In situ formation of nano-scale PMMA network structures on the surface of immiscible polymer blends by solvent extraction and redeposition

2012 ◽  
Vol 32 (3) ◽  
Author(s):  
Giorgiana Giancola ◽  
Richard L. Lehman
Keyword(s):  
Polymer Blends ◽  
Network Formation ◽  
High Surface ◽  
High Surface Area ◽  
Scanning Calorimetry ◽  
Immiscible Polymer Blends ◽  
Nano Scale ◽  
Immiscible Polymer ◽  
Potential Applications ◽  
General Network

Abstract A continuous open structured network, with a high surface area, low solids fraction, and nano-scale domain morphology, was observed to grow from dissolved blend components on cold fractured surfaces of immiscible polymer blends, when reacted with dimethylformamide (DMF). In this work, we showed that the network is comprised of polymethyl methacrylate (PMMA), with a strong glassy character similar to or even in excess of conventional PMMA pellets used in the preparation process, in contrast to the amorphous but not glassy PMMA produced when similar materials were synthesized away from the PMMA host. Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analyses confirmed the chemical and physical character of the network. This general network formation phenomenon, which was initially observed in PMMA/high density poly ethylene (HDPE) blends produced by conventional extrusion, PMMA/HDPE blends compression molded from powder precursors, and subsequently on bulk PMMA, produces a unique structure that has potential applications as an interfacial modification substance or as a functional material in biomaterials and catalysis.

Morphological effects on Glass Transitions in Immiscible Polymer Blends

2004 ◽  
Vol 856 ◽  
Author(s):  
Vivek M. Thirtha ◽  
Richard L. Lehman ◽  
Thomas J. Nosker
Keyword(s):  
Glass Transition ◽  
Polymer Blends ◽  
Volume Fraction ◽  
Glassy Polymers ◽  
Melt Processing ◽  
Modulated Dsc ◽  
Systematic Change ◽  
Scanning Calorimetry ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer

ABSTRACTThis paper describes the effects of structures on the glass transition of glassy polymers blended with a semi-crystalline polymer. Immiscible blends of PS/PP and PS/HDPE were prepared from commercially available polymers using melt processing and extrusion without additives. The weight fractions of the components were varied from 0 to 1. SEM analysis of the blends showed a range of morphologies over the composition range from small inclusions at low volume concentrations through intertwined co-continuous structures at specific intermediate compositions, and a reversal of this configuration at high volume fractions. The glass transition of the glassy polymer was measured with differential scanning calorimetry using the sensitive and high resolution modulated DSC method. A systematic change in glass transition of glassy polymers is observed as a function of composition in various immiscible polymer blends. Results show that the glass transition of polystyrene increases with a reduction in volume fraction, by approximately 5.4°C in polypropylene and 6.5°C in polyethylene. Probable models which might explain this effect are mentioned.

scholarly journals Metal-Organic Framework-Based Engineered Materials—Fundamentals and Applications

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1598 ◽  
Author(s):  
Tahir Rasheed ◽  
Komal Rizwan ◽  
Muhammad Bilal ◽  
Hafiz M. N. Iqbal
Keyword(s):  
Drug Delivery ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Co2 Reduction ◽  
Biological Species ◽  
Crystalline Materials ◽  
Potential Applications ◽  
Metal Organic ◽  
Catalytic Chemistry

Metal-organic frameworks (MOFs) are a fascinating class of porous crystalline materials constructed by organic ligands and inorganic connectors. Owing to their noteworthy catalytic chemistry, and matching or compatible coordination with numerous materials, MOFs offer potential applications in diverse fields such as catalysis, proton conduction, gas storage, drug delivery, sensing, separation and other related biotechnological and biomedical applications. Moreover, their designable structural topologies, high surface area, ultrahigh porosity, and tunable functionalities all make them excellent materials of interests for nanoscale applications. Herein, an effort has been to summarize the current advancement of MOF-based materials (i.e., pristine MOFs, MOF derivatives, or MOF composites) for electrocatalysis, photocatalysis, and biocatalysis. In the first part, we discussed the electrocatalytic behavior of various MOFs, such as oxidation and reduction candidates for different types of chemical reactions. The second section emphasizes on the photocatalytic performance of various MOFs as potential candidates for light-driven reactions, including photocatalytic degradation of various contaminants, CO2 reduction, and water splitting. Applications of MOFs-based porous materials in the biomedical sector, such as drug delivery, sensing and biosensing, antibacterial agents, and biomimetic systems for various biological species is discussed in the third part. Finally, the concluding points, challenges, and future prospects regarding MOFs or MOF-based materials for catalytic applications are also highlighted.

Interface Characterization of Immiscible Polymer Blends by Means of XR and NR Investigations

2000 ◽  
Vol 321-324 ◽  
pp. 475-480
Author(s):  
D. Jehnichen ◽  
P. Friedel ◽  
S. Kummer ◽  
L. Häußler ◽  
K. Eckstein ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Immiscible Polymer Blends ◽  
Interface Characterization ◽  
Immiscible Polymer

The Impact of Janus Nanoparticles on the Compatibilization of Immiscible Polymer Blends under Technologically Relevant Conditions

ACS Nano ◽  
2014 ◽  
Vol 8 (10) ◽  
pp. 10048-10056 ◽  
Author(s):  
Ronak Bahrami ◽  
Tina I. Löbling ◽  
André H. Gröschel ◽  
Holger Schmalz ◽  
Axel H. E. Müller ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer ◽  
Janus Nanoparticles ◽  
The Impact

Rheological properties and reactive compatibilization of immiscible polymer blends

2000 ◽  
Vol 44 (6) ◽  
pp. 1227-1245 ◽  
Author(s):  
M. Moan ◽  
J. Huitric ◽  
P. Médéric ◽  
J. Jarrin
Keyword(s):  
Polymer Blends ◽  
Rheological Properties ◽  
Immiscible Polymer Blends ◽  
Reactive Compatibilization ◽  
Immiscible Polymer
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