Atanu Kumar Das

Flexible and transparent chitin/acrylic nanocomposite films with high mechanical strength

Chitin-nanofibers (CNFs) of <50 nm in width were successfully extracted from shrimp shell using ordinary household food blender by introducing electrostatic repulsion force, without altering the original chemical structure of chitin. The generated nanofibers were small enough and compatible with liquid acrylic to retain the transparency of acrylic resin films, even at nanofibers share of about 25 %. Young’s modulus of CNFs reinforced resin films has been increased 115-fold and the tensile strength 3-fold. The resulting nanocomposites had almost the same bending resistance of acrylic resin films. It is conceived that this finding is of a significant step in advancing the field of optoelectronic technology.

Introducing Areca catechu as a raw material of cement-bonded board through determining the properties of Areca catechu cement-bonded board

Abstract The study was conducted to assess the properties of cement bonded board made from Areca catechu (betel nut) stem. Fine, coarse and fine-coarse boards were prepared. The ratios of particles weight and cement were 1:2 and 1:3 for each type of board. The laboratory tests for characterization of physical and mechanical properties were carried out for each type of board. In case of physical properties, moisture content, density, water absorption, thickness swelling and linear expansion were evaluated. Modulus of elasticity (MOE) and Modulus of rapture (MOR) were evaluated for mechanical properties. From all the cement bonded boards, the board made with the ratio of 1:3 showed the best performance. Cement bonded particle board made from betel nut may be an alternative raw material for manufacturing cement bonded board.

Quality evaluation of dissolving pulp fabricated from banana plant stem and its potential for biorefinery

The study was conducted to evaluate the quality of dissolving pulp of Musa sapientum L. (banana) plant stem and its potential for biorefinery. Introduction of pre-hydrolysis prior to any alkaline pulping process helps to reduce the content of hemicellulose and consequently produce acceptably high content of cellulose pulp. Water pre-hydrolysis was done at 150°C for 90min. The amount of lignin, xylan and glucan in the extracted pre-hydrolysis liquor (PHL) was 1.6, 4.9 and 1.6%, respectively. Pulping of pre-extracted chips was done following soda-AQ, alkaline sulfite and kraft process. The ratio of chip to liquor was 1:7 for both pre-hydrolysis and pulping. The kraft pulping process with 20% active alkali and 25% sulfidity at 150°C for 90min showed the best result. The lowest kappa number was 26.2 with a considerable pulp yield of 32.7%. The pulp was bleached by acidic NaClO2 and the consistency was 10% based on air-dried pulp. The lowest amount of 7% NaClO2 was used for the bleaching sequence of D0ED1ED2. After D0ED1ED2 bleaching, the pulp showed that α-cellulose, brightness and ash were 91.9, 77.9 and 1.6% respectively. The viscosity was 19.9cP. Hence, there is a possibility to use banana plant stem as a raw material for dissolving grade pulp and other bioproducts.