K. Priya Dasan

Chemical, morphology and thermal evaluation of cellulose microfibers obtained from Hibiscus sabdariffa.

Cellulose is the most abundant biomass material in nature and finds a range of application. Cellulose microfibers were extracted from Hibiscus sabdariffa fibers by steam explosion technique. Structural and surface analysis of the microfibers showed a reduction in diameter and changes in surface morphology from that of the raw fibers. The chemical composition of fibers were analyzed according to the TAPPI standards and showed increase in α-cellulose content and decrease in lignin and hemicelluloses for the microfibers. This has been further confirmed by SEM, XRD and FTIR results. Thermal characterization showed enhanced thermal stability of celluloses microfibers compared to raw fibers.

Morphological, Physical, and Thermal Properties of Chemically Treated Banana Fiber

Environmental consciousness and increasing awareness of green technology have stirred the entire gamut of industry to move toward new materials instead of using synthetic polymeric fibers. Natural fiber can be a good substitute as they are available in fibrous form at low cost. In this study, the chemical treatment of banana fiber (Musa sapientum) using sodium hypochlorite NaClO/H2O (1:1) at 60°C is discussed. The purpose of chemical treatment is to improve the fiber-matrix compatibility, interfacial strength, physical, and thermal properties, etc. The chemical composition of fibers on treatment indicated increase of cellulose content and decrease of noncellulosic material. The changes due to chemical treatment were analyzed by Fourier transform infrared and X-ray diffraction methods. Scanning electron microscope studies revealed the changes in surface morphology after chemical treatment. And also, the treated fibers showed reduced water uptake and improved thermal properties.

Effect of Chemical Treatment on the Mechanical and Water Absorption Properties of Coir Pith/Nylon/Epoxy Sandwich Composites

Multilayered coir pith/nylon fabric/epoxy hybrid composites were fabricated by the hand lay-up technique. Coir pith was subjected to chemical treatment before processing and the volume fraction of coir pith was maintained in the range of 60–65%. The effect of treatment was analyzed by SEM and optical microscopy. The effects of layering and treatment on the mechanical and water transport nature of composite were analyzed. The mechanical properties of the composite decreased on exposure to water. However, the retention of impact strength increased with chemical treatment of coir pith.

Barrier properties of celluloses microfibers (CMF)/ethylene-co-vinyl acetate (EVA)/composites

The effect of celluloses microfibers (CMF) reinforcement in ethylene-vinyl acetate (EVA) on its barrier properties was evaluated using xylene, toluene, and benzene as penetrant molecule. CMF were obtained from Hibiscus sabdariffa by steam explosion technique and was reinforced in EVA by melt extrusion. The barrier properties of the composites were found to be improved with CMF loading. This has been attributed to good interfacial interaction between CMF and EVA which is further confirmed using Kraus equation. Arrhenius activation parameters for the diffusion, permeation, and thermodynamic parameters were also estimated from the sorption data. The mode of the transport was found to follow regular Fickian trend.

Nanoclay/Polymer Composites: Recent Developments and Future Prospects

Clay can be counted among the most widely investigated and commercially high demand filler in the polymer industry. Recently there has been a growing interest for the development of polymer/clay nanocomposites due to their superior properties compared to conventional filled polymers even at a very low fraction of filler addition. The easy availability, processability, low cost, and nontoxicity of clay and the advancements in the processing of clay nanocomposites have invited a lot of commercial attention for these materials. The value-added properties enhanced without sacrificing of pure polymer properties make the clays more and more important in the modern polymer industry. Today it finds a wide range of applications ranging from household items to aerospace to medicine. This chapter looks at the chemical and physical aspects of this wonderful material, clay/polymer nanocomposite processing techniques, and the commercial importance of these nanocomposites.

PET Nanocomposites: Preparation and Characterization

Abstract The chapter deals with a brief account of various characterizing techniques using for PET-based nanocomposites in this chapter mainly explained about the morphology, thermal behavior, tensile behavior, etc.

Solvent Transport Phenomenon of Cellulose Microfiber (CMF) Reinforced Poly (ethylene-co-vinyl acetate) (EVA) Composites

Composite films based on EVA with CMF were prepared and characterized for their solvent transport nature. CMF were derived from Hibiscus sabdariffa by steam explosion technique and incorporated in the EVA matrix by extrusion. Solvent transport by the composites was analyzed using hexane, heptane and octane as penetrant molecules. The solvent uptake behavior of EVA/CMF composites is explained on the basis of the penetrant size, temperature and the filler loading. The composite had improved barrier property compared with unfilled EVA. This in turn is an indication of good fiber-matrix interaction in the composite system. Diffusion parameters such as diffusion coefficient, permeation coefficient and Arrhenius activation parameters and thermodynamic parameters such as enthalpy and entropy were evaluated in detail. The mode of transport was found to be Fickian.

Mechanical, Water Imbibing and Microbial Growth Studies of Coir Fiber/Pith Substituted Cement Blocks

The environmental and health issues posed by agro wastes have prompted many researchers to look at an alternate use for these materials. The present work looks at using coir fiber and pith as a substituent in cement blocks. Fillers were subjected to chemical treatments and loaded in cement blocks at different loadings. Compression property and water imbibing of the blocks were studied with respect to loading and chemical treatment. The microbial growths on these blocks were studied using E. coli.