scholarly journals Effect of natural fibers on thermal and mechanical properties of natural fiber polypropylene composites studied by dynamic mechanical analysis

2006 ◽  
Vol 101 (6) ◽  
pp. 4341-4349 ◽  
Author(s):  
Mehdi Tajvidi ◽  
Robert H. Falk ◽  
John C. Hermanson
Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4037
Author(s):  
Michelle Souza Oliveira ◽  
Fernanda Santos da Luz ◽  
Fabio da Costa Garcia Filho ◽  
Artur Camposo Pereira ◽  
Vinícius de Oliveira Aguiar ◽  
...  

Dynamic mechanical analysis (DMA) is one of the most common methods employed to study a material’s viscoelastic properties. The effect of thermal aging on plain epoxy and a fique fabric-reinforced epoxy composite was investigated by comparing the mass loss, morphologies, and DMA properties of aged and unaged samples. In fact, thermal aging presents a big challenge for the high-temperature applications of natural fiber composites. In this work, both plain epoxy and fique fabric-reinforced epoxy composite were found to have different molecular mobility. This leads to distinct transition regions, with different changes in intensity caused by external loadings from time-aging. Three exponentially modified Gauss distribution functions (EMGs) were applied to loss factor curves of fique fabric-reinforced epoxy composite and plain epoxy, which allowed identifying three possible mobility ranges. From these results it was proposed that the thermal degradation behavior of natural fibers, especially fique fiber and their composites, might be assessed, based on their structural characteristics and mechanical properties.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ashley Amanda Freeman ◽  
Judith Lee ◽  
Cecil Krarup Andersen ◽  
Naoki Fujisawa ◽  
Michał Łukomski ◽  
...  

AbstractNanoindentation and dynamic mechanical analysis were used to measure changes in the surface and bulk mechanical properties of Winsor & Newton Yellow Ochre oil paint films following exposure to deionized water, aliphatic mineral spirits (Shellsol D40™), and D5 silicone solvent (decamethylcyclopentasiloxane). Yellow ochre paint films were exposed to the selected solvents by 24-h immersion, and sponge-cleaning. 24-h immersion in deionised water and Shellsol D40 caused measurable changes to bulk and surface mechanical properties. However, there were no measurable changes to the bulk or surface mechanical properties following sponge cleaning.


2019 ◽  
Vol 23 ◽  
pp. 6-30
Author(s):  
Volkan Uğraşkan ◽  
Abdullah Toraman ◽  
A. Binnaz Hazar Yoruç

In early composite materials, the use of petroleum based fibers such as glass and carbon fibers, aramid etc. was common. In order to reduce the dependency on petroleum based sources and environmental pollution, researchers have focused on the search for alternative sources. Natural fibers are abundant, recyclable and biodegradable plant derived materials. Besides, thanks to good physical, thermal and mechanical properties, natural fibers become promising alternative for composites. This review includes information about natural fiber reinforced composites’ components, manufacturing methods, mechanical properties and applications.


Author(s):  
Roja Esmaeeli ◽  
Haniph Aliniagerdroudbari ◽  
Seyed Reza Hashemi ◽  
Hammad Al-Shammari ◽  
Muapper Alhadri ◽  
...  

Abstract The quality of the collected data from a measurement system affects eventual decision making process. Therefore, the reliability of any measurement system is an important factor to be studied. Gauge repeatability and reproducibility (Gauge R&R) is the standard method to evaluate the measurement system and assess the adequacy of variation in the measurement data. Gauge R&R is a statistical tool which evaluates two main characteristics of the measurement system: repeatability and reproducibility. The Dynamic Mechanical Analysis (DMA) is a common measurement system for studying the dynamic mechanical properties of viscoelastic materials such as polymers. The newly developed High Frequency Dynamic Mechanical Analysis (HFDMA) is able to directly run the simple shear test at high frequencies without changing the specimen temperature. The complex shear modulus and damping factor of the viscoelastic materials are reported by the HFDMA system. In this study the uni-variable Gauge R&R study based on Analysis of Variance (ANOVA) is done on each measured characteristic of the HFDMA measurement system. The source of variations for each characteristic is distinguished. Then the multivariate Gauge R&R based on the Multivariate Analysis of Variance (MANOVA) is done and the percentage of multivariate Gauge R&R for the measurement with the multiple variables is reported. The results indicate that the HFDMA measurements are both repeatable and reproducible. Thus, the new HFDMA can be used as a measurement system to measure the mechanical properties of viscoelastic materials at high frequencies.


Author(s):  
A Arul Jeya Kumar ◽  
M Prakash

In today's scenario, most of the research works are carried out on the replacement of synthetic fibers using eco-friendly materials called natural fibers. Although there are many research findings in connection with natural fibers, in this work, a new combination of natural fiber having high biomedical potential is reinforced in the polymer composite. Three different weight fractions of polylactic acid, basalt, and Cissus quadrangularis fibers were melt mixed using twin-screw extruder named as PBCQ 1, PBCQ 2, and PBCQ 3. The mechanical, physical, and thermomechanical properties were studied by testing tensile, flexural, impact, hardness, water absorption, Fourier-transform infrared spectroscopy, and dynamic mechanical analysis of the injection-molded biomedical composite specimens prepared as per ASTM standards. It was noticed that the PBCQ 2 composite has the maximum elongation strength, bending strength, shear strength, and shore D hardness compared to other composites taken in this study. Water absorption of PBCQ 1 and PBCQ 2 composites are relatively less than PBCQ 3. The scanning electron microscopy micrograph of PBCQ composites shows tight bonding between the matrix and fibers. The adhesion of matrix and fibers was confirmed by Fourier-transform infrared spectroscopy graph, which indicates the stretching of molecular structure for the occurrence of O–H, C=O, and C–H links. The dynamic mechanical analysis curve of the PBCQ 2 composite indicates high storage modulus and less loss modulus compared to PBCQ 1 and PBCQ 3 due to the low weight percentage of basalt fiber in these composites.


2007 ◽  
Vol 353-358 ◽  
pp. 1729-1732 ◽  
Author(s):  
Lei Chen ◽  
Hong Liang Pan

The storage modulus, loss modulus, loss tangent (tanδ), stress and strain have been determined for painted steel specimens by dynamic mechanical analysis (DMA) operated in Dual Cantilever mode. Analysis of the composite system enabled the elastic modulus of the paint layer to be calculated and the result can be useful to analyze the mechanical properties of the coil coating. The calculation was found to be very sensitive to the geometry (especially thickness of the substrate and coating) and properties of the substrate and coating, leading to considerable variability in the calculated coating modulus. The DMA method was successful in detecting the glass transition temperature (Tg) as a peak in the tanδ curve. The value of Tg is sensitive to the preparation conditions (e.g. curing temperature) and composition of the paint. The results show that DMA in Dual Cantilever can be useful as a characterization tool for painted steel.


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