No abstract

No abstract

Nanocellulose is a new-age material derived from cellulosic biomass and has large specific surface area, high modulus and highly hydrophilic in nature. It comprises of two structural forms viz., nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). This review provides a critical overview of the recent methods of bio-and chemo-mechanical processes for production of nanocellulose, their energy requirements and their functional properties. More than a dozen of pilot plants/commercial plants are under operation mostly in the developed countries, trying to exploit the potential of nanocellulose as reinforcing agent in paper, films, concrete, rubber, polymer films and so on. The utilization of nanocellulose is restricted mainly due to initial investment involved, high production cost and lack of toxicological information. This review focuses on the current trend and exploration of energy efficient and environment-friendly mechanical methods using pretreatments (both chemical and biological), their feasibility in scaling up and the future scope for expansion of nanocellulose application in diverse fields without impacting the environment. In addition, a nanocellulose quality index is derived to act as a guide for application based screening of nanocellulose production protocols.

Over the past few decades, masterbatch production has been increasing year by year. Pigments are used primarily in masterbatches because of their ability to impart colour or opacity to a matrix. The effectiveness of pigments depends not only on their intrinsic ability to absorb or scatter light, but also, importantly, on the dispersiblity and distribution of the pigments that can be achieved in plastics. Nowadays, stringent environmental as well as excellent quality controls are making inevitable the use of non‐dusty monoconcentrated predispersed pigments for the production of masterbatches for the colouring of plastics. Commercially, for the most part, two types of monoconcentrated predispersed pigments are being used for the colouring of thermoplastic masterbatches. These are polymer‐ and wax‐based predispersed pigments. This study has been undertaken to provide a comparison of the colouring properties of polymer‐ and wax‐based monoconcentrated predispersed pigments. Four commercially used organic pigments have been selected. Both types of monoconcentrate predispersed pigments have been developed on a co‐rotating twin‐screw compounding extruder with a length/diameter ratio of 44. A detailed analysis on the comparison of the colouring properties is presented. Results indicate that good colour properties are achieved when operating conditions are optimised.

The performance of the composites is determined on the basis of the interface bonding of the

Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in cables and wires for electrical insulation. PVC has very good-to-excellent electrical and mechanical properties which make it suitable for use as an electrical insulating material in many domestic and industrial electrical insulation applications. Mica-filled PVC composites may become the cost-effective substitutes for other types of cable and wire compositions with their improved properties. In this study, water ground mica samples of different particle sizes, surface areas, and concentrations were used for fabrication of PVC composites with and without its surface treatment. Haake Rheochord 9000 compounder using roller-type blades was used for the fabrication of different PVC test composites. Melt-compounded composite was compression molded for making sheets. Mechanical and electrical properties were determined using these test sheets. Mechanical properties such as Young’s modulus, stiffness, and shore hardness increased with increase in mica concentration, whereas tensile strength and elongation at break values are found to decrease with increase in mica concentration. Dielectric properties also increase with mica loading. Morphological studies revealed that there was good adhesion and dispersion of the mica in the PVC composite. It was revealed that mechanical and electrical properties were marginally improved with the use of silane-treated mica.

No abstract

No abstract