The slurry polymerization of ethylene was studied by employing a (TiCl4/Mg(OEt)2/TEA) catalyst system in hexane. The effects of triethylaluminum concentration and temperature on polymer yield and polymer viscosity average molecular weight, Mv, were investigated. The maximum polymer yield was obtained at an Al/Ti molar ratio of 124. The highest yield and Mv were achieved at 60 °C. The concentrat...

A two-dimensional single particle finite element model was used to examine the effects of particle fragmental pattern on the average molecular weights, polymerization rate and particle overheating in heterogeneous Ziegler-Natta olefin polymerization. A two-site catalyst kinetic mechanism was employed together with a dynamic two-dimensional molecular species in diffusion-reaction equation. The i...

Indirect reductive amination of aldehydes, catalyzed by polymer supported triphenylphosphine-palladium acetate complex PS-TPP-Pd(OAc)2 catalyst have been developed. The imine is prepared with molecular sieves in the first stage, followed by reduction with potassium formate catalyzed by PS-TPP-Pd(OAc)2. The recovered catalyst could be reused for four consecutive cycles without loss in activity a...

The synthesis of mesoporous Cr–AlPO was carried out under hydrothermal conditions. Characterisation of the catalyst was done with low angle XRD, N2 adsorption, UV–VISDRS, ESR and thermal analysis. The catalytic activity was tested for partial oxidation of toluene with molecular oxygen in vapour phase. It was observed that Cr–AlPO functions both as acid and redox catalyst. 2002 Elsevier Science ...

We describe the synthesis of [bis(N-(3-tert-butylsalicylidene)anilinato)] titanium (IV) dichloride (Ti-FI complex) and examine the effects of comonomer (feed concentration and type) on its catalytic performance and properties of the resulting polymers. Ethylene/1-hexene and ethylene/1-octene copolymers were prepared through copolymerization using Ti-FI catalyst, activated by MAO cocatalyst at 3...

The recent surge of interest in non-noble-metal porphyrin and phthalocyanine catalysts has been prompted by their potential to replace Pt as cathodic catalysts in polymer electrolyte membrane fuel cells (PEMFCs). However, to realize the apparent benefits of the metal–N-coordinated catalysts in high-power fuel cells, advances in catalyst design and synthesis are required to produce catalysts wit...

The present study describes the application of Fischer Tropsch biowaxes as a feedstock in a pilot-scale hydroprocessing unit at operating conditions very similar to industrial size hydrotreating plants of traditional refineries. The project focus on a future coprocessing of biowax/gasoil blends due to produce bio-products derived from lignocellulosic biomass: crack gases, naphtha, kerosene, die...

Lithium perchlorate is a Lewis acid catalyst which activates a large number of organic reactions providing high yields with enhanced reaction rates. Moreover, it makes some of the reactions possible to proceed under solvent-free conditions which is an important aspect for the development of green chemistry. This paper canvasses the chemical literature on lithium perchlorate as a catalyst for or...