Authors:P. V. Surse, S. Wagholikar, S. Mayadevi, and S. Sivasanker
reported, studies on anisole alkylation with C 6 hydrocarbons/alcohol are scarce. In this paper, we report the alkylation of anisole with 1-hexene and 1-hexanol (hexyl alcohol) over zeolite H-beta. The influence of process parameters like temperature
Authors:Qingrong Peng, Chunrong Zhang, Youzhu Yuan, and Shicong Hou
A series of (o-alkylaminophenyl)diphenylphosphine ligands (P–N ligands) containing different alkyl carbon numbers or amino groups have been
synthesized and characterized by IR and NMR (1H, 13C, 31P). The rhodium complexes ligated with P–N ligands in the hydroformylation of 1-hexene showed a considerable enhancement with
the addition of water. NMR characterization studies suggested that the addition of water would engage in hydrogen bonding
to the nitrogen atom of the coordinated P–N ligand, inhibiting the internal Rh–N interaction and generating more of the active
unsaturated Rh-species that could react with 1-hexene to start the hydroformylation.
The investigation of the intermolecular composition distribution of an ethylene/1-hexene copolymers using DSC method has been
carried out. The known methods: step crystallization (SC) and successive self-nucleation/annealing (SSA) have been adapted
for this purpose, and particularly, the optimal condition of the process have been chosen to enable the best fractional crystallization
of the copolymer. The method has been applied for fractionation of two ethylene/1-hexenecopolymers synthesized with supported
vanadium and zirconocene catalysts and having similar concentrations of 1-hexene. Although metallocene catalysts are known
from their more homogeneous structure of active sites in comparison to multi-site Ziegler–Natta catalysts, the copolymers
obtained over both catalytic systems gave DSC curves resolved into several peaks but with different melting points. Using
the Thomson–Gibbs equation, comparable average lamellar thickness of the separated peaks has been calculated. The amounts
of copolymer fraction with defined lamellar thickness have been determined. It was obtained that the copolymer produced from
the metallocene system contains a thinner and more homogeneous lamella thickness than that obtained with Ziegler–Natta vanadium
catalyst supported on the same carrier.
Authors:Yazhen Wang, Libo Wang, Jie Chen, Sihan Wang, Yulin Yang, and Qian Chen
1-Hexene is an important co-monomer in the preparation of high-performance linear low density polyethylene, which is also the main raw material of synthesizing some plasticizers, detergents and other chemical
Authors:Madhavi Vadlamudi, Rufina Alamo, David Fiscus, and Manika Varma-Nair
Here we report the melting and isothermal crystallization behavior of two sets of fractions obtained from a film-grade metallocene
catalyzed ethylene-1-hexene resin with enhanced mechanical properties. One set of fractions was obtained by molecular weight
fractionation, the second set was obtained fractionating by content of 1-hexene. The melting behavior, crystallization kinetics
and supermolecular morphology of the fractions are analyzed in reference to the behavior of model systems with uniform inter-chain
branching content and a random intra-chain distribution. While melting and crystallization kinetics of molecular weight fractions
conforms to the bivariate (molecular weight-comonomer content) distribution of the original copolymer, the behavior of 1-hexene
compositional fractions indicate a blockier branching distribution in the highly branched high molar mass fractions. Major
differences with model random copolymers are also observed in the supermolecular morphology of the latter fractions.
The pulse-height distributions for131mXe in PPO solutions of aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, 2,4-dimethylpentane, 2,3,4-trimethylpentane, 1-pentene, 1-hexene and 1-heptene are investigated as a function of temperature. The pulse-height distributions are found to be shifted toward higher pulse-heights with decreasing temperature. The count rates of131mXe remain unchanged with decreasing temperature. The mechanism of the effect is also discussed.
Authors:Swee Yap, Yuan Yuan, Lu Zheng, Wai Wong, Ning Yan, and Saif Khan
In this paper, we present detailed experimental and modeling studies of a recently developed triphasic segmented flow millireactors for rapid nanoparticle-catalyzed gas–liquid reactions. We first present detailed observations of the hydrodynamics and flow regimes in a pseudo-biphasic mode of operation, which enable the design and selection of optimal operating conditions for the triphasic millireactor. We particularly focus on and analyze the presence of wetting films of the organic phase on the reactor walls at high flow speeds, a consequence of the phenomenon of forced wetting, which is a key ingredient for optimal reactor performance. Next, we describe the development of a simple phenomenological model, incorporating the key mass transport steps that accurately captures the observed experimental trends for the rhodium nanoparticle (RhNP) catalyzed hydrogenation of a model substrate (1-hexene). We further discuss and analyze the consequences of this model.
Authors:R. łopatka, L. Wachowski, H. Boniuk, I. CieŚlowska, J. Zawadzki, and W. Skupiński
Results of TG and DTA studies as well as an analysis of the liberated gas products have led us to recognize differences in the mechanisms of transformations taking place in the systems NH4ReO4/Al2O3-SiO2 (25 wt% SiO2 and NH4ReO4/Al2O3 containing 1.1, 3.3 and 3.3, 9.9, 17.8 wt% NH4ReO4. Thermal decomposition of NH4ReO4 on the supports used begins with release of ammonia, which is strongly bound with the surface in the system of 3.3 wt% NH4ReO4/Al2O3, and undergoes oxidation to nitrogen oxides in the air atmosphere. In the other systems studied, the process of ammonia release starts already at 473 K and ammonia does not get oxidized. Moreover, it has been established that ammonia perrhenate supported on the surface of Al2O3-SiO2 in the amount of 1.1 or 3.3 wt% undergoes partial thermal decomposition to ReO2 which is further oxidized in the air atmosphere. As follows from the thermal studies as well as the measurements of activity in a reaction of 1-hexene metathesis, the active centres of the reaction of olefin metathesis are formed on the surface of the studied systems after their calcination at 473 K.