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Search results for: emerytowany profesor Uniwersytetu
Łódzkiego. Zajmuje się kulturą i recepcją literatury romantycznej; poeta-
mi dwudziestolecia międzywojennego Krystyna Ratajska – prof. dr hab.
By combining poly(1,4-isoprene) (PI) with poly(ferrocenylmethyl methacrylate) (PFMMA) in a diblock copolymer structure by means of anionic polymerization we obtained narrowly dispersed PI-b-PFMMA copolymers with molecular weight ranging from 13000 to 62000 g/mol. The products were stable up to 228 °C, according to thermal gravimetry, which allowed us to further investigate their viscoelastic and X-ray...
We present the synthesis and characterization of poly(ethyl 2-(imidazol-1-yl)acrylate) (PEImA) using free radical polymerization in various solvents with and without acids as additive. In addition, PEImA was also prepared using anionic polymerization with KOtBu as initiator in DMF and in THF at different M:I ratios. The resulting polymers of moderate dispersity were characterized by 1H-NMR, solid...
A dumbbell-shaped polystyrene (PS) sample, where rings are attached on both ends of a linear chain, was anionically synthesized by a coupling reaction between highly-purified ring PS (R-30; Mw = 33.7 kg/mol) with two diphenylethylene (DPE) type vinyl groups and bifunctional living linear PS (L-80; Mw = 84.0 kg/mol). The crude coupling product obtained was confirmed to include a targeted dumbbell polymer...
Following our previous paper on the course of the formation of star-polymers from oligo(oxyethylene)alcoholates as arms precursors and diglycidyl ethers as core building units [1], the nature of polymer alcoholate groups formed in this process has been studied. Primary alcoholate groups reacting with diepoxide or epoxide function in polymer give initially predominantly secondary alcoholate groups...
Homogeneous polymer hybrid consisting of poly(β-alanine) and silica gel was synthesized by an in-situ anionic polymerization method. Acrylamide (AAm) as an organic monomer was introduced into a sol–gel reaction of tetramethoxysilane (TMOS). The polymerization of AAm was initiated by potassium tert-butoxide (t-BuOK), while sol–gel reaction of TMOS proceeded to generate a silica gel matrix. The obtained...
Following our earlier papers [1–7] on star formation from oligo(oxyethylene)alcoholates as arms precursors and diglycidyl ethers as core the course of reaction of monomethyl ethers of poly(ethylene glycol) (as alcoholate, MPEG-OӨ) and diglycidyl ether of neopentyl glycol (DGNG) has been studied. Epoxy groups (E) react not only with primary alcoholates (p-OӨ), from the starting MPEG, but also with...
We report in this paper an easy method for the synthesis of cylindrical polymer brushes with dendritic side chains through anionic reaction. The synthesis is accomplished by iteratively grafting a living block copolymer, polyisoprene-b-polystyrenyllithium (PI-b-PSLi), to the main chain and subsequently to the branches in a divergent way. PI segment is short and serves as a precursor for multifunctional...
Model diblock copolymers of poly(butadiene-1,3) and poly(dimethylsiloxane) (PB-b-PDMS) of different compositions were synthesized by the sequential anionic polymerization (high vacuum techniques) of butadiene 1,3 and hexamethyl(ciclotrisiloxane), (D3), monomers. The block copolymers were characterized by nuclear magnetic resonance ( 1 H− and 13 C NMR), size-exclusion chromatography...
A novel vinyl monomer, (S)-3-vinyl-2,2′-bis(methoxymethoxy)-1,1′-binaphthyl 2, was synthesized and underwent helix-sense-selective anionic polymerization to obtain helical polymers with an excess screw sense. The polymer ([α]36525 = −1610.0°) exhibited optical rotation as large as fourfold that of the monomer ([α]36525 = −356.0°). Poly-2 was confirmed to keep a prevailing helicity of backbone in solution...
Rational design and successful synthesis of a novel double side-chain liquid crystalline (SCLC) diblock copolymer bearing a common flexible polyether backbone were achieved via sequential anionic polymerization. The distinct differences in transition temperatures as well as phase ranges of the constituting blocks counterparts merited the full exploration of complex phase structures of the diblock...
Side-chain liquid crystalline (SCLC) polyethers with different spacers are successfully synthesized via anionic polymerization for the first time. The molecular weights of the polymers can range up to ∼53 kg/mol with M w /M n <1.1. The precise chemical structures including end groups have been characterized by employing Matrix-Assisted Laser Desorption/Ionization-Time of Flight...
Methacrylic anhydride was anionically polymerized for the first time by a lithium ester enolate with the aid of the bulky aluminum bisphenoxides in dichloromethane at −78 °C to afford polymers consisting of six-membered cyclized units as confirmed by NMR and IR spectroscopy, while a less bulky trialkylaluminum was ineffective. At higher temperatures, no polymeric product formed partly due to the carbonyl...
The sulfinyl precursor route for the synthesis of poly(p-phenylene vinylene) (PPV) materials via an anionic polymerization procedure employing dedicated initiators is evaluated in depth. Reaction kinetics are investigated to gain more control over the polymerization, since polymerization proceeds to full conversion already on the timescale of mixing of the reaction components. Even at −78 °C almost...
The polymerization of N-isopropylacrylamide (NIPAAm) with dilithium tetra-tert-butylzincate (TBZL) has been investigated in toluene at low temperatures in the presence of alkyl and fluorinated alcohols. Of the alcohols examined, 1,1,1,3,3,3-hexafluoro-2-propanol induced isotactic specificity and accelerated the polymerization process, affording the corresponding poly(NIPAAm)s with meso (m) diad contents...
Polyisoprenes (PI) and polybutadienes (PB) both having vinyl-type side chains preferentially were prepared and characterized. Both polymers were anionically polymerized with cumyl potassium or pottassium naphthalenide as initiators in a polar solvent, tetrahydrofuran, at low temperature. From the 1 H NMR measurement, the PI contains 3,4- and 1,2-microstructures and PB does 1,2-microstructure...
A novel type of clickable polymers with a very high local density of allyl side groups was developed. These polymers were obtained by the anionic ring-opening (co)polymerization of diallyl cyclopropane-1,1-dicarboxylate using as an initiating system a protic precursor whose acid–base reaction with the t-BuP 4 phosphazene base generated the initiator in situ. The obtained polymers display geminated...
Isotactic rich polystyrene was synthesized at 30 °C by the t-BuLi initiated polymerization in the presence of sodium dodecylbenzenesulfonate (SDBS) in hexane or cyclohexane. The polymerization rates at 30 °C were very fast and typically gave quantitative conversions. At SDBS/t-BuLi molar ratios between 0.5 and 1.0, the unfractionated polystyrene had almost the same stereoregularity, with triad and...
The semibatch anionic ring-opening polymerization of octamethylcyclotetrasiloxane in emulsion was studied under the condition of no seed particles used in polymerization system. Concentration of emulsifier was set above critical micelle concentration. Effect of monomer feed rate on the chemical kinetics, average particle size and distribution and on the polymer molar mass and distribution was investigated...
Batch anionic ring-opening polymerization of octamethylcyclotetrasiloxane in emulsion using nonionic and cationic emulsifiers was studied. The concentration of emulsifiers was set above their critical micelle concentration. Effects of emulsifier concentration, nonionic/cationic emulsifier ratio and cationic emulsifier/initiator (KOH) ratio on the kinetics, average particle size and distribution and...
The anionic polymerization of ethylene oxide (EO) initiated by lithium derivatives is extremely sluggish and only yields very low molar mass EO oligomers because of the low reactivity of lithium alkoxide species. We show here that using the monomer-activated anionic polymerization approach, one can activate the C–O–Li bonds towards EO polymerization at low temperature and in non polar media. Starting...
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