Study of Electrospun Poly\acrylonitrile (PAN) and PAN/CNT Composite Nanofibrous Webs

2015 ◽  
Vol 19 (1) ◽  
pp. 36-45 ◽  
Author(s):  
M. K. Sinha ◽  
B. R. Das ◽  
A. Srivastava ◽  
A. K. Saxena
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Specific Conductivity ◽  
Research Work ◽  
Fibre Diameter ◽  
Nonwoven Fabric ◽  
Coating Process ◽  
Carbon Nano Tube ◽  
Conductive Properties ◽  
Poly Acrylonitrile

The electrospinng of PAN and PAN/CNT composite webs is carried out with the commercially available Nanospider machine. The webs are spun under similar processes and coated on Polypropylene spun bonded nonwoven fabric. This research work reports on the influence of multi-walled carbon nano tube (MWCNT) on the morphology, tensile properties, conductivity, thermal, chemical and crystalline structure of PAN and PAN/CNT composite nanofibrous webs. The morphological developments are explained on the basis of nanofibre diameter and web density as depicted by FESEM images. An addition of CNT greatly affects the morphology of webs, increases fibre diameter, decreases web density and leads to a roughened web surface. The mechanical properties of PAN /CNT composite webs are also found to be influenced by CNT concentration. The addition of MWCNT to PAN enhances the conductive properties of webs. The specific conductivity of PAN/CNT composite webs is found to be in order of 10-6 S/cm, which falls in the semiconducting regime and follows Ohm's law of conductivity. The TGA plots confirmed that the PAN/CNT composite web is more thermally stable than the PAN web. The presence of CNT in the polymer matrix is evidenced by D and G band, indicating a successful electrospun coating process.

Improvement of Mechanical Properties and Self-Healing Efficiency by Ex-Situ Incorporation of TiO2 Nanoparticles to a Waterborne Poly(urethane-urea)

2019 ◽  
Author(s):  
Iñigo Díez-García ◽  
Arantxa Eceiza ◽  
Agnieszka Tercjak
Keyword(s):  
Mechanical Properties ◽  
Tio2 Nanoparticles ◽  
Polymer Matrix ◽  
Research Work ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Self Healing ◽  
Force Microscopy ◽  
Healing Efficiency ◽  
Conductive Properties

This research work was focused on the incorporation of TiO2 nanoparticles into synthesized solvent-free waterborne poly(urethane-urea) based on hydrophilic poly(ethylene oxide) (PU0) in order to improve both mechanical properties and self-healing effectiveness of polymer matrix. The incorporation of TiO2 nanoparticles resulted in a successful enhancement of mechanical properties of nanocomposite films if compare to PU0. Simultaneously, obtained nanocomposite films did not only maintain the self-healing ability of PU0 film, measured by means of mechanical properties after successive cutting/recovery cycles, but also showed higher self-healing efficiency than the PU0 film. Moreover, well-dispersed TiO2 nanoparticles, visualized by atomic force microscopy (AFM), kept their electrical conductive properties when embedded in the PU0 matrix, as was confirmed by electrostatic force microscopy (EFM). This research work described a simple and industrially appealing way to control the dispersion of commercially available TiO2 nanoparticles in waterborne poly(urethane-urea) for the designing of inorganic/organic hybrid nanocomposites with enhanced mechanical properties and self-healing efficiency in which TiO2 nanoparticles preserved their conductive properties within the polymer matrix.

scholarly journals Improvement of Mechanical Properties and Self-Healing Efficiency by Ex-Situ Incorporation of TiO2 Nanoparticles to a Waterborne Poly(Urethane-Urea)

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1209 ◽  
Author(s):  
Iñigo Díez-García ◽  
Arantxa Eceiza ◽  
Agnieszka Tercjak
Keyword(s):  
Mechanical Properties ◽  
Tio2 Nanoparticles ◽  
Polymer Matrix ◽  
Research Work ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Self Healing ◽  
Force Microscopy ◽  
Healing Efficiency ◽  
Conductive Properties

This research work was focused on the incorporation of TiO2 nanoparticles into synthesized solvent-free waterborne poly(urethane-urea) (WPUU) based on hydrophilic poly(ethylene oxide) (PU0) in order to improve both the mechanical properties and self-healing effectiveness of a polymer matrix. The incorporation of TiO2 nanoparticles resulted in a successful enhancement of the mechanical properties of nanocomposite films when compared to PU0. Simultaneously, the obtained nanocomposite films did not only maintain the self-healing ability of the PU0 film, measured by means of mechanical properties after successive cutting/recovery cycles, but they also showed a higher self-healing efficiency than the PU0 film. Moreover, the well-dispersed TiO2 nanoparticles, visualized by atomic force microscopy (AFM), kept their conductive properties when embedded in the PU0 matrix, as was confirmed by electrostatic force microscopy (EFM). This research work described a simple and industrially appealing way to control the dispersion of commercially available TiO2 nanoparticles in waterborne poly(urethane-urea) for the designing of inorganic/organic hybrid nanocomposites with enhanced mechanical properties and self-healing efficiency, in which TiO2 nanoparticles preserved their conductive properties within the polymer matrix.

scholarly journals Dynamic Response of Thermally Bonded Bicomponent Fibre Nonwovens

2011 ◽  
Vol 70 ◽  
pp. 405-409 ◽  
Author(s):  
Emrah Demirci ◽  
Memiş Acar ◽  
Behnam Pourdeyhimi ◽  
Vadim V. Silberschmidt
Keyword(s):  
Mechanical Properties ◽  
Dynamic Response ◽  
Fibre Diameter ◽  
Orientation Distribution ◽  
Nonwoven Fabric ◽  
Woven Fabrics ◽  
Core Material ◽  
Finite Element Software ◽  
Anisotropic Mechanical Properties ◽  
Fibre Matrix

Having a unique microstructure, nonwoven fabrics possess distinct mechanical properties, dissimilar to those of woven fabrics and composites. This paper aims to introduce a methodology for simulating a dynamic response of core/sheath-type thermally bonded bicomponent fibre nonwovens. The simulated nonwoven fabric is treated as an assembly of two regions with distinct mechanical properties. One region - the fibre matrix – is composed of non-uniformly oriented core/sheath fibres acting as link between bond points. Non-uniform orientation of individual fibres is introduced into the model in terms of the orientation distribution function in order to calculate the structure’s anisotropy. Another region – bond points – is treated in simulations as a deformable bicomponent composite material, composed of the sheath material as its matrix and the core material as reinforcing fibres with random orientations. Time-dependent anisotropic mechanical properties of these regions are assessed based on fibre characteristics and manufacturing parameters such as the planar density, core/sheath ratio, fibre diameter etc. Having distinct anisotropic mechanical properties for two regions, dynamic response of the fabric is modelled in the finite element software with shell elements with thicknesses identical to those of the bond points and fibre matrix.

scholarly journals INFLUENCE OF CONDUCTIVE POLYMER FILLER ON ELECTRICAL CONDUCTIVITY AND MICROHARDNESS OF COMPOSITES WITH DIELECTRIC POLYMERIC MATRICES

2020 ◽  
Vol 2020 (60) ◽  
pp. 14-21
Author(s):  
Galyna MARTYNІUK ◽  
◽  
Olena AKSIMENTYEVA ◽  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Conjugated Polymers ◽  
Polymer Matrix ◽  
Specific Conductivity ◽  
Conductive Polymer ◽  
Polymer Matrices ◽  
Material Strength ◽  
Contact Method ◽  
Polymer Filler

Nowadays special attention is given to the so-called “smart-materials” or “intellectual” materials, which have the ability to purposefully change their physical and physical-chemical properties depending on changing external conditions. Conductive conjugated polymers–polyaniline (РАNi) and its derivatives may alter their properties in response to external action–exhibit sensory sensitivity, electrochromic, thermochromic and solvatochromic effects. When creating РАNi composites with industrial polymer matrices, an important issue is to determine the physical and mechanical properties, in particular, the microhardness as a material strength characteristic. The composite samples were obtained by the method of thermal pressing of highly dispersed powders of the conductive polymers dispersed in the polymer matrices. The mechanical properties of the composites were studied by the method of measuring microhardness and boundary microhardness on a Heppler consistometer. The determination of the electrical conductivity of the composites in the molded samples was determined by the standard 2-contact method at a temperature T = 293 K. The influence of the acid doped polyaniline (РАNi) as a conductive polymer filler on the microhardness of composites with polymer matrices of different structure (polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), polybuthyl methacrylate (PBMA), epoxy resin ED-20) was studied. It is found that the nature of the interaction between the polymer matrix and the conductive polymer filler depends on its content and the structure of the matrix, which is manifested in the growth of microhardness for composites PBMA–РАNi and ED-20−РАNi and its reduction for composites PVA–РАNi at the contents of the filler 5−20 %. The dielectric polymer matrix preserves the properties inherent in both high polymers (high elasticity, thermoplasticity) and the semiconductor nature of the electrical conductivity inherent in the conjugated polymers. The value of the specific conductivity of the composites obtained well correlated with changes in microhardness, which is a confirmation of the enhancing or loosening nature of the interaction between the polymer matrix and the conductive polymeric filler.

Influence of conductive polymer filler on electrical conductivity and microhardness of composites with dielectric polymeric matrices

2019 ◽  
pp. 80-86
Author(s):  
G. V. Martyniuk ◽  
O. I. Aksimentyeva
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Conjugated Polymers ◽  
Polymer Matrix ◽  
Specific Conductivity ◽  
Conductive Polymer ◽  
Polymer Matrices ◽  
Material Strength ◽  
Contact Method ◽  
Polymer Filler

Nowadays special attention is given to the so-called "smart-materials" or "intellectual" materials, which have the ability to purposefully change their physical and physical-chemical properties depending on changing external conditions. Сonductive conjugated polymers - polyaniline (РАNi) and its derivatives may alter their properties in response to external action - exhibit sensory sensitivity, electrochromic, thermochromic and solvachromic effects. When creating РАNi composites with industrial polymer matrices, an important issue is to determine the physical and mechanical properties, in particular, of microhardness as a material strength characteristic. Composite samples were obtained by the method of thermal pressing of highly dispersed powders of conductive polymers dispersed in polymer matrices. The mechanical properties of the composites were studied by the method of measuring microhardness and boundary microhardness on a Heppler consistometer. The determination of the electrical conductivity of the composites in the molded samples was determined by the standard 2-contact method at a temperature T = 293 K. The influence of the acid doped polyaniline (РАNi) as an conductive polymer filler оn on the microhardness of composites with polymer matrices of different structure (polyvinyl alcohol (PVA), polymethylmethacrylate (PMMA), polybuthylmethacrylate (PBMA), epoxy resin ED-20) was studied. It is found that the nature of the interaction between the polymer matrix and the conductive polymer filler depends on its content and the structure of the matrix, which is manifested in the growth of microhardness for composites PBMA – РАNi and ED-20 - РАNi and its reduction for composites PVA– РАNi at the contents of the filler 5-20 %. The dielectric polymer matrix preserves the properties inherent in both high polymers (high elasticity, thermoplasticity) and the semiconductor nature of the electrical conductivity inherent in the conjugated polymers. The value of the specific conductivity of the composites obtained well correlated with changes in microhardness, which is a confirmation of the enhancing or loosening nature of the interaction between the polymer matrix and the conductive polymeric filler.

Economics of coated paper production made from deinked pulp

TAPPI Journal ◽  
2013 ◽  
Vol 12 (4) ◽  
pp. 19-27
Author(s):  
PATRICK HUBER ◽  
LAURENT LYANNAZ ◽  
BRUNO CARRÉ
Keyword(s):  
Mechanical Properties ◽  
Optimization Methods ◽  
Coating Process ◽  
Coated Paper ◽  
Paper Production ◽  
Base Paper

The fraction of deinked pulp for coated paper production is continually increasing, with some mills using 100% deinked pulp for the base paper. The brightness of the coated paper made from deinked pulp may be reached through a combination of more or less extensive deinking, compensated by appropriate coating, to optimize costs overall. The authors proposed general optimization methods combined with Kubelka-Munk multilayer calculations to find the most economical combination of deinking and coating process that would produce a coated paper made from DIP, at a given target brightness, while maintaining mechanical properties.

Effect of fibre content on the mechanical properties of hemp fibre woven fabrics/polypropylene composite laminates

2021 ◽  
pp. 096739112110239
Author(s):  
Sheedev Antony ◽  
Abel Cherouat ◽  
Guillaume Montay
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Woven Fabrics ◽  
Fibre Content ◽  
Viscoelastic Behaviour ◽  
Hemp Fibre

Nowadays natural fibre composites have gained great significance as reinforcements in polymer matrix composites. Composite material based on a polymer matrix reinforced with natural fibres is extensively used in industry due to their biodegradability, recyclability, low density and high specific properties. A study has been carried out here to investigate the fibre volume fraction effect of hemp fibre woven fabrics/PolyPropylene (PP) composite laminates on the tensile properties and impact hammer impact test. Initially, composite sheets were fabricated by the thermal-compression process with desired number of fabric layers to obtain composite laminates with different fibre volume fraction. Uniaxial, shear and biaxial tensile tests were performed and mechanical properties were calculated. Impact hammer test was also carried out to estimate the frequency and damping parameters of stratified composite plates. Scanning Electron Microscope (SEM) analysis was performed to observe the matrix and fibre constituent defects. Hemp fabrics/PP composite laminates exhibits viscoelastic behaviour and as the fibre volume fraction increases, the viscoelastic behaviour decreases to elastic behaviour. Due to this, the tensile strength increases as the fibre content increases. On the other hand, the natural frequency increases and damping ratio decrease as the fibre volume fraction increases.

Effects of the Mould Pressure and Mould Pressing Time on the Properties of Graphite/Phenolic Resin Composites

2013 ◽  
Vol 706-708 ◽  
pp. 95-98
Author(s):  
Mi Dan Li ◽  
Dong Mei Liu ◽  
Lu Lu Feng ◽  
Huan Niu ◽  
Yao Lu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Flexural Strength ◽  
Polymer Matrix ◽  
Phenolic Resin ◽  
Polymer Matrix Composites ◽  
Resin Composites ◽  
Matrix Composites ◽  
Natural Graphite ◽  
Pressing Time

Polymer matrix composites made from phenolic resin are filled with natural graphite powders. They are fabricated by compression molding technique. The density, electrical conductivity and flexural strength of composite are analyzed to determine the influences of mould pressure and mould pressing time on the physical, electrical and mechanical properties of composite. It is found that the density, electrical conductivity and flexural strength of composites increased with increasing mould pressure. Under pressure of 40 MPa for 60 min, the density, electrical conductivity and flexural strength of composites were 1.85 g/cm3, 4.35  103 S/cm and 70 MPa, respectively. The decreased gaps could be the main reason for the increasing of density, electrical conductivity and flexural strength as mould pressure increases. The results also show that the density of composites increased with increasing mould pressing time.

Morphology and Mechanical Properties of Poly(Lactic Acid) and Propylene-Ethylene Copolymer Blends: Effect of Organoclay Types

2017 ◽  
Vol 737 ◽  
pp. 269-274
Author(s):  
Sirirat Wacharawichanant ◽  
Chaninthon Ounyai ◽  
Ployvaree Rassamee
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Tensile Properties ◽  
Polymer Matrix ◽  
Poly Lactic Acid ◽  
Dispersed Phase ◽  
Copolymer Blends ◽  
Morphology Analysis ◽  
Ethylene Copolymer ◽  
Morphology And Mechanical Properties

The effects of four types of organoclay on morphology and mechanical properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) blends were investigated. The ratio of PLA and PEC was 80/20 by weight and the organoclay content was 5 phr. The morphology analysis showed that the addition of all oganocaly types could improve the miscibility of PLA and PEC blends due to the decreased of the domain sizes of PEC dispersed phase in the polymer matrix. The tensile properties showed Young’s modulus of the PLA/PEC blends was improved after adding clay treated surface with 25-30 wt% trimethyl stearyl ammonium.

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