02613nas a2200229   4500008004100000022001400041245011300055210006900168260006800237300001400305490000700319520173200326653001602058653004902074653001302123653002702136100002202163700002802185700002102213700002502234856012402259       2010                        eng d  a0887-626600aHydrophobically modified poly(vinyl alcohol) using alkoxy-substituted methyl gallate: synthesis and rheology0 aHydrophobically modified polyvinyl alcohol using alkoxysubstitut  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAY  a1054-10630 v483 a<p>Hydrophobically modified poly(vinyl alcohol) (HMPVA) polymers were synthesized by potassium t-butoxide-catalyzed reaction of PVA with methyl 3,4,5-tris(n-octyloxy) benzoate (MGC(8))/3,4,5-tris(n-dodecyloxy) benzoate (MGC(12)) and 1,3-propane sultone. The concentration of 1,3-propane sultone was kept constant at 10 mol %. and that of MGC(8) (2, 3, and 4 mol %)/MGC(12) (2 and 3 mol %) was varied to obtain HMPVAs with different hydrophobic contents. The incorporation of MGC(8)/MGC(12) and 1,3-propane sultone onto HMPVA was confirmed by NMR spectroscopy. Rheological properties of aqueous solutions also confirmed the presence of hydrophobic and charged functional groups on HMPVAs. In the semidilute regime, the specific viscosity of HMPVAs followed concentration scaling that is typical of polyelectrolytes. At higher concentrations, the HMPVA solutions with 3 and 4 mol % of MGC(8) exhibited large increase in specific viscosity. Oscillatory experiments on these solutions exhibited gel-like behavior at polymer concentrations of 40-50 g/L. Confocal microscopy images of HMPVA with 4 mol % of MGC(8) clearly indicated the existence of microgels. The tendency of formation of microgels further increased with increasing chain length of the hydrophobe, that is, with MGC(12). These samples exhibited rheological behavior that is typical of soft solids and was therefore probed by the strain-rate frequency superposition technique reported recently in the literature. HMPVAs with improved rheological properties show potential applications as thickeners in cosmetic creams, lotions and as drug carriers in pharmaceutical formulations. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1054-1063, 2010</p>10agallic acid10ahydrophobically modified poly(vinyl alcohol)10aRheology10awater-soluble polymers1 aShedge, Aarti, S.1 aWadgaonkar, Prakash, P.1 aLele, Ashish, K.1 aBadiger, Manohar, V.  uhttps://library.ncl.res.in/content/hydrophobically-modified-polyvinyl-alcohol-using-alkoxy-substituted-methyl-gallate-002489nas a2200301   4500008004100000022001400041245013200055210006900187260009900256300001200355490000800367520135800375653002301733653002701756653001401783653001301797653002201810653003201832100002201864700002401886700002801910700002401938700002301962700002301985700002302008700002502031856013102056       2015                        eng d  a0144-861700aSynthesis and characterization of PEPO grafted carboxymethyl guar and carboxymethyl tamarind as new thermo-associating polymers0 aSynthesis and characterization of PEPO grafted carboxymethyl gua  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAR  a331-3380 v1173 a<p>New thermo associating polymers were designed and synthesized by grafting amino terminated poly(ethylene oxide-co-propylene oxide) (PEPO) onto carboxymethyl guar (CMG) and carboxymethyl tamarind (CMT). The grafting was performed by coupling reaction between-NH2 groups of PEPO and -COOH groups of CMG and CMT using water-soluble EDC/NHS as coupling agents. The grafting efficiency and the temperature of thermo-association, T-assoc in the copolymer were studied by NMR spectroscopy. The graft copolymers, CMG-g-PEPO and CMT-g-PEPO exhibited interesting thermo-associating behavior which was evidenced by the detailed rheological and fluorescence measurements. The visco-elastic properties (storage modulus, G'; loss modulus, G'') of the copolymer solutions were investigated using oscillatory shear experiments. The influence of salt and surfactant on the T-assoc was also studied by rheology, where the phenomenon of ``Salting out'' and ``Salting in'' was observed for salt and surfactant, respectively, which can give an easy access to tunable properties of these copolymers. These thermo-associating polymers with biodegradable nature of CMG and CMT can have potential applications as smart injectables in controlled release technology and as thickeners in cosmetics and pharmaceutical formulations. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarboxymethyl guar10aCarboxymethyl tamarind10aPluronics10aRheology10aSolution behavior10aThermo-associating polymers1 aGupta, Nivika, R.1 aTorris, Arun, A. T.1 aWadgaonkar, Prakash, P.1 aRajamohanan, P., R.1 aDucouret, Guylaine1 aHourdet, Dominique1 aCreton, Costantino1 aBadiger, Manohar, V.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-pepo-grafted-carboxymethyl-guar-and-carboxymethyl-tamarind-1