An approach to improve the existing ribbon retting of jute fibre using concrete tank and natural catalyst

The ribbon retting method has been developed as a remedy for the issues associated with the conventional water retting method. But this method has not yet gained popularity among jute growers due to the unavailability of catalyst, inadequate training and lack of interest of farmers. The study deals with the improvement of the existing ribbon retting process by using a concrete tank with or without fermented soybean as a natural catalyst in different proportions. For this purpose, 25 fibre samples were developed using different conditions such as concrete tank without natural catalyst, concrete tank with 2.5%, 5% and 7.5% natural catalyst and a micro pond without natural catalyst for various observational time periods. After that, samples collected under mentioned conditions which were measured to assess the fibre properties. The samples produced in a concrete tank with 7.5% natural catalyst demonstrated better fibre characteristics than the other conditions, including fibre fineness, fibre strength, improved fibre color, open surface structure and smooth surface etc. The best conditions for microbial growth were achieved using a concrete tank with more natural catalysts, which improved bacterial growth, fibre quality and reduced the retting time. The use of more natural catalysts increased microbial activity, which in turn affected total dissolved solids (TDS), Biochemical oxygen demand (BOD), Chemical oxygen demand (COD), and pH value of the retted water. In comparison to the existing ribbon retting method, this improved method is significantly faster and produces fibers with better properties. Farmers will gain more from the successful implementation of an improved ribbon retting method because it shortens retting time, conserves water, and uses a concrete tank during retting that can be used for multiple purposes.

Natural halloysite nanotubes as an efficient catalyst in strecker reaction: the synthesis of α-amino nitriles under solvent-free conditions

In this work, a green and cost-effective method based on halloysite as natural catalyst for the synthesis of α-amino nitriles via Strecker three-component reaction is introduced. The chemical and physical structure of natural halloysite has characterized thoroughly, and then the effect of different parameters such as the amount of catalyst, solvent, and temperature was optimized in the synthesis of 2-phenyl-2-(phenylamino)acetonitrile as the model reaction. Then, various substituted benzaldehydes and anilines were converted to the desired α-amino nitriles under the optimized conditions. Electronic properties of substituents on aldehydes and aromatic amines have been affected the reaction efficiency. For all substrates, good to excellent yields of the corresponding α-amino nitriles were obtained under solvent-free conditions at room temperature. The catalyst has been recovered and reused five times in successive Strecker reaction.

Rapid four-component synthesis of dihydropyrano[2,3-c]pyrazoles using nano-eggshell/Ti(IV) as a highly compatible natural based catalyst

Nano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.