Microwave Modification of Polymer-Carbon Materials

2019 ◽  
Vol 945 ◽  
pp. 443-447
Author(s):  
D. Zavrazhin ◽  
C. Zavrazhina
Keyword(s):  
Carbon Nanotubes ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Melting Zone ◽  
Polyamide 6 ◽  
Electrically Conductive ◽  
Microwave Exposure ◽  
Microwave Effect ◽  
Improved Performance ◽  
Conductive Particles

Studies of microwave radiation on polymeric materials have shown the possibility of modifying the characteristics of materials. At the same time, the efficiency of the microwave effect can be increased by introducing into the polymer matrix electrically conductive particles (carbon, metal particles, etc.). In this case, the absorption coefficient of the microwave waves is greatly increased. The paper evaluated the physical and mechanical properties of polyamide 6 subjected to microwave exposure. To intensify the microwave, well-proven carbon nanotubes were used, which were added to the polymer in small amounts. The most effective was the addition of carbon nanotubes in an amount of 1 wt%. The data obtained are changes in strength under tensile, Shore D hardness conditions, as well as thermophysical characteristics (heat resistance and change in the specific energy absorption rate in the melting zone of the samples). Microwave can be used as a modifying radiation, and as a method of heating polymers for subsequent molding in products. This method significantly reduces the technological process of obtaining materials and products with improved performance characteristics.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

scholarly journals Selection of Immiscible Polymer Blends Filled with Carbon Nanotubes for Heating Applications

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1827 ◽  
Author(s):  
Marischal ◽  
Cayla ◽  
Lemort ◽  
Campagne ◽  
Devaux
Keyword(s):  
Carbon Nanotubes ◽  
Melt Spinning ◽  
Filler Content ◽  
Conductive Polymer ◽  
Polyamide 6 ◽  
Electrically Conductive ◽  
Joule Effect ◽  
Immiscible Blends ◽  
Selective Localization ◽  
Application Fields

In many application fields, such as medicine or sports, heating textiles use electrically conductive multifilaments. This multifilament can be developed from conductive polymer composites (CPC), which are blends of an insulating polymer filled with electrically conductive particles. However, this multifilament must have filler content above the percolation threshold, which leads to an increase of the viscosity and problems during the melt spinning process. Immiscible blends between two polymers (one being a CPC) can be used to allow the reduction of the global filler content if each polymer is co-continuous with a selective localization of the fillers in only one polymer. In this study, three immiscible blends were developed between polypropylene, polyethylene terephthalate, or polyamide 6 and a filled polycaprolactone with carbon nanotubes. The morphology of each blend at different ratios was studied using models of co-continuity and prediction of fillers localization according to viscosity, interfacial energy, elastic modulus, and loss factor of each polymer. This theoretical approach was compared to experimental values to find out differences between methods. The electrical properties (electrical conductivity and Joule effect) were also studied. The co-continuity, the selective localization in the polycaprolactone, and the Joule effect were only exhibited by the polypropylene/filled polycaprolactone 50/50 wt.%.

scholarly journals Effect of polymer and functional additives on the properties of bitumen and asphalt-concrete

2020 ◽  
Vol 1 (11-12) ◽  
pp. 47-49
Author(s):  
N. P. Kotenko ◽  
Yu. S. Shcherba ◽  
A. S. Evforitskiy
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Asphalt Concrete ◽  
Warm Season ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Repair Work ◽  
Concrete Mixtures ◽  
Functional Additives ◽  
Functional Additive

The possibility of modifying the oil road bitumen of the BND 70/100 grade is investigated; it belongs to the category of viscous bitumen and is used for road works in the warm season, with an average daily temperature not lower than +5°C. The material is widely used for repair work, and for laying new roads. Copolymers of styrene with butadiene and ethylene with vinyl acetate were used as polymeric materials for polymer-bitumen binders (PBV). Their optimal concentrations were determined for obtaining PBV with increased heat resistance and elasticity. Carbon nanotubes were used as a functional additive to bitumen.. The physical and mechanical properties of modifi ed bitumen and asphalt concrete mixtures based on them are given. It was shown that the introduction of even a small amount of nanotubes into asphalt concrete leads to an increased shear stability and strength at diff erent temperatures from 0 to 50°C.

Nanocomposite Films derived from Alkoxysilane Terminated Amide Acid Oligomers and Carbon Nanotubes

2002 ◽  
Vol 733 ◽  
Author(s):  
Joseph G. Smith ◽  
John W. Connell ◽  
Peter Lillehei ◽  
Kent A. Watson ◽  
Craig M. Thompson
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Color Space ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Nanocomposite Films ◽  
Single Wall Carbon Nanotubes ◽  
Sulfuric Acid Treatment ◽  
Potential Applications ◽  
Radiation Resistant

AbstractLow color, space environmentally stable, polymeric materials with sufficient electrical conductivity for static charge dissipation are of interest for potential applications on Gossamer spacecraft. One method of imparting electrical conductivity while maintaining optical clarity is through the use of single wall carbon nanotubes (SWNTs). Both theory and research on SWNTs have shown them to be conductive. However, SWNTs are very difficult to uniformly disperse in a polymer. The approach described herein was to use oligomers endcapped with functional groups that could condense with functionalities present on purified, laser ablated SWNTs. Low color, radiation resistant amide acid oligomers endcapped with trialkoxysilane groups were combined with SWNTs. Since the SWNTs were purified by an oxidative process (nitric/sulfuric acid treatment), they have functionalities such as hydroxyl and carboxylic acid groups that can condense with the terminal alkoxysilane groups. After mixing at room temperature, the mixtures were used to cast films that were subsequently stage-cured up to 300°C for 1 hour in air. During this thermal treatment, imidization and condensation occurred. The chemistry, physical, and mechanical properties of the resulting nancomposite films will be presented.

Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Chemical Modification ◽  
Medical Devices ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Modern Medicine ◽  
Structural Failure ◽  
Chemical Grafting ◽  
One Step

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.

scholarly journals Electrically Conductive Networks from Hybrids of Carbon Nanotubes and Graphene Created by Laser Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1875
Author(s):  
Alexander Yu. Gerasimenko ◽  
Artem V. Kuksin ◽  
Yury P. Shaman ◽  
Evgeny P. Kitsyuk ◽  
Yulia O. Fedorova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Laser Irradiation ◽  
Flexible Electronics ◽  
Threshold Energy ◽  
Wavelength Region ◽  
Hybrid Nanostructures ◽  
Graphene Sheets ◽  
Electrically Conductive ◽  
Walled Carbon Nanotubes

A technology for the formation of electrically conductive nanostructures from single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), and their hybrids with reduced graphene oxide (rGO) on Si substrate has been developed. Under the action of single pulses of laser irradiation, nanowelding of SWCNT and MWCNT nanotubes with graphene sheets was obtained. Dependences of electromagnetic wave absorption by films of short and long nanotubes with subnanometer and nanometer diameters on wavelength are calculated. It was determined from dependences that absorption maxima of various types of nanotubes are in the wavelength region of about 266 nm. It was found that contact between nanotube and graphene was formed in time up to 400 fs. Formation of networks of SWCNT/MWCNT and their hybrids with rGO at threshold energy densities of 0.3/0.5 J/cm2 is shown. With an increase in energy density above the threshold value, formation of amorphous carbon nanoinclusions on the surface of nanotubes was demonstrated. For all films, except the MWCNT film, an increase in defectiveness after laser irradiation was obtained, which is associated with appearance of C–C bonds with neighboring nanotubes or graphene sheets. CNTs played the role of bridges connecting graphene sheets. Laser-synthesized hybrid nanostructures demonstrated the highest hardness compared to pure nanotubes. Maximum hardness (52.7 GPa) was obtained for MWCNT/rGO topology. Regularity of an increase in electrical conductivity of nanostructures after laser irradiation has been established for films made of all nanomaterials. Hybrid structures of nanotubes and graphene sheets have the highest electrical conductivity compared to networks of pure nanotubes. Maximum electrical conductivity was obtained for MWCNT/rGO hybrid structure (~22.6 kS/m). Networks of nanotubes and CNT/rGO hybrids can be used to form strong electrically conductive interconnections in nanoelectronics, as well as to create components for flexible electronics and bioelectronics, including intelligent wearable devices (IWDs).

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