Hybrid Monomers Research Articles

Synthesis and photo-curing behaviors of silicon-containing (vinyl ether)-(allyl ether) hybrid monomers

A series of silicon-containing (vinyl ether)–(allyl ether) hybrid monomers used in nano-imprint lithography resists were synthesized and subjected to photo-initiated polymerization. The surface energies of the monomers and the resulting polymer films were then investigated. The surface energies of the monomers were very low at less than 15 mJ m–2. The photo-curing behaviors of the five hybrid monomers were investigated using real-time Fourier transform infrared spectroscopy. The monomers were sequentially initiated with cationic (PAG201) and mixed (cationic initiator PAG201, radical initiator ITX or TPO) initiators. The vinyl ether double bond polymerized both rapidly and completely, whereas the allyl ether double bond remained when PAG201 was used as the photo-initiator and polymerized completely with mixed initiators. The different double bonds of the silicon-containing (vinyl ether)–(allyl ether) hybrid monomer increased the efficiency of the polymerization and overcame the intrinsic limitations of the free radical and cationic polymerization processes, including strong oxygen inhibition, large volume shrinkage and high humidity sensitivity. The five monomers with low viscosity, low surface energy, good thermal stability and good photo-polymerization properties were suitable for nano-imprint photoresists. © 2013 Society of Chemical Industry

Synthesis and electro-optical properties of new conjugated hybrid polymers based on furan and fluorene units

A novel series of hybrid monomers containing furan and fluorene units, namely 2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (FFF), 2,7-di(furan-2-yl)-9H-fluoren-9-one (FOF) and 2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan (FHF), was synthesized and their electrochemical polymerization was achieved via potential cycling. Optical and electrochemical properties of the polymers, poly(2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (PFFF), poly(2,7-di(furan-2-yl)-9H-fluoren-9-one) (PFOF) and poly(2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan) (PFHF), were investigated and it was found that polymer films exhibited quasi-reversible redox behavior (Epox=0.92V for PFFF, Epox=1.08V for PFOF and Epox=0.99V for PFHF) accompanied with a reversible electrochromic behavior, yellow to dark blue for PFFF, orange to green for PFOF and orange to green for PFHF. Their band gap values (Eg) were found to be 2.49, 2.32 and 2.61eV for PFFF, PFOF and PFHF, respectively.

Producing ORMOSIL scaffolds by femtosecond laser polymerization

Structures with different geometries and sizes were built via direct femtosecond laser writing, starting from new organic/inorganic hybrid monomers based on hybrid methacrylate containing triethoxysilane, in addition to urethane and urea groups. Multifunctional oligomer of urethane dimethacrylate type was chosen as comonomer in polymerization experiments because dimethacrylates give rise to the formation of a polymer network, having a number of favorable properties including biocompatibility and surface nanostructuring. Free standing polymeric structures were designed and created in order to be tested in fibroblast cells culture. Investigations of the cellular adhesion, proliferation, and viability of L929 mouse fibroblasts on free-standing laser processed scaffolds were performed for different scaffold designs.

Towards hybrid carbazole/pyrrole-based carboxylated monomers: chemical synthesis, characterisation and electro-oxidation properties

Six novel hybrid carbazole (Cbz)–pyrrole (Pyr)-based carboxylated monomers were synthesised and unambiguously characterised using common spectroscopic tools. Clauson-Kaas, amide coupling, LAH (lithium aluminium hydride)-mediated reduction, esterification and debenzylation reactions were used as key chemical reactions towards their multi-step synthesis. The electro-oxidation features of all these six hybrid Cbz/Pyr-monomers were investigated for the electro-deposition of corresponding polyCOOH conducting coatings. Quite interestingly, and due to the fact that such electro-oxidisable monomers contain both types of oxidisable heterocycles, that is, Pyr and Cbz species, it was found that the successful electro-polymerisation of these hybrid Cbz/Pyr-monomers was highly dependent on the relative number of Cbz versus Pyr unit(s) present in corresponding monomers. Indeed, a successful electro-deposition of the corresponding conducting polymeric films onto a working Pt electrode was observed only for hybrid monomers characterised by a Cbz/Pyr unit(s) ratio greater than or equal to 1. This result has been validated by systematically tuning the number of oxidisable Cbz and Pyr unit(s) present in monomers through proper chemical design and monomer multi-step synthesis. In that case, cyclic voltammogram analyses readily confirmed the exclusive electro-deposition of conductingpolyCbz-films.

Synthesis of Poly(Phenylene Ethynylene)s Containing Trialkoxysilane Side Chains

New hybrid monomers and polymers consisting of rigid π-conjugated rods flanked with trialkoxylsilane side chains have been successfully synthesized. It has been shown that the monomer undergoes a sol-gel process to form transparent gels, from which the organic rods can be subsequently removed to produce nanoporous materials.

Nanostructured Organic–Inorganic Composite Materials by Twin Polymerization of Hybrid Monomers

AbstractForming two structurally different but associated polymer structures in a single step is a possible route for the production of nanostructured materials. By means of twin polymerization of specially constructed monomers consisting of two different covalently bonded building blocks (hybrid monomers), this route is realized. What is important is that two different macromolecular structures are formed from one monomer in a single process. The two polymers formed can be linear, branched, or cross‐linked structures. The molecular composition of the hybrid monomer defines the degree of cross‐linking of the corresponding macromolecular structures that is theoretically possible.

Light emission on heating polymer networks formed by radical polymerization

Organic–inorganic hybrid monomers based on alkoxysilanes bearing methacrylate groups, or the pure organic dimethacrylate monomers were photo-polymerized to densely cross-linked networks. Storage of the polymer samples in nitrogen and at ambient laboratory temperature was associated with a slow decay of trapped free radicals and formation of new cross-links. In air, reactions with oxygen lead competitively to formation of peroxides due to easier diffusion in the polymer matrix. The formation and existence of peroxides in samples stored in air was shown by the chemiluminescence (CL) induced at elevated temperatures. The peroxide accumulation proceeds in three stages. At first, approximately up to 6 weeks, a high rate of accumulated peroxides activated by long living radicals is assumed. During the next 20 weeks a steady state oxidation stage is observed before another accumulation of peroxides occurs. The glass transition temperature ( T g) changes were used to estimate variation of cross-link density during ageing the networks. As far as the entirely organic network is concerned the main portion of precursors giving rise to cross-links in the post-curing period was deactivated within 9 weeks under the influence of oxygen. Contrary to this finding in networks based on organic–inorganic hybrid monomers and a copolymer of the inorganic and organic monomers the additional cross-linking is considerably less influenced by oxygen. It is anticipated that a pronounced network structure favours further cross-linking over oxygen addition.

Advances in Hybrid Organic-Inorganic Proton Exchange Polymer Membranes Incorporating Heteropoly Acids

We describe a new class of materials for proton conduction for proton exchange membrane (PEM) fuel cell applications based on the heteropoly acids (HPAs). HPAs are readily functionalized by a variety of moieties including polymerizable organic groups. These hybrid monomers are polymerized into polypolyoxometallates (polyPOMs). The materials are characterized by IR, NMR, and SAXS. Proton diffusion coefficients are measured by Pulse Field Gradient Spin Echo NMR and are observed to increase with temperature. In-plane proton conductivity measurements show that performance similar to a state-of-the-art PFSA ionomer is obtained at 80 {degree sign}C and 100% RH. Conductivities at lower RH or higher temperature are not yet sufficiently high. For these first generation materials many problems still need to be addressed in order to fabricate materials with all the required properties for a next generation PEM.

The design and synthesis of porphyrin/oligiothiophene hybrid monomers

In an effort to build effective photovoltaic cells based on porphyrin-functionalised polythiophenes we have focused on synthetic routes to three monomer types. By controlling the geometric structure of the monomer, oxidation of these materials should produce polymers with different architectural structures, and as a result, different opto-electronic properties. Employing Wittig protocols allowed access to monomers in which the porphyrin moiety is connected to the beta-position of the thiophene via an alkene linkage. In addition, monomers were constructed using porphyrin condensation methods to afford alpha-thiophene meso-substituted porphryins. Another set of monomers was also prepared via porphyrin condensation routes, but instead utilising beta-formylthiophenes. By utilising different formyloligothiophenes we were able to generate a series of monomers that can be used to control the loading of the porphyrin in the polythiophene matrix.

Organic–inorganic hybrid networks by the sol–gel process and subsequent photopolymerization

AbstractOrganic–inorganic hybrid materials were prepared by a convenient two‐step curing procedure based on sol–gel condensation and subsequent photopolymerization. Novel bismethacrylate‐based hybrid monomers with pendant, condensable alkoxysilane groups were prepared by Michael addition and possessed number‐average molecular weights between 580 and 1600 g/mol. The formation of inorganic networks by sol–gel condensation of the alkoxysilane groups in the presence of aqueous methacrylic acid was monitored with rheological measurements. The condensation conversion was monitored with solid‐state 29Si cross‐polarization/magic‐angle spinning NMR spectroscopy. Subsequent photopolymerization led to organic–inorganic hybrid networks and low volume shrinkage, ranging from 4.2 to 8.3%, depending on the molecular weight of the hybrid monomer applied. Highly filled composite materials with glass filler fractions greater than 75% showed attractive mechanical properties with Young's moduli of 2700–6200 MPa. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4274–4282, 2001

Bismethacrylate-Based Hybrid Monomers via Michael-Addition Reactions

Bismethacrylate monomers and macromonomers bearing various alkoxysilyl units were prepared by convenient Michael addition of ethylene glycol acrylate methacrylate (EGAMA) and ethylene glycol bisacrylate (EGBA) to various α,ω-alkoxysilylamines. The resulting monomers and macromonomers have been characterized in detail by NMR spectroscopy, VPO measurements and FAB-MS. Average molecular weights M n ranged between 530 and 1600 (VPO) in addition reactions with bisacrylates. FAB-MS evidenced the formation of a homologous macromonomer series. Viscosities of the liquid monomers are relatively low, ranging from 52 to 305 mPa.s. This renders these compounds interesting as reactive diluents in dental composite formulations. Polymerization of the monomers and macromonomers resulted in low volumetric shrinkage in the range of AV = 2.2-7.8% at high methacrylate conversion. Cross-linking was monitored by photo-DSC. Furthermore, composites were prepared by mixing Bis-GMA with the new hybrid monomers, initiator and glass filler. The composites showed compressive strengths of 190-329 MPa, flexural strengths from 23 to 53 MPa and Young's moduli between 2090 and 5060 MPa. Low volumetric shrinkage was observed also for the composites upon photopolymerization, ranging from only 0.8% to 2.2% in comparison to over 3% shrinkage of commercially available composites. Besides the viscosity reducing effect due to the branched structure, the pendant alkoxysilyl groups of the synthesized hybrid monomers can be polymerized to form nanoparticles with reactive acrylate surface, permitting the in situ preparation of nanocomposites.

Oxidation-resistant thermosets derived from thermal copolymerization of acetylenic monomers containing boron and silicon

Polymerization of acetylenic monomers containing silicon and boron produces materials that are resistant to oxidation at elevated temperature. In addition to homopolymerization, these inorganic–organic hybrid monomers can be copolymerized with an otherwise all carbon containing system. Inorganic elements incorporated by this method enhance the thermooxidative stability of the copolymer. This stability is a function of the amount of boron in the final product. We show that a thermoset containing an initial 5% by weight of boron can be charred to a material that when heated in air at 1000 °C loses less than 10% of its mass. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4356–4359, 1999

Polymerisation of cyclic monomers, 8. Synthesis and radical polymerisation of hybrid 2-vinylcyclopropanes

Hybrid 2-vinylcyclopropanes were synthesised by the esterification of 1-methoxycarbonyl-2-vinylcyclopropane-1-carboxylic acid with hydroxy group containing (meth)acrylates in the presence of 1,3-dicyclohexylcarbodiimide (DCC). The structure of the new hybrid monomers was confirmed by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The radical polymerisation of the hybrid monomers in bulk with 2,2'-azoisobutyronitrile (AIBN) results in transparent cross-linked polymers, whereas solution polymerisation partially results in soluble polymers with pendant 2-vinylcyclopropyl groups.

Novel Hybrid Monomers Bearing Cycloaliphatic Epoxy and 1-Propenyl Ether Groups

The synthesis of a novel series of hybrid monomers containing cationically polymerizable cycloaliphatic epoxide and 1-propenyl ether functional groups in the same molecule has been conducted. Detailed structure−reactivity studies of the diaryliodonium salt-induced cationic photopolymerizations of these monomers indicate that the rate of epoxide ring-opening polymerization is markedly enhanced by the presence of the 1-propenyl ether group. At the same time, the polymerization of the 1-propenyl ether groups in such hybrid monomers is retarded. A mechanism involving the free-radical-induced decomposition of the photoinitiator has been proposed which serves to amplify the rate of the photoinitiated cationic epoxide ring-opening polymerization.

Networks with a cholesteric structure from acrylate-vinyl ether hybrid monomers

The synthesis of the novel nematic monomer 2 with two different polymerizable groups is described. The acrylate and the vinyl ether group in 2 can be polymerized independent from each other. In a first step, free radical polymerization of the acrylate functions of 2 together with the chiral comonomer 1 leads to the cholesteric oligomers 10a–f. Densely crosslinked networks with a cholesteric structure are obtained by cationic photopolymerization of the vinyl ether groups in the mesophase. The networks exhibit bright reflection colors in the whole visible range.

Networks with a cholesteric structure from acrylate-vinyl ether hybrid monomers

The synthesis of the novel nematic monomer 2 with two different polymerizable groups is described. The acrylate and the vinyl ether group in 2 can be polymerized independent from each other. In a first step, free radical polymerization of the acrylate functions of 2 together with the chiral comonomer 1 leads to the cholesteric oligomers 10a–f. Densely crosslinked networks with a cholesteric structure are obtained by cationic photopolymerization of the vinyl ether groups in the mesophase. The networks exhibit bright reflection colors in the whole visible range.

The Synthesis of Novel Hybrid Monomers

Novel hybrid amide–ester crosslinking monomers were prepared by using methodology which utilizes the differential functionalities present within a convenient amino alcohol. Modification of the procedure to a simple one-pot reaction enables the generation of these unique monomers to be scaled to commercial levels.

Synthesis of new hybrid monomers and oligomers containing cationic and radical polymerizable vinyl groups and their photoinitiated polymerization

New hybrid vinyl monomers with both cationic- and radical-polymerizable vinyl groups were synthesized by the reaction of bis[1(chloromethyl)-2-(vinyloxy)ethyl]terephthalate (3) with unsaturated carboxylic acids using 1,8-diazabicyclo[5.4.0]-undecene-7 (DBU) as a base. The reaction of 3 with methacrylic acid 4a was carried out using DBU in DMSO at 70°C for 24 h to give an 86% yield of the hybrid vinyl monomer (5a). Polycondensation of 3 with unsaturated dicarboxylic acids was also performed using DBU to give hybrid vinyl oligomers with radical polymerizable C (DOUBLE BOND) C groups (VR) in the main chain and cationic polymerizable vinyl ether moieties (VC) on the side chain. The photopolymerization of these hybrid vinyl compounds proceeded smoothly in bulk using either a cationic photoinitiator such as a sulfonium salt or a radical photoinitiator such as acyl phosphine oxide under UV irradiation. © 1996 John Wiley & Sons, Inc.

Vinylcyclopropanone Cyclic Acetal-Synthesis, Polymerization, Structure of the Polymer and Mechanism of the Polymerization

Synthesis and radical polymerization of a few hybrid monomers between vinylcyclopropane and cyclic ketene acetal (vinylcyclopropanone cyclic acetals, 1-vinyl-4,7-dioxaspiro[2,4]heptane (1a), 1-vinyl-4,9-dioxaspiro[2.6]nonane (1b), 1-vinyl-5-phenyl-4,7-dioxaspiro[2.4]heptane (1c), and 1-vinyl-6,7-benzo-4,9-dioxaspiro[2.6]nonane (1d)) were carried out. Radical polymerization of 1 was carried out in the presence of an appropriate initiator. The structures of the polymers were found to change dramatically according to ring size and substituent of the monomers

IgA:IgM and IgA:IgA hybrid hybridomas secrete heteropolymeric immunoglobulins that are polyvalent and bispecific.

Polyvalent bispecific antibodies were secreted by hybrid hybridoma cells when both parental clones expressed a naturally polymerizing immunoglobulin. Hybrid hybridomas made from IgA lambda 2 anti-trinitrophenyl (TNP) and IgA kappa anti-phosphocholine (PC) parental cells secreted polymeric IgA antibodies that bound both TNP and PC. Some of the TNP binding was dissociated from the PC binding under conditions of mild reduction and alkylation suggesting that the bispecific polymeric IgA contained disulfide-linked parental monomers as well as bispecific hybrid monomers. Hybrid hybridomas constructed from IgA lambda 2 anti-TNP and IgM kappa anti-ox erythrocyte parental cells secreted bispecific, polymeric immunoglobulin that contained mu-, alpha-, kappa-, and lambda 2-chains. The mu and kappa-chains dissociated from the alpha- and lambda 2-chains under conditions of mild reduction and alkylation, indicating that both parental monomers had been incorporated into the same polymeric immunoglobulin to form a heteropolymeric antibody molecule. Heterologous pairing of alpha and mu heavy chains in monomers was not detected. Hybrid hybridomas constructed from IgA lambda 2 and IgG3 lambda 2 or IgA lambda 2 and IgG1 kappa parents co-secreted both parental immunoglobulins, but the antibodies secreted by these clones did not form heteropolymers or exhibit heterologous heavy chain pairing. These findings establish that polyvalent, bispecific, polymeric immunoglobulin molecules can be produced by hybrid hybridomas when both parents express a naturally polymerizing class of heavy chain but not when only one parent does. Hybrid hybridomas that produce heteropolymeric immunoglobulins are sources of high avidity bispecific antibodies that may find a number of basic and practical applications. The hybridoma cells that produce these antibodies may provide useful tools for investigating the in situ determinants of immunoglobulin chain association and the regulation of antibody assembly and secretion.