Vikas V. Gite

High performance moisture cured poly(ether–urethane) amide coatings based on renewable resource (cottonseed oil)

In this investigation, polyetheramide resin was prepared through the condensation polymerization of N,N-bis (2-hydroxyethyl) cottonseed oil fatty amide (HECOFA) with bisphenol-A. It was further modified by 2,4-toluene diisocyanate (TDI) in 10–30 wt% of polyetheramide to develop a series of moisture curing urethane-modified polyetheramide resins (UMCOPEtA). The synthesized resin was characterized using 1H NMR, 13C NMR, FTIR and solubility in various organic solvents at room temperature. The thermal and curing behavior of the resin was investigated using thermogravimetric analysis and differential scanning calorimetric techniques. The physico-chemical properties such as hydroxyl value, iodine value, specific gravity and mechanical properties like scratch hardness, impact, and flexibility were determined by standard laboratory methods. Coatings of UMCOPEtA resin were prepared on mild steel panels to evaluate chemical resistance performance against acid, alkali, water and xylene. The newly developed UMCOPEtA coatings showed improved hardness, impact, gloss, water and chemical resistance when compared with unmodified polyetheramide coatings, and thus were found to be suitable as a high performance coating material.

Controlled Release Study of Phenol Formaldehyde Microcapsules Containing Neem Oil as an Insecticide

Many of the biological pesticides are supposed to be more effective than synthetic ones in controlling pests. In this communication, we report a successful encapsulation of neem oil, one of the most effective biological insecticides, in phenol formaldehyde microcapsules. This was achieved by adopting an in-situ polymerization process in oil-in-water emulsion. The synthesis consists of two parts, namely emulsification of the oil and wall formation. The synthesized microcapsules were characterized by FTIR, SEM, TGA, and particle size analyzer. The controlled release was monitored by measuring optical observation in the UV range.

Synthesis and characterisation of polyurethane coatings based on trimer of isophorone diisocyanate (IPDI) and monoglycerides of oils

SummariesMonoglycerides (MGs) of four oils (castor, linseed, soybean and sesame) were prepared. They were reacted with a trimer in definite proportions to prepare polyurethane (PU) coatings. These coatings were applied in the form of thin films on tin plates and analysed for various coating properties such as gloss, scratch resistance, flexibility properties and physicochemical tests. A highly cross-linked product was obtained due to the higher functionality associated with MGs compared with their molecular weight. The trimer also imparted cross-linking due to its trifunctionality, and a hard yet flexible, tough, glossy polyurethane coating was obtained.RésuméDes monoglycérides (MGs) de quatre huiles (ricin, lin, soya et sésame) ont été préparés. On les a fait réagir, dans des proportions définies, avec une trimère afin de produire des revêtements polyuréthaniques (PU). Ces revêtements ont été appliqués, sous la forme de minces films, à des plaques d’étain, et ont été analysés afin de constater des propriétés de revêtement variées, telles que le brillant, la résistance aux éraflures, les propriétés de flexibilité et [leur performance au cours] des essais physicochimiques. On a obtenu un produit qui était très réticulé grâce à la fonctionnalité plus élevée associée aux MGs par rapport à leur poids molaire. La trimère, aussi, a donné de la réticulation, grâce à sa trifontionnalité, et l’on a obtenu un revêtement polyuréthanique qui était robuste et brillant mais aussi flexible.ZusammenfassungDie Monoglyzeride (MGs) von vier Ölen (Rizinus, Leinsamen, Soja und Sesam) wurden hergestellt und mit einem Trimer in bestimmten Proportionen reagiert, um Polyurthanlacke herzustellen. Diese Lacke wurden in dünnen Schichten auf Zinkplatten aufgebracht und nach verschiedenen Eigenschaften wie Glanz, Kratzfestigkeit, Flexibilität und ihren physiochemischen Eigenschaften bewertet. Dank der grösseren Funktionalität im Verhältnis zu ihrem Molekulargewicht erzielten wir mit den MGs ein stark kreuzvernetztes Produkt. Die dreifache Funktionalitat der Trimere trug auch zu der Kreuzvernetzung bei, und der erhaltene Polyurethanlack war sowohl hart als auch flexibel, widerstandsfähig und glänzend.

Development of anticorrosive two pack polyurethane coatings based on modified fatty amide of Azadirachta indica Juss oil cured at room temperature – a sustainable resource

We report the modification of Azadirachta indica Juss oil (renewable source) fatty amide by the piperazine molecule to develop a new polyol. Two pack polyurethane (PU) coatings on mild steel plates were prepared by reacting newly developed polyol with toluene diisocyanate (TDI) at room temperature. Spectral studies of Azadirachta indica Juss oil based fatty amide and piperazine modified fatty amide were carried out using spectroscopic techniques to confirm the modification. The prepared resins were also characterized by end group analysis such as amine and hydroxyl values. Anticorrosive properties of the prepared PU coatings were examined by immersion test in an aqueous salt solution. The thermal stability of coatings was studied by TGA. Other coating properties such as gloss, scratch hardness, adhesion, flexibility, impact resistance and chemical resistance were evaluated using standard methods. It was observed that the presence of nitrogen containing piperazine moiety in the back bone of the PU chain shows better anticorrosive properties compared with the Azadirachta indica Juss oil fatty amide based PU coatings.

Fabrication of dendritic 0 G PAMAM-based novel polyurea microcapsules for encapsulation of herbicide and release rate from polymer shell in different environment

New sequence of microcapsules with dendritic PAMAM-based novel polyurea as shell wall material containing herbicide as a core moiety has been prepared by interfacial polymerization technique. Dendrimer-based polymeric microcapsules were fabricated with aim to study the effect of different reaction parameters such as surfactant dose, core loading, agitation speed, and amount of solvent on particle size, particle size distribution, and appearance of microcapsules. Prepared microcapsules were characterized by FTIR, thermo gravimetric analysis, particle size analysis, scanning electron microscope, and other microscopic technique. In present investigation, surfactant dose of 2.5% with 5 mL of solvent at 400 rpm was found to be optimum for fabrication of stable new polyurea microcapsules containing 1 g of core. The synthesized microcapsules with optimized parameters were evaluated quantitatively for controlled release study by gas chromatography in different environmental conditions. The highest percent release of core was found in acidic conditions compared to that of basic and least in neutral medium.

Preparation and Characterization of Polypropylene Nanocomposites Filled with Nano Calcium Phosphate

The synthesized nano calcium phosphate by matrix mediated growth and controlled technique was used as nanofiller in the preparation of polypropylene nanocomposites. Nanocomposites with different filler concentrations were prepared. The content of nano calcium phosphate was varied from 1 to 3 wt% in the preparation of PP nanocomposites. During preparation of nanocomposites shear rate was varied by means of increase in rpm, i.e., 60, 70, 80 and 90 with the help of Brabender Plastograph and the effect of shear rate was studied with respective to mechanical and thermal properties of composites. The comprehensive evaluation of the PP nanocomposites filled with nano calcium phosphate was done to observe the substantial improvement in the performance properties. The mechanical and thermal properties were determined by Universal Testing Machine (UTM) and Thermogravimetric Analyzer (TGA), respectively. The morphology of the fracture surfaces of the prepared PP nanocomposites filled with nano calcium phosphate was studied by Scanning Electron Microscopy (SEM).

Synthesis and Characterization of Resorcinol-Based Cross Linked Phenol Formaldehyde Microcapsules for Encapsulation of Pendimethalin

A series of resorcinol-based novel phenol formaldehyde (PF) microcapsules containing pendimethalin core were produced by in situ polymerization. Novel PF microcapsules were characterized by FTIR, particle size analyzer and TGA. Surface morphology was studied by optical microscope and SEM confirmed spherical shape, smooth surface and rigid nature of the microcapsules. Release rate of pendimethalin from polymeric microcapsules was calculated by ultraviolet spectrophotometer and also by a simple gravimetric method, which is easier and does not need any special equipment. The beauty of our present research work represented resorcinol-based PF as a new shell material for the microencapsulation of pendimethalin.

Renewable resource-based polymeric microencapsulation of natural pesticide and its release study: an alternative green approach

Recently, the use of renewable sources in synthesizing polymers has been remarkably increased due to numerous reasons, such as finite as well as unreliable petroleum sources and increasing environmental awareness. Considering the need of the day, we are reporting the preparation of polymeric microcapsules based on cardanol as a renewable source by an in situ polymerization technique to encapsulate the biobased core. Comparative study for successful encapsulation of karanja oil by cardanol formaldehyde and conventional phenol formaldehyde-based microcapsules is made. The success of polymerization is characterized by structure and thermal analysis using FTIR and TGA, respectively. Distinctive surface morphologies of the prepared microcapsules are examined by SEM, which confirmed formation of wrinkle-free and globular-shaped microcapsules. The size of prepared microcapsules is determined by a particle-size analyzer. The amount of encapsulated core material released is estimated quantitatively by solvent extraction, and gravimetric and UV spectrophotometric methods. Thus, the current research is oriented towards the exploration of biobased, renewable shell material for the microencapsulation of biobased cores for the structural design of a new generation of pesticide formulations. Therefore, the most recent advancements include an interdisciplinary combination of biobased polymers and agrochemicals, which is a significant requirement for attaining a cleaner global environment.

Synergism between LDH and Nano-Zinc Phosphate on the Flammability and Mechanical Properties of Polypropylene

The synergistic effect of layered double hydroxide (LDH) and prepared nano-zinc phosphate was studied by melt compounding of polypropylene (PP) on a Brabender Plastograph. The obtained lumps of composites were grinded and injection molded to test the performance of nanocomposites with respect to their mechanical, physical, thermal, flame-retardant and morphological properties. The outcome of the present work revealed that the use of LDH and nano-zinc phosphate acted as synergistic fillers in PP nanocom-posites that improved the flammability, as well as other performance properties of PP substantially as compared to pristine PP.

Studies on the flame retardant, mechanical and thermal properties of ternary magnesium hydroxide/clay/EVA nanocomposites

Ethylene vinyl acetate copolymer (EVA) nanocomposites were prepared by melt blending of EVA with nano-sized magnesium hydroxide [Mg(OH)2] and modified montmorilonite clay. Nano Mg(OH)2 was synthesized in the laboratory by matrix-mediated growth and controlled technique. Particle size of Mg(OH)2 crystals was performed using X-ray diffraction technique and was found to be in nanometer range. Ternary EVA, clay and Mg(OH)2 nanocomposites were prepared by melt blending using Brabender Plastograph EC. The prepared samples were characterized by flame test, tensile tests and thermogravimetric analysis (TGA). Morphological study of the composites was studied by scanning electron microscopy (SEM). Flame retardant properties of samples were significantly improved in the EVA/clay/Mg(OH)2 nanocomposites without losing its mechanical properties. Ternary system showed better thermal, flame retardant and mechanical properties compared with nanocomposites of EVA filled only with the nano Mg(OH)2.