02692nas a2200241   4500008004100000022001400041245011600055210006900171260009900240300001400339490000700353520173200360653002902092653004302121653003302164100002202197700002902219700001602248700002002264700002402284700001802308856012402326       2009                        eng d  a0032-386100aPreparation and nonisothermal crystallization behavior of polypropylene/layered double hydroxide nanocomposites0 aPreparation and nonisothermal crystallization behavior of polypr  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAR  a1505-15150 v503 a<p>Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared via melt intercalation using dodecyl sulfate anion modified LDH and maleated PP as compatibilizing agent. Evidently the interlayer anions in LDH galleries react with maleic anhydride groups of PP-g-MA and lead to a finer dispersion of individual LDH layers in the PP matrix. The nanostructure was characterized by XRD and TEM; the examinations confirmed the nanocomposite formation with exfoliated/intercalated layered double hydroxides well distributed in the PP matrix. The nonisothermal crystallization behavior of resulting nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates. In nonisothermal crystallization kinetics, the Ozawa approach failed to describe the crystallization behavior of nanocomposites, whereas the Avrami analysis and Jeziorny method well define the crystallization behavior of PP/LDH nanocomposite. Combined Avrami and Ozawa analysis (Liu model) also found useful. The results revealed that very small amounts of LDH (1%) could accelerate the crystallization process relative to the pure PP and increase in the crystallization rates was attributed to the nucleating effect of the nanoparticles. Polarized optical microscopy (POM) observations also support the DSC results. The effective crystallization activation energy was estimated as a function of the relative degree of crystallinity using the isoconversional analysis. Overall, results indicated that the LDH particles in nanometer size might act as nucleating agent and distinctly change the type of nucleation, growth and geometry of PP crystals. (C) 2009 Elsevier Ltd. All rights reserved.</p>10aLayered double hydroxide10aNonisothermal crystallization kinetics10aPolypropylene nanocomposites1 aLonkar, Sunil, P.1 aMorlat-Therias, Sandrine1 aCaperaa, N.1 aLeroux, Fabrice1 aGardette, Jean, Luc1 aSingh, R., P.  uhttps://library.ncl.res.in/content/preparation-and-nonisothermal-crystallization-behavior-polypropylenelayered-double-002507nas a2200265   4500008004100000022001400041245010100055210006900156260007600225300001400301490000700315520155300322653002201875653003001897653001901927653001801946653001301964653003201977100002202009700002202031700002002053700002402073700002002097856012402117       2011                        eng d  a0959-810300aInfluence of reactive compatibilization on the structure and properties of PP/LDH nanocomposites0 aInfluence of reactive compatibilization on the structure and pro  aCOMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USAbWILEY-BLACKWELLcDEC  a1688-16960 v603 a<p>Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared by the direct melt intercalation method usingmaleic anhydride grafted polypropylene (PP-g-MAH) as a reactive compatibilizer. The compatibilization effects provided by PP-g-MAH in different weight fractions and their influence on the structure and properties of the final nanocomposites were investigated. The interactions and structural morphology of the nanocomposites were examined by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electronmicroscopy. Thermal, mechanical and rheological properties of these nanocomposites were investigated as a function of compatibilizer concentration. The detailed morphological and X-ray diffraction results revealed that the degree of LDH dispersion increases as the amount of PP-g-MAH increases. Study of the linear viscoelastic properties showed that the storage modulus G' is very sensitive to the microstructure of the nanocomposite. The thermal properties of the nanocomposites were significantly influenced by the weight fraction of PP-g-MAH due to the shielding and nucleating effect of exfoliated layers. Both the tensile strength and modulus showed substantial improvements with increasing PP-g-MAH content, while the elongation at break substantially decreased, although the presence of PP-gMAH somewhat improves these values. The overall results showed that 10 wt% of compatibilizer is optimum to achieve nanocomposites with better performance. (C) 2011 Society of Chemical Industry</p>10acompatibilization10alayered double hydroxides10aNanocomposites10apolypropylene10aRheology10athermomechanical properties1 aLonkar, Sunil, P.1 aTherias, Sandrine1 aLeroux, Fabrice1 aGardette, Jean, Luc1 aSingh, Raj, Pal  uhttps://library.ncl.res.in/content/influence-reactive-compatibilization-structure-and-properties-ppldh-nanocomposites-002070nas a2200193   4500008004100000022001400041245011500055210006900170260006700239300001400306490000700320520131000327100002201637700002201659700002001681700002401701700002001725856013101745       2012                        eng d  a0032-388800aThermal, mechanical, and rheological characterization of polypropylene/layered double hydroxide nanocomposites0 aThermal mechanical and rheological characterization of polypropy  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcSEP  a2006-20140 v523 a<p>Polypropylene (PP)/organomodified layered double hydroxide (LDH) nanocomposites were prepared in order to examine the influence of LDH content on thermal, mechanical, and rheological properties. The nanostructure examinations by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the exfoliated/intercalated dispersion of LDH. Incorporation of the LDH resulted in a noteworthy improvement in the thermal stability of PP. It was shown that the addition of LDH contributed to the reinforcement effect by increasing the elastic modulus. The mechanical performance, as evaluated by stressstrain curves, reveal that PP/LDH hybrid materials showed significant contribution toward increment in elastic modulus, tensile strength but at the expense of impact strength. The rheological response showed a strong influence of LDH particles on the flow behavior of the PP/LDH melt which resulted in enhancement of storage, loss of moduli, and complex viscosity of nanocomposites. Therefore, the nanocomposites have higher moduli but better processibility compared with pure PP. Overall, the results indicated that the LDH particles in nanometer size might act as potential reinforcing agent for polypropylene. POLYM. ENG. SCI., 52:20062014, 2012. (c) 2012 Society of Plastics Engineers</p>1 aLonkar, Sunil, P.1 aTherias, Sandrine1 aLeroux, Fabrice1 aGardette, Jean, Luc1 aSingh, Raj, Pal  uhttps://library.ncl.res.in/content/thermal-mechanical-and-rheological-characterization-polypropylenelayered-double-hydroxide-0