Preparation and Characterization of Nanocellular Poly(phenylquinoxaline) Foams. A New Approach to Nanoporous High-Performance Polymers

2007 ◽  
Vol 40 (6) ◽  
pp. 2070-2078 ◽  
Author(s):  
Samuel Merlet ◽  
Catherine Marestin ◽  
Fréderic Schiets ◽  
Olivier Romeyer ◽  
Régis Mercier
Keyword(s):  
High Performance ◽  
New Approach ◽  
High Performance Polymers

Thermal Analysis of Kenaf Sandwich Panel

2013 ◽  
Vol 812 ◽  
pp. 271-274
Author(s):  
Johari Nor Hasnidawani ◽  
Noor Azlina Hassan ◽  
Zahurin Halim
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
High Performance ◽  
Sandwich Panel ◽  
Galvanized Steel ◽  
New Approach ◽  
Composite Sandwich ◽  
Analytical Tools

The introduction of the eco-core sandwich panel composite is contributing a new approach to the designer to achieve high performance and light weight. In this research project, the new kenaf eco-core sandwich panel will be developed and then laminated with galvanized steel. The final goal is to find the optimum eco-core metal matrix composite sandwich structure with maximum mechanical properties such as stiffness and buckling. Kenaf eco-core sandwich will be fabricated and study on the interaction between eco-core sandwich panel and metal faces will be performed. The characterization of the eco-core sandwich panel will be done using different analytical tools. This study would provide a way to enhance the application of this new eco-core metal matrix composite sandwich structure.The amount of sample used was approximately 12 mg. The temperature profile was from 27°C to 1000°C at a heating rate of 10°C/min. In this study, result shows that degradation of composites starts to occur at about 180°C. Increasing the kenaf percent ratio will decrease the percent residue.

Two-stage self-seeding method for preparation of single crystals of poly(phenylene sulfide)

1989 ◽  
Vol 47 ◽  
pp. 368-369
Author(s):  
Sengshiu Chung ◽  
Peggy Cebe
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Dilute Solution ◽  
Two Stage ◽  
Annealing Behavior ◽  
High Performance Polymers ◽  
Seeding Method ◽  
Phenylene Sulfide

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

CHEMICAL CONVERSION OF 2.4.6-TRINITROTOLUENE (TNT) TO NEW HIGH PERFORMANCE POLYMERS

2002 ◽  
Vol 5 (1-6) ◽  
pp. 1031-1047
Author(s):  
A. L. Rusanov ◽  
L. G. Komarova ◽  
M. P. Prigozhina ◽  
V. A. Tartakovsky ◽  
S. A. Shevelev ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Conversion ◽  
High Performance Polymers

Theoretical Interpretation of High-Performance Chromatographic Data for a Heterogeneous Series of Compounds

1992 ◽  
Vol 57 (1) ◽  
pp. 33-45
Author(s):  
Vladimír Jakuš
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Theoretical Interpretation ◽  
Retention Data ◽  
Theoretical Evaluation ◽  
New Approach ◽  
Free Energy Of Solvation ◽  
Rp Hplc ◽  
Mobile Phases ◽  
Reversed Phases

A new approach to theoretical evaluation of the Gibbs free energy of solvation was applied for estimation of retention data in high-performance liquid chromatography on reversed phases (RP-HPLC). Simple and improved models of stationary and mobile phases in RP-HPLC were employed. Statistically significant correlations between the calculated and experimental data were obtained for a heterogeneous series of twelve compounds.

Preparation and Characterization of the High Molecular Weight [3H]Hyaluronic Acid

1992 ◽  
Vol 57 (10) ◽  
pp. 2151-2156 ◽  
Author(s):  
Peter Chabreček ◽  
Ladislav Šoltés ◽  
Hynek Hradec ◽  
Jiří Filip ◽  
Eduard Orviský
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
High Molecular Weight ◽  
Methyl Bromide ◽  
High Performance ◽  
Hydrogen Atoms ◽  
Isolation And Characterization ◽  
Labelling Procedure ◽  
Enzymatic Depolymerization

Two methods for the preparation of high molecular weight [3H]hyaluronic acid were investigated. In the first one, hydrogen atoms in the molecule were replaced by tritium. This isotopic substitution was performed in aqueous solution using Pd/CaCO3 as the catalyst. In the second method, the high molecular weight hyaluronic acid was alkylated with [3H]methyl bromide in liquid ammonia at a temperature of -33.5 °C. High-performance gel permeation chromatographic separation method was used for the isolation and characterization of the high molecular weight [3H]hyaluronic acid. Molecular weight parameters for the labelled biopolymers were Mw = 128 kDa, Mw/Mn = 1.88 (first method) and Mw = 268 kDa, Mw/Mn = 1.55 (second method). The high molecular weight [3H]hyaluronic acid having Mw = 268 kDa was degraded further by specific hyaluronidase. Products of the enzymatic depolymerization were observed to be identical for both, labelled and cold biopolymer. This finding indicates that the described labelling procedure using [3H]methyl bromide does not induce any major structural rearrangements in the molecule.

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