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Organic Modification (organic + modification)
Selected AbstractsEffect of Organic Modification on the Compatibilization Efficiency of Clay in an Immiscible Polymer BlendMACROMOLECULAR RAPID COMMUNICATIONS, Issue 20 2005Suprakas Sinha Ray Abstract Summary: This communication describes the effect of organic modifier miscibility with the matrices, and the effect of the initial interlayer spacing of the organoclay, on the overall morphology and properties of an immiscible polycarbonate/poly(methyl methacrylate) blend. By varying the organic-modifier-specific interactions with the blend matrices at the same time as changing the initial interlayer spacing of the organoclay, different levels of compatibilization were revealed. The evidence for the interfacial compatibilization of the organoclay was assessed by scanning electron microscopy observations and was supported by differential scanning calorimetry analyses. The effect on the level of clay exfoliation was also examined. Differential scanning calorimetry scans of virgin, montmorillonite, and various organically modified montmorillonite-compatibilized 40PC/60PMMA blends [source] Measurement of the condensation temperature of nanosilica powder organically modified by a silane coupling agent and its effect evaluationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Xiao Liu Abstract The proper condensation temperatures of nanosilica powder modified by silane coupling agents such as 3-methacryloxypropyl trimethoxy silane (MEMO), [3-(2-aminoethyl)aminopropyl] trimethoxy silane (AMMO), and bis[3-(triethoxysilyl)propyl] disulfide (TESPD) were measured with Fourier transform infrared. Moreover, the structure and properties of solution-polymerized styrene,butadiene rubber (SSBR) filled with nanosilica powder that was organically modified by the three silane coupling agents at different temperatures were investigated. The results showed that the proper condensation temperatures of nanosilica powder modified by MEMO, AMMO, and TESPD were about 80, 80, and 100°C, respectively. Compared with SSBR filled with silica powder, SSBR filled with silica powder modified by a silane coupling agent exhibited not only better filler-dispersion and mechanical properties but also lower internal friction loss in a selected range of strains. Furthermore, when the organic modification was carried out at the proper condensation temperature, the improvement of the modification effect became more obvious. Among these silane coupling agents, AMMO presented the most remarkable modification effect for nanosilica. The mechanism of modification for silica powder and its enhancement of the properties of SSBR were examined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Architecture and performance of mesoporous silica-lipase hybrids via non-covalent interfacial adsorptionAICHE JOURNAL, Issue 2 2010Shan Lu Abstract To investigate the effects of surface property of mesoporous supports on the lipase immobilization and the performance of immobilized lipase, the mesoporous molecular sieve SBA-15 is functionalized with three organic moieties, dimethyl (DM), diisopropyl (DIP), and diisobutyl (DIB), respectively, by post-synthesis grafting and one-pot synthesis methods. Porcine pancreas lipase (PPL) is immobilized on SBA-15 supports through hydrogen bonding and hydrophobic interaction. The hydrophobic adsorption involves no active sites of PPL, and neither hyper-activation nor total inactivation occurs. The study on the intrinsic stability of PPL, including thermal stability, pH stability, and storage stability, indicates that the entrapment in mesoporous supports, and especially in organic-functionalized supports, makes PPL more resistant to temperature increment but more sensitive to pH change. The reusability investigation shows that the organic modification of mesoporous surface inhibits the enzyme leaching to some extent, resulting in a better operational stability. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Effect of clay exfoliation and organic modification on morphological, dynamic mechanical, and thermal behavior of melt-compounded polyamide-6 nanocompositesPOLYMER COMPOSITES, Issue 2 2007Smita Mohanty Abstract Polyamide-6/clay nanocomposites were prepared employing melt bending or compounding technique followed by injection molding using different organically modified clays. X-ray diffraction and transmission electron microscopy were used to determine the molecular dispersion of the modified clays within the matrix polymer. Mechanical tests revealed an increase in tensile and flexural properties of the matrix polymer with the increase in clay loading from 0 to 5%. C30B/polyamide-6 nanocomposites exhibited optimum mechanical performance at 5% clay loading. Storage modulus of polyamide-6 also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of nanoclays. Furthermore, water absorption studies confirmed comparatively lesser tendency of water uptake in these nanocomposites. HDT of the virgin matrix increased substantially with the addition of organically modified clays. DSC measurements revealed both , and , transitions in the matrix polymer as well as in the nanocomposites. The crystallization temperature (Tc) exhibited an increase in case of C30B/polyamide-6 nanocomposites. Thermal stability of virgin polyamide-6 and the nanocomposites has been investigated employing thermogravimetric analysis. POLYM. COMPOS., 28:153,162, 2007. © 2007 Society of Plastics Engineers [source] | ||||||||||