19 research outputs found
Studie in mechanical, Thermal and Morphological Analusis of EPDM/PolyPropylene Conconut Pith Composites
Increasing concern about global warming and depleting petroleum reserves have made scientists to focus more on the use of natural fibers such as bagasse, coir, sisal, jute etc. This has resulted in creation of more awareness about the use of natural fibers based materials mainly composites. Eco-friendly coconut pith fillers are used as cost effective filler in many of the rubber based composites. The advantages of coconut pith over traditional reinforcing materials such as glass fibers, talc, and mica are acceptable specific strength properties, low cost, low density, non abrasivity, good thermal properties, enhanced energy recovery and biodegradability, and recyclable in nature. Among various natural fibers, both coir and jute fibers are widely available cheap, relatively water – proof and is resistant to damage by salt water. Coconut piths have an outstanding potential as reinforcement in thermoplastics. Commonly used thermoplastics are Polyethylene, Polypropylene, Polystyrene, Nylon etc. These composites are used in automotive components, building materials. EPDM/Polypropylene blends and composites are the most commonly used ones in the thermoplastic elastomers (TPE) in industry. In this current study morphology, thermal behaviour mechanical properties of EPDM/ Polypropylene coconut pith composites have been investigated. Coconut pith in different ratios was added into EPDM / Polypropylene thermoplastics vulcanizates using Brabender Plasticorder
Studies in use of coir fiber in blend of ethylene Propylene diene Rubber and Polypropylene
Thermoplastic elastomers are a special class of polymeric materials that combine the propertiesof thermo plasticity during processing and rubber-like behaviour in service. They can beprocessed in conventional plastic processing equipment, such as twin screw extruders, internalbatch mixers, extruders and injection moulding machine, but exhibit vulcanized rubber likeultimate properties (i.e. long-range reversible extensibility) immediately on cooling.Dynamically vulcanized thermoplastic fibrous composites based on melt processed hybridethylene-propylene diene rubber (EPDM)/maleic anhydride (MA) grafting and polypropylene(PP) with coir fibers were prepared. Coir fiber acts as a nucleating agent for polypropylenecrystallization; they also form physical interlocking between EPDM/Polypropylene blends whichserve the function of compatibalization along with EPDM – g – Maleic anhydride. Results fromRubber Process Analyzer, Mechanical Analysis, Scanning Electron Microscope, DifferentialScanning Calorimetery, reflect upon the microstructure developed during dynamic cross linking.The coir fiber forms well dispersed structures in the EPDM/PP / EPDM-g-MA thermoplasticvulcanizates. The EPDM/PP TPV fiber composites show a matrix-disperse type of morphologyin which the cross linked EPDM particles appear in the form of agglomerates covered by a layerof PP coir fiber composites. This has been assigned to the formation of a coir fiber networkstructure by the layer of coir fiber PP covered EPDM rubber particles
Effect of hydroxyl value of acrylic polyol and type of crosslinkers on the properties of Polyurethane coetings
Acrylic polyol base polyurethane coatings were prepared by reacting polyol with hexamethylene diisocyanate (HDI) base prepolymer. Five different types of acrylic polyol based on their hydroxyl value and two type of HDI prepolymer i.e. HDI biuret and HDI trimer were used as a hardners, for preparation of Polyurethane coating. The effect of hydroxyl value of acrylic polyol on PU coating properties like physical, mechanical and chemical properties were studied. The base and hardners were mixed prior to application of coating in a NCO: OH ratio of 1:1. Â It was found that the as hydroxyl value of polyol increases, it forms a hard film due to high cross-linked structure than low hydroxyl value polyol. Also HDI prepolymer with higher functionality gives better coating properties
Mechanical thermal X-Ray diffraction studies in nanocomposites based on thermoplastic polyurethanes and nanosilica for radiation resistance
Thermoplastic polyurethane provides opportunities to the modern industry by its outstanding versatility, by improving the performance of any product from shoe sole, seals, films, conveyor belts and cables. Thermoplastic polyurethanes have high elongation and tensile strength, its elasticity and its ability to resist oils, greases, solvents, chemicals and abrasion. Thermoplastic Polyurethane are classified in to Polyether based and Polyester based, which have following characteristics within them, Polyester TPUs are unaffected by oils and chemicals, provide excellent abrasion resistance, offer a good balance of physical properties and are perfect for use in polyblends, but on the other side Polyether TPUs are slightly lower in specific gravity than polyester TPU’s and offer low temperature flexibility, good abrasion and tear resilience. They are also durable against microbial attack and provide excellent hydrolysis resistance – making them suitable for applications where water is a consideration. The mentioned work deals with preparation of nano composites based on thermoplastic polyurethane and nanosilica via melt blending process in a laboratory mixer and prepared nanocomposites were tested for mechanical/thermal/electrical/structural properties and also the irradiation properties were determined. The aim of this work is to obtain nanocomposites and the improved properties that those materials can display
NANOFILLERS IN SURFACE COATINGS: A REVIEW
Nanofillers since many years have a high significance in various polymer based industries. Nanocoatings are coatings that are produced by usage of some component at nanoscale to obtain desired properties. Much research is being done to develop effective material combinations of polymer nanocomposites with tailored properties. Nanocomposite is a multiphase solid material where at least one of the phases should have dimensions of less than 100 nm. The properties of composites are largely dependent on the area of interface surface and the intensity of intermolecular interaction between the materials of the matrix and the filler. Nanoscale dispersion of filler or controlled nanostructures in the composite can introduce new physical properties and novel behaviors that are absent in the unfilled matrices. This paper reviews various types of fillers used for different applications in coatings such as anticorrosion resistant paints, ceramic coatings, super hydrophobic coatings, self-healing coatings, sol gel coatings, etc
Silver nanoparticles green synthesis: A mini review
Nanotechnology is a significant field of contemporary research dealing with design, synthesis, and manipulation of particle structures ranging from in the region of 1-100 nm. Nanoparticles (NPs) have broad choice of applications in areas such as fitness care, cosmetics, foodstuff and feed, environmental health, mechanics, optics, biomedical sciences, chemical industries, electronics, space industries, drug-gene delivery, energy science, optoelectronics, catalysis, single electron transistors, light emitters, nonlinear optical devices, and photo-electrochemical applications. Nano Biotechnology is a speedily mounting scientific field of producing and constructing devices, an important area of research in nano biotechnology is the synthesis of NPs with different chemical compositions, sizes and morphologies, and controlled dispersities. Silver nanoparticles (NPs) have been the subjects of researchers because of their unique properties (e.g., size and shape depending optical, antimicrobial, and electrical properties). A variety of preparation techniques have been reported for the synthesis of silver NPs; notable examples include, laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, microwave processing, and biological synthetic methods. This assessment presents a general idea of silver nanoparticle preparation. The aim of this analysis article is, therefore, to replicate on the existing state and potential prediction, especially the potentials and limitations of the above mentioned techniques for industries
POLYMERIC PARTICLE BOARD:A SUSTAINABLE SUBSTITUTE TO WOODEN BOARDS
The aim of this paper is to give overview about particleboards and its development.Particle boards are wood composite prepared from wood waste , stalks, wood shaving, etc and polymeric resin.Urea-Formaldehyde(UF) and Phenol Formaldehye (PF) being widely used resin for preparation of particle board.Here we discuss about different types wood and resin used for manufacture of particleboard.The effect of different woods and resin on properties like internal bond strength, thickness swelling, modulus of rupture, modulus of elasticity and water absorption.Various chemical additives used to modify the properties of particle board and also fire retardant property of particle board.World is leading towards sustainable development thus use of particle board can help us in achieving a small part of it.
A greener and sustainable approach for converting polyurethane foam rejects into superior polyurethane coatings
Recycling is a crucial area of research in green polymer chemistry. Various developments in recycling are driven by Environmental concerns, interest in sustainability and desire to decrease the dependence on non-renewable petroleum based materials. Polyurethane foams [PUF] are widely used due to their light weight and superior heat insulation as well as good mechanical properties. As per survey carried Polyurethane Foam Association, 12 metric tonnes of polyurethane foam are discharged during manufacturing and/or processing and hence recycling of PUF is necessary for better economics and ecological reasons. In present study, rejects of PUF is subjected to reaction with a diethylene amine in presence of sodium hydroxide [NaOH
Common variants in CLDN2 and MORC4 genes confer disease susceptibility in patients with chronic pancreatitis
A recent Genome-wide Association Study (GWAS) identified association with variants in X-linked CLDN2 and MORC4 and PRSS1-PRSS2 loci with Chronic Pancreatitis (CP) in North American patients of European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525—OR 1.71, P = 1.38 x 10-09; rs12008279—OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220—OR 1.72, P = 9.20 x 10-09; rs6622126—OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI [0.31–0.78], P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients