Sustainable natural fibre reinforcements and their morphological structures

Bhimal fibres are quite a newer kind of bio-degradable fibres. They have never been heard before in literatures from the view point of their utility as engineering material. These fibres have been utilized for investigation of their properties. Characterization of this fibre is essential to determine its properties for further use as reinforcing fibre in polymeric, bio-degradable and other kinds of matrix. With this objective, the fabrication method and other mechanical properties of Bhimal-reinforced-PVA biocomposite have been discussed. The stress-strain curves and load-deflection characteristics are obtained. The tensile, compressive, flexure and impact strengths have been calculated. The results are shown in tables and graphs. The results obtained are compared with other existing natural fibre biocomposites. From the observations, it has been concluded that the tensile strength of Bhimal-reinforced-PVA biocomposite is higher than other natural fibre composites. Hence these can be used as reinforcement to produce much lighter weight biocomposites.

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Incorporation of Natural Fibres in Rendering Mortars for the Durability of Walls

Infrastructures ◽

10.3390/infrastructures6060082 ◽

2021 ◽

Vol 6 (6) ◽

pp. 82

Author(s):

Cinthia Maia Pederneiras ◽

Rosário Veiga ◽

Jorge de Brito

Keyword(s):

Modulus Of Elasticity ◽

Drying Shrinkage ◽

High Water ◽

Natural Fibre ◽

Accelerated Ageing ◽

Flax Fibres ◽

Aesthetic Appearance ◽

Cement Binder ◽

Drying Rates ◽

Adherence Strength

One of the main functions of renders, together with the overall aesthetic appearance of the building, is the protection of the walls against external aggressive actions, such as water, salts solutions, erosion, and mechanical impacts. However, some anomalies of renders may drastically hinder their protection ability. In fact, cracking, high water permeability, and loss of adherence to the substrate of renders limit their barrier effect and favour the exposure of the substrate to external actions. The incorporation of fibres in mortars is commonly pointed out to reduce their cracking susceptibility, due to the probable enhancement in tensile strength and ductility of the composite. The use of lime in substitution of the part of the cement binder is seen as a method to reduce the modulus of elasticity and therefore enhance the resistance to cracking due to drying shrinkage. Therefore, this study investigates the wall protection-related properties of natural fibre-reinforced renders with cement-lime as a binary binder at 1:1:6 volumetric ratio. With this purpose, wool, coir, and flax fibres are used at 20% by total mortar volume and the water behaviour, cracking susceptibility, and adherence to the substrate of the mortars are assessed. Specifically, the water absorption by capillarity, drying rates, permeability to water under pressure, adherence strength, and shrinkage are evaluated. In order to evaluate the renders’ durability and therefore the durability of the protection to the walls, an artificial accelerated ageing test is performed based on heating-freezing and humidification-freezing cycles. The results indicate that the fibres’ addition reduced the shrinkage and modulus of elasticity of the mortars, which suggests lower susceptibility to cracking. The addition of fibres in mortars seemed to slightly affect their water performance and only at early ages. From the results, it was concluded that the adherence strength is not affected by the fibres’ incorporation. The fibres seem also to reduce the impacts of the ageing cycles on the mortar and the improvements provided by the fibres’ addition to the mortars’ performance remained after ageing when compared to the mortars without fibres, thus being a potential alternative to increase their durability. These aspects are particularly important for buildings, since they can extend their service life and promote their sustainability.

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Effects of Water and Chemical Solutions Ageing on the Physical, Mechanical, Thermal and Flammability Properties of Natural Fibre-Reinforced Thermoplastic Composites

Molecules ◽

10.3390/molecules26154581 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4581

Author(s):

Baljinder K. Kandola ◽

S. Ilker Mistik ◽

Wiwat Pornwannachai ◽

A. Richard Horrocks

Keyword(s):

Salt Water ◽

Flexural Modulus ◽

Moisture Sorption ◽

Natural Fibre ◽

Thermoplastic Composites ◽

Wool Fibre ◽

Poly Lactic Acid ◽

Natural Polymers ◽

Chemical Solutions ◽

Pp Composites

Biocomposites comprising a combination of natural fibres and bio-based polymers are good alternatives to those produced from synthetic components in terms of sustainability and environmental issues. However, it is well known that water or aqueous chemical solutions affect natural polymers/fibres more than the respective synthetic components. In this study the effects of water, salt water, acidic and alkali solutions ageing on water uptake, mechanical properties and flammability of natural fibre-reinforced polypropylene (PP) and poly(lactic acid) (PLA) composites were compared. Jute, sisal and wool fibre- reinforced PP and PLA composites were prepared using a novel, patented nonwoven technology followed by the hot press method. The prepared composites were aged in water and chemical solutions for up to 3 week periods. Water absorption, flexural properties and the thermal and flammability performances of the composites were investigated before and after ageing each process. The effect of post-ageing drying on the retention of mechanical and flammability properties has also been studied. A linear relationship between irreversible flexural modulus reduction and water adsorption/desorption was observed. The aqueous chemical solutions caused further but minor effects in terms of moisture sorption and flexural modulus changes. PLA composites were affected more than the respective PP composites, because of their hydrolytic sensitivity. From thermal analytical results, these changes in PP composites could be attributed to ageing effects on fibres, whereas in PLA composite changes related to both those of fibres present and of the polymer. Ageing however, had no adverse effect on the flammability of the composites.

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A Comprehensive Review on Advanced Sustainable Woven Natural Fibre Polymer Composites

Polymers ◽

10.3390/polym13030471 ◽

2021 ◽

Vol 13 (3) ◽

pp. 471

Author(s):

H. A. Aisyah ◽

M. T. Paridah ◽

S. M. Sapuan ◽

R. A. Ilyas ◽

A. Khalina ◽

...

Keyword(s):

Polymer Composites ◽

Polymeric Materials ◽

Major Effect ◽

Natural Fibre ◽

Natural Fibres ◽

Lignocellulosic Materials ◽

Structural Composites ◽

Detailed Review ◽

Green Materials ◽

Manufacturing Parameters

Over the last decade, the progressive application of natural fibres in polymer composites has had a major effect in alleviating environmental impacts. Recently, there is a growing interest in the development of green materials in a woven form by utilising natural fibres from lignocellulosic materials for many applications such as structural, non-structural composites, household utilities, automobile parts, aerospace components, flooring, and ballistic materials. Woven materials are one of the most promising materials for substituting or hybridising with synthetic polymeric materials in the production of natural fibre polymer composites (NFPCs). These woven materials are flexible, able to be tailored to the specific needs and have better mechanical properties due to their weaving structures. Seeing that the potential advantages of woven materials in the fabrication of NFPC, this paper presents a detailed review of studies related to woven materials. A variety of factors that influence the properties of the resultant woven NFRC such as yarn characteristics, fabric properties as well as manufacturing parameters were discussed. Past and current research efforts on the development of woven NFPCs from various polymer matrices including polypropylene, polylactic acid, epoxy and polyester and the properties of the resultant composites were also compiled. Last but not least, the applications, challenges, and prospects in the field also were highlighted.

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A Review on Mechanical Properties of Natural Fibre Reinforced Polymer Composites under Various Strain Rates

Journal of Composites Science ◽

10.3390/jcs5050130 ◽

2021 ◽

Vol 5 (5) ◽

pp. 130

Author(s):

Tan Ke Khieng ◽

Sujan Debnath ◽

Ernest Ting Chaw Liang ◽

Mahmood Anwar ◽

Alokesh Pramanik ◽

...

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Polymer Composites ◽

Stress Transfer ◽

Natural Fibre ◽

Transfer Efficiency ◽

Strain Rates ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer ◽

Fibre Matrix

With the lightning speed of technological evolution, the demand for high performance yet sustainable natural fibres reinforced polymer composites (NFPCs) are rising. Especially a mechanically competent NFPCs under various loading conditions are growing day by day. However, the polymers mechanical properties are strain-rate dependent due to their viscoelastic nature. Especially for natural fibre reinforced polymer composites (NFPCs) which the involvement of filler has caused rather complex failure mechanisms under different strain rates. Moreover, some uneven micro-sized natural fibres such as bagasse, coir and wood were found often resulting in micro-cracks and voids formation in composites. This paper provides an overview of recent research on the mechanical properties of NFPCs under various loading conditions-different form (tensile, compression, bending) and different strain rates. The literature on characterisation techniques toward different strain rates, composite failure behaviours and current challenges are summarised which have led to the notion of future study trend. The strength of NFPCs is generally found grow proportionally with the strain rate up to a certain degree depending on the fibre-matrix stress-transfer efficiency. The failure modes such as embrittlement and fibre-matrix debonding were often encountered at higher strain rates. The natural filler properties, amount, sizes and polymer matrix types are found to be few key factors affecting the performances of composites under various strain rates whereby optimally adjust these factors could maximise the fibre-matrix stress-transfer efficiency and led to performance increases under various loading strain rates.

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Current State and Challenges of Natural Fibre-Reinforced Polymer Composites as Feeder in FDM-Based 3D Printing

Polymers ◽

10.3390/polym13142289 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2289

Author(s):

Nishata Royan Rajendran Royan ◽

Jie Sheng Leong ◽

Wai Nam Chan ◽

Jie Ren Tan ◽

Zainon Sharmila Binti Shamsuddin

Keyword(s):

Mechanical Properties ◽

Natural Fibre ◽

Critical Discussion ◽

Fused Deposition Modelling ◽

Preparation Methods ◽

Fused Deposition ◽

Current State ◽

Future Challenges ◽

Raster Angle ◽

Fibre Reinforced Polymer

As one of the fastest-growing additive manufacturing (AM) technologies, fused deposition modelling (FDM) shows great potential in printing natural fibre-reinforced composites (NFRC). However, several challenges, such as low mechanical properties and difficulty in printing, need to be overcome. Therefore, the effort to improve the NFRC for use in AM has been accelerating in recent years. This review attempts to summarise the current approaches of using NFRC as a feeder for AM. The effects of fibre treatments, composite preparation methods and addition of compatibilizer agents were analysed and discussed. Additionally, current methods of producing feeders from NFRCs were reviewed and discussed. Mechanical property of printed part was also dependent on the printing parameters, and thus the effects of printing temperature, layer height, infill and raster angle were discussed, and the best parameters reported by other researchers were identified. Following that, an overview of the mechanical properties of these composites as reported by various researchers was provided. Next, the use of optimisation techniques for NFRCs was discussed and analysed. Lastly, the review provided a critical discussion on the overall topic, identified all research gaps present in the use of NFRC for AM processes, and to overcome future challenges.

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