02489nas 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