A5028141754- Organometallic Complex Synthesis and Catalysis
- Synthetic Organic Chemistry Methods
- Carbon dioxide utilization in catalysis
- biodegradable polymer synthesis and properties
- Organoboron and organosilicon chemistry
- Polymer composites and self-healing
- Crystallization and Solubility Studies
- Polymer crystallization and properties
- X-ray Diffraction in Crystallography
- Synthesis and characterization of novel inorganic/organometallic compounds
- Polymer Nanocomposites and Properties
- Lignin and Wood Chemistry
- Catalytic Alkyne Reactions
- Asymmetric Hydrogenation and Catalysis
- Advanced Cellulose Research Studies
- Advanced Polymer Synthesis and Characterization
- Synthesis and properties of polymers
- Silicone and Siloxane Chemistry
- CO2 Reduction Techniques and Catalysts
- Orthopaedic implants and arthroplasty
- Fluorine in Organic Chemistry
- Advanced NMR Techniques and Applications
- Carbon Nanotubes in Composites
- Fiber-reinforced polymer composites
- Luminescence and Fluorescent Materials
National Research Council
2012-2024
Istituto di Scienze e Tecnologie Chimiche "Giulio Natta"
2021-2023
Istituto di Chimica Biomolecolare
1997-2021
Consorzio Roma Ricerche
2012-2021
Mylan (South Africa)
2021
Institute for Macromolecular Studies
2010-2019
Université du Québec à Montréal
2013
Centre National de la Recherche Scientifique
2013
University of New Hampshire
2013
Université de Montréal
2013
This paper provides a bio-based polyurethane foam (PUR) solution, following cradle-to-factory approach. The design of rigid PURs, reinforced with sustainable fillers have gained remarkable attention in "green" construction sector. Their marked performances make them viable solution for synthetic counterparts' replacement. In this work, functionalized hemp fibers and silica powders were selected as reactive fillers, imparting multifunctional properties to the designed PURs. Hemp underwent...
Complex [Pd(κ2-P,O-{2-(2-MeOC6H4)2P}C6H4SO3)Me(dmso)] (1) was investigated as a single component catalyst for the copolymerization of ethylene with norbornene affording P(E-co-N) in excellent yields and molar masses significantly higher than those polyethylene. Copolymer increased N concentration. Determination microstructure reactivity ratios revealed strong inherent tendency to form alternating copolymers. The ability palladium complex 1 effectively copolymerize functionalized derivatives...
Nowadays, the chemical industry is looking for sustainable chemicals to synthesize nanocomposite bio-based polyurethane foams, PUs, with aim replace conventional petrochemical precursors. Some possibilities increase environmental sustainability in synthesis of PUs include use and additives derived from renewable sources (such as vegetable oils or biomass wastes), which comprise increasingly wider base raw materials. Generally, exhibit chemico-physical, mechanical functional properties, are...
Bio-polyols from epoxidized soybean and linseed oils caprylic acid or 3-phenyl butyric were prepared using an environmentally friendly, solvent-free method evaluating the presence of triethylamine as catalyst. Side reactions, leading to a cross-linking structure with high density, reduced, introducing catalyst properly tuning reaction conditions. A medium functionality value around 3 along hydroxyl number up 90 mg KOH/g, narrow polydispersity index, relatively low molecular mass 2400 g/mol...
A best-fitting procedure for the quantitative determination of molar fractions stereosequences that define microstructure an ethylene−norbornene (E−N) copolymer from 13C NMR spectra has been set up. The will allow one to clarify E−N copolymerization mechanism. This method utilizes observed peak areas signals and takes into account consistency between stoichiometry chain. Thus, a further extension signal assignments is made possible by guessing unknown discarding inconsistent hypotheses....
Ethylene−norbornene (E−N) copolymers were synthesized with the C2 metallocene rac-Me2Si(2-Me-[e]-benzindenyl)2ZrCl2 (3) and constrained geometry Me2Si(Me4Cp)(NtBu)TiCl2 (4) in presence of methylaluminoxane. The E−N copolymerizations carried out using a variety monomer feed compositions. Copolymers fully characterized by 13C NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry. Copolymer microstructures analyzed detail, through procedure which accounts for...
Ethylene−norbornene (E−N) copolymers were synthesized by catalytic systems composed of racemic isospecific metallocene or a constrained geometry catalyst (CGC) and methylaluminoxane. The following metallocenes used: rac-Et(indenyl)2ZrCl2 (1), rac-Me2Si(indenyl)2ZrCl2 (2), rac-Me2Si(2-Me-[e]-benzindenyl)2ZrCl2 (3), Me2Si(Me4Cp)(NtBu)TiCl2 (4). characterized 13C NMR the copolymer microstructures analyzed in detail. A procedure for computing molar fractions stereosequences that completely...
Two dinuclear aluminum complexes bearing dinaphthalene bridging Schiff bases have been synthesized and investigated as catalysts in ring-opening polymerization (ROP) of cyclic esters such rac-lactide (rac-LA) ε-caprolactone (ε-CL) the copolymerization (ROCOP) phthalic anhydride (PA) with cyclohexene oxide (CHO) limonene (LO). The polymerizations were living, producing polymers narrow molar mass distributions. Kinetic studies showed that first order respect to monomers. Cooperative effects...
A rotational-isomeric-state treatment of ethylene−norbornene copolymers has been worked out for the purpose establishing a correlation between conformation and 13C NMR chemical shifts this new class polymers clarifying their microstructure. comparison conformer populations computed stereoregular alternating (N−E)x chains including such defects as N−N, E−E, E−E−E, N−N−N indicates need accounting tacticity chain, besides its composition, in interpretation spectra. Some stereochemical were...
This study involves research on possible relationships between the composition of ethylene/norbornene copolymers and their thermal properties. The were fully characterised by differential scanning calorimetry (DSC), 13C NMR spectroscopy, Fourier transformation infra-red (FTIR) Raman spectroscopy. results this show that there is no linear correlation amount norbornene incorporated in behaviour when containing high content different microstructures are considered. latter which was found to be...
Poly(ethene-co-norbornene) was synthesized in toluene using Me2Si(Me4Cp)(NtBu)TiCl2 activated with methylaluminoxane (MAO) as catalyst. We found that at 50 °C the molecular weight increases time for up to 1 h, and very little chain transfer occurs; thus, copolymerization can be considered quasi-living. The quasi-living nature requires high norbornene feed fractions; it is more pronounced low temperatures short reaction times. Mw/Mn = 1.3 (Mn 100 kg/mol) lowest polydispersity index obtained...
An investigation of the copolymerization cyclohexene sulfide and carbon disulfide using salphen salen Cr complexes as catalysts [PPN]+X– salts cocatalysts, at different temperatures reaction times, is reported. Both catalytic systems produce both polymer cyclic products. For first time, poly(trithiocyclohexylcarbonates) (PCS) have been synthetized in high yields molecular weights. Salphen-based catalysts, comparison with salen-based ones, show higher productivity selectivity for polymers...
Currently, the scientific community has spent a lot of effort in developing “green” and environmentally friendly processes products, due contemporary problems connected to pollution climate change. Cellulose nanocrystals (CNCs) are at forefront current research their multifunctional characteristics biocompatibility, high mechanical properties, specific surface area, tunable chemistry renewability. However, despite these many advantages, inherent hydrophilicity poses substantial challenge for...
We report on copolymerizations of ethylene with norbornene half-sandwich rare-earth metal catalysts generated by activation dialkyl complexes [Ln(η5-C5Me4SiMe2R)(η1-CH2SiMe3)2(THF)] (Ln = Sc, R Me (1); Ln C6F5 (2); Y, (3); Lu, (4)) [Ph3C][B(C6F5)4]. Complexes 1 and 2 showed excellent activities, whereas complex 3 gave poor activity 4 was practically inactive. Weak stabilization center bulkier silyl group the tetramethylcyclopentadienyl ring in allows controlled copolymerization (Mw/Mn <...
Organic quaternary phosphonium salts are used in conjunction with chromium salen complexes the alternating copolymerization of CO2 and cyclohexene oxide (CHO) or propylene (PO). A highly efficient formation atactic polycarbonate narrow distribution molecular weights comparable superior to those obtained bis(triphenylphosphine)iminium (PPN+) can be achieved such as triphenyl(4-pyridinylmethyl)phosphonium chloride hydrochloride (UHFFA) tetraphenylphosphonium (TPPCl). For CHO-based copolymers,...
It is well known that the traditional synthetic polymers, such as Polyurethane foams, require raw materials are not fully sustainable and based on oil-feedstocks. For this reason, renewable resources biomass, polysaccharides proteins still recognized one of most promising approaches for substituting oil-based (mainly polyols). However, polyurethanes from sources exhibit poor physical functional performances. best technological solution production polyurethane obtained through a partial...
Abstract This work provides original insights to the better understanding of complex structure–activity relationship Zr IV –pyridylamido‐based olefin polymerization catalysts and highlights importance metal‐precursor choice (Zr(NMe 2 ) 4 vs. Zr(Bn) prepare precatalysts unambiguous identity. A temperature‐controlled reversible σ‐bond metathesis/protonolysis reaction is found take place on ‐amido complexes in 298–383 K temperature range, changing metal coordination sphere dramatically (from a...
The mechanical properties and the structural transformations occurring during deformation of some commercial grades ethylene/1-octene multiblock copolymers (OBCs) obtained from chain shuttling technology are analyzed. samples characterized by a statistical architecture, where soft amorphous blocks with high octene concentration (≈18.9 mol %) alternate hard crystalline low (≈0.5 %). length (BL) number blocks/chain (NB) change to according distribution. selected have molecular mass in range...
Aminolysis is widely recognized as a valuable chemical route for depolymerizing polymeric materials containing ester, amide, or urethane functional groups, including polyurethane foams. Bio-based foams, pristine and reinforced with 40 wt% of sustainable fillers, were depolymerized in the presence bio-derived butane-1,4-diamine, BDA. A process comparison was made using fossil-derived ethane-1,2-diamine, EDA, by varying amine/polyurethane ratio (F/A, 1:1 1:0.6). The obtained systems analyzed...
The copolymerization of ethylene and norbornene by catalytic systems composed i-Pr[(3-R−Cp)(Flu)]ZrCl2 (R = Me or Pri) methylaluminoxane was investigated. Isotactic, alternating ethylene−norbornene (E−N) copolymers with percentages pentads NENEN up to 21% incorporation 40% were obtained. NEENE sequences observed in synthesized both metallocenes. microstructural analysis 13C NMR such isotactic completely obtained at pentad level a methodology that exploits all the peak areas spectra accounts...
Abstract A new methodology for selective alkylation of the 2,6‐diiminopyridine (pdi) ligands allows ready synthesis derivatives displaying 2‐methyl‐2‐phenylpropyl (neophyl), benzyl, or allyl groups in 4‐position pyridine ring. set Fe and Co complexes containing have been synthesized fully characterized. The presence 4‐neophyl ‐benzyl does not perturb performance as ethylene polymerization catalysts, but introduction 4‐allyl group leads to production higher molecular weight polymers. (©...
A series of propene−norbornene (P−N) copolymers were synthesized in the presence rac-Et(indeny)2ZrCl2/MAO toluene at 30 °C. P−N characterized by 13C NMR spectroscopy, SEC, and DSC. Results compared with those a rac-Me2Si(Indenyl)2ZrCl2/MAO under same experimental conditions. Polymerization activity appears to be quite low comparison ethene−norbornene (E−N) copolymerization. first assignment main signals containing isolated N units was obtained on basis distortionless enhancement polarization...