Analysis of electrical, thermal and compressive properties of alkali-treated jute fabric reinforced composites

2017 ◽  
Vol 47 (6) ◽  
pp. 1407-1423 ◽  
Author(s):  
S Sudha ◽  
G Thilagavathi

The effect of alkali treatment on thermal, electrical and compressive behaviour of jute composite has been studied. The plain woven jute fabrics were manufactured using handloom. The manufactured fabrics were treated with alkali at the optimized treatment conditions of 5% NaOH for 4 h at 30℃ made into a composite of [0°]4 lay-up sequence by means of compression moulding technique using vinyl ester resin. The improvement in the crystallization of the alkali-treated jute fabric was characterized using differential scanning calorimetry and X-ray diffraction technique. The composites were characterized for compression strength, thermal conductivity and electrical resistance properties. It is observed from the results that the alkali-treated jute composites showed increased compression strength, electrical conductivity and thermal conductivity of the composites. This may be due to the better adhesion of the fabric–matrix interface with the removal of lignin and hemicelluloses that impart hydrophobicity on the fabric.

2016 ◽  
Vol 47 (5) ◽  
pp. 640-655 ◽  
Author(s):  
Ammayappan Lakshmanan ◽  
Rakesh Kumar Ghosh ◽  
Swati Dasgupta ◽  
Sujay Chakraborty ◽  
Prasanta Kumar Ganguly

Jute fiber has poor compatibility with hydrophobic thermosetting polymeric resin for the development of a biocomposite. In this present study, plain weave jute fabric was treated with 1% sodium hydroxide (owf) in three different time (30, 60 and 90 minutes), temperature (30, 40 and 50℃) and material-to-liquor ratio (1:5, 1:10 and 1:15) as per orthogonal array and the treated jute fabrics were used for the preparation of the biocomposite sheet by hand laying-cum-compression moulding method. Developed biocomposite sheets were evaluated for their mechanical properties as per ASTM standards and results were analyzed by Taguchi model to optimize the sodium hydroxide treatment condition. Results inferred that jute fabric reinforcement treated with 1% sodium hydroxide at 50℃ for 60 minutes in 1:10 material-to-liquor ratio could be the optimum condition to develop the biocomposite sheet with higher mechanical properties than other conditions.


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1016
Author(s):  
Xiao-Cun Liu ◽  
Ming-Yan Pan

AgBiSe2, which exhibits complex structural phase transition behavior, has recently been considered as a potential thermoelectric material due to its intrinsically low thermal conductivity. In this work, we investigate the crystal structure of Sn-doped AgBiSe2 through powder X-ray diffraction and differential scanning calorimetry measurements. A stable cubic Ag1−x/2Bi1−x/2SnxSe2 phase can be obtained at room temperature when the value of x is larger than 0.2. In addition, the thermoelectric properties of Ag1−x/2Bi1−x/2SnxSe2 (x = 0.2, 0.25, 0.3, 0.35) are investigated, revealing that Ag1−x/2Bi1−x/2SnxSe2 compounds are intrinsic semiconductors with a low lattice thermal conductivity. This work provides new insights into the crystal structure adjustment of AgBiSe2 and shows that Ag1−x/2Bi1−x/2SnxSe2 is a potentially lead-free thermoelectric material candidate.


2017 ◽  
Vol 36 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Dorota Głowacz-Czerwonka

The conditions and methods for obtaining polyurethane foams based on melamine-formaldehyde-cyclohexanone resins are presented These foams were obtained from melamine solution in reactive solvents based on cyclohexanone and 4,4′-diphenylmethane diisocyanate. Some properties of obtained polyurethane foams were examined, e.g. apparent density, water absorbing capacity, dimensional stability, thermal conductivity, thermal stability, flammability and compression strength. Also a thermal analysis using the differential thermal analysis and differential scanning calorimetry methods was carried out. Polyurethane foams with increased thermal stability were obtained.


2014 ◽  
Vol 16 (2) ◽  
pp. 106-113 ◽  
Author(s):  
S. Basak ◽  
Kartick K. Samanta ◽  
S.K. Chattopadhyay ◽  
S. Das ◽  
R. Narkar ◽  
...  

Abstract Flame retardant and antimicrobial functionalities were imparted in jute textile using sodium metasilicate nonahydrate (SMSN), commonly known as “water glass”. Sodium metasilicate nonahydrate (SMSN) was applied in jute fabric in different concentration by padding method followed by drying. Flame retardancy of the fabric was evaluated by Limiting Oxygen Index (LOI) and burning behaviour under vertical flammability tester including the char length. Burning rate was found to decrease by almost 10 times after an application of 2% SMSN compared to the control sample. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis of both the control and treated jute fabrics were utilized to understand the mechanism of developed flame retardance in jute fabric. It was observed that the SMSN treated samples showed excellent antimicrobial property against both gram positive and gram negative bacteria. Antimicrobial properties of both the control and treated jute fabrics were also measured quantitatively.


2020 ◽  
pp. 096739112095407 ◽  
Author(s):  
Ali Shaan Manzoor Ghumman ◽  
Mohamed Mahmoud Nasef ◽  
M Rashid Shamsuddin ◽  
Amin Abbasi

Sulfur-based polymers are unique renewable materials that are receiving a growing attention. The utilization of elemental sulfur with a variety of monomers in their preparation in the absence of solvents using the inverse vulcanization are granting them green nature and unique properties. Several characterization techniques have been used to evaluate the properties of sulfur-based polymers. However, the complex structure and lack of solubility undermine the applicability of some standard characterization techniques in the usual manners. This article reviews the characterization methods used for the evaluation of various properties of sulfur-based polymers such as chemical, morphological, structural, thermal, rheological and mechanical properties, all of which vary depending on the type of comonomer involved in the reaction and heat treatment conditions. The successful applications of different characterization techniques including Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nuclear magnetic resonance (NMR), scanning electron microscopy/X-ray energy dispersion (SEM-EDX), X-ray diffraction (XRD), mechanical tester, rheometer, thermal gravimetric analyzer (TGA) and differential scanning calorimetry (DSC) are discussed. The challenges to the evaluation of the properties of sulfur-based polymers and the innovative applications of the conventional techniques to overcome them are also deliberated.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Fatima-tuz-Zahra ◽  
M. Anis-ur-Rehman

Polymeric nanofibers have been produced in the last few years by electrospinning of polymer solutions. Polyvinyl alcohol (PVA) was the selected polymer for the preparation of nanofibers. Processing parameters like flow rate, needle gauge, needle to collector distance, and molarity of the solution have been optimized during electrospinning process. Sol-gel method has been used for the preparation of thermoelectric cobaltite nanoparticles having composition NaCoO2. Sol-gel combined electrospinning technique was used to prepare the composites of the NaCoO2 with PVA nanofibers. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) have been used for the structural analysis of the prepared samples. Scanning electron microscopy (SEM) was used to observe the morphology of the prepared fibers. SEM micrographs showed that, by increasing the flow rate, diameter of the fibers increased from 185 nm to 200 nm. Two-probe method and Advantageous Transient Plane Source (ATPS) were used to study the electrical and thermal transport properties, respectively. Thermal conductivity and electrical conductivity showed a direct dependence on temperature. It was observed that particles, sample has lower thermal conductivity (0.610 W/m-K) as compared to that of composite nanofibers (1.129 W/m-K). The measurements reported are novel and are useful for energy applications.


2018 ◽  
Vol 53 (7) ◽  
pp. 851-861 ◽  
Author(s):  
Siqi Du ◽  
Xiongqi Peng ◽  
Hailin Gu

Jute woven fabrics in as-received and alkali-treated conditions were respectively combined with polylactic acid resin to fabricate completely biodegradable composites by compression molding in one step. Scanning electron microscopy and differential scanning calorimetry and tensile tests were conducted to estimate the surface morphology, thermal, and mechanical properties of jute fabrics and the composites manufactured. The formability of the composites was evaluated by a thermal-stamping experiment. The results demonstrate that alkali treatment removes the surface impurities of fabrics and refine the fiber structures, lifting the thermal property of composites. As for the mechanical properties, the strength of the fabrics and composites declines while the modulus increases after alkali treatment of fabrics. Although some defects occur, the thermal-stamping experiments confirm the possibility of shaping jute/polylactic acid composite into complicated geometries. And the formability of the composites is influenced by many factors including sample sizes, the holding time of temperature, layup sequence, and so on while the number of layer makes no obvious difference to it.


Fibers ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 49
Author(s):  
Palanisamy Sivasubramanian ◽  
Mayandi Kalimuthu ◽  
Murugesan Palaniappan ◽  
Azeez Alavudeen ◽  
Nagarajan Rajini ◽  
...  

As possible substitutes for non-biodegradable synthetic fibre, ligno-cellulosic fibres have attracted much interest for their eco-friendliness; a large number of them are already used for the production of green polymer composites. The search for further green candidates brings into focus other fibres not previously considered, yet part of other production systems, therefore available as by-products or refuse. The purpose of this study is to explore the potential of alkali treatment with 5% sodium hydroxide (NaOH) to enhance the properties of bark-extracted Acacia Caesia Bark (ACB) fibres. The microscopic structure of the treated fibres was elucidated using scanning electron microscopy (SEM). Moreover, the fibres were characterised in terms of chemical composition and density and subjected to single-fibre tensile tests (SFTT). Following their physico-chemical characterisation, fibre samples underwent thermal characterisation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and their crystallinity was assessed using X-ray diffraction (XRD). This level of alkali treatment only marginally modified the structure of the fibres and offered some improvement in their tensile strength. This suggested that they compare well with other bark fibres and that their thermal profile showed some increase of degradation onset temperature with respect to untreated ACB fibres. Their crystallinity would allow their application in the form of fibres with an average length of approximately 150 mm, even in thermoplastic biocomposites.


2019 ◽  
Vol 9 (01) ◽  
pp. 21-26
Author(s):  
Arif Budiman ◽  
Ayu Apriliani ◽  
Tazyinul Qoriah ◽  
Sandra Megantara

Purpose: To develop glibenclamide-nicotinamide cocrystals with the solvent evaporation method and evaluate their solubility and dissolution properties. Methods: Cocrystals of glibenclamide-nicotinamide (1:2) were prepared with the solvent evaporation method. The prediction of interactive cocrystals was observed using in silico method. The solubility and dissolution were performed as evaluation of cocrystals. The cocrystals also were characterized by differential scanning calorimetry (DSC), infrared spectrophotometry, and powder X-ray diffraction (PXRD). Result: The solubility and dissolution profile of glibenclamide-nicotinamide cocrystal (1:2) increased significantly compared to pure glibenclamide as well as its physical mixture. Characterization of cocrystal glibenclamide-nicotinamide (1:2) including infrared Fourier transform, DSC, and PXRD, indicated the formation of a new solid crystal phase differing from glibenclamide and nicotinamide. Conclusion: The confirmation of cocrystal glibenclamide-nicotinamide (1:2) indicated the formation of new solid crystalline phases that differ from pure glibenclamide and its physical mixture


Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.


Sign in / Sign up

Export Citation Format

Share Document