scholarly journals Influence of Needle-punching Parameters for the Preparation of Polypyrrole-coated Non-woven Composites for Heat Generation

Tekstilec ◽  
2021 ◽  
Vol 64 (2) ◽  
pp. 172-183
Author(s):  
Subhankar Maity ◽  
◽  
Shivangi Pandey ◽  
Alok Kumar ◽  
◽  
...  
Keyword(s):  
Heat Generation ◽  
Surface Resistivity ◽  
Woven Composites ◽  
Coated Sample ◽  
Woven Composite ◽  
Electrically Conductive ◽  
Chemical Polymerization ◽  
Needle Punching ◽  
Fibre Fineness

This work deals with the preparation and characterization of electrically conductive needle-punched non-wo¬ven composites for heat generation. Electro-conductive non-woven composites were prepared through the in situ chemical polymerization of pyrrole with FeCl3 (oxidant) and p-toluene sulfonic acid (dopant). A two-stage double-bath process was adopted for the in situ chemical polymerization of pyrrole. The effect of parameters such as fibre fineness, needle-punching density and depth of needle punching on a polypyrrole add-on, and surface resistivity were studied by employing the Box-Behnken response surface design. It was observed that fibre fineness was the most influential parameter of the polypyrrole add-on. The lowest surface resistivity of the polypyrrole coated sample (200 g/m2, prepared with a punch density of 200 punch/cm2, a punching depth of 6 mm and fibre fineness of 2.78 dtex) was found to be 9.32 kΩ/ with a polypyrrole add-on of 47.93%. This non-woven composite demonstrated good electrical conductivity and exhibited Joule’s effect of heat gener¬ation. Due to the application of a 30 V DC power supply, the surface temperature of the non-woven composite rose to 55 °C from a room temperature of 37 °C. Optical and electron microscopy images of the non-woven composites showed that PPy molecules formed a uniform coating on the non-woven surface. FTIR studies evi¬denced the coating of PPy on a polyester surface. These coated non-woven composites were highly electrically conductive and practically useful for the fabrication of heating pads for therapeutic use.

scholarly journals Textile/Polypyrrole Composites for Sensory Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Subhankar Maity ◽  
Arobindo Chatterjee
Keyword(s):  
Mechanical Strain ◽  
Cotton Fabrics ◽  
Surface Resistivity ◽  
Electrically Conductive ◽  
Chemical Polymerization ◽  
Bending Strain ◽  
Wool Fabrics ◽  
Composite Fabrics ◽  
Humidity Sensitivity

Electrically conductive woven, knitted, and nonwoven composite fabrics are prepared by in situ chemical polymerization of pyrrole using suitable oxidant and dopant. These composite fabrics show surface resistivity in the range ~1 to 2 kΩ. These composite fabric can alter their resistivity with various stimuli such as mechanical strain, pH, and humidity. So, in the present study, their response to pH, humidity, and mechanical strain is investigated. For all fabrics, similar behaviour has been observed regarding pH versus resistivity. The resistance of the composite fabric increases with the increase of alkalinity of pH. However, as bending strain increases, resistance steeply decreases for cotton fabrics, steeply increases for polyester fabrics, and initially decreases and then increases for wool fabrics. Regarding humidity sensitivity, sigmoid curves have been obtained for all kinds of fabrics.

In Situ-Generation of Electrically Conductive Nanoparticles in Bimetallic Phosphate Materials for High Power Lithium Batteries

2019 ◽  
Vol 41 (10) ◽  
pp. 1-7
Author(s):  
Amy C. Marschilok ◽  
Young J. Kim ◽  
Kenneth J. Takeuchi ◽  
Esther S. Takeuchi
Keyword(s):  
High Power ◽  
Lithium Batteries ◽  
Electrically Conductive ◽  
In Situ Generation

A highly sensitive chlorine gas sensor and enhanced thermal DC electrical conductivity from polypyrrole/silicon carbide nanocomposites

RSC Advances ◽  
2016 ◽  
Vol 6 (87) ◽  
pp. 84200-84208 ◽  
Author(s):  
Adil Sultan ◽  
Sharique Ahmad ◽  
Faiz Mohammad
Keyword(s):  
Electrical Conductivity ◽  
Silicon Carbide ◽  
Gas Sensor ◽  
Dodecylbenzenesulfonic Acid ◽  
Chemical Polymerization ◽  
Dc Electrical Conductivity ◽  
Highly Sensitive ◽  
Chlorine Gas

We report the synthesis of polypyrrole (PPy) and polypyrrole/silicon carbide nanocomposites (PPy/SiC) and PPy/SiC/dodecylbenzenesulfonic acid (DBSA) by in situ chemical polymerization and their application as sensors for the detection of highly toxic chlorine gas.

SELF-HEALING OF WOVEN COMPOSITE LAMINATES VIA IN SITU THERMAL REMENDING

2021 ◽  
Author(s):  
ALEXANDER D. SNYDER ◽  
ZACHARY J. PHILLIPS ◽  
JASON F. PATRICK
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Laminated Composites ◽  
Reaction Times ◽  
Carbon Fiber Composites ◽  
Self Healing ◽  
Damage Mode ◽  
Woven Composite ◽  
Internal Damage

Fiber-reinforced polymer composites are attractive structural materials due to their high specific strength/stiffness and excellent corrosion resistance. However, the lack of through-thickness reinforcement in laminated composites creates inherent susceptibility to fiber-matrix debonding, i.e., interlaminar delamination. This internal damage mode has proven difficult to detect and nearly impossible to repair via conventional methods, and therefore, remains a significant factor limiting the reliability of composite laminates in lightweight structures. Thus, novel approaches for mitigation (e.g., self-healing) of this incessant damage mode are of tremendous interest. Self-healing strategies involving sequestration of reactive liquids, i.e. microcapsule and microvascular systems, show promise for the extending service- life of laminated composites. However, limited heal cycles, long reaction times (hours/days), and variable stability of chemical agents under changing environmental conditions remain formidable research challenges. Intrinsic self- healing approaches that utilize reversible bonds in the host material circumvent many of these limitations and offer the potential for unlimited heal cycles. Here we detail the development of an intrinsic self-healing woven composite laminate based on thermally-induced dynamic bond re-association of 3D-printed polymer interlayers. In contrast to prior work, self-repair of the laminate occurs in situ and below the glass-transition temperature of the epoxy matrix, and maintains >85% of the elastic modulus during healing. This new platform has been deployed in both glass and carbon-fiber composites, demonstrating application versatility. Remarkably, up to 20 rapid (minute-scale) self-healing cycles have been achieved with healing efficiencies hovering 100% of the interlayer toughened (4-5x) composite laminate. This latest self-healing advancement exhibits unprecedented potential for perpetual in-service repair along with material multi-functionality (e.g., deicing ability) to meet modern application demands.

An evaluation of elastic properties and coefficients of thermal expansion of graphite fibres from macroscopic composite input data

2005 ◽  
Vol 461 (2054) ◽  
pp. 347-369 ◽  
Author(s):  
P. Rupnowski ◽  
M. Gentz ◽  
J. K. Sutter ◽  
M. Kumosa
Keyword(s):  
Thermal Expansion ◽  
Elastic Properties ◽  
Input Data ◽  
Matrix Material ◽  
Unidirectional Composite ◽  
Woven Composites ◽  
Woven Composite ◽  
Temperature Dependent ◽  
Fibre Properties ◽  
Representative Unit Cell

In this work, a methodology has been presented for the evaluation of stiffness properties and temperature–dependent coefficients of thermal expansion of continuous fibres from the macroscopic properties of either unidirectional or woven composites. The methodology was used to determine the stiffness and thermal properties of T650–35 graphite fibres from the macroscopic input data of unidirectional and woven composites based on the same fibres embedded in a PMR–15 polyimide matrix. In the first part of the analysis, the fibre properties were determined directly from the unidirectional composite macro data using the inversed Eshelby–Mori–Tanaka approach. Subsequently, certain fibre properties were additionally evaluated indirectly from the woven composite, using the finite–element method and the concept of a representative unit cell. It has been shown that the temperature–dependent coefficients of thermal expansion of the fibres can be estimated from the unidirectional composite macro data with significantly smaller errors than in the case of the elastic properties. It has also been shown that the errors in the evaluation of the elastic properties of the fibres from the macro unidirectional composite data could be significantly reduced if the fibres were placed in a stiff matrix material: much stiffer than the polyimide resin. The longitudinal and transverse coefficients of thermal expansions and the shear modulus of the T650–35 fibres determined from the unidirectional composite analysis were successfully verified by investigating the woven composite.

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