Reactive and Functional Polymers (v.46, #2)
Synthesis, characterisation and physicochemical properties of polyphenols prepared by cobalt(II) catalysed oxidative polymerisation by A. Puzari; Jubaraj B. Baruah (101-107).
The catalytic reaction of Co2(DAM)7Cl4 with phenolic compounds such as phenol, p-cresol, o-cresol, m-cresol etc. in the presence of hydrogen peroxide gave C–O bonded oligomers (1–4). The oligomers were characterised by NMR, IR, elemental analysis. The M n values of 1–4 were 3417, 3494, 3438 and 3550, respectively. The oligomers contain OH end groups. The oligomer 1 has resistance profile such that it increases to 50°C and then falls exponentially in the region of 50 to 170°C. The resistance of 2 and 4 are similar to semiconductor in the range of 30–180°C. The oligomer 3 has a resistance profile such that it decreases from 30 to 100°C and then increases from 100 to 140°C and once again falls in the region of 140–200°C. The oligomer 4 has an esr signal at 3220 G and shows the presence of a free radical. The intensity of this signal increases ten times upon heating to 90°C.
Keywords: Polyphenols; Cobalt(II); Oxidative polymerization;
Cosorption of metal (Zn, Pb, Ni) cations and nonionic surfactant (alkylmonoethers) in polyacrylic acid-functionalized cation-exchanger by J Snukiškis; A Gefenien≐; D Kaušp≐dien≐ (109-116).
The mutual influence of metal (Zn, Pb, Ni) cations and nonionic surfactant alkylmonoethers ALM-10 on their cosorption by hydrogen-containing form of Purolite C 106 polyacrylic acid-functionalized cation-exchanger was investigated with respect to the possibility of its application for sewage purification and recycling to prevent the environmental contamination. Sorption isotherms were measured, distribution coefficients calculated and metal(II) sorption proceeding in various forms estimated. The sorption of metal cations, alkylmonoether molecules and products of their interaction proceeds simultaneously. Mutual action of metal(II) and alkylmonoethers leads to a decrease in the equilibrium sorption of both metal(II) and alkylmonoethers. The sorption of alkylmonoethers proceeds in the form of the free molecules and the molecules bonded to metal(II) cations, while the sorption of metal(II) proceeds in the form of the free cations (predominantly) and the cations bonded to the molecules of alkylmonoethers. The sorption of the free cations proceeds as follows: lead(II) – by ionic bonding; nickel(II) – by complex (ionic+coordinate) bonding; zinc(II) – by both complex (ionic+coordinate) and single coordinate bonding. The cosorption of metal (Zn, Pb, Ni ) cations and nonionic surfactant (alkylmonoethers) can be applicable for the purification of sewage including electroplating rinsewater.
Keywords: Zinc(II); Lead(II); Nickel(II); Nonionic surfactant; Cosorption; Cation; Exchanger.;
Synthesis and characterization of poly(dihalophenylene oxide)s by solid-state thermal decomposition of zinc phenolate complexes with ethylenediamine and pyridine by Mehlika Pulat; Ebru Çakir (117-126).
In this study the synthesis and characterization of poly(dihalophenylene oxide)s was achieved. Polymers were obtained from zinc phenolate complexes with ethylenediamine and pyridine ligands by the solid-state thermal decomposition method. The complexes, prepared with 2,4,6-tricholorophenol and 2,4,6-tribromophenol, were characterized by FTIR spectroscopy, TGA curves and C,H,N elemental analysis. The dependence of polymerization yield on temperature and the decomposition time of the complexes was investigated. Maximum polymerization yields were obtained between 180 and 200°C over 48 h. The polymers were characterized by 1H-NMR, FTIR spectroscopy, DSC and viscometric measurements. The polymers had branched and linear structures with high T g and low intrinsic viscosity values.
Keywords: Poly(dihalophenylene oxide)s; Zinc phenolate complexes; Solid-state polymerization; TGA;
Swelling behavior of porous copolymers based on alkyl methacrylate esters by Jun Yan; Xun-hua Wang; Zhi-nong Cao (127-134).
A series of porous copolymer beads based on the alkyl methacrylate esters (AMA) was prepared with toluene as inert diluent, and their swelling behavior, mainly in nonsolvents, were investigated. It was found that all these copolymers with relatively high degree of crosslinking do swell in methanol, a nonsolvent for them, and the swelling extent increases and passes through a maximum with an increase in the degree of crosslinking. The incorporation of methacrylic acid (MAA) into the AMA-based copolymers doesn’t change the swelling ability of the copolymers in a nonsolvent, but changes the type of solvent as a nonsolvent. Thus copolymers with MAA incorporated present swelling behavior in toluene and in buffer at specific pH’s just as in a nonsolvent. From these results we believe that the swelling ability in nonsolvent are characteristic for copolymers with relatively high degrees of crosslinking when prepared in the presence of a large amount of diluent with high solvating power for the polymer.
Keywords: Copolymers; Alkyl methacrylate esters; Swelling behavior;
Removal of metal ions from aqueous solution on low cost natural polysaccharides by Claire Gérente; Pierre Couespel du Mesnil; Yves Andrès; Jean-François Thibault; Pierre Le Cloirec (135-144).
The fixation of Cu2+, Ni2+ and Pb2+ on sugar beet pulp, a low-cost material, has been studied. After a simple treatment of the sorbent, the results have shown that the mode of fixation depends on the metal. The key part of the mode of fixation is attributed to ion exchange, while a non-negligible part of adsorption could sometimes occur. As far as lead ions are concerned, 25% of their fixation capacities are due to adsorption mechanism at pH 4. The overall uptake is at a maximum at pH 6 and gives up to 60 mg g−1 for Pb2+, 30 mg g−1 for Cu2+ and 12 mg g−1 for Ni2+, which seems to be removed exclusively by ion exchange. These capacities increase with the pH. Diffusion models have been tested on samples of different particle size, and they have suggested a transfer to the intraparticular sites.
Keywords: Metal fixation; Sugar beet pulp; Adsorption mechanisms; Diffusion models;
Chemical modification of Si(100) surface by consecutive graft polymerization of 4-vinylaniline and aniline by L.Y Ji; E.T Kang; K.G Neoh; K.L Tan (145-156).
Chemical modification of the Ar plasma-pretreated Si(100) surface was carried out first by UV-induced graft copolymerization with 4-vinylaniline (4-VAn) and subsequently by oxidative graft copolymerization with aniline. The graft-modified Si surface was characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and electrical resistance measurements. The graft copolymerization of 4-VAn on the Si(100) surface (the VAn-g-Si(100) surface) was affected by the Ar plasma pretreatment time of the Si(100) surface, the 4-VAn monomer concentration, and the UV copolymerization time. XPS results showed that the aniline group of the grafted 4-VAn polymer could be utilised for the subsequent oxidative graft copolymerization with aniline (An). The aniline copolymer-modified VAn-g-Si(100) surface (the An-VAn-g-Si surface) exhibited protonation–deprotonation behaviour similar to that of the aniline homopolymer. The resistance of the graft-modified Si surface was in the order of 106 Ω/square. The AFM images revealed that the graft-modified Si surfaces had a uniform morphology. However, the roughness of the Si surface increased after the consecutive grafting processes.
Keywords: Si(100); Graft polymerization; 4-Vinylaniline; Polyaniline; Surface modification; XPS; Plasma;
Synthesis and adsorption properties of poly(2-hydroxyethylmethacrylate-co-methacrylamidophenylalanine) membranes for copper ions by Adil Denizli; Rıdvan Say; Süleyman Patır; Yakup Arıca (157-164).
In the first step of this study, the metal complexing ligand, 2-methacrylamidophenylalanine (MAPA), was synthesized by using methacrylochloride and phenylalanine. The MAPA monomer was characterized by NMR. Then, poly(2-hydroxyethylmethacrylate-co-2-methacrylamidophenylalanine) [p(HEMA-co-MAPA)] membranes were prepared by UV-initiated photo-polymerization of HEMA and MAPA in the presence of an initiator (azobisisobutyronitrile, AIBN). p(HEMA-co-MAPA) membranes were characterized by FTIR and elemental analysis. These p(HEMA-co-MAPA) affinity membranes with a swelling ratio of 133.2%, and containing 18.9 mmol MAPA/m2, were used in the adsorption–desorption of copper(II) ions from synthetic solutions. Adsorption equilibria was reached in about 2 h. The maximum adsorption of Cu(II) ions onto pHEMA was about 0.54 mmol Cu(II)/m2. The MAPA incorporation significantly increased the Cu(II) adsorption capacity by chelate formation of Cu(II) ions with MAPA molecules (23.8 mmol Cu(II)/m2), which was observed at pH 7.0. The chelating membrane can be easily regenerated by 0.1 M HNO3 with higher effectiveness.
Keywords: Methacrylamido phenylalanine; Affinity membranes; Copper(II) removal;
Epoxidation of styrene with hydrogen peroxide in the presence of polymer-supported quaternary ammonium salts and peroxo complexes of W(VI) by Krassimir Vassilev; Rayna Stamenova; Christo Tsvetanov (165-173).
Quaternary ammonium salts immobilized onto poly(2-N,N-dimethylaminoethyl) methacrylate and a mixed network of poly(oxyethylene) and poly(4-vinylpyridine) were prepared. These salts were characterized by an elemental analysis, IR, 1H and 13C NMR spectroscopy. The catalytic activity of the polymeric complexes was studied in the epoxidation of styrene as a model reaction. The system under study consisted of a water-immiscible solvent, aqueous hydrogen peroxide and Na2WO4/H3PO4. The catalytic activity of the polymeric ammonium salts depends on the kind of support employed, as well as on the length of hydrocarbon radicals and the nature of the anion. An increase in the selectivity of the reaction as compared to a system with non-immobilized salts is observed.
Keywords: Catalysis; Polymer-supported quaternary ammonium salts; Poly(2-N,N-dimethylaminoethyl methacrylate); Poly(oxyethylene); Poly(4-vinylpyridine);
Synthesis and characterization of a novel alcohol-soluble ladderlike polysilsesquioxane containing side-chain with amino terminal groups by Chunqing Liu; Yang Liu; Ping Xie; Rongben Zhang; Chaobin He; Neal Taishung Chung (175-184).
A novel kind of alcohol-soluble ladderlike polysilsesquioxane having side-chain with amino terminal groups (NH2–T) was first prepared by reduction of nitro terminal groups on the side chains of ladderlike polynitrosilsesquioxane (NO2–T) with a nearly 100% conversion rate. The parent polymer NO2–T was synthesized by stepwise coupling polymerization. As starting monomer, 3-(4-nitrophenoxy)propyltrichlorosilane (M) was synthesized by hydrosilylation of the corresponding allylic derivative with trichlorosilane in the presence of dicyclopentadienylplatinum (II) chloride (Cp2PtCl2) catalyst in a high yield. A variety of characterization methods including FTIR, 1H NMR, 13C NMR, 29Si NMR, differential scanning calorimetry, thermogravimetric analysis, vapour pressure osmometry, and X-ray diffraction were combined to verify that NH2–T had ladderlike structure. The alcohol-soluble ladderlike NH2–T prepared has promising application in controlled release of catalysts and drugs, NLO materials, alignment layer in liquid crystal display, and as a precursor for further preparing advanced functional polymers and their supramolecular systems.
Keywords: Alcohol-soluble ladderlike polysilsesquioxane; Reduction; Hydrosilylation; Characterization; Polysilsesquioxane;
Synthesis of end-functionalized low molecular weight poly(butyl acrylate) and its elongation using a diisocyanate by Yoshihide Kawaguchi; Hajime Yasuda (185-192).
Bifunctionalized poly(butyl acrylate) and poly(methyl methacrylate) were synthesized by the polymerization of butyl acrylate or methyl methacrylate using an organosamarium complex, [SmMe(C5Me5)2(CH2–CH–CHCH2)]2, as an initiator followed by the insertion of aldehydes. The polymerization proceeds quantitatively to afford the hydroxy-end functionalized polymer (M n>4120) with narrow molecular weight distributions (M w/M n<1.13). The attempted chain elongation of the resulting polymer with 4,4′-methylenebis(phenylisocyanate) has however failed, while the chain extension was realized by the reaction of poly(ϵ-caprolactone-co-butyl acrylate-co-ϵ-caprolactone) (M n>15,200, M w/M n<1.23) with a diisocyanate affording the desired high solid paint with M n of 87,600 using a limited amount of THF as a solvent.
Keywords: Poly(butyl acrylate-co-ϵ-caprolactone; End cap; Rare earth metal complexes; 4,4′-Methylenebis(phenylisocyanate); Chain elongation;
Grafting of hyperbranched polymers onto ultrafine silica: postgraft polymerization of vinyl monomers initiated by pendant initiating groups of polymer chains grafted onto the surface by Shinji Hayashi; Kazuhiro Fujiki; Norio Tsubokawa (193-201).
The grafting of polymers having pendant peroxycarbonate groups onto ultrafine silica surface and the radical postgraft polymerization of vinyl monomers initiated by the initiating groups of polymer chains grafted onto silica surface were investigated. The grafting of polymers having pendant peroxycarbonate groups onto the silica surface was achieved by the copolymerization of vinyl acetate (VAc) with t-butylperoxy-2-methacryloyloxyethylcarbonate (HEPO) initiated by azo groups introduced onto silica surface: the introduction of azo groups onto silica surface was achieved by the reaction of 4,4′-azobis(4-cyanopentanoic acid) with amino groups previously introduced onto the surface. The percentage of grafting (the proportion of grafted polymer to silica) of poly(VAc–co-HEPO) onto the surface was about 51% at 80.0°C after 3 h. The amount of pendant peroxycarbonate groups of grafted chain was determined to be 0.55 mmol/g. Radical postgraft polymerization of various vinyl monomers, such as methyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, vinyl acetate, and N-vinyl-2-pyrrolidinone was initiated by the pendant peroxycarbonate groups of grafted poly(VAc–co-HEPO) to give the corresponding hyperbranched polymer-grafted silica. It was found that the grafting of hydrophilic or hydrophobic polymers readily controls the surface wettability to water.
Keywords: Ultrafine silica; Hyperbranched polymer; Postgrafting; t-Butylperoxy-2-methacryloyloxyethylcarbonate; Peroxycarbonate groups; Surface modification;