In the present work, polypropylene (PP)- and polyethylene (PE)-based composites were cured using microwave energy with 15% weight percentage of jute and kenaf fibres. The detailed mechanism of microwave curing of the composites has been discussed with suitable illustrations. The mechanical characterization of the microwave-cured composites was carried out using various tests. The scanning electron microscope (SEM) fractographs were used to study the mechanisms of failure. The ultimate tensile strength of various microwave-cured composites was in the range of 44–50 MPa. The interlaminar shear strength of the PP-based composites was 62% higher than the PE-based composites. The impact energy of the microwave-cured composites was in the range of 18–24 kJ. The mechanical performance of the microwave-cured composites was comparable to the composites obtained through traditional manufacturing routes.

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The present work aims to study the abrasive wear of kenaf/high-density polyethylene (HDPE) composites with 20% weight fraction reinforcement of the kenaf fiber. A unique technique of the microwave-assisted compression molding (MACM) was used to fabricate the composites. The pin-on-disc setup was used for two-body abrasive wear, in which the kenaf/HDPE composite acts as a pin and the abrasive paper (P100) acts as a counter surface. Two-body abrasive wear tests were conducted for HDPE and kenaf/HDPE composites at normal loads of 10 N, 20 N, and 30 N and the sliding speed of 1 m/s, 2 m/s, and 3 m/s within 100 m of sliding distance. Tribofilm formation was observed at higher values of load and speed, which helps in reducing the wear-rate of the composites. Wear mechanism of the kenaf/HDPE composite is discussed in detail and supported with scanning electron microscope (SEM) fractography.

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The present study was oriented towards microencapsulation of aspirin and the study of its release kinetics. The desired encapsulation was achieved by emulsion solvent evaporation method using ethyl cellulose (EC), cellulose acetate phthalate (CAP) and their mixture (1:1) of polymeric constituents. Characterization of the formulations was performed by size, shape, drug loading efficiency and in-vitro drug release analysis. The in-vitro release profiles from different polymeric microcapsules were applied on different kinetic models. The prepared microcapsules were found free flowing and almost spherical in shape with particle sizes ranging from 300–700μm, having a loading efficiency of 75–85%. The best fit model with the highest correlation coefficient was observed in Higuchi model, indicating diffusion controlled principle. The n value obtained from Korsemeyer-Peppas model varied between 0.5–0.7, confirming that the mechanism of drug release was diffusion controlled. Comparative studies revealed that the release of aspirin from EC microcapsules was slower as compared to that of CAP and their binary mixture.

The present work focused on the investigation of hole quality characteristics in laser-drilled kenaf/high-density polyethylene (HDPE) composites. Microwave-assisted compression molding was used to fabricate kenaf/HDPE composite with 20 wt% of the kenaf fiber reinforcement. The two input parameters pertaining to the experimentation were laser power and cutting speed. Kerf taper angle, heat-affected zone (HAZ), and surface roughness were investigated to evaluate the surface quality and accuracy of the holes generated through laser drilling on composite specimens. The assessment of HAZ was performed qualitatively through image analysis on scanning electron micrographs. Additionally, the effect of composite thickness on laser drilling was also investigated for 3-, 6.7-, and 10-mm composite specimens. The central composite design was used to plan the experiments. The kenaf/HDPE composite drilled at power 120 W and speed 2 mm/s shows a minimum kerf taper angle and surface roughness of 0.056° and 3.83 ± 0.19 µm, respectively. Regression model was obtained for the establishment of relation between input variable parameters and responses. Experimental results and predicted model results exhibited good agreement with each other as they provide error less than 5.35%. The analysis of variance was carried out to obtain the significance of the model chosen for optimization of the output values, that is, surface roughness and kerf taper.

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