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Purpose This study aims to scrutinise the impact of fibre length and its composition on the tribological attributes of oil palm fibre (OPF) polymeric composite as an alternative brake friction material. Design/methodology/approach Fabrication of the sample was conducted by using a hot-compression method. The tribological test was carried out by deploying a ball-on-disk tribometer. Analysis of the data was then done by using the Taguchi approach as well as analysis of variance. Findings The results indicated that all design variables (fibre composition, length and treatment) are not statistically significant, as all p-values are greater than 0.05. Remarkably, irrespective of the fibre treatment, the wear rate and coefficient of friction (COF) distribution suggested that a smaller fibre length with a high fibre composition might enhance the composite’s tribological performance with COF of 0.4 and wear rate below than 1 × 10–9 mm3/Nm. The predominant wear mechanisms were identified as micro-cracks, fine grooves and fibre debonding. Research limitations/implications In this study, all-inclusive scrutiny needs to be carried out for further exploration. Originality/value The main contribution and novelty of this study are opening a new perspective on the formulation of new substances from bio-based material (i.e. OPF) that possess superior tribological characteristics for friction-based applications.

Natural fibre as a reinforcing agent has been widely used in many industries in this era. However, the reinforcing agent devotes a better strength when embedded with a polymer matrix. Nevertheless, the characteristic of natural fibre and polymer matrix are in contrast, as natural fibre is hydrophilic, while polymer is hydrophobic in nature. Natural fibre is highly hydrophilic due to the presence of a hydroxyl group (-OH), while polymer matrix has an inherent hydrophobic characteristic which repels water. This issue has been fixed by modifying the natural fibre’s surface using a chemical treatment combining an alkaline treatment and a silane coupling agent. This modifying process of natural fibre might reduce the attraction of water and moisture content and increase natural fibre surface roughness, which improves the interfacial bonding between these two phases. In this paper, the effect of alkaline and silane treatment has been proven by performing the mechanical test, Scanning Electron Micrograph (SEM), and Fourier Transform Infrared spectrometry (FTIR) to observe the surface structure. The chemical compositions and thermal properties of the composites have been obtained by performing Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) tests. 1.0% silane treatment displayed better strength performance as compared to other composites, which was proven by performing Scanning Electron Micrograph (SEM). The assumption is that by enduring chemical treatment, kenaf fibre composites could develop high performance in industry applications.

There have been review on kenaf fibre (KF) production and mechanical properties but lacks review on the treatment and surface modification on kenaf fibre. Therefore, this study is to show the type of treatment that have been done by previous researcher. A lot of methods have been investigated to find the optimum method to obtain better condition and properties for kenaf fibre. The present review describes those applied to kenaf fibre. The most widely used chemical treatment is the alkaline treatment using a sodium hydroxide (NaOH) solution, followed by a silane treatment. Variety of chemical concentration for NaOH solution and silane solution are investigated and a few combined treatments such as alkaline-silane, alkaline-steam, alkaline-radiation and alkaline-bleaching are also discussed. Thus, this paper presents an overview of investigated treatment methods with application to kenaf fibre and what are the effects of chemical treatment to the surface of kenaf fibre and the mechanical properties of the composites developed based on treated kenaf fibre. Keywords: Natural fibre, Kenaf fibre, Fibre treatment, Material properties, Composite materials

Some studies have evaluated the use of Opuntia as reinforcement for polymeric matrices, obtaining good results in energy absorption tests and increasing the tensile elastic modulus. However, no studies focusing on the previous characterisation of the fibres and their treatment to improve compatibility with polymeric matrices have been found. This work analyses the chemical composition of Opuntia maxima (OM) and Opuntia dillenii (OD) cladodes and fibre, studying how different treatments influence it. AOAC 2000 methods were used to determine non-structural components and the Van Soest method was used to estimate structural components. Surface characteristics of the samples were also evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Opuntia fibre presented higher cellulose (50–66%) and lignin (6–14%) content and lower hemicellulose (8–13%) content than Opuntia cladodes (9–14% cellulose, 20–50% hemicellulose, 1–4% lignin). Despite the variability of lignocellulosic materials, OD cladodes treated with water and acetic acid achieved an increase in the structural components. Alkaline fibre treatment removed pectin and hemicellulose from the fibre surface, slightly increasing the cellulose content. Future research should evaluate whether the treated Opuntia fibre can improve the mechanical properties of reinforced polymer.

As shown in previous chapters, Flax TRMs are characterised by a promising mechanical behaviour.

Bamboo has been traditionally used in sports and musical equipments, household appliances, interior furnishing and decoration for many years. Other than the usefulness of bamboo in the product form, studies indicate that fibres extracted from the bamboo tree can also be used as reinforcement in composites. Bamboo fibres can be easily extracted and are available in chopped form, as long fibres and as woven mats. The bamboo fibres possess superior tensile properties and high strength to weight ratio, an important criteria for reinforcement in composite materials. This article discusses the influence of fibre parameters such as fibre orientation, fibre loading, fibre architecture, etc. on mechanical and thermal properties of the composites. Fibre treatments that has been carried out by researchers to improve the fibre-matrix adhesion between hydrophilic bamboo fibre and hydrophobic polymer matrix along with their mechanism and their impact in the mechanical and thermal properties has also been highlighted.

In the case of fire, the carrying capacity of the textile-reinforced-concrete (TRC) depends greatly on the thermomechanical behaviour of the reinforcement textile at elevated temperatures. Carbon textiles are manufactured in industry as commercial products for application in TRC. The treatment of carbon fibres by products of different natures in the manufacturing chain also influences the thermomechanical behaviour and mechanical property evolution as a function of temperature. This paper presents an experimental study on the tensile behaviour of three different continuous carbon textiles subjected to simultaneous mechanical loading and elevated temperatures (varying from 25 °C to 600 °C). The results on three carbon textiles are compared to understand the effect of fibre treatment on the thermomechanical behaviour of carbon textile. The experimental results are used to calibrate a prediction analytical model (Mouritz and Gibson), which can be applied to the thermomechanical estimation of carbon textile under different temperature and mechanical conditions.

Natural fibres have recently attracted interest due to their beneficial characteristics such as low cost and biodegradability. This work aims to characterise in natura, washed and alkali-treated buriti and ramie fibres and to evaluate the influence of the chemical treatments in the mechanical and dynamic mechanical performances of their composites produced by resin transfer moulding (RTM). Fibres were cut to 45 mm in length, washed in distilled water and treated with 2, 5 and 10 wt.% sodium hydroxide solutions. The chemical composition of the washed fibres was not altered. The 2 wt.% NaOH solution increased the flexural strength of polyester/ramie composites by 70%, and improved the impact performance of the alkali-treated polyester/buriti composites. The polyester/ramie composites exhibited superior dynamic mechanical properties and better adhesion at the fibre/matrix interface, and the morphology of buriti limited the fibre wettability during the RTM processing.

In this study, the mechanical performance assessment of a newly developed carbon fibre-reinforced polyimide composite system T650/NEXIMID® MHT-R is presented. This system was subjected to a series of mechanical tests at ambient and elevated temperature (320℃) to determine basic material properties. Moreover, an additional test was conducted, using a T650/NEXIMID® MHT-R laminate in which the fibre sizing was thermally removed prior to laminate manufacturing, to investigate the effect of fibre treatment on mechanical performance. The experimental results indicated that the T650/NEXIMID® MHT-R composites along with exceptionally high Tg (360–420℃) exhibited competitive mechanical properties to other commercially available polyimide and epoxy-based systems. At elevated temperature, the fibre-dominated properties were not affected whilst the properties defined by matrix and fibre/matrix interface were degraded by approximately 20–30%. Finally, the fibre sizing removal did not affect the tensile and compressive strength, however, the shear strength obtained from short-beam shear test was deteriorated by approximately 15%.

International audience; The use of composite materials reinforced by flax fibres has been increasing steadily over the last 20 years. These fibres show attractive mechanical properties but also some particularities (naturally limited length, presence of a lumen, fibres grouped in bundles in the plant, complex surface properties and composition). An analysis of the available literature indicates that the quality of the composite materials studied is not always optimal (high porosity, incomplete impregnation, heterogeneous microstructure, variable fibre orientation). This paper reviews published data on the specific nature of flax fibres with respect to manufacturing of biocomposites (defined here as polymers reinforced by natural fibres). All the important steps in the process which influence final properties are analyzed, including the plant development, retting, fibre extraction, fibre treatment, preform preparation, available manufacturing processes, the impregnation step, fibre cell wall changes during processing and fibre/matrix adhesion. © 2018, Springer-Verlag France SAS, part of Springer Nature.

Colour is an important property of textile fibres. The colour of mechanically extracted fibre affects the colour of the fibre textiles products. The focus of this investigation is to compare the colour of different pre-treatment process for banana fibre and evaluate the suitability of the banana fibre treatment methods for dyeing process. Experimental research strategies were used to investigate the colour properties. Ambun (AAA/Cavendish) banana variety was selected for this research study. Treated and mechanically extracted banana fibre samples colour measurement was performed by using a data colour machine 600 spectrophotometer and assessed using CIELAB colour values. This experiment was conducted to the suitability of the banana fibre extraction methods for dyeing process. Results indicate that there is a significant change in colour due to the different treatments achieved higher $\Delta \mathrm{E}^{\ast}$ values. Treatment of enzyme and 6% H 2 O 2 , 2% Na 2 SiO 3 , 3% NaOH, combined experiments shows higher $\Delta \mathrm{E}$ values than the other treatments. The FTIR results show that the removal performance of the lignin component is satisfying after the enzyme and chemical combined treatments of banana fibres.

In the present scenario of an increased rate of infrastructural development to match population growth, constructions are adopted in soft soils. Soft soils predominant in coastal regions are characterised by low shear strength and high compressibility and are usually considered as an avoidable option for construction. To meet the demand for constructions in available land, studies are emerging for better, efficient and eco-friendly ground improvement techniques. Soil reinforcements with natural fibres are considered effective as well as efficient mainly because of their biodegradability. The technique of fibre inclusion to soil started in decades, currently reached a point where the fibres are treated at the nanolevel to enhance their performance. Nanoparticles on the fibre surface render better adhesion between soil and fibre matrix and increase in tensile and shear strength. This paper gives a review of the fibre treatment studies, the nanomodification processes and an experimental authorisation by SEM analysis in coir fibre.

Natural hemp fabric reinforced epoxy resin composites were prepared in flame retarded form. Fabrics were treated in three ways: the first method involved the immersion of preheated fabric into cold phosphoric acid solution (allowing penetration into the capillaries of the fibres) and subsequent neutralization, the second way was a reactive modification carried out with an aminosilane-type coupling agent, while the third treatment combined the sol–gel surface coating with the first method. The introduction of phosphorus into the reinforcing fibres decreased the flammability not only of the hemp fabrics, but also of the epoxy composites made thereof. By applying amine-type phosphorus-containing curing agent (TEDAP) in combination with the treated fabrics, V-0 UL-94 rating was achieved. Composites of unexpectedly improved static and dynamic mechanical properties could be prepared only when the simple phosphorous fibre treatment and reactive flame retardancy was combined.

The effect of pulp flow recirculation on energy efficiency and pulp properties development in low consistency refining of TMP has been studied. Trials were made with TwinFlo 58 refiners in two mills in Sweden. The refiners were operated at constant specific refining energy but different flow conditions. No effect of recirculation was seen on refining energy efficiency, pulp quality or fibre wall delamination/internal fibrillation. At high degree of recirculation though, a somewhat larger fibre length reduction was seen. This means that a large degree of recirculation can be used to attain a high specific energy in one stage low consistency refining, without significant negative effects on fibre properties. If a high specific energy input is desirable, it is more cost effective to install one large refiner with recirculation compared to several small without recirculation in series. When recirculation was increased by means of increased flow through the refiner, the outlet pressure dropped. The lower pressure drop over the refiner probably decreased the internal recirculation between rotor and stator, which could explain the observation that there was little effect on fibre development by recirculation. This means that at certain conditions the distribution in fibre treatment might not increase so much when the outer recirculation is increased, since the internal recirculation might be reduced simultaneously.

This chapter reviews flame retardancy of recyclable and biobased polymer composites. Synthesis routes to obtain thermosetting biobased polymer matrices are discussed and environmentally friendly flame-retardancy solutions are proposed. Fire retardancy of thermoplastic biomatrices and fully recyclable self-reinforced composites made thereof are summarized. New methods to characterize flame-retardant biocomposites and understand their thermal degradation and flame-retardant mechanisms are presented. After reviewing chemical treatments to flame retard natural fibres, flame-retardancy results of thermosetting and thermoplastic biocomposites are discussed. Green solutions utilizing synergistic effects, multifunctionality and integrated approaches are highlighted. Finally, application possibilities and future trends in the field of flame-retarded biocomposites are indicated.

A new method for producing insulating pliant synthetic fibre boards (PSFB) utilizing short-fibred wastes of natural and chemical fibre treatment has been developed at the branch research laboratory of the Department of Spinning of Natural and Chemical Fibres of the Vitebsk Technological University. The basic process stage in PSFB production is heat and mechanical treatment for a certain time. The experimental research supports the feasibility of practical application of the equation derived for describing the process of compression casting of pliant synthetic fibre boards of various feed compositions and thicknesses.

Owning to the environmental concerns and sustainable development, green biocomposites are increasingly explored and developed to replace conventional composites. Polymer composites used in tribological application have received great attention from researchers due to its self-lubricating properties, versatile fabrication process, low in cost and easy to tailor their properties with wide range of functional fillers. The past research in using green biodegradable materials reinforced polymers in tribological study has established a good understanding on tribological behaviour of natural fibre-reinforced polymer composites (NFRPCs). In this chapter, the tribological performance of various natural fibres reinforced polymer composites reported in the literature is reviewed. Furthermore, the effect of different important factors of natural fibre on wear and friction of polymers is discussed. Most of the polymer materials showing certain degree of enhancement in tribological properties after reinforced with natural fibre. Further optimization of its performance is possible by selecting optimum fibre loading, fibre length, fibre treatment, sliding orientation and combining with other fillers to form hybrid system composites. Finally, based on our current understanding, we have speculated some future trends and directions of NFRPCs in the field of tribology.

Natural rubber compounds with untreated and treated kenaf were prepared with different loading i.e., 0, 10, 20, 30 and 40 phr. The compounds were cured at 150°C according to its cure time, t90. Curing characteristics, tensile properties, rubber-filler interaction and morphology properties of the rubber compounds were tested. Curing characteristics showed that scorch time, ts2 and cure time, t90 decreased with increasing of fibre loading and treatment. Mechanical properties of kenaf filled natural rubber compounds decreased with increasing of fibre loading but increased with fibre treatment. Swelling measurement and morphological study showed that better rubber-filler interaction was obtained with treated kenaf.

The aim of this study is to determine the impact properties of sugar palm fibre-reinforced epoxy polymer composite after introduce the alkaline treatment to the fibre. The fibre was treated by alkaline solution with 0.25 M and 0.5 M NaOH solution for 1 hour, 4 hours, and 8 hours soaking time. Hand lay up process was used to prepare the composite specimens with 10% volume fraction. The dimensions of the specimen used to carry out the test were adapted from ASTM D256 for Izod Impact testing. The higher impact strength of treated sugar palm fibre reinforced epoxy composite took place at 0.5 M NaOH solution with 8 hours soaking time, i.e., 60 J/m with improving by 12.85% from untreated composite.

Recently, it has been shown that coagulation volumes of interstitial laser therapy (ILT) can be enlarged by introducing a diffuser tip applicator into a cooling catheter system in the treatment of liver, breast and lung neoplasm. The aim of this study was to prove if coagulation volumes in ILT of congenital vascular malformations (CVMs) can also be enlarged by using this system. Cooled laser applicators were used in eight patients with CVM. The procedures were executed with an Nd:YAG laser 1064 nm. The laser power was 25 W. The applicator was introduced into a thermostable Teflon cooling catheter. Cooling flow was 50 ml/min. For online thermo-monitoring, we used three time-optimized MR sequences in an open magnetic resonance imaging (MRI) unit. The volume of MRI-changes ranged from 12 up to 36 ml (mean: 20.5 ml). In comparison with previous results in 600 μm bare fibre treatment (mean spot volume 1.9 ml), treatment spots were 10 times higher in the cooled applicator system. In certain large and deep seeded CVM, ILT becomes more effective with cooled laser applicator systems.

In this study, pitch-based short carbon fibres were treated by both an air oxidation and a cryogenic treatment, thereafter these fibres were incorporated into epoxy matrix for wear investigations. It was found that under an appropriate air oxidative condition, the wear resistance of carbon fibre reinforced epoxy was significantly improved at low contact pressure, whereas that was reduced at high pressures which may due to the damage of fibre mechanical properties after oxidation. On the contrary, carbon fibres preformed better at high sliding pressure after cryogenic treatment. Correlated wear mechanisms were discussed.

Polylactic acid (PLA)/coir fibre biocomposites were fabricated using a compression moulding technique. The effects of fibre content (5-30 wt%) and fibre treatment on mechanical, thermal and biodegradable properties of biocomposites were holistically investigated via mechanical testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and soil burial method to understand the applicability of manufacturing eco-efficient and sustainable “green composites”.

The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre impregnation by the epoxy matrix, and the mechanical properties of the composites are thereby increased. The effective fibre stiffness and strength established from the modelling show that the enzymatic removal of pectin also leads to increased mechanical properties of the fibres. Among the investigated samples, the composites with hydrothermally pre-treated and enzymatically treated fibres have the lowest porosity factor of 0.08 and the highest mechanical properties. In these composites, the effective fibre stiffness and strength are determined to be 83 GPa and 667 MPa, respectively, when the porosity efficiency exponent is set equal to 2. Altogether, it is demonstrated that the applied models provide a concept to be used for the evaluation of performance of treated fibres in composites.

International audience; This paper describes an analysis of the parameters that influence the adherence properties between flaxfibres and PLLA. Microdroplet debonding tests have been used, together with Atomic Force and Scanning Electron Microscopy. The apparent interfacial shear strength of flax/PLLA is significantly higher than that of glass/PP and similar to that of glass/unsaturated polyester. Comparison of results for glass fibres and flax with and without release agent indicate a large contribution of thermal residual stresses to interface properties. The multi-layer nature of vegetal fibres affects debonding mechanisms and partial peeling of the fibre is noted. The cohesion of the fibre cell-wall must therefore also be considered. Awatertreatment of flaxfibres (72 h at 23 °C) is shown to result in a small drop in tensile properties but a significant increase in interfacial shear strength and friction stress. Drying for 14 h at 105 °C reduces fibre Young's modulus and failure strength and also reduces fibre/matrix adhesion by 20%. More extensive fibre peeling is observed after drying, indicating that drying affects fibre wall cohesion.

The importance of understanding the interface and its reactions is paramount to determining optimum composite properties in service. However, many tests are not carried out at the temperatures and humidities which the component may be subjected to in service. The influences of resin type, hardener, cure time and temperature have been well established, although much work continues in ignorance of the precise details of the system being used. Additionally and perhaps more importantly, the temperature at which the composite part will be used and therefore the properties of the resin and the interface at this temperature should be ascertained for each system or well understood and therefore predicted. A specially designed environmental chamber has been built for the purpose of conducting high temperature fragmentation tests. Fractures of the resin at filament breaks in various systems and at various temperatures have also been studied. It is shown that small changes in the temperature of testing (relative to the Tg) can alter the properties of the interface as much as any changes to the fibre treatment and matrix cure. The changes are found to involve not only a shift in the values of the fragment length but also their distribution, as well as the fracture morphology at fragmentation. All these factors must be considered in any analysis of the interface.

A bench-scale continuous fibre treatment line has been built to modify polyethylene fibre surfaces using UV radiation-induced grafting. It is shown that grafting does indeed take place and that the grafts adhere well to the resin. Single-fibre pullout behaviour, interlaminar shear strength, and flexural behaviour were observed to improve considerably. The loss of tensile properties due to treatment was investigated and found to be small in the range of useful treatments. The interlaminar shear strength of the UV-treated fibre is as high as 38 MPa (5.5 ksi) as compared with the untreated fibre value of 10 MPa (1.5 ksi). The most important process parameters are identified and trends established.

A novel fibre treatment recently proposed in the literature was optimised in the case of woven jute fabric/vinylester laminates to obtain the best tensile properties. It consists on an alkali treatment superimposed to biaxial tensile stress. Optimisation was performed by changing the treatment time. The novel fibre treatment was compared with traditional chemical methods. Tensile properties exhibited a maximum with the treatment time at 4 h due to the less efficient period of time and to the excessive fibre damage for times shorter and longer than 4 h, respectively. All composites with fibres treated with alkali under stress exhibited improved tensile strength in comparison with the composites with untreated fibres or with fibres treated with traditional methods due to the better interfacial properties and the structural changes of the fibres promoted by the novel treatment. Stiffness values were only higher for the composite with fibres treated with alkali under stress for 4 h, probably in correspondence with a maximum in the stiffness of the individual fibres. Fil: Vázquez, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Stocchi, Ariel Leonardo. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bernal, Celina Raquel. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Polyelectrolyte multilayers (PEM) consisting of cationic starch and anionic carboxymethylcellulose (CMC) have been applied to different pulp fibres in order to enhance the out-of-plane sheet strength properties of a typical packaging board furnish. An unbleached softwood chemical pulp was treated with multilayers consisting of two layers of cationic starch and one layer of CMC, and then mixed with different mechanical and chemimechanical pulps. Hand sheets were prepared with the aid of the Rapid Köthen sheet former from stocks consisting of 20% treated chemical pulp and 80% mechanical or chemimechanical pulp, which was either PGW from spruce, HT-CTMP from spruce or birch, or a standard spruce CTMP. Multilayer treatment significantly improved Scott Bond values and in some cases improved the tensile index, with the achieved effects being significantly larger than the effects of applying starch alone. Positive effects were obtained by treating only 20% of the furnish, showing a very high efficiency of the adsorbed multilayers. Compared to earlier work, one important finding was that the PEM treatment should preferably be applied only to the chemical pulp and not on the entire stock. It was possible to increase the out-of-plane strength properties, measured as Scott Bond values, with just a very small increase in density of the sheets. Multilayer treatment of the chemical pulp improved the joint strength between the fibres while maintaining the high bulk of the sheets prepared from the stiff mechanical and chemimechanical fibres.

Microwave plasma treatment is presented as a quick technology to modify fibres. A specially designed microwave plasma equipment for fibres is described. Also the first results of carbon, polyethylene and aramid fibre treatment are discussed. The treatment changes the chemical surface structure of the fibres. Depending on the process parameters the fibres can get damaged.

The moisture sensitivity of natural fibre composites limits their use in structural applications. Degradation of the fibre–matrix interface is likely to occur when the material is subjected to variable moisture conditions. This study investigates the damage development in unidirectional flax fibre reinforced epoxy composites during hygroscopic cycling. It is expected that the insertion of a silicone interphase increases interfacial toughness and therefore postpones or avoids interface degradation. Various silicones and a silane coupling agent were used in an attempt to enhance the long-term behavior of the composite. Hygroscopic cycling was performed by varying the relative humidity between approximately 25 and 80% at 80 °C. When examining the flax-epoxy reference composite, regression analysis showed a significant decline of the transverse strength during six consecutive wet-dry cycles. The degradation of the mechanical properties is attributed to fibre–matrix debonding and to cohesive failure in the fibre bundles. Both damage mechanisms are visualized in a unique three-dimensional model. Contrary to the hypothesis, the insertion of a silicone interphase led to an accelerated decrease of the transverse strength. Computed tomography analysis confirmed the weakening of the fibre–matrix interphase. Although the damage development was altered, the composites having a thin silicone interphase did not show a significant decrease in longitudinal stiffness and strength. This result is promising as it suggests that stress transfer is not significantly hindered. ispartof: pages:S273-S279 ispartof: Materials Today: Proceedings vol:31 pages:S273-S279 ispartof: 4th International Conference on Natural Fibers - Smart Sustainable Materials (ICNF) location:Porto, Portugal date:1 Jul - 3 Jul 2019 status: published

Treatment of freshly spun polyacrylonitrile fibre with calcium salts affords the possibility of improving the antistatic properties of the fibre without the use of an antistat. In the process of fibre treatment, both physical sorption and also chemical reaction of the fibre with the calcium cations take place.