Photopolymerization of hydrogels using UV LED system was highly efficient with the aid of synthesized water soluble photoinitiator.

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Luffa fiber, glass wool (yellow) and glass fiber (white) were used into polyurethane (PU) to prepare sandwich composites. Effects of reinforcement in the composites were evaluated in terms of sound absorbance, water absorption and mechanical properties. In addition, the elastic and plastic nature along with the ignition property of the composites due to the reinforcement of the fibers was also revealed. The thermal properties of the composites were determined by differential scanning calorimetry and thermogravimetric analysis, whereas, the surface morphology of the samples before and after the ignition were examined by scanning electron microscopy (SEM). Result analysis revealed that the PU composites reinforced with glass fiber (white) showed the highest sound absorbance (21.3 dB) and tensile strength (0.96 MPa) compare to the others. The thermal stability was enhanced by 10 °C due to the reinforcement of the glass and luffa fiber. The glass transition temperature was increased significantly (58 °C) by the addition of glass fiber. The sound absorption coefficient changed from 0.21 to 0.27 due to the incorporation of the glass fiber. A large number of differentsized pores created in the composites as observed from the SEM analysis.

The main purpose of this paper is to investigate the effect of alkaline treatment on the physical, thermal, mechanical and chemical properties of pristine lemba leaves fibres (LeLeFs). LeLeFs were treated with 6, 8, and 10 wt% sodium hydroxide (NaOH) solution at room temperature for 24 h. In order to determine the functional group presence after the alkaline treatment, LeLeFs were analyzed using Fourier Transform Infrared (FTIR) Spectroscopy. The density of LeLeFs treated with 10 wt% NaOH solution recorded the highest density with 1.168 g/cm³. Morphology study showed that the diameter of fibre reduced with the increment of NaOH concentration. The removal of lignin and hemicellulose could be observed in the thermogravimetric analysis (TGA). Alkaline treatment enhanced the tensile properties of fibre and 10 wt% alkaline treated fibre resulted in the highest tensile strength, modulus and elongation of the fibre at 511.10 MPa, 11.76 GPa and 3.69% respectively. Chemical resistance analysis found that the treated fibre had better chemical resistance compared to untreated fibre. Therefore, it is substantiated that alkaline treatment affects the properties of LeLeF.