Research on mechanics and acoustic properties of Jute fiber composite material.

In this study, the loss of quality from the oxidative thermal decomposition of jute fiber was explored during the production of reinforced composite materials. Amino silicone oil was used to modify jute fiber, which was then subjected to thermogravimetric analysis. The modified fiber's thermal decomposition temperature was found to be 271 °C, enhancing the composite's thermal stability. The study also investigated how different jute fiber content affected the mechanical and sound absorption properties of composite materials. Results showed that jute fiber composites had better mechanical properties than pure polypropylene materials, and the average sound absorption coefficient of jute polypropylene composites increased with fiber content. Adding jute fiber to polypropylene effectively improved the sound absorption and noise reduction performance of the material. The average sound absorption coefficient of the composite material at a mass content of 20 wt% was 120 % higher than that of the polypropylene matrix material.

Characterization of raw and alkali treated cellulosic Grewia Flavescens natural fiber.

The physicochemical, mechanical, thermal as well as morphological characteristics of alkali treated cellulosic Grewia Flavescens are reported in this paper. Using standard test methods, the chemical constituents of Grewia Flavescens fiber (GFF) are evaluated. Fiber treated in 5% (w/v) NaOH for 45 min soaking time is regarded as optimally surface-modified fiber. After optimal alkalization, there is an enhancement of cellulose content from 58.46% to 68.31%. Mechanical properties of GFF are determined by single fiber tensile test and improved tensile strength is achieved after alkalization. Weibull statistical analysis is performed for diameter and mechanical parameters of raw as well as treated GFF. FTIR spectroscopy reveals the removal of amorphous material from the fiber post-treatment and XRD analysis confirms improvement in crystallinity index from 16.01% to 26.72% and crystal size from 62.90 nm to 68.43 nm after alkalization. Thermal stability and thermal degradation temperature are found to be improved after alkali treatment. Morphological analysis of raw and alkali treated cellulosic GFF shows enhanced rough surface of fiber after alkalization because of elimination of impurities and foreign particles from the fiber surface. Presently studied GFF seems to be a good substitute to the harmful man-made fibers for making of bio composites.

Effect of a Bacillus subtilis strain on flax protection against Fusarium oxysporum and its impact on the root and stem cell walls.

In Normandy, flax is a plant of important economic interest because of its fibres. Fusarium oxysporum, a telluric fungus, is responsible for the major losses in crop yield and fibre quality. Several methods are currently used to limit the use of phytochemicals on crops. One of them is the use of plant growth promoting rhizobacteria (PGPR) occurring naturally in the rhizosphere. PGPR are known to act as local antagonists to soil-borne pathogens and to enhance plant resistance by eliciting the induced systemic resistance (ISR). In this study, we first investigated the cell wall modifications occurring in roots and stems after inoculation with the fungus in two flax varieties. First, we showed that both varieties displayed different cell wall organization and that rapid modifications occurred in roots and stems after inoculation. Then, we demonstrated the efficiency of a Bacillus subtilis strain to limit Fusarium wilt on both varieties with a better efficiency for one of them. Finally, thermo-gravimetry was used to highlight that B. subtilis induced modifications of the stem properties, supporting a reinforcement of the cell walls. Our findings suggest that the efficiency and the mode of action of the PGPR B. subtilis is likely to be flax variety dependent.

Bulk vs. Nano ZnO: Influence of fire retardant behavior on sisal fibre yarn.

Flame retardant functionality was imparted in sisal (leaf fibre) yarn whereas a strong scientific finding has been established between fire retardant efficacy of bulk and nano zinc oxide based formulations. Bulk and nano ZnO treated sisal yarns have been compared on the basis of their flame retardant efficacy, weight add-on% and tensile strength. Limiting oxygen index and char length of the 12% ZnO treated sisal was found to be well comparable with the 1% nano ZnO treated yarn. Further, add-on% and the tensile strength of the nano ZnO treated sample is 70-80% lower and 20% more, respectively, compared to the 12% bulk ZnO treated sisal yarn. Besides, thermo-gravimetry and char morphology of the control and both the formulation treated sisal yarn were compared and analysed to understand the pyrolysis path of the sisal yarn. The possible mechanism of attachment of ZnO to the microstructure of sisal has also been established.