Search results for " SILS"

Kopolimery olefin z alkenylosilseskwioksanami

2016

Artykuł stanowi przegląd literatury dotyczącej syntezy i charakterystyki materiałów hybrydowych uzyskanych na drodze kopolimeryzacji alkenylopodstawionych silseskwioksanów z olefinami. Przedstawiono przykłady wykorzystania m.in. procesów kopolimeryzacji koordynacyjnej do syntezy kopolimerów olefin i silseskwioksanów (POSS). Jednocześnie wskazano korzyści płynące z obecności POSS w strukturze polimeru, które przekładają się na jego zwiększoną odporność termiczną oraz parametry mechaniczne.

Single-incision laparoscopic cholecystectomy: Our experience and review of literature

2016

Aim After the revolution in the surgery of gallbladder stones represented by the laparoscopic cholecystectomy, we tried a new technique that further maximize the aesthetic results and that at the same time is of easy learning for young surgeons. Patients and methods From January 2011 to December 2012 we performed at our department 320 cholecystectomy: 27 in laparotomy and 293 in laparoscopy. Of these, 88 underwent to Single Incision Laparoscopic Surgery (SILS), namely the Single Incision Laparoscopic Cholecystectomy (SILC), in recruited patients aged between 19-65 years; 56 patients were females and 32 were males. Results The laparoscopic cholecystectomy with the SILS methodology is a safe …

Novel Imidazolium Based Catalyst for the Chemical Fixation of Carbon Dioxide

2015

Sintesi e studio fotofisico di sistemi Eu@POSS: controllo dell’emissione attraverso isomeria cis-trans.

Synthesis and structural characterization of ethylene copolymers containing double-decker silsesquioxane as pendant groups and cross-linkage sites by…

2018

Abstract The copolymers of ethylene with the double-decker silsesquioxane (DDSQ) were synthesized by copolymerization with the use of metallocene and bis(phenoxy-imine) catalysts. The influence of the kind of the catalyst and polyreaction conditions on the performance of copolymerization as well as on the properties of the copolymers was studied. Depending on polyreaction parameters, the DDSQ contents in the copolymer varied in the range of 0.93–11.53 wt% which determined the compositions and the structural properties of copolymers. DDSQ incorporated into the polymer chain could constitute pendant groups in the main chain or it could act as a cross-linking agent. The ethylene/DDSQ copolymer…

Light-induced trans-cis isomerization of terpyridine functionalized POSS nanostructures self-assembled in presence of Eu3+ ions

DESIGN OF NOVEL IMIDAZOLIUM BASED NANOSTRUCTURES FOR SUSTAINABLE CATALYTIC APPLICATIONS

Polyhedral Oligomeric Silsesquioxane Based Catalyst for the Efficient Synthesis of Cyclic Carbonates

2015

In this work, the synthesis of a novel imidazolium-based polyhedral oligomeric silsesquioxane (POSS-mim-Cl) material is presented. The new nanometer-size organosilica based compound was employed for chemical fixation of CO2 into epoxide under homogeneous conditions. The target reaction was represented by the obtention of cyclic carbonates starting from epoxides and CO2. Particularly, styrene oxide was chosen as reference substrate. In addition, different parameters (solvent, temperature, pressure of CO2, and mass of the catalyst) were modified to find the best condition for CO2 conversion. The catalyst POSS-mim-Cl displayed good catalytic performances, the best results being obtained at 40 …

Thermal behavior of ethylene copolymers with di- and tri-alkenylsilsesquioxane comonomers synthesized by post-metallocene catalysts

2020

AbstractThis paper reported thermal properties of ethylene copolymers with di- and tri-alkenylsilsesquioxanes (POSS) synthesized by bis(phenoxy-imine) Ti, Zr, V, and V salen-type complexes. Ethylene copolymers with multi-alkenyl POSS obtained by such complexes contain multi-alkenyl POSS incorporated into the polymer chain as a side group. They were characterized by different thermal behavior depending on the kind of multi-alkenyl POSS comonomer, and type of the catalyst used, as well as polymerization conditions and thus the structure of the copolymer chain. Ethylene/POSS copolymers differed in incorporation of POSS into the polymer chain, content of specific unsaturation groups, and molecu…

Ethylene/POSS copolymerization behavior of postmetallocene catalysts and copolymer characteristics

2017

Copolymerization of ethylene with iso-butyl substituted monoalkenyl(siloxy)- or monoalkenylsilsesquioxane (POSS) comonomers over bis(phenoxy-imine) and salen-type titanium and zirconium catalysts was studied. It was found that the polyreaction performance was significantly depended by the kind of the catalyst and by the structure and concentration of POSS in the feed. The POSS comonomer was efficiently incorporated into the polymer chain at up to 0.2 mol %. The differences in the copolymer compositions as the functions of the catalyst kind and the POSS comonomer were observed, including the varied number-average sequence length of ethylene and unsaturated end groups, as determined by 1H NMR…