Hydrophilic Crosslinking Agent Research Articles

Anti-crease Finishing of Cotton Fabrics Based on Crosslinking of Cellulose with Oxidized Sucrose

ABSTRACT In anti-crease finishing, the hydrophilicity of cotton fabric treated with traditional anti-crease finishing agents such as dimethylol dihydroxy ethylene urea (DMDHEU), 1,2,3,4,-butanetetracarboxylic acid (BTCA), citric acid (CA) was reduced significantly. Oxidized sucrose (OS) was prepared by partial oxidation with sodium periodate. The OS was used as a hydrophilic cross-linking agent instead of conventional anti-crease agents. The chemical structure of the OS characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and aldehyde groups were found in the OS. The effects of OS mass concentration, catalyst mass concentration, pH, curing temperature and curing time on the crease recovery angle (CRA), whiteness index (WI) and strong retention rate (TS %) of fabrics were studied. The optimal finishing process was an OS mass concentration of 150 g/L, a catalyst mass concentration of 20 g/L, pH 3 and curing for 3 min at160°C. The OS-treated cotton fabrics could obtain a maximum CRA of 245°, WI of 82.8 and TS% of 65%. Compared with DMDHEU, glutaraldehyde, BTCA and CA finishing fabrics, the OS finishing fabric had a shorter wetting time of 5.01 s and a higher water retention.

Preparation and application of polyaldehyde trehalose as a new hydrophilic anti-crease finishing agent for cotton fabric

Polyaldehyde trehalose (OTr) was prepared and applied to cotton fabric as an anti-crease finishing agent under Lewis acid conditions. OTr contains reactive groups (aldehyde groups) and hydrophilic groups (hydroxyl groups). After the aldehyde groups crosslink with the hydroxyl groups of the fibers, the hydroxyl groups of the OTr improve the hydrophilicity of the finished fabric. The target product was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. The optimum process conditions for anti-crease finishing were studied. The optimal anti-crease finishing process for OTr was 10.0%, a MgCl2concentration of 2.0%, a pH of 3, and curing for 3 min at 150℃. The efficiency of the OTr-treated cotton fabrics was examined, and the anti-crease property, whiteness, tensile strength, hydrophilicity, and staining property of the OTr and conventional anti-crease finishing reagents were compared. The anti-crease property, whiteness, and tensile strength of the OTr-treated fabric improved significantly, but were lower than those of the butane tetracarboxylic acid and glutaraldehyde. Fabric that was treated with the new prepared agent presented a satisfactory hydrophilicity, which indicates that OTr can be used as an effective hydrophilic crosslinking agent.

Design and fabrication of biocompatible wrinkled hydrogel films with selective antibiofouling properties

In this article, we explored the selective antibiofouling capacity acquired by functional wrinkled hydrogel films via a fine tuning of their chemical structure through the gradual insertion of hydrophobic radical groups in their network. The hydrogel consists of three main components: hydroxyethyl methacrylate (HEMA, amphiphilic monomer), trifluoroethyl methacrylate (TFMA, hydrophobic monomer), and poly(ethylene glycol) diacrylate (PEGDA, hydrophilic crosslinking agent). Interestingly, the manipulation of the chemical composition affects both, surface morphology and physicochemical characteristics of the patterns, inducing transitions between different surface microstructures, i.e. from wrinkles to creases, to folds, and to crumples. Contact angle measurements show that the insertion of TFMA produces a slight decrease in surface wettability, remaining however highly hydrophilic. By using confocal Raman spectroscopy, important information about wrinkle formation mechanism could be obtained. The procedure presented in this article involves two consecutive thermal and photopolymerization steps, generating a “pseudo” two-layer system, which contracts at different extents when is exposed to external stimuli, leading to the formation of wrinkled surfaces. Finally, bacterial and cellular adhesion/proliferation studies were carried out, evidencing that the amount of TFMA included clearly reduce the bacterial adhesion while mammalian cells are able to still proliferate.

Hydroxyl functionalized thermosensitive microgels with quadratic crosslinking density distribution

N-isopropylacrylamide (NIPA) based uniform thermosensitive microgels were synthesized by dispersion polymerization by using relatively hydrophilic crosslinking agents with hydroxyl functionality. Glycerol dimethacrylate (GDMA), pentaerythritol triacrylate (PETA) and pentaerythritol propoxylate triacrylate (PEPTA) were used as crosslinking agents with different hydrophilicities. A protocol was first proposed to determine the crosslinking density distribution in the thermosensitive microgel particles by confocal laser scanning microscopy (CLSM). The microgels were fluorescently labeled by using hydroxyl group of the crosslinking agent. The CLSM observations performed with the microgels synthesized by three different crosslinking agents showed that the crosslinking density exhibited a quadratic decrease with the increasing radial distance in the spherical microgel particles. This structure led to the formation of more loose gel structure on the particle surface with respect to the center. Then the use of hydrophilic crosslinking agents in the dispersion polymerization of NIPA made possible the synthesis of thermosensitive microgels carrying long, flexible and chemically derivatizable (i.e., hydroxyl functionalized) fringes on the surface by a single-stage dispersion polymerization. The microgels with all crosslinking agents exhibited volume phase transition with the increasing temperature. The microgel obtained by the most hydrophilic crosslinking agent, GDMA exhibited higher hydrodynamic diameters in the fully swollen form at low temperatures than those obtained by PETA and PEPTA. Higher hydrodynamic size decrease from fully swollen form to the fully shrunken form was also observed with the same microgel.

An easy preparation of ‘monolithic type’ hydrophilic solid phase: Capability for affinity resin to isolate target proteins

An easy preparation method of monolithic type hydrophilic solid phase was discussed. Newly invented functional monomer with a hydrophilic cross-linking agent was co-polymerized to realize well-controlled monolithic co-continuous structure by use of diethylene glycol as porogenic solvent. We were able to control the content of the functional monomer up to 40 vol% without loss of monolithic structure. Those prepared were utilized as affinity resins after immobilization of FK506, an immunosuppressive drug as a ligand. It was found that the affinity resins prepared were hydrophilic enough to eliminate non-specific adsorption of proteins, while two of the target proteins of FK506 tested were successfully captured.

An Examination of the Gelation of Methacrylate Type Crosslinking Agents for the Preparation of Polymer Monolith with 3D Ordered Network Structures

Abstract The gelation of dimethacrylate type crosslinking agents was studied from the perspective of formation of ordered three dimensional (3D) network structures. Dynamic light scattering (DLS) data showed that the gelation of hydrophilic crosslinking agents having OH groups such as glycerol dimethacrylate (GDMA) was enhanced through hydrogen bonding in a hydrophobic solvent system such as toluene, which afforded more ordered 3D structures.

Tri(propylene glycol) glycerolate diacrylate cross-linked polystyrene: a new resin support for solid-phase peptide synthesis.

A highly flexible, mechanically and chemically stable copolymer, tri(propylene glycol) glycerolate diacrylate cross-linked polystyrene (PS-TRPGGDA), was synthesized by the suspension polymerization and employed as a solid support for peptide synthesis. The beaded polymer support containing secondary hydroxyl functional groups in the cross-linker was used as the growth site for peptide synthesis. The procedure is unique and cost-effective in that it avoids the initial functionalization steps required for most of the styrene-based polymer supports. The resin was characterized by 13C-CP-MAS NMR spectroscopy and the morphologic features of the resin were investigated using scanning electron microscopy. Swelling studies conducted on the new support revealed that the PS-TRPGGDA resin undergoes more effective swelling and solvation than PS-DVB resin in all solvents used in peptide synthesis. The efficiency of the new support was demonstrated by synthesizing a 'difficult' sequence Ala-Arg-(Ala)6-Lys and comparing it with commercially available Merrifield and Sheppard resins. The synthetic efficiency was further demonstrated by the synthesis of a 24-residue NR 2A peptide substrate of calcium/calmodulin-binding peptide. The high yield and purity of the peptide synthesized on the novel support indicates the positive role of the flexible and hydrophilic cross-linking agent in the solid support.

Poly(1-vinyl-2-pyrrolidinone) hydrogels as vitreous substitutes: a rheological study

In order to develop an artificial vitreous, a large series of hydrogels have been previously produced by polymerization of 1-vinyl-2-pyrrolidinone, with or without crosslinking. Based on the assumption that a functional vitreous substitute should possess viscoelastic properties after its delivery, a number of selected gels were characterized rheologically by both oscillatory shear stress analysis and shear creep analysis, using a controlled stress rheometer in the cone/plate configuration. The experiments demonstrated a dramatic effect of injecting the gels through small-gauge needles, as many lost their viscoelasticity to become free-flowing fluids, probably because of the cleavage of chains and crosslinks. It was also found that the increase of comonomer content (2-hydroxyethyl methacrylate) and of crosslinking level generally had a strengthening effect. However, the effects of hydrophilic crosslinking agents (diallyl ether and divinyl glycol) were irregular. Eventually, only four hydrogels in this series showed viscoelastic characteristics after injection through a 30-gauge (0·13mm diameter) needle, maintaining behaviour typical of crosslinked networks and warranting further assessment as potential vitreous substitutes. © 1998 SCI.

A novel hydrophilic crosslinker in preparation of hydrophilic sorbents

A new highly hydrophilic crosslinking agent, 2,3-dihydroxybutane-1,4-diyl dimethacrylate (DHDM), was synthesized from 1,2: 3,4-diepoxybutane by the reaction with methacrylic acid. Highly hydrophilic spherical particles were prepared by suspension copolymerization of 2-hydroxyethyl methacrylate (HEMA) with DHDM in an aqueous medium in the presence of cyclohexanol and 1-dodecanol as inert diluents. Porous properties of HEMA-DHDM copolymer were compared with those of commercially available poly(2-hydroxyethyl methacrylate- co-ethylene dimethacrylate) and poly(glycidyl methacrylate- co-ethylene dimethacrylate) sorbents.

Hydrophilic Sponges Based on 2-Hydroxyethyl Methacrylate. III. Effect of Incorporating a Hydrophilic Crosslinking Agent on the Equilibrium Water Content and Pore Structure

The effect of using a hydrophilic crosslinking agent (divinyl glycol, DVG) on 2-hydroxyethyl methacrylate (HEMA) sponge swelling and pore morphology was evaluated. Concentrations of crosslinking agent, redox initiators and HEMA (75–90wt%) in the initial aqueous monomer mixture were varied. Anomalous sponge swelling behaviour, together with the formation of non-uniform stratified sponges was rationalised in terms of the assumed disparate free radical reactivities of DVG and HEMA. Environmental scanning electron microscopy indicated that the stratified sponges did not exhibit suitable porosity for biomedical use. © of SCI.

Synthesis, characterization, and application of tetraethylene glycol diacrylate crosslinked polystyrene support for gel phase peptide synthesis

Styrene and tetraethylene glycol diacrylate (TTEGDA) were copolymerized by the free radical aqueous suspension polymerization technique, employing toluene as the monomer diluent at 80°C. The resulting beads were functionalized by chloromethylation. The copolymer was characterized by IR and high-resolution solid-state 13C-NMR techniques. Scanning electron microscopy was employed to observe shape, size, and morphological features of the crosslinked bead copolymer. The swelling capacities of the copolymer were measured in various solvents. Reactivity of the amino functionalized polymer was compared with divinylbenzene-polystyrene (PS) resin. Stability of the copolymer was tested under various peptide synthetic conditions. High capacity chloromethyl TTEGDA-crosslinked PS was employed as a solid support in the synthesis of the hydrophobic peptide Boc(Ala-Leu-Ala)4-OMe. The coupling and deprotection steps in the synthetic scheme proceeded in near quantitative yields, supporting the positive role of the flexible and hydrophilic crosslinking agent. The fully protected 12-residue peptide was cleaved from the support by a transesterification procedure in 85% overall yield and characterized by thin-layer chromatography, amino acid analysis, and 1H-NMR. © 1996 John Wiley & Sons, Inc.

Synthesis and metal binding behavior of hydroxamic acid resins from poly(ethyl acrylate) crosslinked with divinylbenzene and hydrophilic crosslinking agent

AbstractPorous poly(hydroxamic acid) chelating resin was prepared by the reaction with poly(ethyl acrylate) crosslinked with divinylbenzene and hydrophilic crosslinking agent, and hydroxylamine. The hydrophilic crosslinking agents and diluent used in this article were ethylene glycol dimethacrylate or butanediol dimethacrylate, and 2,2,4‐trimethyl pentane, respectively. The characterization of this type chelating resin was carried out by IR spectroscopy, density measurement, and scanning electron microscopy. Various metal binding properties such as extraction, kinetics, and selectivity were investigated with atomic absorption spectrometer and inductively coupled plasma spectrometer. Poly(hydroxamic acid) resins crosslinked with mixed crosslinking agents showed better metal extraction properties and faster adsorption rate than those crosslinked with divinylbenzene alone. And alkali treatment enhances the binding rate for metal ions because of the formation of other chelating ligands or micropores. © 1995 John Wiley & Sons, Inc.

Metal complexation of crosslinked polyacrylamide-supported dithiocarbamates: Effect of the molecular character and extent of crosslinking on complexation

Dithiocarbamate functions were incorporated into different polyacrylamide matrices crosslinked with a flexible and hydrophilic crosslinking agent, tetraethyleneglycol diacrylate (TEGDA), and their complexation behaviours were investigated. Crosslinked polyacrylamides with varying extents of the tetrafunctional TEGDA crosslinks were prepared by free radical solution polymerization at 60°C using potassium persulphate as initiator in ethanol. The dithiocarbamate functionality was incorporated into these polyacrylamides by a two-step polymer-analogous reaction involving (i)trans-amidation with ethylenediamine and (ii) dithiocarbamylation of the aminopolyacrylamide with carbon disulphide and alkali. The complexations of dithiocarbamate with Cu(II), Ni(II), Zn(II), Co(II) and Hg(II) ions were followed under different conditions. The metal ion intake varied with the extent of the crosslinking agent and the observed trend in complexation is Hg(II) > Cu(II)> Zn(II)> Co(II)> Ni (II). The time-course of complexation, the possibility of recycling, swelling characteristics, and spectral and thermal analyses were carried out. The thermal stability increases upon complexation with metal ions.

Macromolecular diffusion through collagen membranes

Collagen is a major constituent of connective tissue and is unique in possessing different levels of structural order: primary, secondary, tertiary, and quaternary. The membrane fabrication method altered the collagen structure and porosity. The effect of collagen structure, crosslinking density, hydrophilicity of crosslinker, and membrane porosity on macromolecular diffusion were studied. Permeability, partition, and diffusion coefficients were determined for proteins varying in molecular weight (14,000–16,000). ‘Pore’ type permeation was the predominant mechanism. The quaternary structure, crosslinking density, and membrane porosity of the membranes were found to regulate the diffusion of macromolecules. The highest diffusion coefficients were found for the least crosslinked membranes, random collagen fibril structure, and membranes fabricated with the hydrophilic crosslinking agent.

Preparation of new hydrophilic poly‐vinylpyridine beads and their application to immobilization of urease

AbstractMacroporous hydrophilic poly‐vinylpyridine beads were prepared by suspension copolymerization of 4‐ (or 2‐)vinylpyridine and hydrophilic cross‐linking agents, such as ethylene glycol dimethacrylate (1EG) and tetraethylene glycol dimethacrylate (4EG), and their physical properties were studied. Immobilized enzymes were obtained by adsorption of urease on vinylpyridine polymers and commercially available hydrophobic polymers. The poly‐4‐vinylpyridine resin crosslinked with 4EG (degree of crosslinkage, 25%) showed higher water regain, larger average pore radius, and the highest adsorption of urease. Leakage of urease from immobilized urease was scarcely observed in the buffer solution used. The hydrophilicity and hydrophobicity of support affected markedly the enzymatic reaction of the immobilized enzyme. As one of the applications of the polymer‐supported urease, blood urea nitrogen in human sera was determined.

Cross-Linked Cotton of High Moisture Regain

Two general methods for retaining the high moisture regain of cotton after resin- finishing to improve wash-wear properties have been studied. The first method was the use of hydrophilic cross-linking agents, and the second method was the use of hydrophilic additives with conventional resins. The hydrophilic cross-linking agents included methylolated derivatives of N,N'-di hydroxyethylenebisamides, dimethylaminoethyltriazone, trimethylammoniumethyltriazone iodide, and bis( 2-carbamoylethyl)dimethylammonium iodide. Several mixtures of di methylolethyleneurea and one of these agents gave better combinations of high moisture regain and crease-recovery angles than either component alone. The best combination of these properties was obtained with methylolated dimethylaminoethyltriazone. It is believed that agents of this type are effective because of the formation of hydrophilic derivatives of cellulose. The hydrophilic additives included polyethylene glycols and simple quaternary ammonium salts. These were added to trimethylolmelamine and dimethylolethyleneurea resins. Best results, on the basis indicated above, were obtained with benzyltrimethyl ammonium chloride and dimethylolethyleneurea. It is believed that these additives, like the salts and the polyethylene glycol ethers studied by other workers, function by preventing fiber collapse during curing. The polyethylene glycol that was retained in the fabric by coreaction with the trimethylolmelamine did not appear to have any effect on the moisture absorptivity.