Polychelates of poly[N-(4-carboxy-3-hydroxyphenyl)maleimide]

The reactions of the bidentate polymeric chelating ligand poly[N-(4-carboxy-3-hydroxyphenyl)maleimide] with Co(II), Ni(II), Cu(II), Zn(II) and UO₂(II) metal ions were investigated. Analytical, magnetic, spectral and thermal studies were used to characterize these polychelates. All these polychelates are stable, intensely coloured solids and insoluble in common organic solvents.     

Synthesis and behaviour of two copolymers of poly[acrylamide-co-(N-(hydroxymethyl)acrylamide)] in ultrafiltration experiments

Summary Water absorbing materials on the basis of acrylamide copolymers have been investigated. The cross-linking of polymer chains strongly effects the degree of water absorption. The influence of starting composition of polyacrylamide : sodium hydroxide, duration of hydrolysis and irradiation conditions on cross-linking have been determined and optimized technological parameters have been derived. Water super absorbents with the ability to absorb up to 900g water by one gram material have been prepared. Received: 20 December 1999/Revised version: 19 June 2000/Accepted: 17 July 2000     

Two Syntheses of [2.2.2] (1,2,3)Cyclophane

Two syntheses are presented for [2.2.2] (1,2,3)cyclophane (7), the remaining member of the symmetrical [2_n]cyclophanes whose preparation has not previously been described. The first method involved the dimerization of 2,6-bis (4′, 4′-dimethyl-2′-oxazolinyl)toluene ( 1 ) to give 2 which, on hydrolysis, produced the tetracarboxylic acid 3 . Conversion of 3 , via the acid chloride ( 4 ), to the tetraol 5 , followed by treatment with phosphorus tribromide yielded the tetrabromide 6 . The overall scheme was then completed by reaction of 6 with phenyllithium to give [2.2.2] (1,2,3) cyclophane ( 7 ). An alternate, more convenient, method began with the pyrolysis of 2,6-bis (chloromethyl)toluene ( 8 ) to give 3-chloromethylbenzocyclobutene ( 9 ). Formation of the Grignard of 9, followed by reaction with ferric chloride, yielded the dimer 10 . Pyrolysis of 10 then gave [2.2.2] (1,2,3)cyclophane (7).     

Interchain EDA complexes of poly[N-(2-hydroxyethyl) carbazolyl methacrylate] with poly (ω-hydroxyalkyl-3,5-dinitrobenzoyl methacrylate)s

Summary The solid state behavior of the interchain electron donor-acceptor (EDA) complexes of poly[N-(2-hydroxyethyl)carbazolyl methacrylate] (PHECM) with poly(ω-hydroxyalkyl-3,5-dinitrobenzoyl methacrylate)s (PDNBM-n) (where n is the number of methylene groups in the hydroxyalkyl group) with n=2, 3, 4, 5 and 6 was studied by differential scanning calorimetry. All these systems form thermodynamically miscible blends. The dependence of the glass transition temperature (T_g) on the blend composition can be best aproximated by the Kwei's equation.     

4-(N-乙基,N-2-羟乙基)氨基苯甲醛的制备

以4－（N－乙基，N－2－羟乙基）氨基苯为起始原料经乙酸酐酯化，苯环对位甲酰化，再水解制得4－（N－乙基，N－2－羟乙基）氨基苯甲醛，每步反应平衡，并用TLC跟踪每一步反应进行的程度，总收率达60％。     

Preparation and characterization of camptothecin-loaded alginate/poly[N-(2-hydroxypropyl) methacrylamide] hydrogel beads for anticancer treatment

Encapsulation of poor water-soluble drugs into a biocompatible polymeric matrix is a good strategy for in vitro drug delivery. Present study deals with the preparation and optimization of alginate/poly[N-(2-hydroxypropyl) methacrylamide] beads (SA/pHPMA) for the delivery of an anticancer drug such as camptothecin (CPT). Beads were prepared by ionotropic gelation technique using calcium chloride and optimized concentrations of 10?w/v% of sodium alginate beads and 10:10?w/v% of poly[N-(2-hydroxypropyl) methacrylamide]:sodium alginate (SA/pHPMA) beads were prepared. Twenty ppm of CPT was incorporated into the beads by the imbibition method. XRD, thermogravimetric analysis, and differential scanning calorimetry studies of the beads showed no free pHPMA and CPT indicating their uniform dispersion into the matrix. FTIR analysis showed weak interaction between CPT and polymers. In vitro release of CPT from SA/pHPMA beads showed slow and sustained release of 80% while SA beads showed 62% retaining the shape of the beads in phosphate-buffered saline at pH 7.4. The presence of CPT inside the prepared beads has the potential to be used as soft bandages for treatment of cancer.     

Poly(vinylidenefluoride)-hexafluoropropylene gel electrolytes based on N-(2-hydroxyethyl)-N-methyl morpholinium ionic liquids

Poly(vinylidenefluoride)-hexafluoropropylene (PVdF(HFP))-ionic liquid gel electrolytes were prepared by using ionic liquids based on N-(2-hydroxyethyl)-N-methyl morpholinium tetrafluoroborate and N-(2-hydroxyethyl)-N-methyl morpholinium hexafluorophosphate. TGA and FT-IR analyses confirmed that the solvent, N,N-dimethylacetamide (DMAC), used for mixing the PVdF(HFP) polymer with the ionic liquid, was almost totally removed during the gelling and drying processes. SEM photographs were taken of the surface structure of the PVdF(HFP)-ionic liquid in order to evaluate the morphology of the film’s surface according to the mixing ratio, as well as the nature of the ionic liquid. The thermal behaviors of PVdF(HFP)-ionic liquid gels were observed to be similar to those of neat ionic liquids through a DSC analysis, and the compatibility between the polymer and the ionic liquid was investigated by an XRD analysis. The ionic conductivities of all the gels were 10⁻⁴–10⁻⁸S·cm⁻¹ in a temperature range of 20°C to 70°C.     

pH-Dependent thermoresponsive poly[2-(diethylamino)ethyl acrylamide]-grafted PVDF membranes with switchable wettability for efficient emulsion separation

Plenty of oily wastewater discharged from industrial and domestic sewage has deteriorated the environment severely, so stimuli-responsive membranes with switchable wettability have been of considerable attraction for its potential application in oil/water separation. In this work, a novel pH-dependent thermoresponsive membrane fabricated by grafting the poly[2-(diethylamino)ethyl acrylamide] (PDEAEAM) from the poly(vinylidene fluoride) (PVDF) membrane via surface-initiated atom transfer radical polymerization is explored to achieve the oil/water separation. The PDEAEAM-g-PVDF membrane shows hydrophilicity at room temperature under neutral condition while hydrophobicity at 50°C under alkaline condition. Wettability of the membrane at different temperatures is dominated by the lower critical solution temperature (LCST) of PDEAEAM, and the LCST of PDEAEAM is pH dependent. Due to the LCST of PDEAEAM, the membrane shows a variation of separation efficiency for separating hexadecane/water emulsion with temperature and pH. Typical separation efficiencies are 97.10% at 25°C under neutral condition and 30.26% at 50°C under alkaline condition.     

Elasticity of poly(acrylamide) gel beads

Summary The elastic behavior of swollen ionic poly(acrylamide) (PAAm) gel beads was investigated as a function of the bead diameter. For this purpose, an experimental setup was designed to measure the modulus of hydrogel beads. An inverse suspension polymerization technique was used to obtain spherical beads of sizes 3 to 11 mm. It was observed that the effective crosslink density of PAAm gel beads produced in the same synthesis batch increases with increasing bead diameter, which was attributed to the inverse suspension polymerization condition. Received: 6 November 2002/Revised version: 4 April 2003/ Accepted: 4 April 2003 Correspondence to Oguz Okay     

Crosslinked particles of poly[n-(1-phenylethyl)acrylamide]: Preparation and application as chromatographic stationary phases

Crosslinked particles of poly [N-(1-phenylethyl)acrylamidel have been successfully prepared by suspension polymerization of N-(1-phenylethyl) acrylamide and ethylene dimethacrylate in water using poly(vinyl alcohol) as dispersant. The particle morphology is investigated by optical microscope and scanning electron microscope (SEM). The pressure resistance of the crosslinked particles, evaluated after packing as stationary phases of high-performance liquid chromatography (HPLC), increases from 7 to 20 kg/cm² as the mole percent of ethylene dimethacrylate increases from 10% to 30%. The particles were sieved into four sieve fractions, i.e. 37–63 m, 63–88 m, 88–105 m, and 105–149 m, and packed into HPLC columns, respectively. The chromatographic performances of these columns have been investigated in HPLC system thoroughly, using benzene as solute and mixtures ofn-hexane and 2-propanol as eluents. The crosslinked particles show potential application as stationary phases for HPLC.     

相转移催化法合成新树型配体——N,N′,N″-(三苄基)-三乙氨基胺和N,N′,N″-(三苯甲酰)-三乙氨基胺

报道了以相转移催化法合成一类新有机试剂——三乙氨基胺类树型配体 N,N′,N″-(三苄基)-三乙氨基胺(TBAA)和N,N′,N″-(三苯甲酰)-三乙氨基胺(TBOAA),产率 85% 以上。此类化合物具有近似三角架形结构,能产生荧光,可以与稀土离子进行选择性配位。     

Crosslinked poly[acryloylN,N,-bis(2,2-dimethoxyethyl) amine] and crosslinked poly[acryloylmorpholine/acryloyl N,N,-bis(2,2-dimethoxyethyl) amine] gel networks and their application to the immobilization of β-d-glucosidase

The synthesis and homopolymerization of acryloyl N,N,-bis(2,2-dimethoxyethyl)amine is described. Gel networks were obtained by copolymerization of acryloyl N,N,-bis(2,2-dimethoxyethyl)amine and N,N,′-methylenediacrylamide (molar ratio 8:1) and by copolymerization of acryloyl morpholine, acryloyl N,N,-bis(2,2-dimethoxyethyl)amine and N,N,′-methylenediacrylamide (molar ratio 8:2:1). Following treatment of the gel networks with tartaric dihydrazide in dilute hydrochloric acid and subsequent activation with nitrous acid, conjugates of β-d-glucosidase were prepared. In both cases the immobilized enzyme was more resistant to heat denaturation than the native enzyme in solution. The nature of the polymer-enzyme linkage is discussed with reference to studies on the model compound phenylacetyl N,N-bis(2,2-dimethoxyethyl)amine.     

Preparation of poly(acrylamide) grafted onto crosslinked poly (HEMA-MMA-EGDMA) beads for the removal of phenol

ABSTRACT

Poly(acrylamide) (PAAM) was grafted onto crosslinked poly(hydroxy ethyl methacrylate) (HEMA)-based beads for the removal of phenol from aqueous solution. A beaded polymer with a PAAM surface shell was prepared in two steps: synthesis of crosslinked poly (HEMA (50% mol) - MMA (40% mol) - EGDMA (10% mol)) terpolymers spherical beads (200–420 µm) (resin 1) via the suspension polymerization method; and the grafting of PAAM was carried out by redox initiation from hydroxyl groups on resin1 by using cerium (IV) ammonium nitrate as the initiator.

The resulting polymeric sorbent (resin 2) with about 82 wt.% grafted PAAM has been demonstrated to be efficient to remove phenol from water. Moreover, phenol sorption capacities of resin 1 and resin 2 were compared and sorption experiments were performed depending on the initial phenol concentration and pH. Kinetic measurements and models were studied for resin 1 and resin 2.     

N-(1,1-二甲基-3-氧代丁基)丙烯酰胺的合成

对以丙酮和丙烯腈为原料,浓硫酸催化合成N (1,1 二甲基 3 氧代丁基)丙烯酰胺(DAAm)的工艺进行了改进,通过结晶获取中间产物并对其进行洗涤的方法,可提高产品纯度,简化工艺操作。确定的最佳工艺条件为:n(丙烯腈)∶n(丙酮)∶n(浓硫酸)=1∶2 3∶2 3;反应时间4h;反应温度50℃;结晶稀释剂(相对1mol丙烯腈)240mL。得到DAAm白色晶体,纯度:w(DAAm)=99 8%,熔点:56 3～56 8℃,相对丙烯腈的收率为50 6%。用熔点、IR、1HNMR确认产物。     

Infrared study of the complexation of poly(acrylic acid) with poly(acrylamide)

Infrared spectroscopy was used to study the interpolymer complexation of poly(acrylic acid) with polyacrylamide. The spectrum of the interpolymer complex showed characteristic absorption bands which are different from those of the spectra of the individual components, particularly in the O H and N H stretching vibration regions. The effects of ionic strength and poly(acrylic acid) weight fractions on the spectral features of the complex were investigated. It was found that hydrogen bonding is the primary mechanism of interaction between the two polymers. © 1996 John Wiley & Sons, Inc.     

[2,2]-对二甲苯环二体的合成

用对甲基氯苄和三甲胺合成季铵盐及利用Hofmann消除反应制备了[2,2] 对二甲苯环二体,讨论了溶剂、反应时间、反应温度等工艺条件对两步反应物产率、纯度的影响,确定了适宜的合成工艺条件,制备季铵盐的最佳条件为:n(对甲基氯苄)∶n(三甲胺)=1∶1 1,乙醇为溶剂,反应时间2h,反应温度45℃。制备对二甲苯环二体的最佳条件为:n(碱)∶n(季铵盐)=5∶1,硫酸铜为催化剂,通入氮气,反应温度110℃,反应时间为10～15h。所得产品中w(对二甲苯环二体)>99.5%。     

High strength poly(acrylamide)-clay hydrogels

A series of polyacrylamide nanocomposite hydrogels were synthesized by in situ free radical polymerization of acrylamide (AAm) with ethylene glycol dimethacrylate (EGDMA) as a crosslinker in the presence of sodium montmorillonite (NaMMT) and organically modified montmorillonite (OrgMMT) clays. Modification of MMT was carried out with a quaternary salt of coco amine as intercalant having a styryl group whose contribution to both polymerization and crosslinking reactions via its reactive double bond was confirmed by solid state NMR. Exfoliation success was checked with X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques whereas mechanical performance was followed with uniaxial compression experiment. It has been found that exfoliated PAAm nanocomposites having 0.5% OrgMMT had both the maximum equilibrium swelling in water and compression strength as well as improved thermal stability due to the special and beneficial morphology observed via scanning electron microscopy (SEM).