2-hydroxylethyl Methacrylate Research Articles

Guided cell adhesion and outgrowth in peptide-modified channels for neural tissue engineering

A hydrogel scaffold of well-defined geometry was created and modified with laminin-derived peptides in an aqueous solution, thereby maintaining the geometry of the scaffold while introducing bioactive peptides that enhance cell adhesion and neurite outgrowth. By combining a fiber templating technique to create longitudinal channels with peptide modification, we were able to synthesize a scaffold that guided cell adhesion and neurite outgrowth of primary neurons. Scaffolds were designed to have numerous longitudinally oriented channels with an average channel diameter of 196±6 μm to ultimately promote fasciculation of regenerating cables and a compressive modulus of 192±8 kPa to match the modulus of the soft nerve tissue. Copolymerization of 2-hydroxylethyl methacrylate (HEMA) with 2-aminoethyl methacrylate (AEMA) scaffolds, provided primary amine groups to which two sulfhydryl terminated, laminin-derived oligopeptides, CDPGYIGSR and CQAASIKVAV, were covalently bound using the sulfo-( N-maleimidomethyl)cyclohexane-1-carboxylate (sulfo-SMCC) crosslinking agent. The concentration of peptides on the scaffolds was measured at 106±4 μmol/cm 2 using the ninhydrin method and 92±9 μmol/cm 2 using the BCA protein assay. The peptide modified P(HEMA- co-AEMA) scaffolds were easily fabricated in aqueous conditions, highly reproducible, well-defined, and enhanced neural cell adhesion and guided neurite outgrowth of primary chick dorsal root ganglia neurons relative to non-peptide-modified controls. The copolymerization of AEMA with HEMA can be extended to other radically polymerized monomers and is advantageous as it facilitates scaffold modification in aqueous solutions thereby obviating the use of organic solvents which can be cytotoxic and often disrupt scaffold geometry. The combination of well-defined chemical and physical stimuli described herein provides a means for guided regeneration both in vitro and in vivo.

The application of acrylic monomers with acidic groups to the synthesis of proton-conducting polymer gels

Novel proton-conducting gels suitable for electrochromic applications were prepared by the co-polymerisation of 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPSA) and ethylene glycol methacrylate phosphate (EGMP) either with methyl methacrylate (MMA), glycidyl methacrylate (GMA) or 2-hydroxyl ethyl methacrylate (HEMA) in polar aprotic solvents, such as propylene carbonate (PC), ethylene carbonate (EC) or N, N-dimethylformamide (DMF). The gels obtained, were characterised by impedance spectroscopy, FT-ir and Raman spectroscopies and DSC experiments. Electrochemical stability was studied by voltammetry from which it can be concluded that the investigated gels do not show any appreciable electroactivity over a range of potentials (−1.2 to +1.2V). The electrolytic properties of the resulting gel electrolytes are affected by the polymer matrix content, type and concentration of the acidic component, i.e., AMPSA or EGMP as well as the type of solvent used as plasticizer. The highest conductivities reached values of respectively 1.5×10 −3 and 6.7×10 −4 S cm −1 at room temperature for AMPSA- and EGMP-based electrolytes. These were achieved for DMF-plasticized samples. All EGMP-based systems had lower conductivities than AMPSA-based systems. The use of PC–DMF, EC–DMF or PC–EC–DMF solvent mixtures, on the other hand, improves adhesion to a glass substrate and resistance to the influence of traces of water. We found that the poly(AMPSA-co-MMA)–PC–DMF (30 wt.% polymer) and poly(AMPSA-co-HEMA)–PC–EC–DMF (20 wt.% polymer) systems are the most promising for electrochromic applications.

Synthesis of Hemispherical Poly(2-hydroxylethyl methacrylate-co-methyl methacrylate)/Poly(styrene-co-glycidyl methacrylate) Composite Particles with Heterobifunctional Groups by Soap-Free Seeded Emulsion Polymerization

Poly(2-hydroxylethyl methacrylate-co-methyl methacrylate)/poly(styrene-co-glycidyl methacrylate) (P(HEMA−MMA))/P(St−GMA)) composite polymer particles were prepared by soap-free seeded emulsion polymerization. The P(HEMA−MMA) seed latexes cross-linked by 0, 10, and 20 wt % ethylene glycol dimethacrylate (EGDMA) were prepared by soap-free emulsion polymerization with different HEMA/MMA monomer composition at 80 °C. 2,2‘-Azobis(2-amidinopropane) dihydrochloride (V-50) was used as an initiator in the two stages. The morphologies of composite particles were investigated by using seed particles with various HEMA content and cross-link degree, and the effects of solvent addition, preswelling of seed particles by monomers and solvent, and the weight ratio of secondary monomer to seed particles (M/P) on the particle morphology were discussed. Un-cross-linked P(HEMA−MMA) seed latex showed the property of gel particles capable of being swollen by water, which led to the instability of seed particles and a specific m...

Preparation of oxide with nano-scaled pore diameters using gel template

Silica, MgO and ZnO with various nano-scaled pore diameters were prepared with template gel synthesized from hydroxyl ethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA), where the latter worked as the cross-linker. The effects of the molar ratio [HEMA]/[EGDMA] in the gel were discussed in relation to the resultant porous structure. The pore diameter of the oxide was shown to be varied by the molar ratio [HEMA]/[EGDMA] which directly affects the structure of gel, particularly the mesh size. From the different trend in the variation of the pore size in the oxide, a contrasting trend depending on the molar ratio [HEMA]/[EGDMA] has been found for silica, MgO and ZnO. The mesh-filling and hydrogen bonding mechanism has been considered to explain the formation process of gel templated nanoporous silica and ZnO or MgO, respectively.

Preparation of nanoporous MgO using gel as structure-direct template

MgO with various nanoscaled pore diameters were formed from magnesium nitrate adsorbed into the gel templates that are synthesized from hydroxyl ethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) where the EGDMA worked as the cross-linker. The effects of molar ratio [HEMA]/[EGDMA] in the gel template on the porous structure of MgO formed in the template were investigated. The results indicated that the pore diameter of MgO could be varied by the [HEMA]/[EGDMA] molar ratio which directly affects the templating structure of gel. The smaller pore size and distribution were obtained with the increased molar ratio. The mechanism of the reaction was simply speculated.

Preparing an acrylic ester copolymer as an ultrathick negative photo resist

The characteristics of the acrylic ester copolymer as an ultrathick negative photo resist are investigated in this paper, which analyzed both thermal property and film performance. Several materials are involved in this experiment. Dimethyl-acryl-tricyclo[5,2,1,0 2,6]decame dimethyl ester (TA) of difunctional photo monomer is produced by esterifying tricyclo[5,2,1,0 2,6]decame dimethanol (TDMol) and methyl acrylate (MA). The acrylic ester resin base of the photo resist is obtained by copolymerizing methacrylic acid (MAA), benzyl methacrylate (BzMA) and 2-hydroxyl ethyl methacrylate (2-HEMA). A few designed formulas at different ratios are conducted by co-mixing 1-(4-methylthiophenyl-2-( N-morpholino) propan-1-one) (PI-777) of the photo initiator, 2-isopropylthioxanthone (ITX) of the photo sensitizer, TA, dipentaerythrithol hexaacrylate (DPHA) of the multifunctional photo monomer, and the acrylic ester resin base. Comparison with characteristics among formulas is also proposed. It is found that the thermal reliability of ultrathick negative photo resist is extremely excellent by I-line lithography process and scanning electronic microscopy (SEM) and thermal gravimetric analyzer (TGA) measurements.

Preparation of nanoporous ZnO using copolymer gel template

Mesoporous ZnO were prepared using copolymer gel template of hydroxyl ethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) where the latter worked as the cross-linker. The effects of molar ratio [HEMA]/[EGDMA] in copolymer on the porous structure of ZnO formed in the template gel were investigated. The results indicated that the pore size and its distribution of the mesoporous ZnO could be drastically varied by [HEMA]/[EGDMA] molar ratio which directly affects the templating gel structure. Smaller pores and narrow pore size distribution were obtained with the molar ratio increased. The formation mechanism of mesoporous structure was discussed based on these experimental results.

Phase behavior of side-chain liquid-crystalline elastomers and their precursors containingpara-nitro azobenzene

Side-chain liquid-crystalline copolymethacrylates (PMm's), containing para-nitro azobenzene as the mesogenic group and 2-hydroxylethyl methacrylate (HEMA) as a comonomer, were synthesized by radical polymerization, and their corresponding liquid-crystalline elastomers (LCEm's) were prepared through chemical crosslinking. All of the polymers (PMm's) and the elastomers studied showed enantiotropic smectic A phases; the clearing temperature (Ti) of the PMm polymers decreased with increasing amount of HEMA, and the Ti of the corresponding LCEm's decreased compared to that of their precursors. Small-angle X-ray scattering studies on the copolymers quenched from their liquid-crystalline phases indicated that the characteristic distance increased with increasing amorphous component content and thus, the amorphous components were in between the smectic layers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2275–2279, 2003

Formation and Morphology of Methacrylic Polymers and Block Copolymers Tethered on Polymer Microspheres

We report the use of atom transfer radical polymerization (ATRP) to graft off polymeric microspheres. Residual vinyl groups on nonswellable poly(divinylbenzene-80) microspheres were converted into ATRP initiators by hydroboration/oxidation followed by esterification. Subsequent grafting by ATRP of poly(hydroxylethyl methacrylate) (poly(HEMA)) and poly((dimethylamino)ethyl methacrylate) (poly(DMAEMA)) led to hydrophilically modified microspheres. The surface properties of these microspheres, FT-IR spectra, and potentiometric titration confirm the successful modification. In addition, swellable, lightly cross-linked poly(DVB-co-HEMA) microspheres were modified in a similar manner by grafting, i.e., methyl methacrylate (MMA) and glycidyl methacrylate (GMA), to form graft block copolymers including poly(MMA-b-DMAEMA), poly(MMA-b-trimethylammonium ethylmethacrylate (TMAEMA)), and poly(MMA-b-GMA). Microphase separation of the grafted amphiphilic block copolymers was studied by scanning electron microscopy. The microspheres modified with poly(MMA-b-DMAEMA) and poly(MMA-b-TMAEMA) show polyelectrolyte properties.

Preparation of nanoporous silica using copolymer template

Silica solids with different nanoscaled pore diameters were formed from tertraethoxysiliane (TEOS) and copolymer gel of hydroxyl ethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) where the latter worked as the cross-linker. The effects of molar ratio [HEMA]/[EGDMA] of copolymers on the porous structure of silica formed in the template gel were discussed. The properties and structure of gel and porous silica were characterized by Fourier transform infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results indicated that the pore diameter of silica could be varied by the [HEMA]/[EGDMA] molar ratio which directly affects the templated structure of copolymer gel. The larger pore diameter was obtained with the increased molar ratio, which corresponds to the decrease in the cross-link density. FT-IR and TGA suggested that the silica moiety is bonded to the network of the copolymer gel due to the gel/silica affinity based on the hydrogen bonding.

Polymer-Mediated Proton Transfers of 7-Azaindole Embedded in Poly(2-hydroxylethyl methacrylate) Matrix

Host-guest interactions including polymer-mediated proton transfer dynamics are investigated for 7-azaindole embedded in poly(2-hydroxyethyl methacrylate) matrix using time-resolved fluorescence and transient absorption spectroscopy. Upon absorption of a photon the dye molecule having cyclic H-bonds with a polymeric group undergoes excited-state double proton transfer in 100 ps to form its tautomer, while the molecule without an H-bond bridge does not experience the proton transfer within the lifetime of 1200 ps. The reverse proton transfer takes place on the time scale of 60 µs in the ground state.

Polymer-Mediated Proton Transfers of 7-Azaindole Embedded in Poly(2-hydroxylethyl methacrylate) Matrix

Host-guest interactions including polymer-mediated proton transfer dynamics are investigated for 7-azaindole embedded in poly(2-hydroxyethyl methacrylate) matrix using time-resolved fluorescence and transient absorption spectroscopy. Upon absorption of a photon the dye molecule having cyclic H-bonds with a polymeric group undergoes excited-state double proton transfer in 100 ps to form its tautomer, while the molecule without an H-bond bridge does not experience the proton transfer within the lifetime of 1200 ps. The reverse proton transfer takes place on the time scale of 60 µs in the ground state.

Poly(solketal methacrylate)-block-poly(2-cinnamoyloxyethyl methacrylate)-block-poly(allyl methacrylate): Synthesis and Micelle Formation

A triblock copolymer, poly(solketal methacrylate)-block-poly(2-trimethylsiloxylethyl methacrylate)-block-poly(allyl methacrylate) or PSMA-b-P(HEMA-TMS)-b-PAMA, was synthesized by anionic polymerization. The TMS groups were removed from the P(HEMA-TMS) block by hydrolysis in methanol to yield poly(2-hydroxylethyl methacrylate) or PHEMA. Reacting PSMA-b-PHEMA-b-PAMA with cinnamoyl chloride yielded PSMA-b-PCEMA-b-PAMA, where PCEMA denotes poly(2-cinnamoyloxyethyl methacrylate). The PSMA-b-PCEMA-b-PAMA triblock was characterized by gel permeation chromatography, NMR, and light scattering and possessed the weight-average repeat units of 300 for SMA, 190 for CEMA, and 180 for AMA. The triblock was further derivatized by hydrolyzing the acetonide groups of the PSMA block to yield PGMA-b-PCEMA-b-PAMA, where PGMA denotes poly(glyceryl methacrylate). PGMA-b-PCEMA-b-PAMA formed spherical micelles in methanol with 5%, by volume, of THF and branched cylindrical micelles in pure methanol. The micelles formed had the soluble PGMA block as the coronas and the insoluble PCEMA and PAMA blocks as the shells and cores, respectively. In toluene containing 2% methanol, only the PGMA block was insoluble. PGMA-b-PCEMA-b-PAMA formed spherical micelles, consisting of PAMA coronas, PCEMA shells, and PGMA cores. Electron microscopy and NMR studies were performed to elucidate the structure of the micelles.

Adhesion and adhesion reliability enhancement of evaporated copper on surface modified poly(tetrafluoroethylene) films from graft copolymerization

Surface modifications of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film via UV-induced graft copolymerization were carried out to improve the adhesion and adhesion reliability with evaporated copper. The PTFE film surface was modified by graft copolymerization with a monomer, such as 2-hydroxylethyl methacrylate (HEMA), acrylic acid (AAc), methacrylic anhydride (MAAn), and glycidyl methacrylate (GMA). A double graft copolymerization process, involving initially the graft copolymerization with HEMA, AAc or MAAn, which contained the functional moities for curing the epoxide groups, and subsequently by graft copolymerization with GMA, which contained the epoxide group, was also employed. The adhesion strength of the evaporated Cu on the singly and doubly graft-copolymerized PTFE film was affected by the type of monomer used during graft copolymerization, the concentration of the graft, the extent of O/sub 2/ plasma post-treatment after graft copolymerization, and the extent of thermal treatment after metallization. The T-type peel adhesion strength of the Cu/PTFE laminate obtained under the optimum conditions was about 19 N/cm. The adhesion strengths of the Cu/PTFE laminates remained practically unchanged after the Level I test (85/spl deg/C and 85% relative humidity for 168 h). The good adhesion strength and adhesion reliability must have resulted from the strong affinity of the graft chains for Cu, the extensive crosslinking of the graft chains at the metal/polymer interface, and the fact that the graft chains where covalently tethered on the PTFE surface. The cohesive failure of the metal/polymer laminates was also investigated.

An aqueous process to graft 2-hydroxyl ethyl methacrylate onto polyvinyl chloride through its functional group

A simple aqueous method has been discussed to graft 2-hydroxyl ethyl methacrylate (HEMA) onto the surface of polyvinyl chloride through its functional group (-OH). This method involves the conversion of the -OH group of HEMA to -ONa using metallic sodium. The modified surface has been characterized using FT ATR-IR and Scanning electron microscopic methods. The advantage of the method is the feasibility of using the intact double bond of HEMA for further reaction.

Porous Polymer Monoliths: Preparation of Sorbent Materials with High-Surface Areas and Controlled Surface Chemistry for High-Throughput, Online, Solid-Phase Extraction of Polar Organic Compounds

Porous monolithic materials with high surface areas have been prepared from commercial 80% divinylbenzene. The pore properties of these materials are controlled by the type and composition of the porogenic solvent and by the percentage of cross-linking monomer (divinylbenzene) in the polymerization mixture. Surface area was found to increase with the divinylbenzene content of the monolith. Using high-grade divinylbenzene and a suitable porogenic solvent, monolithic materials with specific surface areas as high as 400 m2/g yet still permeable to liquids at reasonable back pressure were obtained for the first time. A macroporous material with hydrodynamic properties optimized for solid-phase extraction has been designed and its permeability and adsorption ability was demonstrated by adsorbing phenols at flow velocities that exceed those of current materials by a factor of 30. A unique set of polymerization conditions had to be developed to allow the incorporation of polar 2-hydroxylethyl methacrylate into the hydrophobic nonpolar backbone of the divinylbenzene monolithic material. This improves wettability while high-flow properties are maintained and unusually high recoveries of polar compounds are allowed.

Hollow-fiber membranes coated with polymerizable bicontinuous microemulsions

A new method has been successfully employed to prepare hollow-fiber membranes by coating and polymerizing bicontinuous microemulsions onto the internal surfaces of hollow-fiber membranes. The bicontinuous microemulsion consisting of water, a polymerizable zwitterionic surfactant of acryloyloxyundecyl dimethylammonio acetate, methyl methacrylate, and 2-hydroxylethyl methacrylate (HEMA) can form a transparent polymer thin film after polymerization. The hollow-fiber membranes as the supports for microemulsion coatings were fabricated from the spinning solution of polyethersulfone/diethylene glycol/ N-methyl-2-pyrrolidone. The microemulsion coated hollow-fiber membranes were evaluated by the separation efficiency and the permeation rate of polyethylene glycol (PEG) solutions. The performance of coated membrane on the PEG separation is strongly dependent on the concentration of HEMA and water in precursor bicontinuous microemulsions. The pore size of the hollow-fiber membranes can be regulated between about 2 to 40 nm by varying the composition of precursor bicontinuous microemulsions. The characteristics of the coated membranes is believed to be directly related to the bicontinuous structures of precursor bicontinuous microemulsions. The use of polymerizable bicontinuous microemulsions enable one to better control the microstructures of coated membranes via in situ polymerization.

Crosslinkings of polyacrylonitrile using NCO terminated urethanes

High nitrile terpolymers comprised of acrylonitrile (92 wt%), methyl acrylate (4 wt%), and hydroxylethyl methacrylate (4 wt%) (PAN) were synthesized and crosslinked using hexamethylene diisocyanate (HDI) terminated urethane prepolymer prepared from different molecular weights of poly(tetramethylene adipate) glycol (PTAd). The effects of urethane crosslinking and crosslinker length are studied. The degree of swell and soluble fraction of PAN increased dramatically and density decreased with crosslinker length. Wide angle X-ray diffraction showed an increase in the lateral repeat distance of hexagonal lattice as well as the crystalline size. The tan 6 peak temperature of PAN decreased by crosslinking, however, the rubbery state extended with higher temperature, with the modulus ( G N o) increasing as the crosslinker shortened. The undrawn crosslinked PAN showed ductile fracture with pronounced yielding and necking, whereas the undrawn linear PAN showed brittle fracture. The drawn linear PAN sample split into fibrils at the fracture tip, whereas the crosslinked PAN showed smooth fracture surfaces.

Studies on interpentrating polymer networks of polyurethane and polybismaleimide. I. Polyurethane and bismaleimide-urethane copolymer

The interpenetrating polymer networks (IPNs) of polyurethane (PU) and the mixture of bismaleimide (BMI) and the 2-hydroxylethyl methacrylate (HEMA)-terminated PU prepolymer (HPU) were prepared by using a simultaneous polymerization technique. The effects of the PU molecular weight and the amounts of the PU on the mechanical properties, thermal stability, and dynamic mechanical properties are discussed. The IPNs exhibited superior ultimate tensile strength as the polyol of PU and HPU in the IPNs is based on poly(tetramethylene oxide) (PTMO) glycol of molecular weight 1000 (PTMO1000). Izod impact property of the IPNs indicated that the PU(PTMO1000)/BMI-HPU(PTMO1000) IPNs had much more significant improvement than that of the PU(PTM02000)/BMI-HPU(PTMO2000) IPNs. Better thermal stability was shown by the IPNs as compared with the components of the networks, i.e. PU or BMI-HPU copolymers. The dynamic mechanical analysis (DMA) indicates that these IPNs show various shifts in the loss moduli(E”) at the high and low temperature transition peaks for various molecular weight of the polyol employed in the PU. Better compatibility between BMI and PU was found as the PU(PTMO1000) was employed.

Syntheses and Properties of Novel Vinyl Monomers Bearing a Glycoside Residue

Abstract Novel acrylic monomers bearing a monosaccharide residue were synthesized in reactions of some methyl glycosides with 2-hydroxylethyl acrylate or methacrylate in the presence of heteropoly acid. All of them were highly soluble in water and readily polymerized by radical initiators.