Development of Boron Cage Compound Nanocomposite Elastomers

2009 ◽  
Vol 1239 ◽  
Author(s):  
Eric Allen Eastwood ◽  
Daniel Edward Bowen ◽  
Mark W. Lee

AbstractA wide variety of nanofillers of varying compositions have been used to create polymer nanocomposites, including tubes, wires, fibers, sheets, and particles. A new class of compounds has been identified for use as nanofillers, boron cage compounds. Boron cage compounds are discrete, icosahedral closed cage molecules of high boron content and examples include carboranes and dodecaborate salts. Several chemically modified boron cage compounds have been incorporated into polyolefin elastomers, such as poly(ethylene-co-vinyl acetate), poly(ethylene-co-vinyl acetate-co-vinyl alcohol), poly(ethylene-co-ethyl acrylate), and poly(ethylene-co-octene), among others. The resulting thermal and thermomechanical properties were evaluated in order to determine when plasticization and reinforcement occur to better understand the chemical structure/physical property relationships. Materials with a wide range of properties were produced, however under certain conditions, advanced materials were created with high boron contents, improved thermal stability, mechanical strength, and significant reinforcement.

2007 ◽  
Vol 31 (6) ◽  
pp. 387-410 ◽  
Author(s):  
Alexander B. Morgan ◽  
Jeffrey M. Cogen ◽  
Robert S. Opperman ◽  
Joseph D. Harris

2015 ◽  
Vol 1718 ◽  
pp. 123-130 ◽  
Author(s):  
Matthias Heuchel ◽  
Laith Al-Qaisi ◽  
Karl Kratz ◽  
Ulrich Nöchel ◽  
Marc Behl ◽  
...  

ABSTRACTCrosslinked poly[ethylene-co-(vinyl acetate)] (cPEVA) has been recently introduced as a polymer material, which can be functionalized with various shape-memory effects by solely altering the thermomechanical treatment called programming.In this study two series of cPEVAs with different vinyl acetate contents of 18 wt% (cPEVA18) and 28 wt% (cPEVA28) comprising different crosslink densities were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) in the temperature range of -130 °C to 120 °C. DMTA tests were performed in torsion mode, because such movements are highly relevant in the context of complex shape changes in shape-memory polymer based devices. Finally, the obtained DMTA results were compared with DMTA conducted in tension mode. Swelling experiments revealed a gel content in the range from 81% to 90% for cPEVA18 samples while for cPEVA28s a complete conversion was observed. The degree of swelling was found to decrease substantially with increasing crosslink density for both cPEVA series.The influence of VA content and extent of crosslinking on the appearance of the respective melting (Tm) and glass transition (Tg) as well as the thermomechanical properties of cPEVA systems could be demonstrated by discussing both DSC and DMTA results. The temperature range of mechanical stability correlates with the VA content and is determined by decreasing Tm values. The cross links do barely alter the stiffness of a PEVA up to the Tm rang, but lead to constant mechanical rigidity in the rubbery range above Tm.


1980 ◽  
Vol 45 (8) ◽  
pp. 2315-2318 ◽  
Author(s):  
Vladimír Pollák ◽  
Andrej Romanov

The relative charge of the internal energy, fU/f, during deformation of cross-linked elastomers, poly(ethylene-co-propylene) and poly(ethylene-co-vinyl acetate), was determined at various temperatures. Anomalies in the dependence of fU/f on relative dilatation in the region of small deformations ( 35%) are to a large extent besides other factors due to the sensibility of the formula used to calculate fU/f to temperature changes.


2021 ◽  
pp. 1-10
Author(s):  
Dong Wook Lee ◽  
Eun Mi Kim ◽  
Gi Seok Heo ◽  
Ju Hwan Lee ◽  
Dong Hyun Kim ◽  
...  

Langmuir ◽  
2021 ◽  
Author(s):  
Mingzhen Zhao ◽  
Joseph Baker ◽  
Zhiyuan Jiang ◽  
Zewen Zhu ◽  
Hong-Mao Wu ◽  
...  

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