Novel propargyl-ended heterobifunctional poly(ethylene glycol) (PEG) derivatives with hydroxyl, carboxyl, mercapto or hydrazide end groups were synthesized with simplicity yet high efficiency. PEG (Mw = 3500 Da) with an α-hydroxyl group and an ω-carboxyl was used as the starting polymer. The carboxyl group of the bifunctional PEG was modified into a propargyl, then carboxyl, mercapto or hydrazi...

Abstract In Polyethylene terephthalate (PET) processing the raw materials are purified terephthalic acid (PTA), moderately (MTA), monoehalene glycol (MEG). The of PTA is very difficult and costly. For reducing percent we using different percentages MTA blend in PET processing. affected properties polyester melt spinning process. such as elongation, tenacity, molecular chain length, b-color IV, ...

In the crystal structure of the title coordination polymer, {[Zn(2)(C(24)H(18)N(4)O(10))(H(2)O)(4)]·H(2)O}(n), the mol-ecular building block (MBB), viz [Zn(2)(CO(2))(4)(H(2)O)(4)], comprises two Zn(II) cations, each bridged by three carboxyl-ate groups from different ligand mol-ecules. These two Zn(II) cations exhibit different coordination environments: a distorted trigonal-pyramidal coordinat...

Although focus groups are commonly used in health research to explore the perspectives of patients or health care professionals, few studies consider methodological aspects in this specific context. For this reason, we interviewed nine researchers who had conducted focus groups in the context of a project devoted to the development of an electronic personal health record. We performed qualitati...

The synthesis of N-acetyl-L-isoasparagine and of N-acetylL-isoglutamine is reported. The acid dissociation constants of these compounds, and those of their corresponding Ncarbobenzoxy derivatives, have been measured. Since these compounds are uncharged molecules of the type -NH-CH(-CH,COOH)-COor the corresponding glutamyl homologue, their dissociation constants represent the intrinsic dissociat...

Functionalized carbon nanotubes have tremendous potential for nanotechnology applications such as in the fabrication of polymeric carbon fibers. However, approaches to design carbon nanotube structures by using functional groups as glue and carbon nanotubes as stiff building blocks to reach superior mechanical strength and toughness at the fiber level with limited amount of materials remains po...

The reactivity of different diazoalkane reagents was examined using the coupling reaction with methyl β-Dglucopyranosiduronic acid as a model. 9H-Fluoren-2-yl-diazomethane (FDAM), prepared from its precursor 9H-fluoren2-carbaldehyde hydrazone by MnO2 oxidation, was found suitable as a new labeling agent for carboxyl groups in carbohydrate materials. The reaction with methyl β-D-glucopyranosidur...

This work explains the functionalization of polyallylamine (PAA) on graphene oxide (GO) sheets following a chemical route. The resulting GO-PAA complex is characterized by using various imaging and analytical tools. In Raman spectroscopy for both GO GO-PAA, appearance D G characteristic bands correspond to sp2 sp3 contents, respectively, in carbon sheets. observation lowered D/G peak intensity ...

The specificity of the Barrnett-Seligman method for the histochemical demonstration of alpha-acylamido carboxyl groups (C terminal) of proteins is dependent on the conversion of such groups to ketones by the action of acetic anhydride and absolute pyridine. Studies on model compounds show that the side-chain carboxyl groups also react in the method and that most of the final color developed can...