01764nas a2200157   4500008004100000022001400041245014000055210006900195260011000264300001200374490000700386520104600393100001801439700002301457856012601480       2012                        eng d  a1463-926200aTowards biodegradable elastomers: green synthesis of carbohydrate functionalized styrene-butadiene-styrene copolymer by click chemistry0 aTowards biodegradable elastomers green synthesis of carbohydrate  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a348-3560 v143 a<p>Random attachment of sugar molecules to synthetic polymers is an important strategy to induce biodegradability in these polymers. The present study successfully employs ``click'' chemistry to introduce low levels of sugar molecules onto styrene-butadiene-styrene (SBS) copolymer, a widely used commodity polymer which is not biodegradable. Spectral, morphological and thermal studies of the modified polymers were carried out to show the dramatic changes in the properties of these modified polymers. Thermal stability of glucose linked SBS had onset of degradation at 428 degrees C, down from 478 degrees C observed for SBS. Morphology studied by WAXRD and SEM showed destructuring of the polymer domains of SBS, which is beneficial for biodegradation of these polymers. Previous studies showed that sugars anchored by hydrolysable ester groups onto polystyrene were biodegradable; current studies show that sugars anchored by unhydrolyzable C-C bonds on the butadiene component of SBS copolymer are also significantly biodegradable.</p>1 aSingh, Rakesh1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/towards-biodegradable-elastomers-green-synthesis-carbohydrate-functionalized-styrene-002292nas a2200241   4500008004100000022001400041245012400055210006900179260009900248300001200347490000800359520139000367653000601757653000601763653002701769653002301796653002601819653001401845653001201859100002501871700002301896856013101919       2014                        eng d  a0144-861700aThermal stability of cellulose and their nanoparticles: Effect of incremental increases in carboxyl and aldehyde groups0 aThermal stability of cellulose and their nanoparticles Effect of  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcDEC  a339-3430 v1143 a<p>Oxidized cellulose containing carboxyl and aldehyde functional groups represent an important class of cellulose derivatives. In this study effect of incrementally increasing COOH and CHO groups at C2, C3, and C6 positions of cellulose and nanocellulose has been investigated, with a view to understanding their effect on thermal treatment of cellulose. The results show that 2,3-dialdehyde cellulose (DAC) is the most thermally stable oxidized product of cellulose while the most unstable derivatives contain carboxyl group at the C6 position (6CC). Carboxymethylcellulose (CMC), with carboxymethyl group on C6 position, is more stable than 6CC. Multi-functionalized celluloses 2,3,6-tricarboxycellulose and 6-carboxy-2,3-dialdehyde, have the same level of thermal stability as 6CC, showing that the presence of carboxyl at the C6 is a key destabilizing factor in the thermal stability of oxidized cellulose products. More the number of reducing end groups on the polymer chain, lower the thermal stability of the cellulose, as proved by comparing the TGA/DTG of monomeric analogs dextrose, cellobiose and glucuronic acid with the oxidized celluloses. The thermal stability trend observed for oxidized celluloses was DAC &gt; DCC &gt; nanoparticles &gt; dextrose &gt;glucuronic acid, caused by extent of reducing ends and COOH groups. (C) 2014 Elsevier Ltd. All rights reserved.</p>10a210a310a3-Dialdehyde cellulose10a6-Carboxycellulose10a6-Tricarboxycellulose10acellulose10aTGA/DTG1 aSharma, Priyanka, R.1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/thermal-stability-cellulose-and-their-nanoparticles-effect-incremental-increases-carboxyl-0