Polymerization and self‐assembly of thermally responsive in‐chain functionalized double‐hydrophilic macromonomers

Double‐hydrophilic in‐chain functionalized macromonomers consisting of poly(N‐isopropylacrylamide) (PNIPAM) and poly(ethylene oxide) were prepared by a multistep procedure including esterification of PNIPAM monoester of maleic acid with α‐methoxy‐ω‐hydroxypolyoxyethylene or its amidation with α‐methoxy‐ω‐aminopolyoxyethylene. The polymerization of the macromonomers was carried out in aqueous solutions. The temperature was the key parameter controlling the polymerization process that was performed in the organized domains formed by the macromonomers below and above the phase transition temperature (T_tr). Polymacromonomers with higher degrees of polymerization were prepared at temperatures just below the T_tr. Static light scattering measurements on dilute aqueous solutions of thermally‐responsive macromonomers and their polymerization products demonstrated that they formed aggregates below the T_tr. Supramolecular structures with low density cores, formed by the polymacromonomers at room temperature, were imaged by SEM. Morphological tuning was achieved by varying both the composition of the copolymer and the concentration of the aqueous solution. The rheological behavior of the polymacromonomers in 25 wt % aqueous solution was compared to that of the respective macromonomers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4720–4732, 2007     

HETEROCYCLIC PHOSPHONIUM SALTS BY REACTION OF DIMETHYL(1,2-ALKADIENYL)-PHOSPHINE OXIDES WITH ELECTROPHILIC REAGENTS

Abstract

Salts of 2,5-dihydro-1,2-oxaphosphole have been prepared by reaction of dimethyl(1,2-alkadienyl)phosphine oxides with halogens, sulfenyl and selenenyl chlorides. The essential influence of tertiary carbenium ions for realization of oxaphospholic cyclization of phosphorylated allenes has been established.     

Eine Farbenreaktion zum Nachweise von Methylalkohol

Ohne Zusammenfassung     

Influence of the solid-state modification of MCM-22 with Cs on toluene disproportionation

The catalytic performance of MCM-22 modified with Cs to different extents by Solid-State Ion Exchange has been investigated in toluene disproportionation. It was suggested that protons on the external surface were preferentially replaced by Cs cations. It was observed that the Cs modifications did not provide improved p-xylene selectivity at conversions close to that of the H-form. The remaining unaffected proton sites in the 10 MR channels are considered as responsible for secondary xylene isomerization proceeding upon toluene disproportionation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Über die Reaktion von Biphenyl mit Magnesium in flüssigem Ammoniak

The interaction between magnesium and biphenyl in liquid ammonia has been studied. It was shown that the metal adduct formed reacts slowly with the reaction medium to give tetrahydroderivatives of biphenyl.A comparative study was carried out in order to reveal the influence of the metal used on the reaction pathway. It was found that the nature of the reaction products markedly differs when lithium, sodium or magnesium were used in the reaction.Possible reaction mechanisms are discussed.     

1,2-oxaphosphorin-3-ene derivatives in the reaction of SO2Cl2 with dichlorides of 2-chloro-3-alkyl-1,3-alkadienephosphonic acids

2,4,5-Trichloro-2-oxo-1,2-oxaphosphorin-3-enes was sinthesised using the interaction of sulfuryl chloride with dichlorides of 2-chloro-3-alkyl-1,3-alkadienephosphonic acids.     

Untersuchung des Systems NaAl(SO4)2−CsAl(SO4)2−H2O bei 25°C und der daraus entstehenden festen Phasen

The solubility diagram of the system NaAl(SO₄)₂–CsAl(SO₄)₂–H₂O was investigated at 25°C. This is a system in which -and -alums participate. The fields of cristallization are outlined. There is one wide field of cesium aluminium alum and one, very narrow, of sodium aluminium alum. The eutonic point of the system lies at the composition of the liquid phase corresponding to 27.90 wt.% NaAl(SO₄)₂ and 0.008 wt.% CsAl(SO₄)₂. It was found that mixed crystals are not formed in the system. The solid phases were investigated by X-ray diffraction andDTA.

---

---

Mit 3 Abbildungen     

Untersuchung der Ionengleichgewichte in Tetrahydrofuranlösungen des 2-Naphthonitril-Natriums

With the aid of conductometric measurements the ion equilibria inTHF solutions of 2-naphthonitrile sodium were studied. It was established that in the concentration interval of 10^–4–10^–5 mol/l the equilibrium ion pairs—free ions is predominant . The ion pairs are contact (average interion distance about 4.1 Å). In the temperature interval of 25 to 40° the heat of dissociation –H=3.1 kcal/mol, whereas between –40 and –70°–H is 1.26 kcal/mol. At higher concentrations (10^–2–10^–3 mol/l) triple ion formation is observed.