Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m2, respectively. Then E-glass fiber (woven)-reinforced polypropylene-based composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.
This research work blooms the new idea of developing a safe and controlled drug releasing matrix using multi-walled carbon nanotubes (MWCNTs). In aqueous solution, uniform and highly stable dispersion of MWCNTs was obtained after secondary functionalization with polyethylene glycol (PEG) which was studied by Fourier transmission infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Solution casting method was used to prepare MWCNTs/gelatin-chitosan nanocomposite films and the effect of MWCNTs on physico-mechanical, thermal and water uptake properties of the nanocomposites were evaluated. Incorporation of MWCNTs into the porous gelatin-chitosan matrix showed interesting stiffness and dampness along with developed microfibrillar structures within the pore walls intended at being used in tissue engineering of bone or cartilage. A common antibiotic drug, ciprofloxacin was incorporated into nanocomposite matrix. The evaluation of the effect of MWCNTs on drug release rate by dissolution test and antimicrobial susceptibility test was performed. Sharp release of the drug was found at early stages (∼1 h), but the rate was reduced afterwards, showing a sustained release. It was observed that for all microorganisms, the antibacterial activities of drug loaded MWCNTs/gelatin-chitosan nanocomposites were higher than that of drug loaded gelatin-chitosan composite films containing no MWCNTs. Comparative statistical studies by ANOVA techniques also showed remarkable difference between the antibacterial activities, exhibited by MWCNTs-incorporated and non-incorporated composite films.
ABSTRACT:To improve the physicomechanical properties of jute yarn, grafting with 1,6-hexanediol diacrylate (HDDA) monomer was performed by a UV radiation technique. A series of HDDA solutions of various concentrations in methanol were prepared. A small quantity of photoinitiator (Darocur-1664) was also added to HDDA solutions. To optimize the conditions for grafting, the effects of monomer concentration, soaking time, and radiation doses were studied by varying the number of soaking times along with variation of monomer concentrations and UV radiation intensities. The extent of polymer loading and the mechanical properties like tensile strength (TS), elongation at break (Eb), and tensile modulus of both treated and untreated jute were investigated. The highest tensile strength, polymer loading, and modulus were achieved with 5% HDDA concentration, 5 min soaking time, and the 4th pass of UV radiation. This set of conditions was selected as optimum and produced enhanced tensile strength (67%), modulus (108%), and polymer loading (11%) over those of virgin fiber. To further improve the mechanical properties the jute yarns were pretreated with alkali (5% NaOH) solution and after that the alkali-treated yarn were treated under UV radiation of various intensities. The pretreated samples were grafted with optimized monomer concentration (5% HDDA). Increased properties of alkali ϩ UV-pretreated and grafted samples such as polymer loading (12%), tensile strength (103%), elongation at break (46%), and modulus (114%) were achieved over those of virgin jute yarn.
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