Julia Pretula

Double‐Hydrophilic Block Copolymers with Monophosphate Ester Moieties as Crystal Growth Modifiers of CaCO3

The synthesis of double-hydrophilic block copolymers with a poly(ethylene glycol) block (PEG) and a block with pendant monophosphate ester groups based on a hydroxylated polybutadiene block (poly[2-(2- hydroxy ethyl)ethylene] (PHEE) with variable degrees of phosphate substitution (up to 40%) is described. It is shown that these block copolymers are very efficient scale inhibitors for CaCO 3 . The efficiency of these polymers is compared with block copolymers with an ionic block based on phosphorylated polyglycidol (PGL) with phosphorylation degrees up to 100%. The phosphorylated polyglycidols were also used to modify the morphology of CaCO 3 crystals. Instead of the typical rhombohedral calcite single crystals, superstructures of nanometer-sized particles are formed in the presence of these block copolymers when two different techniques were used: the fast double-jet technique and the slow Kitano-method. In the double-jet method, only spherical superstructures are obtained, whereas for the slower growth region covered by the Kitano method, complex cone-like or flower-like superstructures are formed.

Dihydrophilic block copolymers with ionic and nonionic blocks. I. Poly(ethylene oxide)-b-polyglycidol with OP(O)(OH)2, COOH, or SO3H functions: Synthesis and influence for CaCO3 crystallization

Dihydrophilic block copolymers of poly(ethylene oxide)-b-polyglycidol were prepared and polyglycidol blocks converted into ionic blocks containing OP(O)(OH)2, COOH, or SO3H groups. Although phosphorylation of polyhydroxy compounds with POCl3 usually leads to insoluble products, phosphorylation of poly(ethylene oxide)-b-polyglycidol using a POCl3/OH ratio equal to 1/1 gave soluble products, predominantly monoester of phosphoric acid (after hydrolysis) (provided that the reaction was conducted in triethyl phosphate as solvent). All copolymers were characterized by 1H NMR, 13C NMR, and/or 31P NMR spectra for confirming their structure. The degree of substitution was determined from quantitative 13C NMR spectroscopy (inverted-gate decoupling-acquisition mode). Preliminary results indicate that from these three groups of block copolymers the phosphoric acid esters are the most effective ones at least in controlling the growth of CaCO3 crystals in aqueous solution.

Spectroscopic studies of polyaniline protonation with poly(alkylene phosphates)

Abstract Polyaniline doped with poly(alkylene phosphates) has been studied by Fourier transform infra-red, X-ray photoelectron and ultraviolet/visible spectroscopies. The protonation of the polymer was indicated by the appearance of infra-red modes characteristic of polyaniline salts and by the bands typical of polyphosphates at ca. 1000 cm−1. X-ray photoelectron spectra showed a decrease in the concentration of imine groups as well as the co-existence of ionized and unionized phosphates independent of the doping level. The influence of the protonation method on the obtained product was observed.

Ring‐opening polymerization processes involving activated monomer mechanism. Cationic polymerization of cyclic ethers containing hydroxyl groups.

Cationic polymerization of cyclic ethers containing hydroxyl groups as substituents is discussed in terms of contribution of Active Chain End (ACE) and Activated Monomer (AM) polymerization mechanisms.

Ionizable hydrogels of new type based on poly(ethylene glycol) phosphates

Abstract Partly charged poly(ethylene oxide) networks have been prepared by the cure reaction of multifunctional poly(ethylene glycol) phosphate precursors with the diglycidyl ether of triethylene glycol as a crosslinking agent. These new hydrogels display all the features of swelling behaviour characteristics of polyelectrolyte networks. The degree of volume swelling of the hydrogels varies from 16–95 (in distilled water) to 11–45 (in 0.1 M sodium chloride solution) and 7–20 ml/ml (in 0.52 M potassium sulfate as a Θ-solvent). Average chain length, ionic group content, and structure of gels are evaluated from the swelling data. The gelation point occurs at much higher crosslinking ratios and overall P-OH groups conversion than those predicted from the precursor functionality. The role of possible side reactions and some kinetic reasons for the ‘delayed’ gelation are discussed.

Hybrids of dihydrophylic ionic-nonionic block copolymers and CaCO3. Determination of the number of CaCO3 molecules attached to the ionic groups

Polymer mediated crystallization of CaCO3, in the presence of dihydrophilic ionic-nonionic block copolymer (DHBC), gave hybrid crystalline particles in the form of partially open empty spheres. The DHBC used were composed of a poly(ethylene oxide) block and a block of phosphorylated glycidol. The outer skin of the empty spheres (hybrid particles) is formed of a double layer of small spherical particles of diameter equal to 20 nm. NMR measurements enabled determination of the DHBC content in the hybrids. The calculations on this basis gave a number of macromolecules of DHBC attached to one small sphere (approx. equal to 50). Finally, it was estimated that every fourth CaCO3 molecule on the surface of the small sphere is attached to one phosphate unit of DHBC.

The MPEG monophosphate ester: synthesis and characterization.

Methods of preparation of the phosphoric ester of monomethyl ether of poly(ethylene glycol) (MPEG-P) from MPEG (M n = 550 and 2000) and phosphoric acid (P), or its derivatives — pyrophosphoric acid (PY), polyphosphoric acid (PP) and POCl3– are described and compared. MPEG-P was isolated in a pure state (no detectable impurities) and characterized.

Monolithic Photorefractive Molecular Glass with Electron-Transporting Fluorene Unit

Multifunctional succinates have been prepared as monolithic molecular photorefractive materials which contain an electron-transporting fluorene moiety and an electrooptically active (EO) chromophore. The synthesized succinates form amorphous glass at room temperature with the aid of a flexible diester spacer and butoxycarbonyl group attached to the fluorene unit. Long-wavelength absorption bands were observed in addition to the peaks from fluorene and the EO chromophore, which are due to the charge transfer interaction between electron-accepting fluorene and electron-donating aniline units. Compounds showed photorefractivity without the addition of a photosensitizer, a polymeric binder or a plasticizer, indicating that they are completely monolithic photorefractive materials. Succinate with a 4-dicyanovinylaniline chromophore showed excellent properties, i.e., 32% diffraction efficiency at 55 V/µm and 125 cm-1 coupling gain at 65 V/µm. The electron-transporting nature of space-charge field buildup was confirmed from the coupling direction.

Poly(Alkylene Phosphate)S Related to Nucleic and Teichoic Acids

Abstract Preparation, some properties and applications of the bioanalogous poly(alkylene phosphatels, obtained according to the methods elaborated in these authors laboratory, are reviewed. Ring-opening polymerization, polyaddition, and two-step polycondensation methods are effective in the synthesis of polymers with various moieties of nucleic and teichoic acids (NA and TA respectively). The major aim of the work is to find relatively simple methods, allowing high molecular weight polymers to be prepared. Thus, preparation of poly(glycerol phosphate), poly(trimethylgne phosphate) bearing NA bases, and other related polymers with M n > 104 are described.

Phosphorylation of Polyols with H3PO4: Towards Simple Synthesis of Poly(alkylene phosphate)s

Polycondensation of ethylene glycol and of glycerol with H 3 PO 4 elaborated recently is summarized. Surprisingly, this apparently simple reaction, leading to a new class of synthetic polymers, has not previously been studied. In both reactions, soluble oligomers are formed, in spite of H 3 PO 4 , the class A3 component, being used. Dealkylation prevents the formation of high molar mass products, while also influencing the stability of the triesters in the case of ethylene glycol condensation. Polycondensation does not proceed directly with H 3 PO 4 . Independent kinetic experiments reveal that in the rate-controlling step, pyrophosphoric acid is formed. In polycondensation of glycerol, five- and six-membered rings are present in the main chain, indicating that the A3/B3 system has been converted into the A2/B2 system (at least partially). Both polymers have been shown to be efficient modulators of the CaCO 3 crystallization.