Study on preparation and properties of novel functionalized polyester copolymers based on siloxanes

Novel functionalized macroporous copolymers were synthesized by reaction of the pendant epoxy groups of poly(glycidyl methacrylate)-co-poly(ethylene glycol dimethacrylate)s with 1,3-bis(3-aminopropyl)tetramethyldisiloxane (TMDS) and α,ω-diamino propyl poly(dimethylsiloxane) (PDMS). It was found that the optimal conditions for the synthesis of functionalized copolymers were: reaction temperature of 80 o C, reaction time of 10 h and a mixture of N-methyl-2-pyrrolidone/toluene (1/3 v/v) as the solvent. The effects of the type of siloxanes and concentration of glycidyl methacrylate on the structure and properties of functionalized copolymers were investigated by solid-state 13C and 29Si NMR spectroscopy, FTIR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The structure of functionalized copolymers was confirmed by solid-state NMR and FTIR spectroscopy. The DSC results showed that the glass transition temperatures of copolymers were in the range from 63 to 65 o C and they slightly depend on the copolymer composition exclusively. The thermal stability was better for copolymers functionalized with TMDS in comparison with PDMS based copolymers. Thermal degradation of the synthesized copolymers starts between 276 and 290 o C. The TG curves of all copolymers display two stages of degradation at 308-368 o C (stage 1) and 395-430 o C (stage 2) which are associated with the ester and siloxane bonds. The results indicated that the thermal stability depends on the type of siloxanes and copolymer composition. The surface and crosssection morphology was investigated by SEM and the porous copolymer beads were confirmed by SEM analysis. SEM studies with energy dispersive X-ray mapping revealed that siloxanes migrate to the surface of samples due to their low surface energy. By varying the structure of siloxanes and copolymer composition, functionalized copolymers can be designed and synthesized with diverse physical properties for different purposes

Structural, thermal and morphological characterization of functionalized macroporous copolymers

Macroporous copolymers of glycidyl methacrylate and ethylene glycol di-methacrylate were functionalized with hexamethylene diamine, 1,3-bis (3-aminopropyl) tetramethyldisiloxane and α,ω-diamino propyl poly(dimethylsiloxane). The samples were characterized by Fourier transform infrared spectroscopy (ATR-FTIR), mercury porosimetry, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Fuctionalization significantly alters porosity parameters, mechanism of thermal degradation and increases thermal stability. The sample functionalized with disiloxane exhibited better thermal stability comparing with the initial and other functionalized samples.[http://savremenimaterijali.info/sajt/doc/file/SM2013/SM2013_KNJIGA_APSTRAKATA.pdf

Analysis of hexavalent chromium sorption on macroporous copolymer grafted with hexamethylene diamine

In this study, macroporous glycidyl methacrylate based copolymers with different crosslinking degree and porosity parameters, functionalized with hexamethylene diamine were tested for Cr(VI) sorption.[http://savremenimaterijali.info/sajt/doc/file/SM2013/SM2013_KNJIGA_APSTRAKATA.pdf

Impact of the TiO2 nanoparticles on the properties of urethane-siloxane copolymers

Rutile/anatase TiO2 was incorporated in different amounts (1, 2, 3 and 5 wt.%) in relative to the polyurethane-siloxane (PUS) matrix in order to investigate the influence of nano-fillers on the hydrophobicity, thermal properties and morphology of the PUS. A series of PUS nanocomposites (PUSN) based on α,ω-dixydroxy-ethoxypropyl-poly(dimethylsiloxane) (EO-PDMS) as the soft segment (SS) and 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD) as the hard segment (HS), was prepared via two-step polyaddition reaction in solvent mixture. Prepared PUSNs were characterized using FTIR spectroscopy, thermogravimetric analysis, water absorption, water contact angle and AFM analysis. In summary, the synthesized PUSNs and especially PUSN with 2 wt.% of TiO2 had better water resistivity and nonwettability, higher thermal stability, and more pronounced surface morphology that can be potentially used as protective coatings

Recovery of molybdenum oxyanions using macroporous copolymer grafted with diethylenetriamine

The presented study describes macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [PGME] functionalized with diethylenetriamine [PGME-deta] as a potential recovery agent for Mo(VI) oxyanions from aqueous solutions. Sorption studies were carried out by varying experimental conditions (pH, time, concentration, temperature). Kinetics of Mo(VI) sorption was investigated in batch (static) experiments, in the temperature range 298-343K. Sorption dynamics data were fitted to seven chemical-reaction and particle-diffusion models. The kinetics studies showed that Mo(VI) sorption adhered to the pseudo-second-order model under all investigated operating conditions. The sorption kinetics was determined to be governed by both the intraparticle diffusion and the external film diffusion to a lesser extent. The temperature rise promotes the molybdate species removal, with the maximum experimental uptake capacity of 4.02mmolg- 1 at 298K, at the selected pH which is consistent with the predominance range of hydrolized polynuclear Mo(VI) forms and optimum electrostatic attraction

Kinetics study of molybdenum sorption on amino-functionalized copolymer

Macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [PGME-deta] functionalized with diethylene triamine was used for removal of Mo(VI) oxyanions from aqueous solutions. Kinetics of Mo(VI) sorption was investigated in batch experiments by varying initial Mo(VI) concentration. Sorption kinetics data was fitted to chemical-reaction and particle-diffusion models. It was shown that Mo(VI) sorption adhered to the pseudo-second-order kinetic model, with a definite influence of pore diffusion. The maximum Mo(VI) sorption capacity at pH 2.0 and 298K was 391 mg g-1

A novel Tc 99m sorbent based on macroporous magnetic polymer

A novel magnetic macroporous poly(glycidyl-co-ethylene glycol dimethacrylate) (mPGME) synthesized by suspension copolymerization and functionalized with diethylene triamine (mPGME-deta) was evaluated as sorbent for pertechnetate ion (TcO4 - ) removal from aqueous solutions. Atomic force microscopy (AFM) was used for characterization. The kinetics of TcO4 - adsorption onto mPGME-deta is relatively fast and depends on pH.Physical chemistry 2016 : 13th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-30 September 201

Intraparticle diffusion and adsorption of heavy metals onto porous polymer

Intraparticle diffusion kinetic model (IPD) was used to elucidate the influence of macroporous glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) copolymer (PGME) with attached diethylene triamine (PGME-deta) on the competitive Cu(II), Cd(II), Co(II) and Ni(II) ions sorption from aqueous solutions. Surface sorption was examined by SEM-EDS analysis.Physical chemistry 2016 : 13th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-30 September 201

Polyethersulfone membranes with integrated adsorbent particles for heavy metals capture

Novel polyethersulfone membranes with integrated submicron adsorbent particles were prepared by combining photoirradiation with liquid phase inversion. These particles consist of cross-linked poly(glycidyl methacrylate-co-acrylamido-2-methylpropane sulfonic acid), pGMA AMPS. After membrane preparation, the epoxide groups were reacted with diethylene triamine to incorporate amine functionalities. Membranes were characterized using FTIR-ATR, SEM and dynamic adsorption of copper from a dilute solution. Effects of monomer concentrations on the properties and separation performance of membrane adsorbers are presented

Kinetičko modelovanje sorpcije teških metala kopolimerom sa osnovom vinil piridina

Commercial macroporous poly(4-vinylpyridine-co-divinylbenzene) [P4VPD], known as Reillex-425, was characterized by mercury porosimetry, nitrogen physisorption, Fourier transformed infrared (FTIR) spectroscopy and elemental analysis. Sorption rates of P4VPD for Cu(II), Co(II) and Cr(VI) ions were determined in static non-competitive experiments, at room temperature (298 K). Rapid sorption was observed, especially for Co(II), with half time, t1/2, of 1.5 min and high experimental maximal capacity, Qmax, of 3.08 mmol g-1. Four kinetic models (pseudo-first and pseudo-second order model, intraparticle diffusion and Boyd model) were used for analyzing metal sorption by P4VPD. Metal ions sorption is well represented by the pseudo-second-order model, with definite influence of pore and film diffusion on sorption rates.Komercijalni makropozni poli(4-vinilpiridin-co-divinilbenzen) [P4VPD], Reillex- 425, bez dodatne funkcionalizacije korišćen je za ispitivanje mogućnosti sorpcije teških metala iz vodenih rastvora. Na taj način su izbegnuti neki problemi do kojih može doći prilikom uvođenja funkcionalnih grupa selektivnih za određene jone metala u polimerne sorbente, kao što su nepoželjne sporedne reakcije i promena porozne strukture. P4VPD je okarakterisan živinom porozimetrijom, određivanjem adsorpciono-desorpcionih niskotemperaturnih izotermi azota, infracrvenom spektroskopijom (FTIR) i elementalnom analizom. U statičkim eksperimentima su određene brzine sorpcije Cu(II), Co(II) i Cr(VI) jona pomoću P4VPD pri nekompetitivnim uslovima i pri sobnoj temperaturi (298 K). Zapažena je brza sorpcija ispitivanih jona, naročito u slučaju Co(II), pri čemu su zapažene vrednosti poluvremena sorpcije, t1/2, od 1,5 min i visoka vrednost maksimalnog kapaciteta sorpcije, Qmax, od 3,08 mmol g-1 (181 mg g-1). Prilikom analiziranja sorpcije ispitivanih metala pomoću P4VPD korišćena su četiri kinetička modela (model pseudo-prvog i pseudo-drugog reda, model difuzije unutar čestica i Bojdov model). Pokazalo se da sorpciju jona metala najbolje opisuje model pseudo-drugog reda, pošto je za ovaj model dobijeno odlično slaganje eksperimentalnih i teorijskih vrednosti kapaciteta sorpcije, kao i vrednosti R2 ≥ 0,99. Analiza eksperimentalnih rezultata pomoću modela difuzije unutar čestica pokazala je da difuzija kroz pore nije jedini stupanj koji određuje brzinu sorpcije i ukazala na delimičan uticaj graničnog sloja na sorpciju teških metala pomoću poroznog kopolimera