii) the extent to which the different types of crosslinks—that is, polysulfidic, disulfidic, and monosulfidic crosslinks—have been debonded or broken during the shearing process in the two roll mill, and (iii) the pattern of bond formation during revulcanization. Mechanical shearing predominantly breaks the majority crosslink type (polysulfidic crosslinks in CV and semi EV cure systems and disulfidic crosslinks in EV samples). Irrespective of the significant reduction in total crosslink density in all three sets of samples, chain shortening reactions similar to the post-crosslinking chemical reactions at curing temperatures also occur during mechanical shear at ambient conditions, which increased the absolute value of monosulfidic links in CV and semi EV systems. However, in the devulcanized EV system, the absolute value of polysulfidic crosslinks increased, which might be due to the re-crosslinking of the cleaved bonds. All the devulcanized samples were revulcanized, and the mechanical and morphological properties were analyzed. The percentage retention of the vulcanizate properties after revulcanization of the devulcanized samples correlated very well with efficiency of devulcanization.

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Modeling of the Elastic Damping Response of a Carbon Nanotube–Polymer Nanocomposite in the Stress-Strain Domain Using an Elastic Energy Release Approach Based on Stick-Slip

Mechanics of Advanced Materials and Structures ◽

10.1080/15376494.2012.677100 ◽

2013 ◽

Vol 20 (10) ◽

pp. 791-800 ◽

Cited By ~ 16

Author(s):

Vasilios Spitas ◽

Christos Spitas ◽

Paul Michelis

Keyword(s):

Carbon Nanotube ◽

Energy Release ◽

Elastic Energy ◽

Polymer Nanocomposite ◽

Stress Strain ◽

Stick Slip

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Self-healing properties of carbon nanotube filled natural rubber/bromobutyl rubber blends

eXPRESS Polymer Letters ◽

10.3144/expresspolymlett.2017.24 ◽

2017 ◽

Vol 11 (3) ◽

pp. 230-242 ◽

Cited By ~ 24

Author(s):

H. H. Le ◽

S. Hait ◽

A. Das ◽

S. Wiessner ◽

K. W. Stoeckelhuber ◽

...

Keyword(s):

Carbon Nanotube ◽

Natural Rubber ◽

Self Healing ◽

Rubber Blends

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A closed-form model for estimating the effective thermal conductivities of carbon nanotube–polymer nanocomposites

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406218797967 ◽

2018 ◽

Vol 233 (8) ◽

pp. 2909-2919 ◽

Cited By ~ 11

Author(s):

Reza Moheimani ◽

M Hasansade

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Carbon Nanotube ◽

Closed Form ◽

Polymer Nanocomposites ◽

Micromechanical Model ◽

Polymer Nanocomposite ◽

Interfacial Thermal Resistance ◽

Full Potential ◽

Thermal Conductivities

This paper describes a closed-form unit cell micromechanical model for estimating the effective thermal conductivities of unidirectional carbon nanotube reinforced polymer nanocomposites. The model incorporates the typically observed misalignment and curvature of carbon nanotubes into the polymer nanocomposites. Also, the interfacial thermal resistance between the carbon nanotube and the polymer matrix is considered in the nanocomposite simulation. The micromechanics model is seen to produce reasonable agreement with available experimental data for the effective thermal conductivities of polymer nanocomposites reinforced with different carbon nanotube volume fractions. The results indicate that the thermal conductivities are strongly dependent on the waviness wherein, even a slight change in the carbon nanotube curvature can induce a prominent change in the polymer nanocomposite thermal conducting behavior. In general, the carbon nanotube curvature improves the nanocomposite thermal conductivity in the transverse direction. However, using the straight carbon nanotubes leads to maximum levels of axial thermal conductivities. With the increase in carbon nanotube diameter, an enhancement in nanocomposite transverse thermal conductivity is observed. Also, the results of micromechanical simulation show that it is necessary to form a perfectly bonded interface if the full potential of carbon nanotube reinforcement is to be realized.

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