Reactive and Functional Polymers (v.73, #3)

Multiarm star with poly(ethyleneimine) core and poly(ε-caprolactone) arms as modifiers of diglycidylether of bisphenol A thermosets cured by 1-methylimidazole by Cristina Acebo; Xavier Fernández-Francos; Francesc Ferrando; Àngels Serra; Josep M. Salla; Xavier Ramis (431-441).
Well-defined multiarm star copolymers, with hyperbranched poly(ethyleneimine) (PEI) as the core and poly(ε-caprolactone) (PCL) arms with different degree of polymerization were synthesized by cationic ring-opening polymerization of ε-caprolactone from a hyperbranched poly(ethyleneimine) core and used to modify diglycidylether of bisphenol A formulations cured with 1-methylimidazole as anionic initiator. The curing process was studied by dynamic scanning calorimetry (DSC) and FTIR. By rheometry the complex viscosity of the multiarm stars synthesized and the influence of their addition to the reactive mixture was analyzed in detail. The resulting materials were characterized by thermal and mechanical tests. The addition of the multiarm star to the formulation led to homogeneous materials with a slightly toughened fracture in comparison to neat DGEBA thermosets without compromising thermal characteristics.
Keywords: Star polymers; Hyperbranched; Epoxy resin; Anionic polymerization; Thermosets;

Ethidium bromide binding to DNA cryogels by Pinar Karacan; Oguz Okay (442-450).
The interaction of the classical intercalator ethidium bromide (EtBr) with the double helical network strands of DNA cryogels was investigated. The cryogels were prepared starting from aqueous solutions of DNA (about 2000 base pairs long) at −18 °C using 1,4-butanediol diglycidyl ether crosslinker under various reaction conditions. In contrast to the solubilization of DNA hydrogels in aqueous EtBr solutions, DNA cryogels remain stable even after complete saturation of their EtBr binding sites. The total binding capacity of the cryogels is 0.6 ± 0.1 EtBr per nucleotide, which is close to the theoretical maximum number of EtBr molecules that can bind to DNA. Even in very dilute solutions (down to 3 μM), cryogels remove EtBr from aqueous solutions with an efficiency of 90%. The equilibrium binding constant and the maximum number of EtBr binding sites of the cryogels almost coincide with the reported values for the secondary binding process of EtBr by DNA in aqueous solutions. At low mole ratios of bound EtBr to DNA, the cryogels swell with increasing amount of bound EtBr, most likely caused by the lengthening of DNA due to the intercalated EtBr. The response of DNA cryogels to changes in EtBr concentration between 3 and 300 μM also suggests that they can be used to detect DNA binding substrates in aqueous solutions.
Keywords: DNA; Cryogels; Ethidium bromide; Binding; Swelling;

Fluorescence resonance energy transfer between polydiacetylene vesicles and embedded benzoxazole molecules for pH sensing by Seongwon Seo; Daigeun Kim; Geunseok Jang; Dong-Myung Kim; Dong Wook Kim; Bum-Kyoung Seo; Kune-Woo Lee; Taek Seung Lee (451-456).
A mixed polydiacetylenes (PDAs) vesicle with a phospholipid unit is functionalized by entrapping fluorescent benzoxazole (BZ) molecules inside the PDA vesicles. Upon photo-polymerization and heat-treatment of the self-assembled vesicles, a weak red fluorescence can be observed. Excitation of BZ molecules enables the amplification of PDA vesicle fluorescence resonance energy transfer (FRET) to more than four times that of the direct excitation of red-phase PDA vesicles. The backbone of the PDA vesicles act as energy acceptors, which absorb energy from embedded BZ donor molecules inside the PDA vesicle, which emit blue fluorescence. The amplified red emission from the PDA vesicle can be altered by pH changes in the aqueous solution and thus the PDA vesicle mixed with a phospholipid and entrapped molecules inside can be a promising candidate as a pH sensor.
Keywords: Polydiacetylene; FRET; Fluorescence; Encapsulation; pH sensor;

Efficient organic solvent and oil sorbent co-polyesters: Poly-9-octadecenylacrylate/methacrylate with 1-hexene by Priyanka Dutta; Bedanta Gogoi; Narendra Nath Dass; Neelotpal Sen Sarma (457-464).
In this work, highly absorbent cross linked co-polymer gels of cis-9-octadecen-1-ol with acrylic/methacrylic acid and 1-hexene in different molar ratios were synthesized by thermal polymerization techniques and studied. The polymers were characterized by Fourier Transform-Infrared Spectroscopy, Thermogravimetric analysis and Scanning Electron Microscopy techniques. Their non-ionic nature was verified with the help of transport number measurement by Wagner polarization technique. The polymers were found to have very high swelling capacities in organic solvents like chloroform, tetrahydrofuran, ethanol, diethylether, thiophene, pyridine, and benzene. These gels show maximum swelling for chloroform which reaches up to 750%. The swelling capacities for different oils like kerosene, gasoline, engine oil, and silicon oil, are also favorable. The swelling kinetics confirmed that the swelling followed second order kinetics. The chloroform retention time was also checked which established that the gels can be recycled and reused again and again. An experiment showing removal of kerosene from kerosene/water mixture is also performed. This confirms that these gels can be used in removing organic contaminants and oil from water and can help in water purification and environmental cleanup purposes.
Keywords: Swelling; Water purification; Cis-9-octadecen-1-ol; Retention time; Swelling kinetics;

Synthesis and characterization of cross-linked polymeric nanoparticles and their composites for reinforcement of photocurable dental resin by Melinda Szaloki; Jozsef Gall; Katalin Bukovinszki; Janos Borbely; Csaba Hegedus (465-473).
Reactive polymeric nanoparticles were formed for reinforcement of photocurable dental resin. Cross-linked polymeric nanoparticles were synthesized by emulsion polymerization of mono- (methyl methacrylate; MMA) and trifunctional (trimethylol propane trimethacrylate; TMPTMA) monomers. The nanoparticles were dispersed in bisphenol A glycol dimethacrylate (Bis-GMA) based dental resin matrix in the range of 5–25 wt% to form photocurable nanocomposites.The effect of reactive polymeric particles on the mechanical properties of photocurable dental resin was investigated. Polymerization shrinkage, polymerization shrinkage stress, viscosity, diametral tensile strength, compressive, and flexural strength of the nanocomposites have been studied.It was observed that the cross-linked nanoparticles significantly influenced the mechanical properties of the reinforced dental resin nanocomposites.
Keywords: Photopolymerization; Reinforced resin; Mechanical properties; Cross-linked prepolymers;

Ion imprinted polymers for the selective extraction of silver(I) ions in aqueous media: Kinetic modeling and isotherm studies by MEH Ahamed; X.Y. Mbianda; A.F. Mulaba-Bafubiandi; Ljiljana Marjanovic (474-483).
Ion imprinted polymers (IIPs) for selective extraction of Ag(I) ions from aqueous solution were synthesized by a precipitation polymerization method using two functional monomers, 4-vinyl pyridine (4-VP) and 1-vinyl imidazole (1-VID), and N,N-ethylene bisacrylamide (EBAm) as the cross linker. Batch adsorption experiments were carried out as a function of Ag(I) imprinted polymer amount, agitation time, pH and initial Ag(I) concentration. The kinetic studies indicated that pseudo-second-order kinetic model best describes the adsorption behavior, while the adsorption data correlated well with the Langmuir isotherm. Furthermore the selectivity studies revealed that the ion imprinted polymers had a higher absorption capacity and a higher selectivity, for the Ag(I) ions, than the control polymers.
Keywords: Ion imprinting polymer; Selective extraction; Kinetic modeling and isotherm; Silver(I) ions;

Inverse dependencies on the polymerization rate in atom transfer radical polymerization of N-isopropylacrylamide in aqueous medium by M. Vachaudez; D.R. D’hooge; M. Socka; J. Libiszowski; O. Coulembier; M.-F. Reyniers; A. Duda; G.B. Marin; Ph. Dubois (484-491).
The controlled and fast atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAm) initiated by ethyl 2-chloropropionate (ECP) and catalyzed by copper chloride ligated with tris(2-dimethylaminoethyl)amine (CuCl·Me6TREN) is reported in water:DMF (1:1 volume based) for a broad range of polymerization conditions (targeted polymerization degree: 50–188; [NIPAm]0  = 0.5–2 M; T: 10–30 °C). For temperatures below 30 °C, a faster ATRP is obtained with decreasing temperature, which is explained by the exothermic formation of a pre-reactive complex during propagation. For sufficiently high initial deactivator concentrations (⩾20 mol%) a faster ATRP also results, which is proposed to be caused by Lewis acid–base interactions between the Cu(II) species and NIPAm. The kinetic study indicates a limited importance of cyclization reactions implying a limited loss of end-group fidelity. Moreover, for an initial NIPAm concentration of 2 M, catalyst disproportionation can be sufficiently suppressed.
Keywords: Poly(N-isopropylacrylamide); Aqueous ATRP; Kinetic study; Dilatometry; Diffusional limitations;

In this article, synthesis and characterization of triazole-based polyimides for solid-phase extraction of metal cations is described. For this purpose, new aromatic diamines containing 1,2,4-triazole and substituted 1,2-diaryl quinoxaline units were synthesized and used in polycondensation reaction with aromatic dianhydrates to yield poly(triazole-imide)s (PTAI)s. These polymers had inherent viscosities in the range of 0.58–0.62 dL/g and were readily soluble in a variety of organic solvents; they formed low-colored and tough thin films via solution casting. The PTAIs exhibited T g between 280 and 338 °C, and their 10% weight loss temperatures were in excess of 540 °C with up to 76% char yield at 700 °C in N2. These polymers emitted green or blue fluorescence in dilute NMP solution and in the solid state. The triazole groups in the polymer chain were efficient chelating/host units for heavy metal ions. One of these polymers, PTAI(1b), was investigated for its extraction capability for environmentally deleterious metal ions such as CrVI, CrIII, CoII, ZnII, PbII, CdII, HgII and MnII from aqueous solutions either individually or in the mixture and at different pH values.
Keywords: Triazole-based polymers; Solid-phase extraction; Metal ions; Thermal properties; Fluorescent;

Cell adhesion on surface patterns generated by the photocrosslinking of hyperbranched polyesters with a trisdiazonium salt by Miguel Lomba; Luis Oriol; Carlos Sánchez-Somolinos; Valeria Grazú; María Moros; José Luis Serrano; Jesús Martínez De la Fuente (499-507).
Aliphatic hyperbranched polyesters of different generation, having different nucleophilic groups (such as hydroxyl or sulfonate) in the periphery, have been photocrosslinked by using a trifunctional low molecular weight diazonium salt. The photocrosslinking process, that does not require photoinitiator, allows to prepare polymeric materials that have shown not to cause cytotoxicity when used as substrate for cell growth. Furthermore, cell adhesion studies carried out in polymeric micropatterns generated in glass by direct laser writing, show that cells preferentially proliferate on the structure demonstrating cell affinity for the material.
Keywords: Polyester; Hyperbranched polymer; Micropatterning; Photopolymerization; Cell adhesion; Diazonium salt;

We report novel thermosensitive supramolecular hydrogels with tunable crosslinking networks by using polypseudo-rotaxanes (PPRs) as macroinitiators in atom transfer radical polymerization and polyethylene glycol diacrylate (PEGDA) as bridge units. The PPRs were prepared by supramolecular self-assembly of α-cyclodextrin or 2-bromoisobutyryl bromide modified α-cyclodextrin (α-CD-BIBB) and triblock copolymer of F127 with bromopropionyl bromide terminals. The supramolecular hydrogels possess the crystal structure of inclusion complexes (ICs) and thermo-sensitive properties. The addition of mono-functional 2-hydroxyethyl methacrylate (HEMA) can enhance gelation. The swelling ratio (SR) was mainly influenced by the concentration of α-CD or modified α-CD, HEMA and PEGDA. The introduction of α-CDs was found to decrease the SR of hydrogels, while the introduction of α-CD-BIBBs could improve the SR. Meanwhile, gelation was tuned by regulating the concentration of HEMA. The SR of hydrogels was increased with the increase of the concentration of PEGDA, but decreased with the increase of that of HEMA. In the temperature range from 20 to 50 °C, the temperature sensitivity of hydrogels was mainly controlled by the state of gels. The introduction of PHEMA chains decreased the temperature responsivity of networks. The hydrogels prepared with α-CD-BIBBs threading onto the F127 chains showed the high thermo-sensitivity. The thermosensitive mechanism of hydrogels is due to the aggregation of PPO blocks in the networks.
Keywords: Supramolecular hydrogel; Polypseudorotaxane; Triblock copolymer; Atom transfer radical polymerization; Self-assembly;

O-Acyloximes are a class of photobase generators (PBGs) that release a primary amine upon irradiation. The generated amine can be used as a crosslinker for polymers bearing epoxy groups, providing a novel photo-induced crosslinking system. However, O-acyloximes also release a ketone by-product that migrates and exudes from the crosslinked polymer. To reduce the migration and elimination of the ketone, 4-vinylacetophenone O-phenylacetyloxime (PaVO) was proposed as a monomeric PBG, and its copolymer with glycidyl methacrylate (PaVO-co-GMA) was compared to poly(glycidyl methacrylate) (PGMA) containing acetophenone O- phenylacetyloxime (PaApO) as a molecular PBG (PaApO/PGMA). Film thickness, infrared (IR), and ultraviolet (UV) spectral changes upon irradiation clarified the vaporization of photoproducts from the PaApO/PGMA films, while such behavior was not observed for the PaVO-co-GMA films. Furthermore, when PaVO-co-GMA was blended with PGMA, less irradiation energy was required for its crosslinking when compared to that of PaApO/PGMA, which contained the same molar ratio of the O-acyloxime unit.
Keywords: Photocrosslink; Photobase generator; By-product; Patterning; O-acyloxime;

An investigation into novel multifunctional cross-linkers effect on microgel prepared by precipitation polymerization by H. Es-haghi; H. Bouhendi; G. Bagheri Marandi; M.J. Zohurian-Mehr; K. Kabiri (524-530).
Novel microgels composed of acrylaic acid and multifunctional cross-linkers, acrylate/methacrylate cross-linkers, were synthesized via thermal initiated free radical precipitation polymerization in organic solvents. The effect of cross-linker functionality on the properties of microgels was investigated. Results showed both the solvent absorbency and apparent viscosity depend on the network structure, the cross-linker functionality and number of hydrophobic groups. Gel content indicated more reactivity of acrylate than methacrylate cross-linkers. A linear relation exists between elastic modulus (G′) and functionality (f). Also the results suggested an equation that confirmed a direct relationship between glass transition temperature (Tg ) and (f). The rotational and apparent viscosity results supported the thickening properties of the microgels. Based on the observations, it is concluded that trifunctional AC cross-linker (TMPTA) choose as an improvement of thickening properties over another cross-linkers.
Keywords: Multi-functional cross-linkers; Poly(acrylic acid) microgels; Precipitation polymerization; Network properties; Rheology;

Chemically modified polysulfones for molecular imprinting. Synthesis and complexation with a fluorescent model template by Nasreddine Kébir; Nathalie Sabathié; Clara Fournier-Noël; Suzanne Fery-Forgues; Jean-François Lahitte; Jean-Christophe Rémigy (531-539).
Polysulfone (PSU) was chemically modified to prepare new molecular imprinted membranes (MIMs). Several amounts of amine and sulfonyl groups were introduced into the PSU chemical structure in order to create interactions with acid or base templates, such as biomolecules or biomacromolecules. A fluorescent dye, Acridine Orange base (AO), was used as a model template and its complexation with the prepared PSUs was monitored by spectroscopic techniques. This study showed an absence of complexation with the native PSU and a strong complexation with the aminated and the sulfonated PSUs. Partially allylated PSU bearing amine or sulfonyl groups were also synthesized. These compounds are expected to be used as precursors for designing new crosslinked molecular imprinting membranes (MIMs), exhibiting high stability of the template memory.
Keywords: Polysulfone; Molecular imprinting; MIP; MIM;

Effect of clay type and loading on thermal, mechanical properties and biodegradation of poly(lactic acid) nanocomposites by Kikku Fukushima; Daniela Tabuani; Maria Arena; Mara Gennari; Giovanni Camino (540-549).
PLA nanocomposites based on two different clays (CLO30B and SOMMEE) at 5 and 10 wt.% clay loading were prepared by melt-blending, obtaining a good level of clay dispersion as well as considerable thermo-mechanical improvements in PLA, according to WAXS, SEM, TEM, DMTA and tensile strength analysis.Addition of clays induced PLA crystallization by nucleation, especially upon addition of SOMMEE, promoting kinetics and extent of crystallization of the polymer, especially at high clay content. Concerning the thermal and mechanical properties, the highest improvements in PLA matrix were obtained upon 10% clay addition, especially SOMMEE, becoming more noticeable with increasing temperature.An effective degradation of PLA and nanocomposites in compost at 40 °C was also achieved. It was found that addition of nanoparticles, especially SOMMEE, accelerated the degradation process of PLA, particularly at higher clay content, probably due to catalysis by the hydroxyl groups belonging to the silicate layers surface and/or to their organic modifier.
Keywords: PLA; Clays; Nanocomposites; Biodegradation; Compost;

An emulsion gel adsorbent which was a polymeric hydrogel containing randomly distributed oil microdroplets of an extractant was developed for improved metal adsorption in our previous study. This study focuses on the preparation of monodisperse, millimeter- or sub-millimeter-sized emulsion gel beads, for which a novel production method combining sedimentation polymerization and two-fluid atomization is proposed. The method involves the drop-wise addition of a pre-gel oil-in-water emulsion solution into a silicone oil through a nozzle, with nitrogen gas flow, and the subsequent free-radical polymerization of the pre-gel droplets during their descent. A novel type of emulsion gel bead composed of a poly(ethylene glycol) methyl ether acrylate hydrogel and di-n-hexylsulfide as an extractant was developed. The size of the emulsion gel beads was controlled by adjusting the gas flow rate. The emulsion gel beads successfully adsorbed Pd(II) ions that were used as a model metal.
Keywords: Spherical gel beads; Emulsion; Sedimentation polymerization; Two-fluid atomization; Metal adsorption;

Synthesis and characterization of new imidazole and fluorene–bisphenol based polyamides: Thermal, photophysical and antibacterial properties by Mousa Ghaemy; Bahareh Aghakhani; Mehdi Taghavi; Seyed Mojtaba Amini Nasab; Mojtaba Mohseni (555-563).
A new para-linked diether-diamine, 9,9-bis{4-[2-(4,5-diphenylimidazol-2-yl)-4-aminophenoxy] phenyl}fluorene (III), bearing fluorene–bisphenol and two ortho-linked diaryl-substituted imidazole rings were synthesized by the catalytic reduction of the nitro groups of compound (II), 9,9-bis{4-[2-(4,5-diphenylimidazol-2-yl)-4-nitrophenoxy]phenyl}fluorene, by using hydrazine monohydrate in the presence of Pd/C. Compound (II) was synthesized by the nucleophilic chloro displacement reaction of the synthesized 2-(2-chloro-5-nitrophenyl)-4,5-diphenyl-1H-imidazole with 9,9-bis(4-hydroxyphenyl)fluorene in refluxing DMAc in the presence of potassium carbonate. This diamine was condensed directly with aliphatic and aromatic diacids via the Yamazaki–Higashi phosphorylation method in the presence of triphenylphosphite (TPP), pyridine (Py) and halide salt to give high molecular polyamides (PAs). The synthesized PAs were obtained in quantitative yields with inherent viscosities between 0.51 and 0.76 dL g−1. The structures of diamine and PAs were characterized by elemental analysis, FT-IR and NMR spectroscopy, and properties of PAs were investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and UV–visible and fluorescence spectroscopy. The PAs showed good solubility in aprotic and polar organic solvents, with high thermal stability exhibiting the glass transition temperatures (T gs) and 10% weight loss temperatures (T 10%) in the range of 226–330 °C and 400–466 °C in air, respectively, and fluorescence emission with maximum wavelengths (λ em) in the range of 417–473 nm with quantum yields (Φ f) of 9–35%. Two of these polymers together with compounds (II) and (III) were also screened for antibacterial activity against Gram positive and Gram negative bacteria.
Keywords: Polyamides based on imidazole and fluorene–bisphenol rings; Solubility; Thermal stability; Photophysical properties; Antibacterial activity;

Folate-conjugated micelles were fabricated from amphiphilic diblock copolymers with poly(ethylene glycol) as the hydrophilic block and a random copolymer of n-butyl methacrylate and methacrylic acid as the hydrophobic block. Doxorubicin (DOX), a model drug that contains an amine group and hydrophobic moiety, was loaded with a high loading capacity into micelles by a combination of ionic bonding and hydrophobic effect. The combined interactions imparted a pH-sensitive delivery property to the system. The release rate of loaded DOX was slow at pH 7.4 (i.e., mimicking the plasma environment) but increased significantly at acidic pH (i.e., mimicking endosome/lysosome conditions). Acid-triggered drug release resulted from the carboxylate protonation of poly(methacrylic acid), which dissociated the ionic bonding between the micelles and DOX. Cellular uptake by folate receptor-overexpressing HeLa cells of the DOX-loaded folate-conjugated micelles was higher than that of micelles without folate conjugation. Thus, the DOX-loaded folate-conjugated micelles displayed higher cytotoxicity to HeLa cells.
Keywords: Doxorubicin; Drug delivery; Folate; pH-sensitive; Polymeric micelles;

Antioxidant activity and characterization of bioactive polypeptides from bovine hair by Wei-Cai Zeng; Wen-Chang Zhang; Wen-Hua Zhang; Bi Shi (573-578).
The antioxidant activity and food protection effect of bioactive polypeptides from bovine hair were investigated. In various in vitro tests, polypeptides showed a strong reducing power and a remarkable antioxidant capability to scavenge free radicals (ABTS, superoxide and hydroxyl radicals). Moreover, polypeptides also exhibited a significant food protection effect to inhibit the oxidation of edible oil by controlling the peroxide value (POV). Furthermore, by using gel filtration chromatography (GFC), high performance size exclusion chromatography (HPSEC), amino acid analysis and atomic force microscopy (AFM), an antioxidant polypeptide (APB) was purified and characterized with a molecular weight of 18.7 KDa in the form of spherical lumps, which was composed of 17 kinds of amino acids and contained sulfydryl group. Our results suggested that the antioxidant polypeptide from bovine hair could be a new potential source for preparing natural antioxidant applied in oil or oil-rich food.
Keywords: Bovine hair; Polypeptide; Oil oxidation; Antioxidant activity; Characterization;

This work focuses on the synthesis and self-assembly of biodegradable and anionic double hydrophilic diblock copolymers (DHBCs) poly(ethylethylene phosphate)-block-poly[2-(succinyloxy)ethyl methacrylate] (PEEP-b-PSEMA) with different molecular weights and compositions, which were prepared via a combination of ring opening polymerization (ROP), atom transfer radical polymerization (ATRP) and polymer reaction. The chemical structures of these well-defined diblock copolymers were confirmed by 1H NMR and FT-IR analyses. GPC results indicated that the copolymers showed symmetric peak and relatively narrow polydispersities. Subsequently, pH-responsive micellization behaviors of PEEP-b-PSEMA diblock copolymers were investigated by fluorescence probe method, dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. The results demonstrated that these diblock copolymers were able to self-assemble into micelles with various sizes depending on the variation of pH values. Naproxen (NAP), a poorly water-soluble drug, was selected as the model drug and encapsulated into the core of micelles via dialysis method. The in vitro release behavior of NAP from these micelles was pH-dependent and could be accelerated in the presence of phosphodiesterase I which could promote the degradation of polyphosphoesters. Cytotoxicity tests by MTT assay showed that these block copolymers possessed favorable biocompatibility against HeLa cells, revealing that this kind of biodegradable, biocompatible and pH-responsive block copolymer would be served as a promising material for drug delivery.
Keywords: Polyphosphoesters; Self-assembly; pH-Responsive polymer; Drug delivery;

Synthesis of isosorbide based polyurethanes: An isocyanate free method by Vincent Besse; Rémi Auvergne; Stéphane Carlotti; Gilles Boutevin; Belkacem Otazaghine; Sylvain Caillol; Jean-Pierre Pascault; Bernard Boutevin (588-594).
The synthesis of isocyanate free polyurethanes is a major concern. This paper first reports the synthesis of new biobased isosorbide dicyclocarbonates from isosorbide. Then polyhydroxyurethanes (PHUs) were synthesized by a cyclocarbonate–amine step growth polyaddition with four commercial diamines (e.g. jeffamine D-400, 1,10 diaminodecane, diethylenetriamine and isophoronediamine). These unprecedented products, obtained with high yield, were characterized by 1H NMR, FTIR, DSC, SEC and TGA analyses. PHUs exhibited glass transition temperatures from −8 °C to 59 °C, and degradation temperatures (Td 5%) between 234 °C and 255 °C. Last but not least, the compounds produced during the degradation of these PHUs were analyzed by ATG-IR technique and showed that carbon dioxide and secondary amines are released.
Keywords: Polyhydroxyurethane; Isosorbide; Renewable resources; Thermal stability; Carbonate;

The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like entrainment and irreversible emulsification. 4-Cyanopyridine was chosen as model pyridine derivative, and 4-nonylphenol was used as solvent. The aim of this study was to select the most suitable resin for this application. While in the literature there are mainly two types of resins used, MPP and Amberlite XAD type, a comparative study has not yet been conducted. In this study, a series of resins were impregnated with the solvent and applied in sorption experiments to study on the effect of the resin properties on the capacity, selectivity and mass-transfer rates of the solvent impregnated resins. It was found that the capacity could be estimated accurately with the previously developed liquid–liquid extraction equilibrium model. Additionally, the selectivity was determined by the solvent properties, and hardly affected by the resin matrix. The mass-transfer rates were primarily determined the by particle diameter, whereas the effect of the porosity is small. On the basis of the results it was established that Amberlite XAD4 had the best combination of capacity, mass-transfer rate, mechanical strength, selectivity and pressure drop over a fixed-bed column and was therefore chosen for a more detailed study. The results showed that the breakthrough curve is broad due to mass-transfer limitations. The loading cycle of the column could be described with great accuracy using the mathematical model developed in this study. Regeneration of the column could be performed efficiently with a pH-swing using hydrochloric acid at a pH of 1. The fixed bed column was percolated with 7000 bed volumes of aqueous solutions varying in composition. No reduction in the capacity was observed which demonstrated that the SIR consisting of Amberlite XAD4 and 4-nonylphenol is highly stable.
Keywords: Solvent impregnated resin; 4-Cyanopyridine; 4-Nonylphenol; Resin screening; Mass-transfer; Equilibrium extraction;

Surface-initiated ring opening polymerization of N-carboxy anhydride of benzyl-l-glutamate monomers on soft flexible substrates by Hatice Duran; Basit Yameen; Hadayat Ullah Khan; Renate Förch; Wolfgang Knoll (606-612).
The potential of pulsed plasma deposited polyallylamine (PAA) adlayer has been successfully demonstrated for fabrication of polypeptide brushes functionalized soft flexible polymeric surfaces. Polymeric substrates functionalized with the plasma deposition PAA adlayer resulted in polymeric surfaces functionalized with amino groups, which are the suitable initiating moieties for ring-opening polymerization (ROP) of N-carboxy anhydride of benzyl-l-glutamate (NCA-BLG) monomer. Poly(γ-benzyl-l-glutamate) (PBLG) brushes were grown on PAA functionalized polypropylene (PP), and polytetrafluoroethylene (PTFE) polymeric substrates. These substrates were intentionally chosen for their inert chemical nature towards most wet chemical surface modification reactions. Surface grafted thin films of poly(γ-benzyl-l-glutamate) PBLG on both the PP and PTFE polymeric substrates yielded high density PBLG brushes. PBLG chain orientation, secondary structure and grafting density were characterized by infra-red spectroscopy. The synthesis of PBLG brushes on a flexible polymeric substrate is unprecedented and technologically important, since PBLG possess good electro-optical activity. Analysis of brush layers by Attenuated Total Reflectance Infra-Red (ATR-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) as well as atomic force microscopy (AFM) fully corroborated the success of the plasma activated soft surface grafting approach.
Keywords: Polymer brushes; Plasma polymerization; Polypeptide; Surface grafting; Soft polymeric surfaces;

Immobilization of flame-retardant onto silica nanoparticle surface and properties of epoxy resin filled with the flame-retardant-immobilized silica (2) by Takashi Kawahara; Akira Yuuki; Kumi Hashimoto; Kazuhiro Fujiki; Takeshi Yamauchi; Norio Tsubokawa (613-618).
To prepare silica nanoparticle having flame-retardant activity, immobilization of flame-retardant onto the surface was investigated. The immobilization of phosphorous flame-retardant was achieved by two-step reactions: (1) introduction of cyclotriphosphazene (PH) groups onto silica nanoparticle by the reaction of terminal amino groups of the surface with hexachlorocyclotriphosphazene and (2) immobilization of bis(4-aminophenoxy)phenyl phosphine oxide (BAPPO) onto silica having PH groups by the reaction of PH groups on the surface with BAPPO. The immobilization of BAPPO was confirmed by FT-IR and thermal decomposition GC–MS. The composite of epoxy resin filled with BAPPO-immobilized silica (Silica–PH–BAPPO) was successfully prepared by heating in the presence of curing agents. Thermal decomposition temperature and glass transition temperature of the epoxy resin filled with Silica–PH–BAPPO was higher than that of epoxy resin filled with untreated silica, free HCTP and BAPPO. Moreover, flame-retardant property of epoxy resin filled with Silica–PH–BAPPO was estimated by limiting oxygen index (LOI). The LOI value of epoxy resin filled with Silica–PH–BAPPO was higher than that of epoxy resin filled with untreated silica, free HCTP and BAPPO. This may be due the fact that char yield of the epoxy resin filled with Silica–PH–BAPPO was higher than that filled with free flame-retardant.
Keywords: Flame-retardant; Nanoparticles; Silicas; Surface grafting; Epoxy resin;