Interfacial studies of natural fibre/polypropylene composites using single fibre fragmentation test (SFFT)

2011 ◽  
Vol 42 (1) ◽  
pp. 50-56 ◽  
Author(s):  
A. Awal ◽  
G. Cescutti ◽  
S.B. Ghosh ◽  
J. Müssig
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hanna M. Brodowsky ◽  
Anne Hennig

Abstract Natural fibre–reinforced composites are more sustainable than other composites with respect to the raw materials. Their properties are attractive due to high specific properties, and especially so wherever high damping is valued. As the interphase between fibre and matrix is the region of highest stresses, a strong bond between fibre and matrix is essential for any composites’ properties. The present study compares two methods of determining the interfacial shear stress in natural fibre–reinforced composites: the single fibre fragmentation test and the single fibre pullout test. The studied composites are flax fibre reinforced epoxy. For a variety of fibre–matrix interaction, the fibres are treated with a laccase enzyme and dopamine, which is known to improve the fibre–matrix shear strength. In the observed samples, single fibre fragmentation test data, i.e. of fracture mode and fragment length, scatter when compared to pullout data. In single fibre pullout tests, the local interfacial shear strength showed a 30% increase in the laccase-treated samples, compared to the control samples. The method also permitted an evaluation of the frictional stress occurring after surface failure.


1993 ◽  
Vol 2 (5) ◽  
pp. 096369359300200 ◽  
Author(s):  
H.D. Wagner ◽  
S. Ling

An energy balance approach is proposed for the single fibre composite (or fragmentation) test, by which the degree of fibre-matrix bonding is quantified by means of the interfacial energy, rather than the interfacial shear strength, as a function of the fibre geometrical and mechanical characteristics, the stress transfer length, and the debonding length. The validity of the approach is discussed using E-glass fibres embedded in epoxy, both in the dry state and in the presence of hot distilled water.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4529
Author(s):  
Hanna M. Brodowsky ◽  
Anne Hennig ◽  
Michael Thomas Müller ◽  
Anett Werner ◽  
Serge Zhandarov ◽  
...  

Natural fibres have a high potential as reinforcement of polymer matrices, as they combine a high specific strength and modulus with sustainable production and reasonable prices. Modifying the fibre surface is a common method to increase the adhesion and thereby enhance the mechanical properties of composites. In this study, a novel sustainable surface treatment is presented: the fungal enzyme laccase was utilised with the aim of covalently binding the coupling agent dopamine to flax fibre surfaces. The goal is to improve the interfacial strength towards an epoxy matrix. SEM and AFM micrographs showed that the modification changes the surface morphology, indicating a deposition of dopamine on the surface. Fibre tensile tests, which were performed to check whether the fibre structure was damaged during the treatment, showed that no decrease in tensile strength or modulus occurred. Single fibre pullout tests showed a 30% increase in interfacial shear strength (IFSS) due to the laccase-mediated bonding of the coupling agent dopamine. These results demonstrate that a laccase + dopamine treatment modifies flax fibres sustainably and increases the interfacial strength towards epoxy.


2016 ◽  
Vol 851 ◽  
pp. 155-162 ◽  
Author(s):  
Nurul Zuhairah Mahmud Zuhudi ◽  
Krishnan Jayaraman ◽  
Richard Lin

Hybridisation is introduced as one way to use bamboo fabric as natural fibre reinforced composites (NFRCs). The research intends to determine the extent to which bamboo fabric can replace glass fibre in glass polypropylene (GPP) composites and whether the proposed hybrids are capable of competing, particularly in comparison to the flammability of GPP composites. This study evaluates the effect of hybridization on the flammability properties of bamboo fabric reinforced polypropylene composites and their hybrids. Flammability tests using cone calorimeter show that the peak Heat Release Rate (HRR) was reduced up to 39% for BPP50%, at 511.8 kW/m2, in comparison with that of neat PP, based on maximum peak values of 842 kW/m2. Interestingly, in the hybrid composites, the peak HRR reduced as glass fibre was replaced with bamboo fibre. These composites demonstrate a significant decrease in peak HRR, over 30% less than the neat PP and GPP composites respectively. These results indicate that a significant portion of the glass in GPP may be replaced with bamboo fabric, with a positive effect on fire resistance. This reduction in flammability and the improved properties obtained demonstrate promise for these hybrid materials in future applications.


2010 ◽  
Vol 425 ◽  
pp. 167-178 ◽  
Author(s):  
Iman M. Taha ◽  
Gerhard Ziegmann

The application of natural fibres as polymer reinforcement is of extreme interest, especially in combination with biodegradable polymers. Such “green” composite represent a step forward to eco-design and environmentally friendly applications. The use of biodegradable polylactic acid (PLA) on the basis of renewable resources in addition to the biodegradable polyvinyl alcohol (PVA) on petrochemical basis is compared in this study with the application of polypropylene (PP) as a surrounding matrix for sisal fibres. According to the law of similarities, the chemically similar structure of natural fibres and PVA and PLA provides stronger fibre-matrix bonding characteristics compared to PP. This was experimentally validated applying single-fibre pull-out tests, where the effect of improved bonding is further investigated in terms of tensile and impact composite behaviour. SEM investigation was further applied to describe failure modes of natural fibre composites.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 4607-4612 ◽  
Author(s):  
SRIDHAR PATHI ◽  
KRISHNAN JAYARAMAN

Natural fibre reinforced thermoplastic composites find a wide array of applications in the automobile, building and construction industries. These composites are mostly produced by injection moulding or extrusion through properly designed dies. During these production processes, the shear forces exerted by the screw or ram leads to the degradation of the natural fibres. A screwless extruder that minimises fibre degradation and employs a reliable and low technology process has already been developed. However, the fibre degradation caused by the screwless extruder has not been compared with that of the conventional extruders. So, this study is focused on the influence of extrusion processes on the degradation of natural fibres in thermoplastic composites. Sisal fibres of 10 mm length were extruded with polypropylene, to furnish extrudates with a fibre mass fraction of 25%, using conventional single screw and screwless extruders. Polypropylene in the extrudates was dissolved in Xylene in a Sohxlet process; the fibres that were extracted were analysed for length variations. While fibre degradation in the form of fibre length variation is similar in both cases, this can be minimised in screwless extrusion by extending the gap between the front face of the cone and the orifice plate.


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