Showing papers by "DSM published in 1973"
DSM1
TL;DR: In this paper, the adsorption and decomposition of nitrous oxide and the chemisorption of oxygen on silver powders and silver-on-carrier catalysts were investigated.
78 citations
DSM1
TL;DR: In this paper, a method is described for the determination of trace amounts of cyclohexanone in concentrated solutions of cycloenanone oxime in toluene, which is achieved by liquid-liquid chromatography using a phase pair obtained from a mixture of 2,2,4-trimethylpentane, ethanol and water.
31 citations
DSM1
TL;DR: The structure of Zn[Cl2Ti(C5H5)2]2·2C6H6 has been determined from Patterson and Fourier syntheses of two projections, and refined toR = 0·117 by full-matrix three-dimensional least-squares methods as discussed by the authors.
Abstract: The structure of crystals of the composition Zn[Cl2Ti(C5H5)2]2·2C6H6 has been determined from Patterson and Fourier syntheses of two projections, and refined toR = 0·117 by full-matrix three-dimensional least-squares methods. The crystals are orthorhombic:Pbcn,a = 18·45(5),b = 15·40(6),c = 11·35(3) A,Z= 4. The complex consists of a central distorted ZnCl 4 2− tetrahedron linked along the Cl—Cl edges to two distorted TiCl2(C5H5)2+ tetrahedra in such a way that their centres are nearly collinear The two C6H6 molecules in the formulae unit may be regarded as benzene of crystallization.
6 citations
DSM1
5 citations
DSM1
TL;DR: A simple static model containing appropriately chosen non-linearities is being used in a feedforward control loop and updated regularly by feedback in an openloop computer control system, results of which are given.
5 citations
DSM1
TL;DR: Three tertiary β-nitroalkyl peroxynitrates 2a, 2b and 2c were prepared by reaction of N2O4 and excess O2 with isobutene (la), 2,3,3-trimethyl-2-butene (1b) and 2, 3-dimethyl-1-butenes (1c), respectively as discussed by the authors.
Abstract: Three tertiary β-nitroalkyl peroxynitrates 2a, 2b and 2c were prepared by reaction of N2O4 and excess O2 with isobutene (la), 2,3,3-trimethyl-2-butene (1b) and 2,3-dimethyl-2-butene (1c), respectively. These compounds are rather unstable and at 23° slow decomposition occurs. It seems likely that this decomposition starts by O-O bond fission yielding an NO3 radical and a β-nitroalkoxy radical. In the case of 2a this alkoxy radical either reacts with NO2 or dimerises but no β-fission is observed. In the case of 2b and 2c extensive β-fission of the alkoxy radical produces alkyl radicals which react with NO3 radical forming alkyl nitrate or react with O2 and NO2 (produced from NO3) forming alkyl peroxynitrate.
4 citations
DSM1
TL;DR: In this article, a method is presented to recover the polymer formed in the free radical bulk polymerization of ethylene as a powder rather than as a melt, which has been used in a study on the production of medium and high density polyethylene with the aid of radical initiators at temperatures below the melting point.
Abstract: A method is presented to recover the polymer formed in the free radical bulk polymerization of ethylene as a powder rather than as a melt. The paper mentions several advantages of this new approach, which has been used in a study on the production of medium and high density polyethylene with the aid of radical initiators at temperatures below the melting point of polyethylene (suspension bulk polymerization). The method of preparing products with a very high stiffness comparable to that of homopolymers made by the Ziegler process is, in principle, also applicable at polymerization termperatures above the melting point of polyethylene, provided (meth) acrylamide is employed as a comonomer.
2 citations
01 Jan 1973
TL;DR: In this article, the dependence of Gibbs free energy on experimental variables, such as temperature and composition, allows precise prediction of the thermodynamic state of any mixture in equilibrium, particularly for systems containing macromolecules in which large variations in liquid-liquid phase relationships may be brought about by relatively small changes of the variables mentioned.
Abstract: Accurate knowledge regarding the dependence of the free enthalpy (Gibbsfree energy) on experimental variables, such as temperature and composition, allows precise prediction of the thermodynamic state of any mixture in equilibrium. This is particularly true for systems containing macromolecules in which large variations in liquid-liquid phase relationships may be brought about by relatively small changes of the variables mentioned. In polymeric systems the molecular weight distributions of the macromolecular constituents also play a decisive role. Calculated and experimental examples are given and methods are discussed that permit accurate determination of the dependence of the free enthalpy on temperature, concentration and molecular weight distribution. The treatment is not limited to any particular molecular model, provided that the free enthalpy can be written in the form of the Flory-Huggins combinatorial entropy terms plus an arbitrary correction function for concentration, temperature and molecular weight distribution(s).
1 citations