Fiber/ Polymer Flammability

In this work, graphene was used as a filler for banyan aerial root fibers
reinforced epoxy composites at various compositions. The synergetic effect of graphene and banyan fibers, on the physical and mechanical characteristics of the epoxy thermoset, was studied. The mechanical tests, hardness, water absorption behavior and morphology of the composites were studied. Significant improvement in tensile strength, flexural strength, shore D hardness and substantial reduction in the percentage of water absorption was observed. This paper also discusses the ideal proportion of banyan fibers with graphene powder for the development of the improved epoxy composites. The optimum concentration of the composites was observed at 4% of graphene powder in the 40% banyan fiber-reinforced hybrid epoxy composites. From the results, it is proved that graphene combined with 40% banyan fiber-reinforced epoxy hybrid composites will efficiently improve the strength of the composites.

It is a polymer of ethylene, CH 2 -CH 2 , having the formula (-CH 2 -CH 2 -) n , and is produced at high pressures and temperatures in the presence of any one of several catalysts, depending on the desired properties for the finished product. Polyethylene is resistant to water, acids, alkalies, and most solvents. Its many applications include films or sheets for packaging, shower curtains, unbreakable bottles, pipes, pails, drinking glasses, and insulation for wire and cable.

shown tremendous growth in Adavanced Materialas, Nano-materials and Pharmaceutical business. As per my knowledge, India is the prominant country in Materaials Scienceand meets its 95% domestic needs and also exportsas well its products to more than 80 countries. However, till date India is facing many health related problems, newer epidemics are creating the alert situations. I hope that the deliberation in the conference will find the solutions and suggest policy maker to develop mechanism to de3velop healthy state and country.

Resist fabric techniques such as tie-dye, batik, adire-eleko e.t.c is a manual procedure that directly exposes workers to various synthetic dyes and chemical used. The aim of this study was to assess the level of knowledge, attitude and practice on the use of personal protective equipment by traditional resist fabric workers in Abeokuta. Cross sectional survey was used for this study to select 403 traditional resist fabric workers. The workers were interviewed by face-to-face questionnaire. The results revealed that the prevalence of good knowledge and appropriate attitude was low equal 3.7% and 4.2% respectively. The prevalence of using nose cover was 29%. Additionally, most of the workers know that synthetic dyes and chemicals used with it cause poisonous gas; 91.6% of the respondents have known that synthetic dyes and chemicals can be harmful to their health, 80% of the respondents received health the information from family, friends and neighbors while few of them receive if through radio. The study proposed appropriate recommendations in order to reduce the impact of health implications on them.

Cotton acquires negative charge in aqueous medium and thus repels negatively charged dye anion during dyeing. Such repulsion between fibre and dye is offset by using large quantity of salt in dye bath, particularly for reactive dyes. A low dye bath exhaustion also leads to low dye fixation of reactive dyes on cotton. Thus, the use of high salt concentration and low reactive dye fixation lead to environmental problems related to highly coloured effluent with high salt content. Hence, modifying the
cotton fibre to increase dye-fibre interaction is therefore the best route to overcome the lack of affinity for cotton to reactive dyes making salt-free reactive dyeing. However, majority of the chemicals used for imparting cationic sites in cotton are themselves not ecofriendly. This paper presents the possibility of salt-free reactive dyeing of cotton by modifying the surface of cotton fabric using soya bean hull. The cationization of cotton was carried out with natural amino acid extract obtained by acid hydrolysis from soya bean hull and cationized in the pad-dry-curing process to investigate its dyeability with reactive dye in both a conventional alkaline dye bath and salt-free acidic dye bath. FTIR spectroscopy confirmed that there was a change in chemical composition after cationization by pad-dry-cure technique. The color strength of modified cotton was better than that of conventional sample which is 3.9865 and 3.7135 respectively. The extent of improvement was 4% in dye exhaustion, 3.34% in dye fixation and 7.12% in the total dye utilization was achieved in this study. The wash, dry rubbing and perspiration fastness of the cationized cotton was found almost similar to that of the normal dyeing. There was a slight increase in flexural rigidity and crease recovery angle in the cationized cotton. The tensile strength of cationized and the conventional dyed cotton were found almost the same. The cationized cotton dyeing technique reduced the BOD, COD and TDS by around 32.4, 27.3 and 75.4% respectively. It was revealed that soya bean hull was found to be effective for cationization in salt-free dyeing of cotton.

Woven hemp fabric was treated with sodium hydroxide, commercial flame retardant chemical, and combination of both to increase its fire-retardant properties. Treatments of fire-retardant changed the properties of woven hemp fabric such as increased its fabric shrinkage and density of fibres which ranges from 0.67 to 5% and 1.43 to 1.53 g/cm 3 respectively. After the treatment, the fire retardancy of the fabric increased tremendously which was observed by the burning, thermogravimetry and limiting oxygen index tests. Some of the samples were not burnt when exposed to flame source and the burning rate needed to be measured under exaggeration of flame at longer time. The limiting oxygen index value increased from 18.6 to 51 after the treatments which explained the scenario happened in the burning tests. Nevertheless, its mechanical properties decreased slightly that ranges from 18 to 32% and 23 to 39% for warp and weft respectively compared to untreated fibre.

En esta investigación se obtiene un polímero biodegradable a partir del almidón de yuca al procesar mezclas de almidón modificado con glicerina y agua como plastificantes, utilizando un molino abierto y una extrusora de monohusillo. Las variables a controlar durante la extrusión son: perfil de temperatura, torque, y velocidad de rotación del husillo. Se evalúan características mecánicas y fisicoquímicas mediante ensayos de tensión, análisis térmicos de Calorimetría Diferencial de Barrido (DSC) y Análisis Termogravimétrico (TGA), Análisis Infrarrojo por Transformadas de Fourier (FTIR) y morfología.

PACS: 81.70.Pg, 87.85.J-

Plate and shell analysis using classical plate theory (CPT) has a lack of accuracy in predicting the influence of transverse deformation, because of its assumption that the line normal to the surface remains straight and normal to the midplane before and after deformation. The next revision by constant shear deformation theory or famous as first order shear deformation theory (CSDT/FOSDT) still suffers a disadvantage that has a constant value in the shear term that is called shear locking phenomenon. This matter has been corrected by higher order shear deformation theory (HOSDT) using a refined assumption that the line normal to the surface should be in a parabolic function and not normal to the midplane, but normal to the surfaces so that it fulfills the zero strain in the surface. The analysis of the bending part of laminated composite flat shell element is applied by higher order lamination theory (HOLT) that is adopted from HOSDT. This model is accurate for thicknesses variation and complex materials. HOLT model is implemented into finite element procedure to find deflection, stresses and internal forces. It can be concluded that the displacement and stresses in HOLT model are higher than FOLT the ones (first order lamination theory) in small ratio of a/h dan its result almost the same value for a/h ratio more than 10. In a square plate case, the displacement gets smaller if the fiber arranged into cross-ply sequence. Interlaminar stresses along the thickness is not distributed continuously, but they have certain modes that depend on the depth of point position, the lamina or layer number, fiber orthotropic angle of each layer and a/h ratio.

In this study, both boron-doped and -undoped poly(vinyl alcohol)/ Calix[4]arene fibers were prepared by using an electrospinning technique. Obtained fibers were characterized by FT-IR, DSC, and SEM techniques. The DSC results show that the degradation of the boron-doped fibers started at much higher temperatures. This result indicates the addition of boron increased the thermal stability of the fibers. SEM pictures show that both of the fiber samples are nonbeaded with diameters ranging from 0.5 to 1 lm. The fiber diameters are not homogeneous and uniformly distributed for boronundoped samples.

In this paper, we assess various natural earth pigments as potential colorants and stabilizers for ethylene-norbornene copolymer composites. Several cycloolefin copolymer (COC) composites colored with 2 wt% of a selected pigment were prepared using a two-step mixing method. The aging resistance of the polymer composites was investigated in terms of changes to their mechanical properties, following accelerated aging in the full sunlight spectrum (100, 200, 300, 400, and 500 h). Fourier-transform infrared spectroscopy (FTIR), surface energy measurements, and spectrophotometry were used to assess the color changes, surface defects, and morphology of the composites. Thermogravimetric analysis (TGA) was used to study their thermal stability. The combustion characteristics of the prepared COC composites were evaluated based on the microcombustion calorimetry test (MCC). The application of earth pigments resulted in interesting color changes and a significant improvement in the aging resistance of the COC-filled samples, as evidenced by higher aging factor values and lower carbonyl index parameters compared to the reference (COC). The best results were observed for hematite (HM), gold ochre (GO), and red ochre (RO). In addition, the application of earth pigments, especially iron ochre (IO) and red ochre (RO), in COC contributed to a significant reduction in the heat release rate (HRR) values, indicating improved flame retardancy. This research opens the possibility of producing colorful COC composites with enhanced photostability and reduced flammability for use in polymer applications.

This article investigates the mechanical behavior of fiber-reinforced cementitious composites using moderate to high contents of fly ash (FA) as a replacement for cement; the goal is to create primary building elements with low environmental impact. The experimental results showed that the compressive strength, modulus of elasticity, and post-cracking flexural strength for specimens with w/cm = 0.60 and 20% FA substitution increased with respect to the control. Moreover, the specimens with high FA substitutions had significantly lower mechanical strength values and elastic modulus values. The results indicate that it is feasible to use fiber-reinforced concrete composites as an alternative for low-environmental impact primary construction. 136 Compuestos cementantes fibroreforzados de bajo impacto ambiental comportamiento mecánico RESUMEN El presente texto expone los resultados del estudio del comportamiento mecánico de compuestos cementantes fibroreforzados utilizando consumos moderados y altos de ceniza volante (CV) en sustitución de volúmenes determinados de cemento (20%, 40% y 60%), con el objetivo de producir elementos constructivos primarios de bajo impacto ambiental. La experimentación realizada indicó que el esfuerzo a compresión, el módulo de elasticidad y la resistencia a flexión post agrietamiento, para los especímenes con relación a/mc = 0.60 y con 20% de sustitución con CV registraron incrementos en sus valores con respecto al control para ambas edades. No se evidenció deterioro en las mallas de fibras naturales por la exposición al medio alcalino. Los resultados hasta ahora obtenidos indican que es viable el uso de estos compuestos cementantes fibroreforzados como alternativa de construcción primaria de bajo impacto ambiental. Palabras clave: fibra; cementicios; compuestos; ceniza volante; material de impacto. Compostos cimentantes reforçados com fibra e de baixo impacto ambiental RESUMO Este artigo apresenta algumas importantes propriedades mecânicas obtidas numa pesquisa de materiais cimentantes reforçados com fibras, nos quais foram utilizados consumos moderados e altos de cinza volante (fly ash, FA), em substituição ao cimento Portland (20%, 40% e 60%), com o objetivo de produzir elementos primários de baixo impacto ambiental. Os resultados experimentais mostraram que a resistência à compressão, o módulo de elasticidade e a resistência à flexão, aumentaram em relação ao de referência, para as misturas de a/cm = 0,60 e 20% de substituição. Para os demais casos de substituição foram encontradas resistências e módulo mais baixos que o de referência. Os resultados mostraram que pode ser viável o uso desses materiais cimentantes reforçados com fibras, como alternativa de construção primária de baixo impacto ambiental.

The ever-increasing importance of vegetable natural fibers on the global scale, the comparatively low production of this group of fibers, and the growing fiber imports by the Iranian textile industry have required numerous studies in recent years to be carried out on long natural cellulosic fibers extracted from Typha australis plant leaf. In this study, such tensile properties of the fiber under study as tenacity, modulus, elongation and work of rupture, X-ray and FTIR are investigated by alkali retting at 100 °C for 2 and 4 h. It is found that Leafiran is lignocellulosic with a tenacity approximately 25–40 cN. Tex-1, a linear density of about 4 tex, and a crystallinity of about 60 %, which are all considered to be suitable properties compared to those of other natural cellulosic fibers.

We present the preparation and characterization of viscoelastic formulations of hyaluronic acid functionalized with polymerizable methacrylate groups. We explored three different processing strategies for controlling microstructure and interchain interactions: lightly cross-linked near-gels, emulsion-cross-linked microspheres, and an elastic microgel formed through centrifuging the microspheres. The component structure and rheological properties of these formulations were compared to those of high molecular weight hyaluronic acid solutions, which displayed classical behavior of high molecular weight polymer solutions reported by other investigators. We demonstrate that these processing strategies allow the tuning of solution properties from strongly viscoelastic behavior, observed in lightly cross-linked near-gels and concentrated microsphere solutions to elastic behavior in elastic microgels, behaving like pseudoplastic liquids having a well-defined yield stress above which viscous behavior was observed. In the centrifuged microspheres, the hyaluronic acid degree of methacrylation was inversely proportional to the gel elasticity, and a mechanism based on failure due to microsphere brittleness is proposed to explain this behavior. These results suggest that processing methacrylated hyaluronic acid can lead to a diversity of solution properties, providing methods for delivering this biologically active polymer in a broad range of applications.

El propósito de este artículo es presentar simulaciones del comportamiento de materiales compuestos basado en restricciones cinemáticas entre las mismas fibras y entre las fibras y la resina circundante. En la revisión de literatura, los autores han encontrado que las restricciones cinemáticas no han sido plenamente explotadas para modelar materiales compuestos, probablemente debido a su alto costo computacional. El propósito de este articulo es exponer la implementación y resultados de tal modelo, usando Análisis por Elementos Finitos de restricciones geométricas prescritas a los nodos de la resina y las fibras. Las descripciones analíticas del comportamiento de materiales compuestos raramente aparecen. Muchas aproximaciones para describir materiales compuestos en capas son basadas en la teoría de funciones C1Z y C0 Z, tal como la Teoría Clásica de Capas (CLT). Estas teorías de funciones contienen significativas simplificaciones del material, especialmente para compuestos tejidos. Una aproximación híbrida para modelar materiales compuestos con Elementos Finitos (FEA) fue desarrollada por Sidhu y Averill y adaptada por Li y Sherwood para materiales compuestos tejidos con polipropileno de vidrio.

PACS: 88.30.mj, 81.05.Lg

MSC: 65L60, 53A17

The synthesis of methylcellulose (MC) from chemically purified cellulose extracted from sugarcane bagasse was carried out with dimethyl sulfate (DMS) in the presence of sodium hydroxide and acetone as solvent under heterogeneous conditions and the degree of substitution (DS) was determined as 1.44. 3D porous composite of methylcellulose/polyvinyl alcohol (MC/PVA) was prepared by freeze drying process. The synthesized products were characterized by FE-SEM, FTIR, 1H NMR and XRD. Porosity was calculated as 86% and the binary image, histogram of pores distribution of MC/PVA porous composite were investigated by ImageJ processing technique which shows the roughness of the topographical structure. Synthesized methylcellulose enhances the value to this abundant agro-industrial residue and may extend its range of biomedical applications.► Extraction of cellulose from agro-waste sugarcane bagasse. ► Synthesis of methylcellulose from cellulose with 1.44 degree of substitution. ► Porous composite of methylcellulose/poly(vinyl alcohol) blend by freeze drying process. ► 86% porosity of porous composite was calculated using gravimetric measurement. ► Topographical pore distribution of porous composite by image analysis using ImageJ software.