polyethylene

The MCM-41 (Mobil Composition of Matter) and SBA-16 (Santa Barbara Amorphous) supported TiCl4 and TiCl4/MgCl2 catalysts with different molar ratios of Mg/Ti were synthesized and used for ethylene polymerization under atmospheric pressure. The nanochannels of these supports serve as a nanoscale polymerization reactor and the polyethylene nanofibers were extruded during the reaction. The effect of MgCl2 on catalytic activity and morphology of resulting polyethylene has been investigated too.

Silica was compared with clays as supports for metallocene. Ethylene homopolymerization with both homogeneous and heterogeneous catalysts was performed. Activation energy was higher for
(n-BuCp)2ZrCl2/SiO2/MAO, although high activities were obtained for catalysts with clay. They showed Ea close to that of homogeneous precursor. Catalyst/clay control polymer morphology until 363 K

Different methods to remove the alcohol of adduct MgCl2nEtOH were studied to obtain Ziegler-Natta catalysts for evaluation in ethylene and propylene polymerization. Thus, the adduct MgCl2nEtOH was submitted to thermal dealcoholation, as well as chemical dealcoholation with different substances: titanium tetrachloride, triethylaluminum, and dichloro-dimethylsilane. Thermogravimetric analyses (TGA) were performed to obtain information on the thermal characteristics of adducts and prepared supported catalysts.

A quantitative structural model of particulate-filled polymer composites impact toughness, based on the fractal analysis ideas, was offered. The model demonstrated good correspondence with the experimental data. It has been shown that the action of nanofiller as nucleator, resulting in crystallinity degree and amorphous phase structure change, exert the main influence on impact toughness value.

The aim of this study was to synthesize ethylene-hexene copolymers of the type LLDPE using a combination of metallocene binary catalysts (Cat 1: Cp2ZrCl2 and Cat 2: Et(IndH4)2ZrCl2), where each catalyst has different microstructural control capacities. The effect of diethyl zinc (DEZ) concentration as a chain shuttling agent (CSA) was evaluated in parameters such as catalytic activity, as well as thermal properties, comonomer content incorporated into the polymer chain, crystal structure, and also dynamic mechanical properties of the obtained copolymers.

In this work 20 new biogegradable materials from polyethylene and lignocellulosic fillers were examined. The samples with and without compatibilizer were compared. This work contains four different methods of investigation: TGA, microscopy, thermal oxidation, biodegradation in soil.

Approach of obtaining molded composites on the basis of the mixtures of powders of nano-dispersed polyethylene, cellulose and ultra-dispersed carbonic materials has been developed. Тhese materials possess the assigned sorption properties and the physic-mechanical characteristics. Тhey are suitable for the usage in the process of cleaning and separation of gas mixtures.