Browsing by Author "SREENIVASAN, K"
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Item A COMBINED CHROMATOGRAPHIC AND IR SPECTROSCOPIC METHOD TO IDENTIFY ANTIOXIDANT IN BIOMEDICAL POLYURETHANE(CHROMATOGRAPHIA, 1991) SREENIVASAN, KA combined chromatographic and infrared spectroscopic method has been developed to identify the antioxidant in biomedical polyurethane. The method facilitate easier identification of the additive which might be essential prior to the intended use of the polymer.Item A NORMAL-PHASE CHROMATOGRAPHIC METHOD TO SEPARATE TRIS(2-ETHYL HEXYL) TRI-MELLITATE FROM OTHER COMMON ADDITIVES OF PVC(JOURNAL OF LIQUID CHROMATOGRAPHY, 1990) SREENIVASAN, KItem A NOVEL DIFFERENTIAL SCANNING CALORIMETRIC METHOD TO STUDY THE COMPLEXATION OF BETA-CYCLODEXTRIN WITH STEROID IN SOLID-STATE(JOURNAL OF THERMAL ANALYSIS, 1995) SREENIVASAN, KThis communication demonstrates that, by simply monitoring the evaporation of water molecules included in beta-cyclodextrin cavity, complexation of beta-cyclodextrin with steriod in solid state can be studied. The reported method is simple, rapid and novel.Item A SIMPLE METHOD FOR REMOVAL OF OLIGOMERS IN POLY(ETHYLENE-TEREPHTHALATE) FOR BIOMEDICAL APPLICATIONS(ACTA POLYMERICA, 1987) NAIR, PD; SREENIVASAN, KItem A SIMPLE NORMAL PHASE ISOCRATIC HPLC METHOD FOR THE FRACTIONATION OF EPOXIDIZED SOYBEAN OIL(JOURNAL OF THE INDIAN CHEMICAL SOCIETY, 1990) SREENIVASAN, KItem ACCELERATED DEGRADATION OF POLY(ESTER URETHANE) BY ADENOSINE-TRIPHOSPHATE(JOURNAL OF APPLIED POLYMER SCIENCE, 1991) SREENIVASAN, K; JAYABALAN, M; RAO, KVCItem AGING OF RADIATION-STERILIZED POLYPROPYLENE - CHANGES IN SEMICRYSTALLINITY(BIOMATERIALS, 1989)Item CHARACTERIZATION OF POLY(URETHANE-G-METHYL METHACRYLATE) BY GPC(ACTA POLYMERICA, 1992) SREENIVASAN, KItem COMBINED DYE ADSORPTION AND HPLC FOR DETERMINATION OF HYDROPHILICITY IN POLYMERS(INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS, 1990)Item CROSS-LINKING EFFECT OF HARD SEGMENT DOMAINS ON THE DIFFUSION OF LIPIDS THROUGH POLYURETHANES BASED ON H12MDI(JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS, 1993) SREENIVASAN, KItem DIFFUSION AS A PROBE TO ASSESS STRETCHING-INDUCED MORPHOLOGICAL-CHANGES IN POLYURETHANE(JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 1993) SREENIVASAN, KAn analysis of the diffusion of toluene through polyurethane based on bis(p-cyclohexyl diisocyanate), poly(tetramethylene glycol) 1000, and 1,4-butane diol, subjected to varied degrees of elongation by stretching, is presented. The diffusion coefficient is increased by 60% in polymers drawn to 200% and above. Beyond 400% elongation, the diffusion coefficient attained a constant value. Associated changes are observed in the wide-angle x-rav diffraction pattern. These diffusion and x-ray changes are correlated with restructuring of the polymer induced by stretching. (C) 1993 John Wiley & Sons, Inc.Item DIFFUSION OF WATER AND ALCOHOL IN CHEMICALLY MODIFIED POLYURETHANE(POLYMER INTERNATIONAL, 1993) SREENIVASAN, KDiffusion of methanol and water in polyurethane and polyurethane chemically modified by grafting different acrylic monomers was carried out. The absorption of these two molecules was found to vary with the nature and percentage grafting of the monomers. The possible use of chemically modified polyurethanes as membranes having high selectivity towards the interaction of alcohol and water is highlighted.Item EFFECT OF HARD SEGMENTS ON THE REFRACTIVE-INDEX OF POLYURETHANE BASED ON H-12-MDI(ACTA POLYMERICA, 1991) SREENIVASAN, KItem EFFECT OF ROOM-TEMPERATURE STRETCHING ON THE THERMAL-STABILITY OF SEGMENTED POLYURETHANE BASED ON H12MDI - A NOTE(POLYMER DEGRADATION AND STABILITY, 1991) SREENIVASAN, KStretching is known to alter the morphology of polymeric materials. However, it is unknown, at least in segmented polyurethanes, to what extent stretching effects thermal stability. The effect of stretching on the thermal stability of polyurethanes with various soft/hard segment content is investigated in this note. TGA studies showed that stretching enhances the thermal stability of polyurethanes.Item EFFECT OF THE TYPE OF POLYOL ON THE SOFT SEGMENT CRYSTALLINITY IN POLYURETHANE BASED ON METHYLENE BIS(CYCLOHEXYL DIISOCYANATE)(EUROPEAN POLYMER JOURNAL, 1991) SREENIVASAN, KTo reveal the influence of the nature of polyols on the soft segment morphology, polyurethanes based on three polyols (polypropylene glycol 2000, polyethylene glycol 2000 and polytetramethylene glycol 2000), Methylene bis(p-cyclohexyl diisocyanate) and 1,4-butanediol were synthesized. These materials were characterized using wide angle X-ray diffraction and differential scanning calorimetry. Polytetramethylene glycol based polyurethane showed soft segment crystallinity while the other two were amorphous. This feature has been connected with the specific nature of the polyols.Item ESTIMATION OF HARD SEGMENT CONTENT IN POLYURETHANE FROM SOLVENT ABSORPTION(POLYMER JOURNAL, 1990) SREENIVASAN, KItem MECHANICAL-PROPERTIES OF STRETCHED AND RELAXED POLYURETHANES BASED ON METHYLENE BIS(PARA-CYCLOHEXYL ISOCYANATE)(ACTA POLYMERICA, 1992) SREENIVASAN, KItem MULTIPLE GAMMA-RADIATION STERILIZATION OF POLYESTER FIBERS(BIOMATERIALS, 1988)Item NEGENTROPY AND RETENTION IN REVERSED PHASE LIQUID-CHROMATOGRAPHY(CHROMATOGRAPHIA, 1990) SREENIVASAN, KItem SORPTION STUDIES IN A POLYURETHANE-BETA-CYCLODEXTRIN BLEND(POLYMER INTERNATIONAL, 1994) SREENIVASAN, KThe sorption of toluene, butanol, methanol and n-hexane in polyurethane and a polyurethane-beta-cyclodextrin blend has been studied. The time to reach equilibrium absorption was several times less in the blend in spite of nearly identical diffusion coefficients and % equilibrium absorptions of the diffusants in both materials. The study indicates that rapidity in polymeric membrane mediated separation can be attained by blending beta-cyclodextrin.