Stability and solid-state polymerization reactivity of imidazolyl- and benzimidazolyl-substituted diacetylenes: pivotal role of lattice water

International audience1,6-Bis(1-imidazolyl)-2,4-hexadiyne (1) and1,6-bis(1-benzimidazolyl)-2,4-hexadiyne (5) have beenpreparedby a novel method that consists in refluxing excess imidazole and benzimidazole with 2,4-hexadiyne-1,6-diol bis(p-toluenesulfonate),pTS (3). This procedure is a viable alternative to the widely used Hay coupling protocol in case the target diyne possesses substituents capable of deactivating the copper catalyst by complexation. Diyne1crystallizes as a hydrate,1?H2O(2). For this compound, water is essential toachieve a crystalline material, and attempts to obtain crystals without included solvent were unsuccessful. In the structure of2, the organic fragments organize around the water molecule and interact with it through a dense network of hydrogen bonds. The CMC-CMC moieties are not oriented suitably for topochemical polymerization, and when trying to alter the organizationof the crystal by heating so as to induce polymerization, water is lost in an abrupt fashion that leads to instantaneous decomposition into polyaromatic-like species. Similar results were observed when water was removedin vacuo at room temperature. The benzimidazole-containing compound can be crystallized with water molecules (4)orwithout(5). X-ray crystallography shows that the structure of 5is organized by numerous C-H...N, C-H...p,andimidazolyl...imidazolyl p-p interactions. The diacetylene molecules almost have the right arrangement for topochemical polymerization, withpossibly reactingCMC-CMC fragments not beingparallel, a rare situation indiacetylene chemistry. Yet, experiments showthat topochemical polymerizationdoes not occur. Incorporationofwater in the lattice of5leads toa solvate that is topochemically reactive. Unlike2, however, water molecules in 4are not isolated but are organized as ribbons. Spectroscopic characterization of the polymer of4indicates that it is a blue phase polymer, with water coordinated to it. This study shows that it is possible to use water, and more generally solvent molecules, to transform a nonreactive diacetylene into a reactive one, even though this approach is less predictable than the cocrystal approach developed by Fowler, Lauher, and Goroff. The solvate approach is simple to implement, quite versatile because of the large rangeof solvents available, andonedoes not face theproblemof having to remove the host in case one needs to recover the polymer. Previous studies describing a similar approach are scarce

Synthèse, polymérisation et application de nouveaux monomères phosphonés

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

New N,N-amino-diphosphonate-containing methacrylic derivatives, their syntheses and radical copolymerizations with MMA

International audienceHydroxy-amino-diphosphonates HO–Cn–NH2, with 2 6 n 6 11, have been successfully synthesized via the Kabachnick-Field reaction at 70 C with high yields. These hydroxy compounds are then reacted with methacryloyl chloride to lead to novel amino-diphosphonate methacrylates MACnNP2 (with 2 6 n 6 11). These highly pure methacrylate monomers were obtained with yields higher than 75%. Radical copolymerizations of MACnNP2 (with 2 6 n 6 11) with MMA have been conducted and the r1 values (related to MACnNP2) are in the range of 1.1–1.3, and r2 values (related to MMA) about 0.8; this shows that the diphosphonate groups are statistically bonded to the methacrylic backbone

Synthesis of Novel Copolymers Obtained from Acceptor/Donor Radical Copolymerization of Phosphonated Allyl Monomers and Maleic Anhydride

International audienceA series of four phosphonated-bearing allyl monomers, that is, diethyl-1-allylphosphonate (AP), dimethyl-1- allyloxymethylphosphonate (AOP), 5-ethyl-5-(allyloxymethyl)-2- oxo-1,3,2-dioxaphosphorinane (AEDPH), and 2-benzyl-5-ethyl-5- (allyloxymethyl)-2-oxo-1,3,2-dioxaphosphorinane (AEDPBn) were synthesized. These monomers were then copolymerized by free radical polymerization in the presence of maleic anhydride, thus leading to alternated copolymers with phosphonate moieties. It was shown that both monomer conversion and reaction rate were dependent on the phosphonate moieties carried out by the allyl monomer: the bulkier the phosphonate group, the higher the polymerization rate. Thermogravimetric analysis of the copolymers revealed a high content of residue, also varying with the nature of the phosphonate moieties

Synthesis, characterization, and photopolymerization of novel phosphonated resins

International audienceNew phosphonated cross-linked polymers were synthesized from telomers obtained by reaction between 10-undecenol and dialkyl hydrogenphosphonates. Telomers were studied using MALDI-TOF MS. It was proven that side products were produced, corresponding to cross-esterification reactions of dialkyl hydrogenphosphonate on telomers and to radical additions of telomer on 10-undecenol. The same behavior was also observed with allyl alcohol. Telomers were then converted to resins by methacrylation reactions. Finally, photopolymerization of the different resins synthesized was achieved and influence of the nature of the phosphonate group (diester, monoacid and diacid) was also evaluated

Grafting of phosphonate groups onto PVA by acetalyzation. Evaluation of the anti-corrosive properties for the acetalyzed PVA coatings

International audienceOne novel aldehyde bearing a phosphonate group, ca. (3-diethylphosphonate)propanal, was successfully synthesized and characterized by means of NMR. Then phosphonic acid ester groups were chemically grafted onto poly(vinyl acetal) pre-made polymers, and especially poly(vinyl butyral) (PVB). Four acetalyzed PVA were then synthesized with different molar contents of either butyral or (3-diethylphosphonate) propanal groups. Only PVAP4 was composed of both groups, i.e. 80 mol% of butyral and 20 mol% of phosphonate. TGA of acetalyzed PVA showed a clear improvement of the PVA thermal stability. Furthermore, for PVAP3, having 50 mol% of phosphonate groups, 40% of weight remained after 600 C under air. This high thermostability was attributed to stable anhydride bonds. Finally, the coatings were subject to the salt spray test for duration up to 120 h. The results indicate that PVAP3 coating shows an excellent resistance to corrosion, thus excellent adhesive properties, as no corrosion was observed until 100 h subject to the salt spray tes

Acrylate Based Anticorrosion Films Using Novel Bis-Phosphonic Methacrylates

International audienceTwo novel phosphonated methacrylate monomers were successfully synthesized and subsequently incorportated into adhesion/anticorrosive coatings. Specifically, they were propyl N,N-tetramethyl-bis(phosphonate)-2-hydroxyl-bis(methylene) amine methylmethacrylate (MAC3NP2) and 2-[2,2-bis(diisopropoxyphosphoryl) ethoxy]-methylmethacrylate, (MAC3P2). The phosphonic forms of each monomer were blended with 85% w.w acrylates (tripropyleneglycol-diacrylate and hexanediol-diacrylate) and 6% w.w of the photo sensitive initiator DarocurVVR. Along with a monophosphonic monomer synthesized in a previous publication (MAC3P), they were polymerized on Q-panels under ultraviolet light, and then subject to the salt spray test (ca. 0.5 mol/L NaCl at 35 C) for a duration of up to 50 days. The results indicate that acrylate blends with low concentration of the bisphosphonic compound MAC3P2 have excellent resistance to corrosion, thus excellent adhesive properties. Importantly, these coatings were formed without the use of a hydrophobic polymer matrix or solvents

Recent progress on phosphonate vinyl monomers and polymers therefore obtained by radical (co)polymerization

International audienceThis review paper gathers almost one hundred recent publications devoted to the synthesis and the free radical (co)polymerization of phosphonate vinyl monomers. Different synthetic approaches are discussed to introduce the phosphonate moieties into vinyl monomers, focusing especially on recent advances. Allyl-type, vinyl-type, styrenic-type and (meth)acrylic-type monomers bearing phosphonate groups (i.e. either mono or bisphosphonate) are considered with a special care about their reactivity in free radical (co)polymerization. It is shown that depending on the position of the phosphonate moieties the reactivity of the vinyl monomers is thus modified. For instance, free radical polymerization of vinyl phosphonate monomers is mainly dominated by transfer reactions, whereas the propagation rate of para-vinylbenzyl phosphonate monomers is enhanced by the phosphonate group. According to the structure of the phosphonate-bearing (co)polymers, the resulting properties are also investigated

Versatile oligo(ethylene glycol)-based biocompatible microgels for loading/release of active bio(macro)molecules

International audienceThe present study aims in the understanding of the effect of oligo(ethylene glycol)-based biocompatible microgels inner structure on the encapsulation/release mechanisms of different types of cosmetic active molecules. For that, multi-responsive microgels were synthesized using three types of cross-linkers: ethylene glycol dimethacrylate (EGDMA), oligo(ethylene glycol) diacrylate (OEGDA) and N,N-methylenebisacrylamide (MBA). The inner morphology of the microgels synthesized was studied by 1H-nuclear magnetic resonance (1H NMR) and small-angle neutron scattering (SANS) techniques and no effect of cross-linker type on microgel microstructure was observed in the case of analysing purified microgel dispersions. Moreover, all the microgels synthesized presented conventional swelling/de-swelling behavior as a function of temperature and pH. Two hydrophobic, one hydrophilic, and one macromolecule as cosmetic active molecules were effectively loaded into different microgel particles via hydrophobic interactions and hydrogen-bonding interactions between −OH groups of active molecules and ether oxygens of different microgel particles. Their release profiles as a function of cross-linker type used and encapsulated amounts were studied by Peppas-Sahlin model. No effect of the cross-linker type was observed due to the similar inner structure of all the microgels synthesized

Red Ionic Water-Soluble Imidazolium-Containing Polydiacetylene

Synthesis of a water-soluble polydiacetylene has been achieved by topochemical polymerization in the solid state of the bis(N-methylimidazolium)diacetylene monomer. Structural characterization for the monomer by X-ray diffraction and NMR spectroscopy supports a photopolymerization initiated at the surface. Characterization of the polymer (NMR, UV and Raman spectroscopy, and dynamic light scattering) is given along with a molecular modelling interpretation of the polymerization in the solid state