Polymerizable Groups Research Articles

Organometallic carboxylate resists for extreme ultraviolet with high sensitivity

We have developed organometallic carboxylate compounds [RnM(O2CR′)2] capable of acting as negative-tone extreme ultraviolet (EUV) resists. The most sensitive of these resists contain antimony, three R-groups and two carboxylate groups, and carboxylate groups with polymerizable olefins (e.g., acrylate, methacrylate, or styrenecarboxylate). Evidence suggests that high sensitivity is achieved through the polymerization of olefins in the exposed region. We have performed a systematic sensitivity study of the molecules of the type RnM(O2CR′)2 where we have studied seven R groups, four main group metals (M), and three polymerizable carboxylate groups (O2CR′). The sensitivity of these resists was evaluated using Emax or dose to maximum resist thickness after exposure and development. We found that the greatest predictor of sensitivity of the RnSb(O2CR′)2 resists is their level of polymerizable olefins. We mathematically define the polymerizable olefin loading (POL) as the ratio of the number of olefins versus the number of nonhydrogen atoms. Linear and log plots of Emax versus POL for a variety of molecules of the type R3Sb(O2CR′)2 lend insight into the behavior of these resists.

Seeded precipitation polymerization for the synthesis of gold-hydrogel core-shell particles: the role of surface functionalization and seed concentration

Polymer encapsulation is an important pathway to stabilize inorganic nanoparticles, allow their phase transfer to different media, and access inter-particle distance control in particle assembly. In the past, hydrogels were shown to be a versatile encapsulation material offering rather thick polymeric shells through free radical precipitation polymerization. In this work, we systematically investigate the influence of nanoparticle surface functionalization and concentration on the formation of core-shell microgels. Spherical gold nanoparticles are used as seeds in the radical polymerization of N-isopropylacrylamide and N,N′-methylenebisacrylamide. We find that the encapsulation occurs via precipitation of oligomers/polymers onto the seed particle surface, independent of the presence of polymerizable groups. Furthermore, we identify the seed concentration regime where almost exclusively core-shell particles are formed. In this concentration range, the hydrogel thickness is precisely controllable by the amount of seeds. Monitoring the polymerizations in situ by dynamic light scattering and absorbance spectroscopy provides first insights into the encapsulation mechanism and its time dependence.

Fabrication of elastic composite hydrogels using surface‐modified cellulose nanofiber as a multifunctional crosslinker

ABSTRACTWe fabricate composite hydrogels using surface‐modified cellulose nanofiber (CNF) and N‐isopropylacrylamide (NIPAm) as a multifunctional crosslinker and monomer, respectively. We expect to produce unique network structures that lead to elastomeric properties rarely reported for CNF‐based materials. The modification of CNF is performed to introduce polymerizable vinyl groups onto the surface of CNF via condensation between the surface hydroxyl groups and 3‐(trimethoxysilyl)propylmethacrylate. The modification and morphology of the surface‐modified CNF (mCNF) are confirmed by FTIR, solid‐state NMR, and FE‐SEM, respectively. We conduct in situ radical polymerization under various conditions using mixtures of the mCNF aqueous suspension, NIPAm monomer, radical initiator, and catalyst. The mechanical properties of the obtained hydrogels (water content = 90 wt %) are evaluated. The gels can be elastically stretched to more than 700 times their original lengths and exhibit an apparent shape recovery with a small permanent deformation (∼1/5 of the applied deformation under the gravity field). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42906.

Waterborne Polymer/Silica Hybrid Nanoparticles and Their Structure in Coatings

The structure control during the formation of films from nanoparticles is investigated. The particles are synthesized by miniemulsion polymerization with different ratios of methyl methacrylate and butyl methacrylate in the presence of silica nanoparticles. The structure of the hybrid particles is controlled by changing the surface properties of the silica through functionalization with 3‐methacryloxypropyltrimethoxysilane (MPS) and octadecyltrimethoxysilane (ODTMS). Fixation of the MPS‐silica due to polymerizable groups leads to a homogeneous distribution inside the polymer, while the inert alkyl chains of ODTMS result in segregation of the silica and the polymer. This difference in the structure is preserved during film formation and aggregation in films can be prevented effectively.

Synthesis, curing kinetics, thermal and mechanical behavior of novel cardanol-based benzoxazines

To improve the crosslink density of bio-polybenzoxazines a series of cardanol-based benzoxazine monomers with different amine compounds (aniline, furfurylamine and 4,4′-methylenedianiline) were synthesized, cured and characterized. The epoxidation of aniline-cardanol-based benzoxazine was another approach to achieve a higher crosslink density of the resulting thermoset. The nuclear magnetic resonance and Fourier transform infrared spectroscopy were used to analyze the chemical structure and purity of synthesized benzoxazine monomers. The influence of different functionalization on the curing, thermal and viscoelastic properties of cardanol-based benzoxazines was studied systematically. The curing kinetics was studied by differential scanning calorimetry and by applying Kissinger, Flynn-Wall-Ozawa and Crane methods. Thermal and mechanical properties were investigated by differential scanning calorimetry and dynamic mechanical analysis. The introduction of additional polymerizable groups (oxazine, epoxy or furan ring) into benzoxazine molecule increased the activation energy and reaction enthalpy of curing. After curing, the crosslink density, glass transition temperature and storage modulus of functionalized thermosets were considerably enhanced, especially those of epoxidized cardanol-aniline-based benzoxazine.

Electrochemical, spectroelectrochemical characterization and electropolymerization of 2-(4-methyl-1,3-thiazol-5-yl)ethoxy-substituted manganese and indium phthalocyanines

In this study, the synthesis of novel, symmetrical, tetrasubstituted metallo-phthalocyanines (MPc; M=manganese, indium) bearing four 2-(4-methyl-1,3-thiazol-5-yl) ethoxy units has been reported. All of the synthesized compounds have been characterized by using elemental analysis, UV–Vis, FT-IR and MS spectroscopic data. Electrochemical, spectroelectrochemical and electropolymerization properties of the phthalocyanines were studied by cyclic voltammetry. Electrochemistry and spectroelectrochemistry of metallophthalocyanines (MPc) bearing redox active and polymerizable thiazole groups were introduced. InIIIClPc gave only Pc ring based reduction process, metal based and Pc based redox processes were observed for during the cathodic potential scans. However both complexes were coated on the working electrode during the oxidation reactions due to the oxidative electropolymerization of thiazole groups on the substituents of the complexes. Thiazole groups were oxidized at around 1.50V, which triggered cationic electropolymerization reactions of the complexes. Type of the metal centers, working electrode, and solvent of the electrolytes and potential range and scan rate of the CV measurements affected the electropolymerization mechanisms of the complexes.

Application of ionic liquids in synthesis of polymeric binders for coatings

Abstract Ionic liquid monomers substituted with a polymerizable group were polymerized using free radical polymerization and group transfer polymerization mechanisms. Homopolymers containing a polycation or a polyanion structure were made as well as various copolymers. The latter include statistical copolymers, alternating copolymers, and block copolymers. The new polymers obtained may become of interest for application as binders for coatings. Furthermore, glass transition temperature of the polymers obtained was discussed as an important parameter for the application temperature needed for film formation. It was shown that a variation of the ionic liquid monomer structure affects the glass transition temperature of the polymer obtained. Moreover, antimicrobial properties of selected polymers were investigated using Escherichia coli and Micrococcus luteus. The results show significant differences in the antimicrobial properties of the polymers investigated. This is highly interesting for applications in which these polymers function as binders in coatings.

Mild One‐Step Synthesis of 4,6‐Benzylideneglycopyranosides from Aromatic Aldehydes and Gelation Abilities of the Glucose Derivatives

AbstractWe report herein an efficient one‐step synthesis of 4,6‐benzylidene glycoside derivatives from aromatic aldehydes bearing electron‐donating or ‐withdrawing groups as well as polymerisable monomer groups. Glucose, mannose and galactose derivatives could also be used successfully. Several of the glucose derivatives thus obtained acted as gelators for various solvents, including water. 4‐(n‐Butoxybenzylidene)glucose derivative 3a produced both a clear squalane gel and a hydrogel at 0.1 wt.‐%. Furthermore, 3‐(n‐butoxybenzylidene)glucose derivative 3i produced a clear organogel and an opaque hydrogel. The critical gelation concentration (CGC) of 3i in squalane was determined to be 0.02 wt.‐%, which is one of the lowest CGC values reported so far. The organogels, hydrogels and aqueous solution gels produced from 3a and 3d exhibited thixotropy. The strength and thixotropy of the organo‐ and hydrogel produced from 3a were estimated by a rheometer. The gel morphologies were observed by field‐emission and wet‐scanning electron microscopy, and the self‐assembly modes were analysed by XRD. We have concluded that super‐gelators can be created by this method.

Diaminium salt as reactive amphiphile for the synthesis of poly(m-phenylenediamine) and paraffin microencapsulation

Poly(m-phenylenediamine) (PmPDA) was synthesized via an oxidative polymerization using benzene-1,3-diaminium dodecyl sulfate (P2) as the monomer. P2 is a new concept of reactive surfactant because, unlike conventional polymerizable surfactants where the polymerizable group is a carbon–carbon double bond, therein, the polymer chain propagates through the diaminium group. Polymerization in aqueous micellar solution, chloroform/water interface, and xylene/water emulsion allowed successful synthesis of PmPDA. Infrared and UV–vis spectroscopy revealed that PmPDA share chemical structure, based on phenazine with open segments, rich in quinoid rings (pernigraniline-like), and partially doped, regardless of the method of synthesis. Conversely, electron microscopy exhibited important effect on morphology (nanofibers, pot-like, and globular nanoparticles) as a function of polymerization method and temperature. Additionally, cyclic voltammetry indicated electroactivity in all products, showing reduced/semi-oxidized and semi-oxidized/oxidized redox transitions with differences concerning synthesis method and temperature. A paraffin/PmPDA core–shell composite was obtained by emulsion polymerization method taking advantage of P2 amphiphilic properties. Electron microscopy evidenced microencapsulation, whereas thermal properties (melting temperature, melting enthalpy, thermal stability, and viscosity as function of temperature) suggested promising properties for the design of form-stable phase change materials.

Radical Polymerization of Pendant (Meth)acrylates on a Rigid Helical Polyisocyanate Backbone Producing Poly(meth)acrylates with “Ideally” Atactic Main Chain Configuration

This study includes a topic that poly(methyl methacrylate) (PMMA) with an “ideally” atactic main chain configuration, approximately triad tacticities of mm/mr/rr = 1/2/1, has been produced in solution by the “one-dimensionally regulated” radical polymerization using rigid helical polyisocyanate as a macromolecular template. Three types of isocyanate monomers with pendant (meth)acryloxy groups, such as 2-(methacryloxy)ethyl isocyanate (MOI), 2-[2-(methacryloxy)ethoxy]ethyl isocyanate (MOI-EO), and 2-(acryloxy)ethyl isocyanate (AOI), were polymerized using a titanium alkoxide complex to produce the corresponding polyisocyanates, MOI-n, MOI-EO-n, and AOI-n, respectively, in which n represents the number-averaged degree of polymerization. From the SAXS measurements of MOI-26 in hexafluoro-2-propanol and MOI-EO-38 in tetrahydrofuran at 25 °C, the polyisocyanates were found to be considered as rigid rod molecules. The radical polymerization of the pendant (meth)acryloxy groups was performed, and the polyisocyanate template was removed by alkali hydrolysis followed by methyl esterification, eventually producing the poly[methyl (meth)acrylate]s. The diad, triad, and pentad tacicities of the products were determined by the 1H and 13C NMR spectra, and these probabilities followed those calculated based on the Bernoulli statistics. The influences of the polymerization conditions, such as polymerization temperature and monomer concentration, on the tacticity of the final polymers were clarified. The effect of the flexible spacer between the polymerizable group and polyisocynate template was also evaluated. The radical polymerizations in which the polymerizable groups are molecularly regulated on a rod-like helical polyisocyanate backbone produced vinyl polymers with inimitable tacticities even in the solution state.

PMMA Microspheres with Embedded Lanthanide Nanoparticles by Photoinitiated Dispersion Polymerization with a Carboxy-Functional Macro-RAFT Agent

Functional poly(methyl methacrylate) (PMMA) microbeads with a very narrow size distribution were synthesized by photoinitiated RAFT dispersion polymerization in aqueous ethanol using an acrylic acid–oligo(ethylene glycol) copolymer as a macro-RAFT agent. These particles are a prototype for multiparameter bead-based assays employing mass cytometry, a technique in which metal-encoded beads are injected into the plasma torch of an inductively coupled plasma mass spectrometer (ICP-MS), and the metal ions generated are detected by time-of-flight mass spectrometry. To label the beads, the polymerization reaction was carried out in the presence of various types of small (ca. 5 nm) lanthanide fluoride (LnF3) nanoparticles (e.g., LaF3, CeF3, and TbF3) with polymerizable methacrylate groups on their surface. The type of metal ion and the metal content of the PMMA microbeads could be varied by changing the composition of the reaction medium. An important feature of these microbeads is that acrylic acid groups in the...

Synthesis and characterization of new redox-active polymers based on 10-(1,3-dithiol-2-ylidene)anthracen-9(10H)-one derivatives

Redox-active materials based on a 10-(1,3-dithiol-2-ylidene)anthracen-9(10H)one core were synthesized by the introduction of a polymerizable vinyl group in 3-position, resulting in a redox-active monomer, which possess both electron donating and electron accepting properties. The electron accepting properties can be tailored by straightforward one-step modifications of the carbonyl functionality to N-cyanoimine, dicyanomethylene or thione moieties, respectively, leading to bipolar compounds. These monomers can be polymerized by free radical polymerization. The resulting polymers could be obtained with molar masses of 6,500 to 24,300 g/mol as well as yields of up to 92% and were examined with 1H NMR and SEC. Their electrochemical behavior reveals reversible reductions comparable with the redox properties of the corresponding monomers. After further optimization, these materials could become potentially interesting for applications in organic batteries.

Preventing Electrical Shorts in Parallel-Plate Capacitors with Single-Printed Dielectric Layer

Double-printing of dielectric layers is commonly used to prevent electrical shorts in parallel-plate capacitors, but this increases the thickness of the dielectric layer and diminishes the corresponding capacitance. Double-printing also complicates the production process and increases production costs. In this paper, it is demonstrated that capacitors with single-printed dielectric layers are without shorts if the layer is completely polymerized. Therefore, electrical shorts could also be related to the state of polymerization in a defect-free dielectric layer. To demonstrate this, the electrical functionality of capacitors with single-printed dielectric layers was studied in terms of intrinsic properties of the ultraviolet (UV) curable dielectric layer, which were varied according to the curing energy. The chemical structure of the cured layer was analyzed with infrared spectroscopy to obtain the appearance of polymerizable groups and crosslinks within the polymer structure. Differential scanning calorimetry was used to measure the glass transition temperature of the dielectric material. It increases rapidly with UV curing until the polymerization is completed, whereas a small increase with further curing confirms crosslinking of the polymer. The influence of structuring effects within a dielectric layer in the presence of electrical shorts between electrodes is discussed. This research confirms that a completely polymerized layer forms a barrier to leakage and helps to prevent the formation of conductive paths between electrodes. Therefore, a connection between the structure of polymerized layer and its electrical properties is highly reasonable.

Synthesis of Vinylic Macromolecular Rotaxane Cross-Linkers Endowing Network Polymers with Toughness.

Macromolecular rotaxane cross-linkers having two radically polymerizable vinyl groups (RCs) were first synthesized and used to prepare network polymers. A crown ether/sec-ammonium-type pseudorotaxane initiator having an OH terminal-containing axle and a crown ether wheel with a vinyl group was subjected to the living ring-opening polymerization of δ-valerolactone followed by end-capping with a bulky isocyanate to yield a polyester axle-tethering macromolecular [2]rotaxane cross-linker (RC). Rotaxane cross-linked polymers (RCPs) were prepared by the radical polymerization of n-butyl acrylate in the presence of RCs (0.25, 0.50 mol %). The properties of the RCPs and covalently cross-linked polymers (CCPs) were characterized mainly by mechanical properties. Both fracture stress and strain values of RCPs were much higher than those of CCPs, probably owing to the increased network homogeneity by the rotaxane cross-link. The hybrid-type RCPs obtained from a mixture of RC and covalently connected cross-linker (CC) showed poorer mechanical properties similar to that of CCPs, indicating the importance of RCs in increasing the toughness of the network polymers.

Polymeric dental composites modified with carboxy phosphazene methacrylates

Oligophosphazenes containing carboxy and polymerizable methacrylate groups were prepared by the reaction of hexa-p-carboxyphenoxycyclotriphosphazene with glycidyl methacrylate. Introduction of these oligomers in an amount of up to 10 wt % into methacrylate filling dental composites enhances their adhesion to tooth tissues and metals by a factor of 5–7 and the compression strength by 20–30%.

Photosensitive functionalized surface-modified quantum dots for polymeric structures via two-photon-initiated polymerization technique.

In this paper, the surface modification of CdSe- and CdZnS-based quantum dots (QDs) with a functional silica shell is reported. Functionalized silica shells are prepared by two routes: either by ligand exchange and a modified Stöber process or by a miniemulsion process with amphiphilic poly(oxyethylene) nonylphenylether also know as Igepal CO-520 (IG) as oligomeric amphiphile and modified silica precursors. The polymerizable groups on the functionalized silica shell allow covalent bonding to a polymer matrix and prevent demixing during polymerization and crosslinking. This allows the homogeneous incorporation of QDs in a crosslinked polymer matrix. This paper furthermore demonstrates that the resulting QDs, which are i) shielded with a proper silica shell and ii) functionalized with crosslinkable groups, can be used in two-photon-initiated polymerization processes in combination with different photoresists to obtain highly luminescent 3D structures. The resulting luminescent structures are attractive candidates for photonics and metamaterials research.

Photoinduced Postsynthetic Polymerization of a Metal–Organic Framework toward a Flexible Stand‐Alone Membrane

AbstractMetal–organic frameworks (MOFs) are a promising class of nanoporous polymeric materials. However, the processing of such fragile crystalline powders into desired shapes for further applications is often difficult. A photoinduced postsynthetic polymerization (PSP) strategy was now employed to covalently link MOF crystals by flexible polymer chains, thus endowing the MOF powders with processability and flexibility. Nanosized UiO‐66‐NH2 was first functionalized with polymerizable functional groups, and its subsequent copolymerization with monomers was easily induced by UV light under solvent‐free and mild conditions. Because of the improved interaction between MOF particles and polymer chains, the resulting stand‐alone and elastic MOF‐based PSP‐derived membranes possess crack‐free and uniform structures and outstanding separation capabilities for CrVI ions from water.

Photoinduced postsynthetic polymerization of a metal-organic framework toward a flexible stand-alone membrane.

Metal-organic frameworks (MOFs) are a promising class of nanoporous polymeric materials. However, the processing of such fragile crystalline powders into desired shapes for further applications is often difficult. A photoinduced postsynthetic polymerization (PSP) strategy was now employed to covalently link MOF crystals by flexible polymer chains, thus endowing the MOF powders with processability and flexibility. Nanosized UiO-66-NH2 was first functionalized with polymerizable functional groups, and its subsequent copolymerization with monomers was easily induced by UV light under solvent-free and mild conditions. Because of the improved interaction between MOF particles and polymer chains, the resulting stand-alone and elastic MOF-based PSP-derived membranes possess crack-free and uniform structures and outstanding separation capabilities for Cr(VI) ions from water.

Assessing the antimicrobial activity of polyisoprene based surfaces.

There has been an intense research effort in the last decades in the field of biofouling prevention as it concerns many aspects of everyday life and causes problems to devices, the environment, and human health. Many different antifouling and antimicrobial materials have been developed to struggle against bacteria and other micro- and macro-organism attachment to different surfaces. However the “miracle solution” has still to be found. The research presented here concerns the synthesis of bio-based polymeric materials and the biological tests that showed their antifouling and, at the same time, antibacterial activity. The raw material used for the coating synthesis was natural rubber. The polyisoprene chains were fragmented to obtain oligomers, which had reactive chemical groups at their chain ends, therefore they could be modified to insert polymerizable and biocidal groups. Films were obtained by radical photopolymerization of the natural rubber derived oligomers and their structure was altered, in order to understand the mechanism of attachment inhibition and to increase the efficiency of the anti-biofouling action. The adhesion of three species of pathogenic bacteria and six strains of marine bacteria was studied. The coatings were able to inhibit bacterial attachment by contact, as it was verified that no detectable leaching of toxic molecules occurred.

Incorporation of iron oxide nanoparticles into temperature-responsive poly (N-isopropylacrylamide-co-acrylic acid) P (NIPAAm-AA) polymer hydrogel

Magnetic polymer particles have attracted much attention because of their ubiquitous use in biomedical field such as biomolecule separation, drug carriers, imaging and etc. Iron oxide magnetic nanoparticles were incorporated into temperature responsive poly (N-isopropylacrylamide) (PNIPAAm) polymer hydrogel by a seed polymerization following a surface modification step. Iron oxide magnetic nanoparticles (50–100 nm) prepared by co-precipitation method were modified with silica (SiO2) and 3-(trimethoxysilyl) propyl methacrylate (MPS) to introduce polymerizable vinyl group (−CH = CH2) at the surface of the nanoparticles. Then, the Fe3O4/SiO2/MPS particles were used as seed in polymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA). Here N, N’-methylenebisacrylamide (MBA) and potassium persulphate (KPS) were used as a cross-linker and initiator respectively. Dynamic Light scattering (DLS) results indicated a decrease of hydrodynamic diameter of magnetic Fe3O4/SiO2/MPS/poly (NIPAAm-AA) polymer particles with increasing temperature. Surface functionality and polymer coating, morphology, chemical composition and presence of iron oxide in the magnetic polymer particles were evaluated by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) respectively. The content of magnetic part was more than 50 wt.% determined by TGA, satisfactory for separation of the final particles from a dispersed media by external magnet. Therefore, the magnetic polymer particles prepared here could be a potential candidate for separation technology.