scholarly journals Dynamic Mechanical Behavior of Graphene Oxide Functionalized Curaua Fiber-Reinforced Epoxy Composites: A Brief Report

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1897
Author(s):  
Ulisses Oliveira Costa ◽  
Lucio Fabio Cassiano Nascimento ◽  
Wendell Bruno Almeida Bezerra ◽  
Vinícius de Oliveira Aguiar ◽  
Artur Camposo Pereira ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Epoxy Matrix ◽  
Natural Fiber ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Neat Epoxy ◽  
Damping Factor ◽  
Fiber Reinforced ◽  
Dynamic Mechanical ◽  
Curauá Fiber

The coating of natural fiber by graphene oxide (GO) has, over, this past decade, attracted increasing attention as an effective way to improve the adhesion to polymer matrices and enhance the composite properties. In particular, the GO-functionalized 30 vol% curaua fiber (Ananas Erectifolius) reinforcing epoxy composite was found to display superior tensile and thermogravimetric properties as well as higher fiber/matrix interfacial shear strength. In this brief report, dynamic mechanical analysis (DMA) was conducted in up to 50 vol% GO-functionalized curaua fiber reinforced epoxy matrix (EM) composites. The objective was not only to extend the amount incorporated but also for the first time investigate the composite viscoelastic behavior. The GO functionalization of curaua fibers (GOCF) improved the DMA storage (E′) and loss (E″) modulus compared to the non-functionalized fiber composites. Values at 30 °C of both E′ (13.44 GPa) and E″ (0.67 GPa) for 50 vol% GO-functionalized curaua fiber reinforced epoxy matrix composites (50GOCF/EM) were substantially higher than those of 20 GOCF/EM with E′ (7.08 GPa) and E″ (0.22 GPa) as well as non-functionalized 50CF/EM with E′ (11.04 GPa) and E″ (0.45 GPa). All these results are above the neat epoxy previously reported values of E′ (3.86 GPa) and E″ (0.09 GPa). As for the tangent delta, the parameters associated with damping factor and glass transition temperature were not found to be significantly changed by GO functionalization, but decreased with respect to the neat epoxy due to chain mobility restriction.

scholarly journals Dynamic Mechanical Properties of Hybrid Layered Silicates/Kaolin Geopolymer Filler in Epoxy Composites

2017 ◽  
Vol 54 (3) ◽  
pp. 543-545 ◽  
Author(s):  
Yusrina Mat Daud ◽  
Kamarudin Hussin ◽  
Azlin Fazlina Osman ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Layered Silicates ◽  
Epoxy Composites ◽  
Damping Factor ◽  
Dynamic Mechanical

Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E�), loss modulus (E�) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E�, E�� and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.

Experimental studies on interlaminar shear strength and dynamic mechanical analysis of luffa fiber epoxy composites with nano PbO addition

2021 ◽  
pp. 152808372110523
Author(s):  
Kumaresan Gladys Ashok ◽  
Kalaichelvan Kani
Keyword(s):  
Shear Strength ◽  
Dynamic Mechanical Analysis ◽  
Epoxy Matrix ◽  
Weight Percent ◽  
Mechanical Analysis ◽  
Interlaminar Shear Strength ◽  
Epoxy Composites ◽  
Dynamic Mechanical ◽  
Interlaminar Shear ◽  
Composite Samples

In the present study, the significance of nanofiller lead oxide (PbO) on the dynamic mechanical analysis (DMA) and interlaminar shear strength (ILSS) performance of luffa fiber–reinforced epoxy composites was investigated. The epoxy matrix was altered with nanofiller PbO of different weight percent through a mechanical stirring process. The PbO-added luffa fiber epoxy composites were made through hand layup preceded by the compression molding method. The prepared composite samples were investigated for ILSS and DMA. The test results lead to the inference that the 1.25 wt% PbO nanofiller–added composite samples attained 25%, 17%, and 55% of higher loss modulus, storage modulus, and ILSS, respectively, as compared with the other prepared samples. The morphological investigation was conducted on the fractured surface of the interlaminar tested samples. The micrographic images show the bonding nature of the luffa fiber with the epoxy matrix, fiber breakage, and fiber pullouts. The characterization studies such as FTIR, XRD, and EDX were conducted on the fabricated composite samples. The XRD studies show that the rise in weight percent of the nanofiller PbO enhances the crystallinity of the composite samples. Moreover, the composite sample prepared with 1.25 wt% nanofiller PbO can be used to prepare low-cost roofing materials for sustainable housing projects.

scholarly journals Dynamic Mechanical Analysis on Delaminated Flax Fiber Reinforced Composites

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2559 ◽  
Author(s):  
Yiou Shen ◽  
Jiayi Tan ◽  
Luis Fernandes ◽  
Zehua Qu ◽  
Yan Li
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Loss Factor ◽  
Composite Laminate ◽  
Low Frequency ◽  
Mechanical Analysis ◽  
Fiber Reinforced ◽  
Dynamic Mechanical ◽  
Reinforced Composite ◽  
Local Flexibility ◽  
Low Amplitude

It is well-known that the presence of the delamination in a plant fiber-reinforced composite is difficult to detect. However, the delamination introduces a local flexibility, which changes the dynamic characteristics of the composite structure. This paper presents a new methodology for composite laminate delamination detection, which is based on dynamic mechanical analysis. A noticeable delamination-induced storage modulus reduction and loss factor enhancement have been observed when the delaminated laminate was subjected to a forced oscillation compared to the intact composite laminate. For delamination area of 12.8% of the whole area of the composite laminate, loss factor of approximately 12% increase was observed. For near-to-surface delamination position, loss factor of approximately an 18% increment was observed. The results indicate that the delamination can be reliably detected with this method, and delamination position shows greater influence on the loss factor than that of the delamination size. Further investigations on different frequencies and amplitudes configurations show that the variation of loss factor is more apparently with low frequency as well as the low amplitude.

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