Effect of sol-gel polymerization of tetraethylorthosilicate on internal aggregate structure in zinc-neutralized ethylene-methacrylic acid ionomers

Grady, Brian P.; Start, Paul R.; Mauritz, Kenneth A.

doi:10.1002/1099-0488(20010115)39:2<197::aid-polb10>3.0.co;2-1

Cited by 8 publications

(5 citation statements)

References 7 publications

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“…A significant challenge of this approach, however, is the lack of molecular and microstructural control now possible with synthetic polymers. In particular, high variability exists in the degree of condensation to silica (SiO 2 ), particle size, and spatial distribution in TEOS-based hybrid materials − even when adopting the biomimetic approach of protein-based biomineralization. − An alternative approach to hybrid materials synthesis that addresses these challenges has been the use of the precondensed polyhedral oligosilsesquioxane (POSS*) moiety, functionalized for polymerization or grafting. − (*POSS is a registered trademark of Hybrid Plastics, Inc.) These large hybrid molecules have the unique feature of containing both an inorganic silicon−oxygen cage (Si 8 O 12 ) and up to eight compatibilizing organic groups pendant to each silicon corner of the cage. Typically, one or more of those groups contains the appropriate functionality to incorporate POSS into a variety of compositions, including thermoplastics − and thermosets ,− through either copolymerization or blending.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biodegradable Thermoplastic Polyurethanes Incorporating Polyhedral Oligosilsesquioxane

et al. 2008

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A new hybrid thermoplastic polyurethane (TPU) system that incorporates an organic, biodegradable poly(D, L-lactide) soft block with a hard block bearing the inorganic polyhedral oligosilsesquioxane (POSS) moiety is introduced and studied. Changes in the polyol composition made through variation of the hydrophilic initiator molecular weight show direct control of the final transition temperatures. Incorporating POSS into the hard segments allows for excellent elasticity above T(g), as evidenced with dynamic mechanical analysis, not seen in most other biodegradable materials. This elasticity is attributed to physical cross-links formed in the hard block through POSS crystallization, as revealed with wide-angle X-ray diffraction. Increasing the POSS incorporation level in the TPU hard block was observed to increase crystallinity and also the rigidity of the material. The highest incorporation, using a statistical average of three POSS units per hard block, demonstrated one-way shape memory with excellent shape fixing capabilities. In vitro degradation of this sample was also investigated during a two month period. Moderate water uptake and dramatic molecular weight decrease were immediately observed although large mass loss (approximately 20 wt %) was not observed until the two month time point.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Biodegradable Thermoplastic Polyurethanes Incorporating Polyhedral Oligosilsesquioxane

et al. 2008

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“…Extended X‐ray absorption fine structure (EXAFS) spectroscopy that was used to probe the effect of this in situ sol–gel reaction for TEOS on Zn 2+ ionic aggregate morphology suggested that there were no large changes in the aggregate structure relative to the unfilled ionomer 29. This suggests that the internal environment of the aggregates did not ‘seed’ the reaction, although it is conceivable that small changes seen in the EXAFS patterns could be due to the influence of the sol–gel reaction on the outer structure of the aggregates.…”

Section: Introductionmentioning

confidence: 99%

Manufacture and properties of chitosan/N,O‐carboxymethylated chitosan/viscose rayon antibacterial fibers

Liu

Zhuang

et al. 2002

J of Applied Polymer Sci

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Chitosan/N,O-carboxymethylated chitosan/viscose rayon antibacterial fibers (CNVFs) were prepared by blending chitosan emulsion, N,O-carboxymethylated chitosan (N,O-CMC), and viscose rayon together for spinning. The fibers were characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). TEM micrographs showed that chitosan microparticles dispersed uniformly along the oriented direction with the mean size ranging from 0.1 to 0.5 m. DSC spectra of these fibers showed that no significant change in thermal property was caused by adding chitosan and N,O-CMC into the viscose rayon. TGA spectra showed that the good moisture retentivity was not affected by the addition of chitosan and N,O-CMC. Both DSC and TGA suggested that the decomposing tendency of the viscose rayon above 250°C seemed to be weakened by the chitosan. The fibers' mechanical properties and antibacterial activities against Escherchia coli, Staphylococcus aureus, and Candida albicans were measured. Although the addition of chitosan slightly reduced the mechanical properties, the antibacterial fibers' properties were obtained and were found to meet commercial requirements. CNVF exhibited excellent antibacterial activity against E. coli, S. aureus, and C. albicans. The antibacterial activity increased along with the chitosan concentration and was not greatly affected by 15 washings in water. Scanning electron microscopy (SEM) was used to observe the morphology of bacteria cells incubated together with the antibacterial or reference fibers. SEM micrographs demonstrated that greater amounts of bacteria could be adsorbed by the antibacterial fiber than by the reference fiber; these bacteria were overwhelmingly destroyed and killed.

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“…Hydrolysis and condensation of the metal alkoxide are the two fundamental steps to produce inorganic network within the polymer matrix in presence of an acid or base catalyst. Silicon alkoxide (e.g., tetraethoxysilane, TEOS) is the most commonly used metal alkoxide due to its mild reaction condition [65,66]. Tang and Mark [67] have reported mechanical properties of sol-gel hybrids prepared .The reaction parameters that influence the sol-gel chemistry are the p H of the solution, the mole ratio of Si to H 2 O, catalysts, solvents and reaction temperature.…”

Section: Melt Intercalationmentioning

confidence: 99%

Design, Development and Testing of Rubber Nanocomposites

Saritha

Joseph

Thomas³

2010

KEM

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This review aims at reporting on very recent developments in the synthesis, properties and (future) applications of rubber nanocomposites. Nanocomposites are the materials for the future, which have improved mechanical properties. Reinforcement is especially important for the application of elastomeric materials because the mechanical strength of unfilled elastomers is generally poor. Commonly isometric fillers like carbon black or fumed silica are used for reinforcing elastomers.Rubber nanocomposites play an important role in engineering, construction and aerospace applications. This new family of materials exhibit enhanced properties at very low filler level, usually ≤ 5 wt %. Rubber nanocomposites exhibit very good Young’s modulus , storage modulus, thermal stability , gas barrier properties and flame retardancy.

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Effect of sol-gel polymerization of tetraethylorthosilicate on internal aggregate structure in zinc-neutralized ethylene-methacrylic acid ionomers

Cited by 8 publications

References 7 publications

Biodegradable Thermoplastic Polyurethanes Incorporating Polyhedral Oligosilsesquioxane

Biodegradable Thermoplastic Polyurethanes Incorporating Polyhedral Oligosilsesquioxane

Manufacture and properties of chitosan/N,O‐carboxymethylated chitosan/viscose rayon antibacterial fibers

Design, Development and Testing of Rubber Nanocomposites

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