Review on Opacifying Polymeric Pigment: Reconceive Hiding

A hollow core-shell latex particle synthesized through sequential semi-continuous emulsion polymerization method has served as a promising substitute to white inorganic pigments useful for the coating applications. Incorporating more amount of Titanium dioxide in the paint is a costly measure with diminishing returns. Severe paint defects such as phase separation, agglomeration or settling arises due to incompatibility between inorganic pigments and organic resins. Opaque polymer helps in minimizing the cost of Titania in surface coating formulations. It provides white appearance and hiding due to diffraction of incoming light in different directions. It has gained widespread importance over the years due to its unique structure and morphology. It has potential applications in other technologies such as micro-encapsulation, paper coatings and controlled release of drugs. Osmotic swelling – the most prominent approach involves the synthesis of an ionizable core particle which is encapsulated by another polymer functioning as shell, followed by neutralization with the addition of suitable alkali. Significant techniques have been developed including hydrocarbon encapsulation and water-in-oil-in-water emulsion in this field

Review on the Use of Nanofillers in Polyurethane Coating Systems for Different Coating Applications

Polyurethane (PU) is the most common, versatile and researched material in the world. It is widely used in many applications such as medical, automotive and industrial fields. It can be found in products such as furniture, coatings, adhesives, construction materials, Paints, elastomers, insulators, elastic fibres, foams, integral skins, etc. because it has extraordinary properties and the facility to tailor-made various formulations according to property requirement using different raw materials which are available. Though the material is having fascinating properties the material is also associated with various problems such as inferior coating properties. Inorganic pigments and fillers are dispersed in organic components and binders to improve different properties of the coating. This paper is intended to review the various nanofillers used in different PU coating systems. It gives a general introduction about the various fillers and it's classification, Mechanism by which the filler enhances the mechanical properties of the materials, various factors which affect the properties of the coatings. Various methods of incorporation of fillers in the coating systems are discussed. Various nanofillers such as SiO2(Silicon Dioxide), TiO2(Titanium Dioxide), AL2O3(Aluminium Oxide), antimony doped tin oxide (ATO), BaSO4(Barium Sulphate), FE2O3(Ferric Oxide) as well as carbon nanotubes, graphene derived fillers and nano-diamonds are discussed in detail. The importance and effect of surface modification of fillers to enhance coating properties are also discussed along with challenges associated with polyurethane coatings and future trends

Production Of Lactic Acid From Tamarind Kernel

ABSTRACT: In present work lactic acid is produced by microbial fermentation of sugar obtained from tamarind kernel powder (TKP) and its feasibility has been studied for use as raw replacement for glucose. Saccharification of tamarind seed powder is carried out by acid hydrolysis using sulfuric acid (H2SO4). Optimization of acid catalyst concentration and hydrolysis time was carried out in a steam autoclave to get higher yield in short time. The highest yield of reducible sugar of 0.71 g/g of substrate has been obtained by using 0.5 N H2SO4 at 121°C, in 30 min. This tamarind kernel hydrolyzate (TKH) after neutralization and charcoal treatment is used as a source of reducible sugar for production of lactic acid. Four commonly used lactobacillus strains were used to study the suitable microorganism for the fermentative production of lactic acid from TKH sugar media. Out of them the strain giving better result Lactobacillus casei -2125, is selected for the further studies. The rate of glucose consumption and lactic acid production by Lactobacillus casei -2125 for standard glucose media and for TKH sugar media was studied in batch fermentation. The results for the standard media of glucose and the TKH was comparable and show nearly 90% conversions in 66 to 72 hour of reaction time, respectively. It gives production of lactic acid up to 81 gl -1 with productivity rate of 1.12g / l / hr. A yield of 0.58 g of lactic acid is obtained from each gram of TKP. It shows that the TKP can be used as a suitable and cheap raw material for the lactic acid production