<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Alariqi, Sameh A. S.</style></author><author><style face="normal" font="default" size="100%">Kumar, A. Pratheep</style></author><author><style face="normal" font="default" size="100%">Rao, B. S. M.</style></author><author><style face="normal" font="default" size="100%">Singh, R. P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of gamma-dose rate on crystallinity and morphological changes of gamma-sterilized biomedical polypropylene</style></title><secondary-title><style face="normal" font="default" size="100%">Polymer Degradation and Stability</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Crystallinity</style></keyword><keyword><style  face="normal" font="default" size="100%">Dose rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Gamma radiation</style></keyword><keyword><style  face="normal" font="default" size="100%">mechanical properties</style></keyword><keyword><style  face="normal" font="default" size="100%">Morphology</style></keyword><keyword><style  face="normal" font="default" size="100%">polypropylene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">FEB</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">2</style></number><publisher><style face="normal" font="default" size="100%">ELSEVIER SCI LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">94</style></volume><pages><style face="normal" font="default" size="100%">272-277</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The present work is aimed to study the changes in crystallinity and morphology of biomedical polyolefins after gamma-sterilization. The isotactic polypropylene (iPP) films were sterilized by gamma-radiation and the changes were characterized by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and atomic force microscopy (AFM) techniques. The effect of dose rate on crystallinity changes also was focused. It was found that crystallinity and morphology significantly changed with gamma-irradiation. There was an increase in crystallinity Lip to 10 kGy accompanied with decrease in viscosity and mechanical properties. The changes in crystallinity mainly depend on gamma-irradiation dose and dose rate. The rise in crystallinity was attributed to chain scission and forming new perfect lamellae. However, the reduction was accompanied by occurrence of gamma- and beta-phases and crosslinking. Possible explanations for transitions in phases are also discussed based on our results. (C) 2008 Elsevier Ltd. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.594</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chavan, Nayaku</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Synthesis and characterization of cholesteric thermotropic liquid crystalline polyesters based on isosorbide</style></title><secondary-title><style face="normal" font="default" size="100%">Materials Sciences and Applications</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cholesteric</style></keyword><keyword><style  face="normal" font="default" size="100%">Crystallinity</style></keyword><keyword><style  face="normal" font="default" size="100%">differential scanning calorimetry</style></keyword><keyword><style  face="normal" font="default" size="100%">Inherent   Viscosity</style></keyword><keyword><style  face="normal" font="default" size="100%">Liquid Crystalline Polymers</style></keyword><keyword><style  face="normal" font="default" size="100%">Optical   Microscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Solubility and Solution Polycondensation</style></keyword><keyword><style  face="normal" font="default" size="100%">Thermo Gravimetric Analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">thermotropic</style></keyword><keyword><style  face="normal" font="default" size="100%">Wide Angle X-Ray Diffraction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">OCT</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">2</style></volume><pages><style face="normal" font="default" size="100%">1520-1527</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Generally main chain cholesteric thermotropic liquid crystalline polymers are prepared form chiral dia-cid or diol monomer. But these monomers are costly. Isosorbide is chiral cycloaliphatic diol accessible from renewable resources in the form of pure enantiomers. Thus it is used to synthesize main chain cholesteric thermotropic liquid crystalline polymers. Incorporation of phenyl hydroquinone into the backbone of the main chain frustrates chain pack-ing, thus lowering the crystallinity and depressing the melting point below the degradation temperature, also improves the solubility due to disruption of packing and maintains the mechanical and thermal performance. Results: Optical microscopy study reveals that more than 50% of isosorbide content with phenyl hydroquinone and terephthalic acid showed “yellow iridescent oily streaks” with a background of mosaic/marble texture. These are the typical textures of cholesteric liquid crystalline phase. Copolyesters based on phenyl hydroquinone, isosorbide and terephthalic acid are soluble in aprotic solvents like N,N-dimethylacetamide (DMAC), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP). Solubility increases with the content of isosorbide percent. Thermal stabil-ity of all copolyesters was more than 300˚C on the basis of 10 wt% loss. Conclusions: It was found that main chain cholesteric thermotropic liquid crystalline polymers can be prepared form chiral cycloaliphatic diol such as isosorbide. Main chain cholesteric thermotropic liquid crystalline polyesters are prepared from phenyl hydroquinone, isosorbide and terephthalic acid showed thermal stability more than 300˚C. Main chain cholesteric thermotropic liquid crystalline polymers are soluble in aprotic solvents like DMAC, DMSO, DMF and NMP&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue><custom2><style face="normal" font="default" size="100%">&lt;p&gt;Council of Scientific &amp;amp; Industrial Research (CSIR) - India&lt;/p&gt;</style></custom2><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">0.20</style></custom4></record></records></xml>