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This study was an attempt to combine fused deposition modelling and hot press moulding technique to fabricate hybrid polymer composites using acrylonitrile butadiene styrene (ABS) polymer, woven glass fibre (GF) and woven carbon fibre (CF). The composite specimens were subjected towere subjected to mechanical and thermal characterization.Tensile strength of GF/ABS and GF/CF/ABS composite were far higher than the virgin ABS. GF/ABS composites displayedimproved thermal resistance by giving a final residue of 42.36%, followed by GF/CF/ABS hybrid composites as per the thermogravimetric analysis. Thermomechanical analysis revealed the coefficient of thermal expansion in the order: ABS > GF/ABS > GF/CF/ABS. The entropy obtained from the DSC curve was of higher value for composites than the ABS. The ABS based composites fabricated from this technique can be applicable to structural parts in the automobiles, aircrafts, shipping vessels, etc. [ABSTRACT FROM AUTHOR]

Using biodegradable polypropylene carbonate (PPC) as the polymer matrix and 5 to 25 wt% content of spent coffee bean powder (SCBP) as filler, completely biodegradable composite films of PPC/SCBP were prepared. These composite films were characterized by polarized optical microscopy (POM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. The POM images indicated the uniform distribution of the SCBP in the composites. The FTIR spectra indicated that the PPC structure was retained by the composite films. The XRD analysis found that the composite films had lower crystallinity than the PPC due to the presence of amorphous hemicellulose containing SCBP. A significant enhancement in thermal stability of the filler reinforced composite was noticed which was more than 30% of the PPC matrix due to the presence of polyphenols in SCBP. A maximum increase of 35% of tensile strength was observed with the addition of 20 wt% SCBP filled composite films. These biodegradable composite films with higher thermal stability and tensile strength can be considered for packaging applications. [ABSTRACT FROM AUTHOR]

Green composites were fabricated using poly(3-hydroxybutyrate-co-3-hydroxyvaierate) (PHBV) as the matrix and spent coffee bean powder (SCBP) as a filler by simple solution casting method. The effect of varying concentrations (5-25 wt.%) of SCBP on the thermal and mechanical properties was studied. The SCBP filler had better thermal properties than the matrix and the composites. There was slight increase in the glass transition temperature of the composites with higher concentration of the filler when compared to the PHBV matrix. The weight remaining at endset temperatures of the composites was found to be higher than for the matrix indicating enhanced thermal stability. The contact angle of the composites increased with increasing filler content changing from 75.8° to 97°. The tensile strength and modulus of the composite films reduced with increasing filler concentration but a reverse trend was observed in case of the % elongation at break. However, the tensile properties were comparable with other synthetic polymers such as LDPE, HOPE etc. Furthermore, the recycling of films did not significantly affect the mechanical and thermal properties. Hence, with comparable thermal and tensile properties, these biocomposite films can be considered for replacing the conventional synthetic non-biodegradable polymers such as polyethylene and polypropylene for packaging applications. [ABSTRACT FROM AUTHOR]

Using biopolymer cellulose as the matrix and tamarind nut powder (TNP) obtained from agricultural waste of tamarind nuts as the filler, the green composites were made. Cellulose was dissolved in environmental friendly solvent of aq. 8 wt. % Lithium hydroxide and 15 wt. % urea which was precooled to -12 ° C. To the cellulose solutions, TNP was added in 5 wt. % to 25 wt. % of cellulose separately. Each solution was evenly spread on glass plates and the wet composites were prepared by regeneration method using ethyl alcohol coagulation bath. The wet films were dried in air at room temperature. The dried composite films were characterized by FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis and also tested for their tensile properties. The tensile strength and the % elongation at break of the composites were higher than those of the matrix and increased with TNP content. While the matrix had a tensile strength of 111.8 MPa, the cellulose/TNP composite loaded with 25 wt.% TNP possessed a tensile strength of 125.4 MPa (12% increase). Though the thermal stability of the composites was lower than cellulose matrix, all the composites were stable up to a temperature of 350 °C. [ABSTRACT FROM AUTHOR]

In this work, the influence of weathering on the creep behavior of the sisal (SSSS), hemp (HHHH), and their hybrid composites (HSSH, and HSHS) was investigated. Composites were exposed to accelerated weathering for 2222 h, which replicates conditions equivalent to 1 year of outdoor exposure. Bio-epoxy based composites were fabricated by the hot press technique. Creep study was performed in a dynamic mechanical analyzer under the dual cantilever creep mode at 30 °C and 50 °C testing temperature under a load of 5 N. The creep-recovery behavior of the weathered composite specimens was evaluated and compared with the unweathered specimens. The investigation revealed that creep strain decreased with the incorporation of the sisal and hemp fibres into the bio-epoxy matrix. The experimental creep response of the composites was also in good agreement with the analytical results from Burger's model. Both the weathering and testing conditions at elevated temperature (50 °C) had a significant impact on the creep resistance of the composites. The creep resistance of the hybrid composites was found to be dependent on the layering sequence. HSHS configuration almost displayed similar creep properties before and after weathering. HSSH configuration was found to have lower creep resistance after weathering. Scanning electron microscopy was used out to examine the fibre-matrix interface of the composites. [ABSTRACT FROM AUTHOR]