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[Display omitted] • Model based design of a novel polymerization process is performed. • The process is applicable to solution and slurry polymerization with phase change. • The process can efficiently control product properties and reactor heat load. • Cooled evaporation streams affect concentration gradients and heat transfer rates. • The feature of ethylene/1-octene copolymerization system is studied as an example. This work aims on developing a novel process that is applicable to solution and slurry polymerization, which can efficiently control production efficiency, product properties and reactor thermal load through changing the flow ratios of cooled evaporation streams between different reactors. Furthermore, various process routes can be created by varying the destinations of cooled evaporation streams, markedly enhancing the process flexibility. To provide a thorough insight into the characteristics of the developed process, numerical simulations based on coupling the constructed models of polymerization reaction kinetics, thermodynamic properties and reactors are conducted to comprehensively study the impact of various factors (e.g. , process routes, pressure, monomer and catalyst concentration, flow rates of cooled evaporation streams in different reactors) on the ethylene/1-octene solution copolymerization system with several stirred reactors connected in series. Some strategies for regulating production efficiency, product properties and reactor heat load of different process routes are obtained. [ABSTRACT FROM AUTHOR]

Abstract: A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar=2,6-Me2C6H3), Co2 (Ar=2,6-Et2C6H3) and Co7 (Ar=2,6-Br2C6H3) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters. [Copyright &y& Elsevier]

The 2-benzazole-1,10-phenanthrolines and their chromium(III) complexes were synthesized and characterized by elemental and spectroscopic analyses as well as by single-crystal X-ray crystallography. X-Ray crystallographic analyses of C6and C8reveal an octahedral geometry around both chromium centers. The electronic spectra of the chromium complexes exhibit d–d transitions typically of a pseudo-octahedral coordinated d3ion, falling into the region ν14A2g→4T2g600–700 nm,ν24A2g→4T1g(F) 430–470 nm, and the 10Dqvalues between 15674 and 16529 cm−1. The variation of the heteroatoms (X = N, O, S) in benzazole group shows regular influence on the 10Dqvalues as 10Dq(O) > 10Dq(N) > 10Dq(S), which reflects the σ-donor/π-acceptor properties of these benzazole ligands. Upon activation with modified methylaluminoxane (MMAO), these complexes exhibited high activities for ethylene oligomerization (up to 7.36 × 106g mol−1(Cr) h−1) and ethylene polymerization (up to 1.28 × 106g mol−1(Cr) h−1). The effects of non-coordinated N, O or S heteroatoms in the ligands have been examined, and interestingly catalytic activities also strictly adhered to the trend O > N > S under various ethylene pressures. Reaction conditions significantly influenced the catalytic properties of the complexes. [ABSTRACT FROM AUTHOR]

Abstract: A series of tridentate NˆNˆN iron(II) and cobalt(II) complexes containing N-((pyridin-2-yl)methylene)-quinolin-8-amine derivatives were synthesized and characterized by elemental and spectroscopic analyses. The molecular structure of 1a was confirmed by X-ray diffraction analyses. On treatment with modified methylaluminoxane, these metal complexes exhibited good catalytic activities up to 2.8×106 gmol−1(Fe)h−1 for ethylene oligomerization, and butenes were the major products with nice selectivity for 1-C4. The steric and electronic effects on catalytic activities of metal complexes were carefully investigated as well as the influence of various reaction parameters. In the catalytic system, Fe(II) complexes performed better catalytic activities than their Co(II) analogues. With ligands having bulky substituents, the better catalytic activity was observed in catalytic system of Fe(II) complex, however, the lower catalytic activity was obtained in catalytic system of Co(II) complexes. [Copyright &y& Elsevier]

Pulse electrochemical deposition is utilized to co‐synthesize hydroxyapatite (HA) and silver (Ag) nanoparticles (NPs) with the mediation of polypyrrole (PPy). PPy acts as the core template for HA–NP and chelation agent for Ag–NP formation. The HA‐Ag‐PPy coatings that contain HA–NPs and Ag–NPs with good osteoconductivity and high antibacterial activity. [ABSTRACT FROM AUTHOR]