Hydroxyl Ethyl Acrylate Research Articles

Biocompatible PVAc-g-PLLA Acrylate Polymers for DLP 3D Printing with Tunable Mechanical Properties.

The technological advancement of Additive Manufacturing has enabled the fabrication of various customized artifacts and devices, which has prompted a huge demand for multimaterials that can cater to stringent mechanical, chemical, and other functional property requirements. Photocurable formulations that are widely used for Digital Light Processing (DLP)/Stereolithography (SLA) 3D printing applications are now expected to meet these new challenges of hard and soft or stretchable structural requirements in addition to good resolution in multiple scales. Here we present a biocompatible photocurable resin formulation with tunable mechanical properties that can produce hard or stretchable elastomeric 3D printed materials in a graded manner. Acrylate poly(lactic acid) (PLA) grafted polyvinyl acetate (PVAc) polymer was mixed with hydroxyl ethyl methacrylate (HEMA) and hydroxyl ethyl acrylate (HEA) as reactive diluents (50-70 wt %) in various compositions to form a series of photocurable resin formulations. Depending on the nature of the reactive diluent (HEMA or HEA) and their weight percentage, the mechanical properties of the 3D printed parts could be fine-tuned from hard (Tensile strength 20.6 ± 2 MPa, elongation 2 ± 1%) to soft (Tensile strength 1.1 ± 0.2 MPa, elongation 62 ± 8%) materials. The printed materials displayed remarkable dye absorption (95%), showing stimuli-responsive behavior for dye release (with respect to both pH and enzyme), while also demonstrating high cell viability (>90%) for mouse embryonic (WT-MEF) cells and degradability in PBS solution. These biobased 3D printing resins have the potential for a variety of applications, including tissue engineering, soft robotics, dye absorption, and elastomeric actuators.

Effects of aminopropyl-terminated polydimethylsiloxane on structure and properties of waterborne polyurethane-acrylate

To achieve a good balance between mechanical properties and water resistance of the waterborne polyurethane (WPU) film, the hydroxylethyl acrylate (HEA) terminated waterborne polyurethane-acrylate (WPUA) emulsion was prepared by chain extension of 3,6-dioxa-1,8-octanedithiol (BOODT) and modification of aminopropyl-terminated polydimethylsiloxane (APT-PDMS). The effects of APT-PDMS on the microphase separation structure and the performance of WPUA film were investigated by varying the molar ratio of APT-PDMS to HEA. The introduction of APT-PDMS caused an increase in the content of hydrophobic groups, which could induce the rearrangement of the PDMS chain segments on the surface of WPUA during film formation. The rearrangement enhanced the surface hydrophobicity of WPUA, also improved the phase separation between hard and soft segments. The former was beneficial to obtaining better water resistance, while the latter was conducive to improving mechanical properties. However, the decrease in cross-linking degree will limit the mechanical properties and the water resistance with the increase in APT-PDMS/HEA molar ratio. The optimal balance between mechanical properties and water resistance can be achieved when the APT-PDMS/HEA molar ratio is 0.25. This work provides a feasible scheme for the industrial production of WPUA emulsions.

Mechanical and microstructural studies in a polysaccharide-acrylate double network hydrogel

Polymeric hydrogels continue to find a wide range of applications. However, a major drawback of hydrogels is the lack of mechanical strength. In this regard, “Double Network Hydrogels” (DN) have shown great promise recently. The toughness in DN hydrogels originates from the synergistic effect of two polymeric networks. In this work, we have synthesized a DN hydrogel consisting of a tightly cross linked carboxymethylcellulose (CMC) as the first network and loosely cross linked poly(hydroxyethylacrylate) (PHEA) as a second network (CMC-PHEA-DN). The required flexibility in the second network (PHEA) was induced by the presence of a small amount of stearyl methacrylate (SM) as a co-monomer in hydroxyl ethyl acrylate (HEA). The compressive strength of the CMC-PEHA-DN hydrogel was found to be 280 times more than that of CMC-SN hydrogel, and the presence of SM in DN hydrogels showed better recovery after deformation. Cell viability studies showed the biocompatibility of DN hydrogels. The micro-structural analysis of DN xerogels by 3D X-ray Microtomography indicated the presence of oriented pores in size range of 30–40 μm. To the best of our knowledge, Microtomography was used for the first time to study the DN gels. These hydrogels can be used to develop implants that can withstand prolonged stress and expand the life span of implants.

Surface Chemical Functionalization of Wrinkled Thiol-ene Elastomers for Promoting Cellular Alignment.

Wrinkled polymer surfaces find broad applicability; however, the polymer substrates are often limited to poly(dimethylsiloxane) (PDMS), which limits spatial control over wrinkle features and surface chemistry. An approach to surface functionalization of wrinkled elastomer substrates is demonstrated through versatile, multistep thiol-ene click chemistry. The elastomer is formed using a thiol-Michael reaction of tetrathiol with excess diacrylates while wrinkle formation is induced through a second free radical UV polymerization of the acrylates on the surface of the elastomer. Due to oxygen inhibition of the free radical polymerization, pendant acrylates at the surface remain unreacted and are subsequently functionalized with a multi-functional thiol, which can be further reacted through a number of thiol-X 'click' reactions. As a demonstration, these thiol surfaces are further modified to either promote cell adhesion of human mesenchymal stem cells (hMSCs) through coupling with RGDS-containing peptides or surface passivation through reaction with hydrophilic hydroxyl ethyl acrylate moieties. Through engineering a combination of surface chemistry and surface topography, hMSCs exhibited increased spreading and cell density on RGDS-functionalized surfaces and a two-fold increase in cell alignment when cultured on wrinkled substrates. Gradient functionalized surfaces created by tuning the wrinkle wavelength with UV irradiation enabled rapid screening of the effect of topography on the hMSCs. Further, this novel application of click chemistry enables simultaneous tuning of wrinkle topology and surface chemistry towards targeted material applications.

Neural tissue regeneration in experimental brain injury model with channeled scaffolds of acrylate copolymers

The objective of the present study was to evaluate the biocompatibility and cell hosting ability of a copolymer scaffold based on ethyl acrylate (EA) and hydroxyl ethyl acrylate (HEA) in vivo after an experimental brain injury. Wistar rats were subjected to cryogenic traumatic brain injury. We evaluated the tissue response to the implanted materials after 8 weeks. The materials were implanted devoid of cells; they provoked a minimal scar response by the host tissue and permitted the invasion of neurons and glia inside them. We also found new blood vessels surrounding and inside the implant. Thus, the copolymer scaffold proves to offer a suitable environment producing a cellular network potentially useful in brain repair after brain injury.

The Synthesis of Polycarboxylates Water Reducer with Phosphate Structure

This article uses hydroxylethyl acrylate and phosphorylation reagent for esterification reaction, synthesis of a phosphate ester monomer with double bonds, and phosphate ester monomer ,Participation as the third monomer polymerization of acrylic acid and isoprene polyoxyethylene ether (TPEG). Polycarboxylate was synthesized with phosphoric acid ester structure,Investigate the impact of Phosphate ester content in single and double to polycarboxylate performance. The results showed that the polycarboxylate with phosphate structure has excellent adaptability and reduction of water slump performance.

Polymeric drug based on acrylates for biological applications: synthesis, characterization, antimicrobial, and drug release study

Chalcone derivative and their polymers are synthesized, characterized, tested for their antimicrobial activity against four different micro-organisms. In vitro cumulative drug release studies are done using UV–visible spectroscopic technique. 2,4-Dichloro-1-ene(4-hydroxyphenyl)phenone (DHP) is synthesized using 4-hydroxy benzaldehyde and 2,4-dichloro acetophenone. 4-[3-(2,4-Dichloro-phenyl)3-oxoprop-1-en-1-yl]phenylacrylate (DCP) is prepared by reacting DHP with acryloyl chloride. Copolymer of DCP is prepared using acrylic acid and hydroxyl ethyl acrylate. The drugs are characterized by IR, 1H NMR, and UV–visible spectroscopic techniques. Molecular weight of the polymer is 4000 g/mol. First decomposition temperature of the polymers is around 320 °C. MIC value of the drug is very high for gram-negative bacteria (1.95 μg/mL). In vitro drug release rate is dependent on the comonomer, pH, and temperature.

Adhesion between polymer surface modified by graft polymerization and tissue during surgery using an ultrasonically activated scalpel device

ABSTRACTIn the field of surgery, achieving adhesion between a polymer implant and tissue poses a challenge considering that suturing is not appropriate for the stability of such implants. An ultrasonically activated scalpel that generates heat by mechanical vibration and promotes adhesion between a polymer implant and native tissue by pressing the two materials together has very good potential for application in the field. To determine the type of polymer that is suitable for the purpose, we investigated polyethylene (PE) and polystyrene (PS) films, the surfaces of which were activated by corona discharge. Graft polymerization was then performed on the corona‐treated surfaces to vary their properties. The corona‐treated PE and PS films grafted with poly(acrylic acid), poly(methacrylic acid), poly(vinyl benzylacrylic acid), and poly(hydroxylethyl acrylate), respectively, adhered to the tissue when the ultrasonically activated scalpel was applied. The heat generated by the mechanical vibration and the applied pressure enabled the carboxyl or hydroxyl groups to bond with the proteins in the extracellular matrix. We therefore concluded that it was possible to integrate this technique in the development of new types of polymer devices that could be stably implanted in a living body. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40885.

Biodegradable sol–gel coatings of waterborne polyurethane/gelatin chemical hybrids

Abstract Gelatin from cold fish skin has strong mechanical properties and biodegradability. Cold fish gelatin was introduced into waterborne polyurethane (WPU) by covalent bonding to reinforce and render biodegradability of WPU. For this, gelatin was chemically modified with vinyltrimethoxysilane (VTMS) via the sol–gel type reactions and incorporated into hydroxyl ethyl acrylate (HEA) termini of WPU by UV curing. Covalent incorporations provided the hybrids with enhanced water resistance, hardness, glassy and rubbery state moduli, yield strength, and thermal resistance of soft segment along with significantly enhanced biodegradability both in trypsin solution and soil.

Research on the Modification of Waterborne UV-Curable Polyurethane Acrylate

In this study, waterborne UV-curable polyurethane acrylic resin was synthesized using polypropylene glycol, toluene diisocyanate, dimethylol propionic acid and hydroxyl ethyl acrylate, and modified by hyperbranched polyester acrylate. The influent factors on hydrophilic properties and UV curing speed of the resin were discussed, and the modified resin has compared with that of unmodified resin. Results showed that the overall performance and UV curing speed of the resin modified by hyperbranched polyester was greatly enhanced, the hydrophilic property of the resin was proportional to hydrophilic group content.

Incorporation of Modified Nano Montmorillonite (MMT) in Polyurethane Coatings Based on Acrylic Copolymer and Trimer of Isophorone Diisocyanate

This work presents the synthesis of acrylic copolymer and trimer of isophorone diisocyanate (IPDI) for preparation of polyurethane (PU) coatings. Further we have studied the effect of silane modified nano montmorillonite (MMT) on the properties of PU coatings. Nano MMT was modified by vinyltriethoxysilane (TEVS) coupling agent and incorporated in PU coatings made from acrylic copolymers and trimer of IPDI. Acrylic copolymer was synthesized in the laboratory using butyl acrylate (BA), methyl methacrylate (MMA), styrene and hydroxyl ethyl acrylate (HEA) monomers. Coating properties of prepared PU coatings studied are gloss, impact resistance, flexibility, cross hatch adhesion and physicochemical properties include chemical resistance. The experimental results revealed that polyurethane coatings based on MMT based acrylic polyol and IPDI trimer showed good gloss and excellent adhesion. Thermal stability of these PU samples was found upto 229 °C. Physicochemical properties reflected that these PU have excellent chemical and solvent resistance.

UV-curing of hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion and TGA/FTIR study of cured films

UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion (HBPUA-PUDA/SiO2) was prepared with isophorone diisocyanate (IPDI), hyperbranched polyester Boltorn H20 (H20), hydroxyl-ethyl acrylate (HEA), polyethyleneglycol (PEG-200) and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nanoSiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUAPUDA/ SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FTIR). The results show that all films exhibit two degradation stages located at about 320 and 440°C corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUAPUDA/ SiO2 film is 15°C higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.

Water and polymer dynamics in poly(hydroxyl ethyl acrylate- co-ethyl acrylate) copolymer hydrogels

Water and polymer dynamics in hydrogels based on random copolymers of hydrophilic poly(hydroxyl ethyl acrylate) (PHEA) and hydrophobic poly(ethyl acrylate) (PEA), in wide ranges of composition, were investigated by means of two dielectric techniques, thermally stimulated depolarization currents (TSDC) and, mainly, broadband dielectric relaxation spectroscopy (DRS) at several levels of relative humidity/water content. Water sorption of the hydrogels was studied by equilibrium sorption isotherms (ESI). Two secondary relaxations ( γ and β sw ) and the primary (segmental) α relaxation associated with the glass transition of the copolymer matrix were followed and analyzed against copolymer composition and water content. The results show that the copolymers are homogeneous at nm scale, except at very high PEA content. Correlations were observed between results on the organization of water in the hydrogels and on water effects on polymer dynamics. Distinct changes in the dielectric response, in particular in the time scale and the dielectric strength of the β sw relaxation, at the water content of the completion of the first hydration layer indicate that water molecules themselves contribute to the dielectric response at higher water contents. Proton conductivity of the hydrogels at various levels of water content was also studied and correlation to segmental dynamics (decoupling) was analyzed.

Proton conducting grafted/crosslinked membranes prepared from poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) copolymer

Poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) (P(VDF‐co‐CTFE)) backbone was grafted with crosslinkable chains of poly(hydroxyl ethyl acrylate) (PHEA) and proton conducting chains of poly(styrene sulfonic acid) (PSSA) to produce amphiphilic P(VDF‐co‐CTFE)‐g‐P(HEA‐co‐SSA) graft copolymer via atom transfer radical polymerization (ATRP). Successful synthesis and microphase‐separated structure of the copolymer were confirmed by 1H NMR, FT‐IR spectroscopy, and TEM analysis. Furthermore, this graft copolymer was thermally crosslinked with sulfosuccinic acid (SA) to produce grafted/crosslinked membranes. Ion exchange capacity (IEC) increased continuously with increasing SA contents but the water uptake increased up to 6 wt% of SA concentration, above which it decreased monotonically. The membrane also exhibited a maximum proton conductivity of 0.062 S/cm at 6 wt% of SA concentration, resulting from competitive effect between the increase of ionic groups and the degree of crosslinking. XRD patterns also revealed that the crystalline structures of P(VDF‐co‐CTFE) disrupted upon graft polymerization and crosslinking. These membranes exhibited good thermal stability at least up to 250°C, as revealed by TGA. Copyright © 2009 John Wiley & Sons, Ltd.

Arrangement of Type IV Collagen and Laminin on Substrates with Controlled Density of –OH Groups

Collagen IV (Col IV) and laminin (Lam) are the main structural components of the basement membrane where they form two overlapping polymeric networks. We studied the adsorption pattern of these proteins on five model surfaces with tailored density of -OH groups obtained by copolymerization of different ratios ethyl acrylate (EA) and hydroxyl EA (HEA): X(OH)=0, X(OH)=0.3, X(OH)=0.5, X(OH)=0.7, and X(OH)=1 (where X refers the ratio of HEA). Atomic force microscopy revealed substratum-specific adsorption patterns of Col IV and Lam, ranging from single molecules deposition on more hydrophilic substrata to the formation of complex networks on hydrophobic ones. Human umbilical endothelial cells were used to study the biological performance of adsorbed proteins, following the overall cell morphology, the quantities for cell adhesion and spreading, and the development of focal adhesion complexes and actin cytoskeleton. Surprisingly, two optima in the cellular interaction were observed-one on the most hydrophilic X(OH)=1 and other on the relatively hydrophobic X(OH)=0.3 substrate-valid for both Col IV and Lam. When the proteins were adsorbed consecutively, a hydrophobic shift to X(OH)=0 substratum was obtained. Collectively, these data suggest that varying with the density of -OH groups one can tailor the conformation and the functional activity of adsorbed basement membrane proteins.

Fibrinogen organization at the cell-material interface directs endothelial cell behavior

Fibrinogen (FG) adsorption on surfaces with controlled fraction of —OH groups was investigated with AFM and correlated to the initial interaction of primary endothelial cells (HUVEC). The —OH content was tailored making use of a family of copolymers consisting of ethyl acrylate (EA) and hydroxyl ethyl acrylate (HEA) in different ratios. The supramolecular distribution of FG changed from an organized network-like structure on the most hydrophobic surface (—OH 0) to dispersed molecular aggregate one as the fraction of —OH groups increases, indicating a different conformation by the adsorbed protein. The best cellular interaction was observed on the most hydrophobic (—OH 0) surface where FG assembled in a fibrin-like appearance in the absence of any thrombin. Likewise, focal adhesion formation and actin cytoskeleton development was poorer as the fraction of hydroxy groups on the surface was increased. The biological activity of the surface-induced FG network to provide 3D cues in a potential tissue engineered scaffold, making use of electrospun PEA fibers (—OH0), seeded with human umbilical vein endothelial cells was investigated. The FG assembled on the polymer fibers gave rise to a biologically active network able to direct cell orientation along the fibers (random or aligned), promote cytoskeleton organization and focal adhesion formation.

Use of block copolymer as compatibilizer in polyimide/zeolite composite membranes

AbstractIn this work, we introduced a diblock copolymer (dBC), i.e., polystyrene‐b‐poly(hydroxyl ethyl acrylate) (PS‐b‐PHEA) as a compatibilizer to enhance interfacial adhesion between PI and zeolite in PI/Zeolite/dBC (1/0.1/0.05 wt%) membrane for gas separation. FT‐IR spectroscopy showed the formation of hydrogen bonding interactions of the carbonyl and the hydroxyl in dBC with both PI and zeolite. The differential scanning calorimeter (DSC) study showed that the glass transition temperature (Tg) of PI increased upon the introduction of dBC, indicating specific interactions in the mixed matrix membranes. The gas permeabilities of H2, N2, O2, and CO2 through PI/zeolite 5A/dBC membranes were reduced but the permselectivity were increased compared to neat PI membrane. Copyright © 2009 John Wiley & Sons, Ltd.

Modular design for the controlled production of polymeric nanotubes from polymer/peptide conjugates

We have established a new strategy to produce functional organic nanotubes of controlled structure from cyclic peptide/polymer conjugates. The structure guiding cyclic peptide motif was coupled to the polymeric chains viacopper-catalyzed azide–alkyne click reaction, to yield very well-defined conjugates. The resulting conjugates were then self-assembled into nanotubes in solution. We were able to control to some extent the length of the nanotubes, by modifying the length of the polymer chain as well as by mixing conjugates of different molecular weights together. In a similar fashion we were able to prepare functional tubes from a range of polymers including poly(butyl acrylate), poly(dimethyl amino ethyl acrylate), poly(acrylic acid), poly(styrene) and poly(hydroxyl ethyl acrylate), as well as tubes with mixed functionality, by self-assembling a mixture of conjugates of differing polymer functionality. This modular approach is a powerful technique to generate a large number of nanotubes of varying size and functionality, in a controlled and rapid process. We believe this new approach will permit the design of a wide range of functional organic nanotubes of controlled structure, in a simple and efficient process.

Use of the human monocytic leukemia THP-1 cell line and co-incubation with microsomes to identify and differentiate hapten and prohapten sensitizers

Consumer and medical products can contain leachable chemical allergens which can cause skin sensitization. Recent efforts have been directed at the development of non-animal based tests such as in vitro cell activation assays for the identification of skin sensitizers. Prohapten identification by in vitro assays is still problematic due to the lack of prohapten bioactivation. The present study evaluated the effect of hapten and prohapten exposure on cell surface markers expression (CD86, CD54 and CD40) in the human monocytic leukemia, THP-1, cell line. Upregulation of activation and costimulatory markers are key events in the allergic sensitization process and have been reported to serve as indicators of skin sensitization. Cells were exposed to the prohaptens benzo(a)pyrene (BaP), 7,12-dimethylbenz(a)anthracene (DMBA), carvone oxime (COx), cinnamic alcohol (CA) and isoeugenol (IEG) at concentrations ranging from 1 to 10 μM for 24 and 48 h. The direct-binding haptens dinitrochlorobenzene (DNCB), benzoquinone (BQ), hydroxylethyl acrylate (HEA) and benzylbromide (BB) were used as positive controls. Cells were also exposed to the irritants sodium dodecyl sulfate (SDS) and sulfanilamide (SFA). Bioactivation of prohaptens was achieved by adding aroclor-induced rat liver microsomes (S9) to the cell cultures. Consistent upregulation of surface expressions of CD86, CD54 (ICAM-1) and CD40 was observed in THP-1 cells treated with direct-acting haptens (±S9) or prohapten (+S9). Upregulation of these markers was not observed after exposure to skin irritants or prohaptens in the absence of exogenously added S9. In conclusion, modification of in vitro cell culture assays to include co-incubation with microsomes enhances identification of prohaptens and allows them to be clearly distinguished from direct-binding haptens.

UV curable polyester‐based polyurethane acrylate nanocoating

PurposeThe paper's aim is to synthesise ultraviolet (UV) curable polyurethane acrylate based on polyester polyol and to study change in its mechanical, chemical, optical and weather resistance properties with varying amount of nanosilica. It also seeks to determine its optimum loading levels for property maximisation.Design/methodology/approachNew UV curable polyurethane acrylate has been synthesised using polyester polyol, blend of isophorone diisocyanate and toluene diisocyanate and hydroxyl ethyl acrylate. This resin was incorporated with nanosilica (1‐3 per cent) on the basis of total solids. The newly synthesised material was characterised by fourier transform infrared spectroscopy, gel permeation chromatography, X‐ray diffraction and scanning electron microscopy. The mechanical, chemical and optical properties of the coating films were studied and compared.FindingsThe hardness, tensile strength and abrasion resistance show significant enhancement with increasing amount of nanosilica. It is also found that UV cured polyurethane acrylate nanocoating exhibited improved weather resistance. The optimum concentration of nanosilica for better performance is found to be 3 per cent of total solids. The improvement is the result of inherent nature of nanosilica.Research limitations/implicationsNanosilica used in present context is having 10 nm mean diameter and near about 600 m2/g surface area. Nanosilica having different particle size, surface area and surface modification can be used to improve more specific properties.Practical implicationsAddition of nanosilica particles to polyurethane acrylate coating is a simple and inexpensive method resulting in phenomenal increase in properties.Originality/valueThe new organic‐inorganic hybrid nanocoating with improved weather resistance was synthesised. These coatings could find applications in demanding fields such as automotive topcoats.