Lavinia Macarie

Synthesis of new phosphorus-containing (co)polyesters using solid-liquid phase transfer catalysis and product characterization.

This paper is directed towards the development of safe, and thermally stable solid polymer electrolytes. Linear phosphorus-containing (co)polyesters are described, including their synthesis, thermal analysis, conductivity, and non-flammability. Polycondensation of phenylphosphonic dichloride (PPD) with poly(ethylene glycol) (PEG 12000) with and without bisphenol A (BA) was carried out using solid-liquid phase transfer catalysis. Potassium phosphate is used as base. Yields in the range of 85.0–88.0%, and inherent viscosities in the range of 0.32–0.58 dL/g were obtained. The polymers were characterized by gel permeation chromatography, FT-IR, 1H- and 31P-NMR spectroscopy and thermal analysis. Their flammability was investigated by measuring limiting oxygen index values. The polymers are flame retardants and begin to lose weight in the 190 °C–231 °C range. Solid phosphorus- containing (co)polyesters were complexed with lithium triflate and the resulting ionic conductivity was determined. Conductivities in the range of 10−7–10−8 S cm−1 were obtained.

Polymers containing phosphorus groups and polyethers: from synthesis to application

BackgroundPhosphorus-containing high performance polymers have aroused wide interest, mainly due to good mechanical properties and their excellent fire resistance. The flexibility of synthetic polyphosphoesters allows the development of polymers in order to obtain solid polymer electrolytes for rechargeable lithium batteries based on solid films with superior fire resistance.ResultsNovel linear Phosphonate-PEG polymers were synthesized by solution polycondensation of 4-chlorophenyldichlorophosphonate as a linking agent and poly(ethylene glycol)s with different molecular weights in the presence of triethylamine or 1-methylimidazole as acid scavenger. The yields were between 54% and 88% and inherent viscosity between 0.18-0.48 dl/g. Molar masses, Mn were about 26300 g/mol for polyphosphonates with PEG 2000 and 4600 g/mol for polyphosphonates with PEG 200. The LOI values for these polymers and membranes are in the range of 26–29. The membranes based on polyphosphonate with PEG 200 and 2000 showed conductivity between 6 × 10-8 S.cm-1 and 6 × 10-7 S.cm-1 at room temperature and total ionic transference number between 0.87- 0.96. The evolution of conductivity vs. temperature is linear.Conclusions1-methylimidazole was found to be better HCl scavenger than triethylamine, and allowed higher yields and more eco-friendly synthesis of the Phosphonate-PEG polymers for SPE. These polymers and membranes based on these polymers showed good LOI values and indicate an improvement of the safety of lithium batteries. The membranes present conductivities around 6 × 10-7 S.cm-1at room temperature and total ionic transference number is higher for membranes based on polymers with high EG unit content. Best results yield 88%, inherent viscosities 0.48 dl/g and Mn 26000 were obtained with 1-methylimidazole and PEG 2000. These membranes based on these polymers showed good LOI values (in the range 26-29%) and indicate an improvement of the safety of lithium batteries.

Phase Transfer Catalysis in Phosphorus Chemistry

Phase-transfer catalysis (PTC) has been widely used for the synthesis of organic compounds for more than three decades. The scope and mechanistic features of PTC have been the aim of numerous studies. This review focuses on the application of phase transfer catalysis in synthesis of phosphorus compounds.

The influence of temperature and photoinitiator concentration on photoinitiated polymerization of diacrylate monomer

The behavior of p-methoxybenzoyldiphenylphosphine oxide, previously synthesized, as a photoinitiator for the polymerization of diacrylate monomer, in the presence of 3% (w/w) tertiary amine (triethyl amine) as synergist additive, was studied. The influence of temperature in the range 30–90°C at 3% (w/w) photoinitiator concentration and the influence of the photoinitiator concentration in the range 0.5–3.5% (w/w) at 30°C was investigated by differential scanning photocalorimetry (photo-DSC). In all experiments the photopolymerization was performed at constant light intensity (3 mW cm−2). The maximum conversion was obtained at temperature of 90°C at 3% (w/w) photoinitiator concentration and 3% (w/w) triethyl amine. The optimal concentration of photoinitiator to obtain maximum conversion was 3% (w/w), at 30°C. No thermal polymerization occurred at higher temperature.

Phosphorus Compounds as Photoinitiators for Radicalic Polymerization

p-Methoxybenzoyldialkylphosphonates, where alkyl = methyl, ethyl andp-methoxy-benzoyldiphenylphosphine oxide were synthesized by Michaelis-Arbuzov reaction. These compounds were used as photoinitiators for radicalic polymerization of acrylic monomers. The photoreactivity parameters were determined by differential photocalorimetry(DPC), in isothermal conditions, using 1,6-hexandioldiacrylate(HDDA)as monomer, in the presence and absence of amine. The influence of concentration on film pendulum hardness was studied.

Polyaniline composite designed for solid polymer electrolyte

Abstract Improved ionic conductivity of solid polymer electrolytes (SPE) was achieved by adding polyaniline (PANI) in membrane formulation. SPE composite membranes contain: tris(4-hidroxybutylacrylate)-phosphate, polyphosphoester, lithium salts and small amount of PANI. The conductivity of membranes increases with PANI content and above a certain amount it decreases. The variation of the conductivity vs temperature is linear, characteristic for a thermally activated process. The activation energy for polymer matrix without PANI is 0.30 eV and 0.26 eV for polymer matrix with PANI. Conductivity enhancement in the composite polymer matrix is caused by the presence of PANI due to the increase in the concentration of free ions. PANI decreases the salt aggregation and as a consequence, the concentration of free ions was increased by improving dispersion of the lithium salt in membranes.

Chemical Modification of Functionalized Copolymers with Phosphonium Groups by Phase Transfer Catalysed Wittig Reactions

The interest for using polymers in Wittig reactions increased in the last years, because of their major advantages. Phase transfer catalyzed reactions are often more easily and cheaply carried out than conventional methods and they are therefore of particular interest. The phosphonium salts grafted on styrene-7%(5%)divinylbenzene copolymers used in this paper were obtained by quaternization polymer-analogous reaction. The degree of functionalization with quaternary phosphonium groups are relatively high, ranging from 1.84 to 1.98 mmoles/g of polymer. These grafted copolymers were used in liquid-liquid-solid Phase Transfer Catalysis(PTC)Wittig reaction. The yields were ranging from 1.84 to 1.98 mmoles of double bonds/gram of polymer.

Synthesis of Polyphosphates Related to Biopolymers

Polyphosphates were synthesized by base promoted liquid-vapor polycondensation of cyclohexylphosphoric dichloride with bisphenol A. The effects of temperature, reaction time, base concentration and molar ratio of reagents on yield, inherent viscosity and molecular weight of the obtained polymer were studied. A second order, central composite, rotatable experimental design was used to find domain experimental field for optimal yields and high inherent viscosities.

Interfacial polycondensation method used in the synthesis of polymers containing phosphorus in the main chain

Abstract Polyphosphoesters gained importance especially due to their use as flame retardants and as biocompatible and biodegradable materials for medicine and in the pharmaceutical industry. This paper presents the results obtained by our research group in the synthesis of polyphosphoesters by interfacial polycondensation. This reaction is rapid and irreversible polymerization at the interface between a phase containing one difunctional intermediate and another phase containing a complementary difunctional reactant. Different methods like liquid–liquid, vapor–liquid or solid<uni-2013;liquid were used in the synthesis of polyphosphates of polyphosphonates using aliphatic/aromatic phosphoric/phosphonic dichlorides and different diols. Aqueous NaOH, or tripotasium phosphate were used as bases. In almost all cases a catalyst is not needed.

Synthesis of Phosphorus Containing Polymers by Phase Transfer Catalysis (PTC). II. Experimental Design for Polycondensation in Liquid-Vapor System

Abstract The simultaneous influence of four factors [reaction time (I), temperature (T), base concentration (c). molar ratio of the reagents (r)] on the yield (q) and on the inherent viscosity (qIv) of the product has been studied for the liquid-vapor system pol ycondensation of cyclohexyldichlorophosphonate (CDP) with bisphenol A (BA) by second order central composite circumscribed design. For a reasonable domain of the parameters [t = 30 ÷ 70 min., T = 20 ÷ 60 °C, c = 1 ÷ 5 mol/l, r = 1 ÷ 3.5 mol(CDP)/mol(BA)], designing the experiments, the η and ηiv values where determined in 31 synthesis (7 center points were used). In order to model the response (hyper)surfaces for η and ηiv, second order equations with interaction terms were used. Analyzing these model equations, T and c appear to be the most important factors, but acting in opposite way. Higher T resulted in greater yield and inherent viscosity. In the above defined domain the hypersurface of η presents a saddle point. From the sequential inspecti...