Styrene-ethylene/butylene-styrene (SEBS) block copolymer was used as the compatibilizer for PP + PS blends. We have investigated effects of the presence of SEBS on tribological and mechanical properties;dynamic mechan...
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Styrene-ethylene/butylene-styrene (SEBS) block copolymer was used as the compatibilizer for PP + PS blends. We have investigated effects of the presence of SEBS on tribological and mechanical properties;dynamic mechanical analysis (DMA) was also performed. Since the copolymer causes formation of smaller particles of the dispersed PS phase in PP matrix blends, there is improved energy transmission and dissipation resulting in higher impact strength. The SEBS additive is relatively soft and causes a decrease in stress at break but an increase in elongation at break in tensile testing. In most cases the friction of the compatibilized blends is higher although in PS-rich blends we find a decrease. Scratch testing shows a change in wear mechanisms when SEBS is added to PP/PS. In uncompatibilized blends we observe adhesive wear, with crazes formed in the middle of the wear track. A compatibilized blend shows more ductile behavior and ploughing wear.
Recently, The Dow chemical Company developed a chain shuttling catalyst technology that can be used to synthesize olefin block copolymers (OBC) in a continuous process. The block copolymers synthesized by chain shuttl...
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Recently, The Dow chemical Company developed a chain shuttling catalyst technology that can be used to synthesize olefin block copolymers (OBC) in a continuous process. The block copolymers synthesized by chain shuttling technology consist of crystallizable ethylene-octene blocks with very low comonomer content and high
PEG （Polyethylene Glycol）-grafted nano-titania has been obtained in a one-step procedure using hexamethylene diisocyanate as the coupling agent and dibutyltin dilaurate as the catalyst in toluene at 80℃ and charact...
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PEG （Polyethylene Glycol）-grafted nano-titania has been obtained in a one-step procedure using hexamethylene diisocyanate as the coupling agent and dibutyltin dilaurate as the catalyst in toluene at 80℃ and characterized qualitatively by FTIR and quantitatively by elemental analysis and thermogravimetric analysis. A comparison of nano-titania with two other commonly used inorganic nanoparticles, nano-silica and nano-alumina, is made, revealing that reactivity order is nano- silica 〉 nano-alumina 〉 nano-titania in view of PEG grafting. Possible mechanism of PEG grafting is also discussed.
Various concentrations of polypropylene (PP) and polystyrene (PS) blends were prepared with styrene-ethylene/butylene-styrene block copolymer (SEBS) added as a compatibilizer between the two main polymers. We have inv...
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Various concentrations of polypropylene (PP) and polystyrene (PS) blends were prepared with styrene-ethylene/butylene-styrene block copolymer (SEBS) added as a compatibilizer between the two main polymers. We have investigated the effect of SEBS on processing, morphology and thermophysical properties of the blends. The compatibilizing agent improves the blend morphology since smaller particles of the dispersed PS phase in the PP matrix blends are obtained;adding more than 5 % SEBS has no further effect on the blends. The presence of SEBS lowers the crystallinity of the PP-rich phase - as reflected in the enthalpy of fusion and also in the enthalpy of crystallization.
A general procedure for surface modification of nano-alumina using N, N＇-dicyclohexyl- carbodiimide （DCC） mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina p...
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A general procedure for surface modification of nano-alumina using N, N＇-dicyclohexyl- carbodiimide （DCC） mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina pretreated with 3-aminopropyltriethoxysilane in the presence of DCC, giving modified aluminas having organic surfaces. The grafted aluminas have been characterized qualitatively by FT-IR or ^13C CPMAS NMR spectroscopy, and quantitatively by thermogravimetric analysis and elemental analysis. The procedure was applied to polyether dendrons bearing carboxyl groups at the focal points, giving successful grafting of dendrimers onto nano-alumina.
The antibacterial property and biodegradability of soluble eggshell membrane protein （SEP） are reported. Unlike the natural eggshell membrane （ESM）, SEP does not possess antibacterial property against E. coli. The...
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The antibacterial property and biodegradability of soluble eggshell membrane protein （SEP） are reported. Unlike the natural eggshell membrane （ESM）, SEP does not possess antibacterial property against E. coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.
In this research,Chitosan has been used for the noncovalent modification of multiwalled carbon nanotubes (MWNTs) and improve their dispersion in *** order to be able to integrate MWNTs with biological systems,it is cr...
In this research,Chitosan has been used for the noncovalent modification of multiwalled carbon nanotubes (MWNTs) and improve their dispersion in *** order to be able to integrate MWNTs with biological systems,it is critical that the solubility of the MWNTs be improved due to their poor solubility in most *** varying the reaction of time of chitin in concentrated NaOH,Chitosan samples with different % degree of deacetylation (%DD) (58%,76%,81%,91%,and 94%) were prepared.
In this study, the pristine or He/N2/O2-plasma treated ultra-high-molecular-weight polyethylene (UHMWPE) fabrics was coated with the PU adhesive agent and then laminated. It was found that the values of peeling streng...
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In this study, the pristine or He/N2/O2-plasma treated ultra-high-molecular-weight polyethylene (UHMWPE) fabrics was coated with the PU adhesive agent and then laminated. It was found that the values of peeling strength of the laminated UHMWPE fabrics for the plasma treated fabrics were significantly higher than that for pristine fabrics. The hydrophilic property revealed from the contact angle of the water drop on the surface of UHMWPE fabrics, the values of the arithmetic mean of the surface roughness (Ra) and the root mean square of the surface roughness (Rms) obtained from Atomic Force Microscopy (AFM) analyses and the dimension of the aperture observed from scanning electron microscope (SEM) of UHMWPE fabrics increased significantly after the treatment of He/N2/O2-plasma.
The concept of entanglement provides the basis of our current understanding of the flow behavior of polymer melts, Current techniques developed to investigate the degree of interpenetration of polymer chains only prov...
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The concept of entanglement provides the basis of our current understanding of the flow behavior of polymer melts, Current techniques developed to investigate the degree of interpenetration of polymer chains only provide indirectly the information of the degree of entanglement in a relatively large scale （several to tens of nanometer）. In this article, we report ^1H-NMR spectroscopy with dipolar filters under fast magic angle spinning for probing chain interpenetration of polymer glasses at the molecular level.
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