Propargyl Methacrylate Research Articles

Hemicellulosic Polysaccharides Mimics: Synthesis of Tailored Bottlebrush-Like Xyloglucan Oligosaccharide Glycopolymers as Binders of Nanocrystalline Cellulose.

We report in this contribution that while low molecular weight hemicellulosic building blocks are known not to interact with cellulosic materials, their multivalent presentation on a polymeric scaffold significantly enhanced the binding interactions that are remarkably in the same range as those usually observed for lectin-carbohydrate interactions. We developed a poly(propargyl methacrylate) scaffold on which we conjugated, by "post-click" reaction, a variety of azide reducing-end functionalized xyloglucan oligosaccharides with controlled enzymatic-mediated rate of degalactosylation. Bottlebrush-like xyloglucan oligosaccharide glycopolymers (poly(XGOn)) were obtained and their self-assemblies in aqueous solution were investigated using dynamic light scattering (DLS). We demonstrated that increasing the extent of degalactosylation promoted self-association of poly(XGOn), which we attribute to the appearance of hydrophobic domains. A sharp thermoresponsiveness, which corresponds to a decrease in aggregate size with increasing temperature, was observed when the extent of degalactosylation was 30% or greater. Importantly, isothermal titration calorimetry (ITC) and polarized/depolarized DLS revealed that poly(XGOn) exhibit a significant capacity to interact with nanocrystalline cellulose (NCC) surfaces particularly for the nondegalactosylated form, emphasizing the important role of galactosyl residues in the binding mechanism and in the 3-dimensional structures of glycopolymers.

Hairy Hybrid Nanorattles of Platinum Nanoclusters with Dual-Responsive Polymer Shells for Confined Nanocatalysis

Nanoparticles of transition metals, particularly noble metals, have been widely used in nanocatalysis. However, enhancing their stability and reusability during catalytic reactions has been a challenge that has limited the full use of the benefits associated with their miniature size. The encapsulation of noble metal nanocores as guest species into the hollow polymeric shells has emerged with the promise to solve this problem, which usually arises from a combined effect of the properties from their inorganic and polymeric components. In the present study, template-assisted synthesis of monodispersed hairy hybrid nanorattles, consisting of a movable platinum nanocluster and a hairy temperature- and pH-responsive polymer shell (Pt@air@P[MAA-co-(PMA-click-βCD-guest-PVCL)] HHNs; PMAA: poly(methacrylic acid); PPMA: poly(propargyl methacrylate); βCD: β-cyclodextrin; PVCL: poly(N-vinylcaprolactam)), was carried out and preformed as nanocatalyst. The novelty of this approach lies in the use of click chemistry and supramolecular assembly (referred to as “grafting to” approaches) to assist the creation of a protective and stimuli-responsive polymer shell to promote efficient mass transfer to encapsulated metal nanoparticles. The polymer shell not only acts as a physical barrier that prevents the coalescence of Pt nanocores but also provides a void space where organic transformation occurs on the surface of the ligand-free Pt nanocluster in a controlled manner. The as-synthesized HHNs were found to perform as a robust and reusable heterogeneous catalyst for catalytic reactions. One may find the present study a general and effective way for the synthesis of monodispersed hollow nanomaterials in a controllable and green manner.

Easy Synthesis of Ageing-Resistant Coatings with Tunable Wettability by Atmospheric Pressure Plasma

This study presents a simple and dry approach to synthesize stable, thin organic coatings with tunable wettability by injecting appropriate quantities of propargyl methacrylate (propaMA) and acrylic acid (AA) into a dielectric barrier discharge operating at atmospheric pressure. Deposition rates of up to 11 nm s−1 can be achieved, thanks to the high reactivity of the propaMA monomer in the discharge. The AA monomer exhibits a weaker reactivity but, as evidenced by IRRAS and XPS analyses, allows introducing polar groups into the coating, thereby modifying the surface wettability. The surface is thus shown to be tunable from highly hydrophobic (WCA = 140°, pure propaMA coatings) to highly hydrophilic (WCA = 15°, pure AA coatings) by adjusting the monomer ratio in the discharge. These coatings have been deposited on polypropylene (PP) substrates, and the resulting WCA is shown to remain constant for at least 64 days, ageing that is remarkably slow compared with plasma functionalization that usually leads to rapid hydrophobic recovery.

Clickable and Antifouling Platform of Poly[(propargyl methacrylate)-ran-(2-methacryloyloxyethyl phosphorylcholine)] for Biosensing Applications

A functional copolymer platform, namely, poly[(propargyl methacrylate)-ran-(2-methacryloyloxyethyl phosphorylcholine)] (PPgMAMPC), was synthesized by reversible addition-fragmentation chain-transfer polymerization. In principle, the alkyne moiety of propargyl methacrylate (PgMA) should serve as an active site for binding azide-containing molecules via a click reaction, i.e., Cu-catalyzed azide/alkyne cycloaddition (CuAAC), and 2-methacryloyloxyethyl phosphorylcholine (MPC), the hydrophilic monomeric unit, should enable the copolymer to suppress nonspecific adsorption. The copolymers were characterized using Fourier transform infrared (FTIR) and (1)H NMR spectroscopies. Thiol-terminated, PPgMAMPC-SH, obtained by aminolysis of PPgMAMPC, was immobilized on a gold-coated substrate using a "grafting to" approach via self-assembly. Azide-containing species, namely, biotin and peptide nucleic acid (PNA), were then immobilized on the alkyne-containing copolymeric platform via CuAAC. The potential use of surface-attached PPgMAMPC in biosensing applications was shown by detection of specific target molecules, i.e., streptavidin (SA) and DNA, by the developed sensing platform using a surface plasmon resonance technique. The copolymer composition strongly influenced the performance of the developed sensing platform in terms of signal-to-noise ratio in the case of the biotin-SA system and hybridization efficiency and mismatch discrimination for the PNA-DNA system.

The dual-role of Pt(iv) complexes as active drug and crosslinker for micelles based on β-cyclodextrin grafted polymer.

With a combination of RAFT and click chemistry an amphiphilic block copolymer with poly(ethylene glycol) methyl ether methacrylate (POEGMEMA) as hydrophilic block and poly(propargyl methacrylate) (PMA) as hydrophobic block has been successfully synthesized. To this, 6-azide-6-deoxy-β-cyclodextrin (N3-β-CD) was clicked creating a hosting environment for a hydrophobic small molecule platinum pro-drug. Oxoplatin, the oxidized version of cisplatin, has been modified on its axial ligand introducing cholic acid groups through esterification. This modified cisplatin forms a host-guest complex with β-cyclodextrin that has been characterised via NMR spectroscopy. The host-guest interaction that the drug established with the β-cyclodextrin grafted copolymer drove the self-assembly into nanoparticles of a diameter of 266 nm able to physical encapsulate the platinum-based drug. In the presence of ascorbic acid, 70% of the pro-drug is released over a period of 24 h. Cytotoxicity assays on ovarian cancer cells show that the polymer carrier improves the cytotoxicity of the platinum pro-drug. The IC50 value decreases from 37.7 μM with the pro-drug to 20.4 μM when the pro-drug is encapsulated into the polymer carrier. This is due to the fact that the uptake of the polymer carrier is up to 6 fold higher than the significantly smaller pro-drug by itself.

Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

Acrylate and methacrylate (acrylic acid type) are compounds with weak polarity which show a non-ideal behaviour. Phase behaviour of these systems play a significant role as organic solvents in industrial processes. High pressure phase behaviour data were reported for binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide. The bubble-point curves for the (carbon dioxide+propargyl acrylate) and (carbon dioxide+propargyl methacrylate) mixtures were measured by static view cell apparatus at temperature range from 313.2K to 393.2K and at pressures below 19.14MPa. The (carbon dioxide+propargyl acrylate) and (carbon dioxide+propargyl methacrylate) systems exhibit type-I phase behaviour. The (carbon dioxide+(meth)acrylate) systems had continuous critical mixture curves with maximums in pressure located between the critical temperatures of carbon dioxide and propargyl acrylate or carbon dioxide and propargyl methacrylate. The solubility behaviour of propargyl (meth)acrylate in the (carbon dioxide+propargyl acrylate) and (carbon dioxide+propargyl acrylate) systems increases as the temperature increases at a fixed pressure. The experimental results for the (carbon dioxide+propargyl acrylate) and (carbon dioxide+propargyl methacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule. The critical properties of propargyl acrylate and propargyl methacrylate were predicted with the Joback–Lyderson group contribution and Lee–Kesler method.

Visible Light-Controlled Radical Polymerization of Propargyl Methacrylate Activated by a Photoredox Catalyst fac-[Ir(ppy)3

Despite the robustness and flexibility of thermal controlled radical polymerization (CRP), it still remains a big challenge to prepare clickable polymers bearing acetenyl groups. In this paper, visible light CRP of propargyl methacrylate (PgMA) is investigated using ethyl-α-bromophenylacetate as initiator and fac-Ir(ppy)3 as a photoredox catalyst. By controlling the polymerization time, a linear increase of Mn with monomer conversion and narrow polydispersity index is achieved. Specifically, with [PgMA]/[Initiator]/[fac-Ir(ppy)3]=210:1:0.0285, the products show Mn=8300 g/mol and Mw/Mn=1.24 at 17% monomer conversion and Mn=17100 g/mol and Mw/Mn=1.52 at 50% monomer conversion. This result is much better than that of thermally activated Cu-ATRP of PgMA. When the ratio of MMA/PgMA is 5:1, the copolymerization product shows Mn=25300 g/mol and Mw/Mn=1.75 at 66% monomer conversion. The FTIR, 1H-NMR and 13C-NMR spectra of the PPgMA show no sp2-sp2 carbon-carbon bond, indicating that acetenyl groups are intact. In conclusion, this technology offers a versatile route for the preparation of (co)polymers with pendant alkynyl groups.

Carbohydrate-Specific Uptake of Fucosylated Polymeric Micelles by Different Cancer Cell Lines.

Inspired by upregulated levels of fucosylated proteins on the surfaces of multiple types of cancer cells, micelles carrying β-l-fucose and β-d-glucose were prepared. A range of block copolymers were synthesized by reacting a mixture of 2-azidoethyl β-l-fucopyranoside (FucEtN3) and 2-azideoethyl β-d-glucopyranoside (GlcEtN3) with poly(propargyl methacrylate)-block-poly(n-butyl acrylate) (PPMA-b-PBA) using copper-catalyzed azide-alkyne cycloaddition (CuAAC). Five block copolymers were obtained ranging from 100 mol % fucose to 100% glucose functionalization. The resulting micelles had hydrodynamic diameters of around 30 nm. In this work, we show that fucosylated micelles reveal an increased uptake by pancreatic, lung, and ovarian carcinoma cell lines, whereas the uptake by the healthy cell lines (CHO) is negligible. This finding suggests that these micelles can be used for targeted drug delivery toward cancer cells.

Direct one-pot synthesis of chemically anisotropic particles with tunable morphology, dimensions, and surface roughness.

Previously, synthesis of anisotropic particles by seeded polymerizations has involved multiple process steps. In conventional one-pot dispersion polymerization (Dis.P) with a cross-linker added, only spherical particles are produced due to rapid and high cross-linking. In this Article, a straightforward one-pot preparation of monodisperse anisotropic particles with tunable morphology, dimensions, surface roughness, and asymmetrically distributed functional groups is described. With a cross-linker of divinylbenzene (DVB, 8%), ethylene glycol dimethacrylate (EGDMA, 6%), or dimethacryloyloxybenzophenone (DMABP, 5%) added at 40 min, shortly after the end of nucleation stage in Dis.P of styrene (St) in methanol and water (6/4, vol), the swollen growing particles are inhomogeneously cross-linked at first. Then, at low gel contents of 59%, 49%, and 69%, corresponding to the cases using DVB, EGDMA, and DMABP, respectively, the growing particle phase separates and snowman- or dumbbell-like particles are generated. Thermodynamic and kinetic analyses reveal that moderate cross-linking and sufficient swelling of growing particles determine the formation and growth of anisotropic particles during polymerization. Morphology, surface roughness, sizes, and cross-linking degrees of each domain of final particles are tuned continuously by varying start addition time and contents of cross-linkers. The snowman-like particles fabricated with DVB have a gradient cross-linking and asymmetrical distribution of pendant vinyl groups from their body to head. The dumbbell-like particles prepared using DMABP have only one domain cross-linked; i.e., only one domain contains photosensitive benzophenone (BP) groups. With addition of glycidyl methacrylate (GMA) or propargyl methacrylate (PMA) together with DVB or EGDMA, epoxy or alkynyl groups are asymmetrically incorporated. With the aid of these functional groups, carboxyl, amino, or thiol groups and PEG (200) are attached by thiol-ene (yne) click and photocoupling reactions.

Self-assembling amphiphilic poly(propargyl methacrylate) grafted DNA copolymers into multi-strand helices.

DNA was covalently grafted onto poly(propargyl methacrylate) (PPMA) via "click" chemistry to synthesize the amphiphilic polymer brush. The PPMA-g-DNA brush could assemble into a primary structure of a nanofiber, which can be compactly spun into a multiple-strand helix in micron-length. The brush could also self-assemble with DNA labelled gold nanoparticles.

One-step strategy for the synthesis of a derivatized cyclodextrin-based monolithic column.

Derivatized β-cyclodextrin (β-CD) functionalized monolithic columns were prepared by a "one-step" strategy using click chemistry. First, the intended derivatized β-CD monomers were synthesized by a click reaction between propargyl methacrylate and mono-6-azido-β-CD and then sulfonation or methylation was carried out. Finally, monolithic columns were prepared through a one-step in situ copolymerization of the derivatized β-CD monomer and ethylene glycol dimethacrylate. The sulfated β-CD-based monolith was successfully applied to the hydrophilic interaction liquid chromatography separation of nucleosides and small peptides, while the methylated β-CD-functionalized monolith was useful for the separation of nonpolar compounds and drug enantiomers in capillary reversed-phase liquid chromatography. The structures of the monomers were characterized by Fourier transform infrared spectroscopy and mass spectrometry. The physicochemical properties and column performance of monoliths were evaluated by scanning electron microscopy and micro high performance liquid chromatography. This strategy has considerable prospects for the preparation of other derivatized CD-functionalized methacrylate monoliths.

A Facile Visible‐Light‐Induced Route to Functionalize Polymeric Substrates by Combining Controlled Radical Grafting Polymerization and Thiol−Yne Click Chemistry with Photoredox Catalyst Ir(ppy)3

A novel strategy, based on surface‐initiated grafting polymerization and post‐polymerization thiol‐yne click chemistry, with Ir(ppy)3 as a sole photoredox catalyst, under visible light irradiation is developed. The “livingness” of the grafting polymerization is demonstrated by the linear increase of the graft yield with irradiation time and the block grafting polymerization. Then, acetenyl groups of poly(propargyl methacrylate) (PPMA) grafting chains are reacted with pentaerythritoltetra‐(3‐mercaptopropionate) via the thiol‐yne click reaction. The successful introduction of reactive thiol groups onto the low‐density polyethylene‐graft‐poly(propargyl methacrylate) (LDPE‐g‐PPMA) films is demonstrated by Fourier transform IR (FTIR) and X‐ray photoelectron spectra (XPS) spectroscopy, and the thiol‐ene click reaction with N‐(1‐pyrenyl) maleimide. image

Well-defined "clickable" copolymers prepared via one-pot synthesis.

Well-defined "clickable" homo- and co-polymers were synthesised using a living polymerisation technique. Specifically propargyl methacrylate was successfully homo- and co-polymerised using group transfer polymerisation, GTP. This one-pot synthesis was performed without the need to protect the acetylenic group. Finally it was confirmed that the acetylenic functional group was unaffected by the polymerisation by clicking with azide 4-azidobenzoic acid.

The effect of pendant benzene-1,3,5-tricarboxamides in the middle block of ABA triblock copolymers: synthesis and mechanical properties

The synthesis and mechanical properties of ABA triblock copolymers containing benzene-1,3,5-tricarboxamide (BTA) moieties in the middle block are described. The triblock architecture was achieved by sequential polymerization of different monomers by atom-transfer radical polymerization (ATRP). The ABA triblock copolymer has a soft–hard–soft block sequence, in which the “A” block consists of soft poly(methyl acrylate), while the “B” block is a random copolymer of isobornyl methacrylate with 20 mol% of propargyl methacrylate partially functionalized with peripheral BTA groups. The pendent BTAs self-assemble into helical aggregates through lateral hydrogen-bond formation. Thermal and mechanical analyses indicated that the Young's modulus is enhanced by the BTAs. AFM images revealed that BTA self-assembly has dramatic influence on the nanoscopic ordered structure. The morphology of the triblock copolymer without BTAs consisted of hard, isolated domains embedded in a soft matrix. The copolymer containing BTAs appears as a continuous, disorganized morphology with nanoscopic domain sizes. This morphological difference presumably influences the Young's modulus. Ductility (i.e., necking) was only observed in the polymer containing BTAs. From these investigations, we conclude that introducing BTA in the hard-midblock results in intermolecular physical crosslinks, and the morphological characteristics translate to improved strength as reflected by the modulus.

Investigation of Click Reaction at an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers

Cu(I)-catalyzed Huisgen click reactions between lipophilic polymer (tri-arm azidofunctionalized polystyrene) and hydrophilic polymer (copolymer of styrene sulfonate sodium and propargyl methacrylate) were investigated and hollow capsules, consisting of composite polymer nanofilms were obtained in chloroform-water biphasic solution. Since the lipophilic polymer, or hydrophilic polymer and copper catalyst were present in the oil or aqueous phase, respectively, the cross-linking reaction proceeded only at the phase interface. The combination of lipophilic and hydrophilic polymers produced hollow capsules consisting of nanofilms with lipophilic core and hydrophilic shell.

A facile and efficient one‐step strategy for the preparation of β‐cyclodextrin monoliths

A novel, facile, and efficient one-step copolymerization strategy was developed for the preparation of β-cyclodextrin (β-CD) methacrylate monolithic columns using click chemistry. The novel mono-(1H-1,2,3-triazol-4-ylmethyl)-2-methylacryl-β-CD monomer was synthesized by a click reaction between propargyl methacrylate and mono-6-azido-β-CD, and then monolithic columns were prepared through a one-step in situ copolymerization of the mono-(1H-1,2,3-triazol-4-ylmethyl)-2-methylacryl-β-CD monomer and ethylene dimethacrylate. The physicochemical properties and column performance of the fabricated monolithic columns were characterized by elemental analysis, SEM, and micro-HPLC. Satisfactory column permeability, efficiency, and separation performance were obtained for the optimized poly(mono-(1H-1,2,3-triazol-4-ylmethyl)-2-methylacryl-β-CD-co-ethylene dimethacrylate) monolithic columns. Additionally, typical hydrophilic interaction chromatography retention behavior was observed on the monoliths at high acetonitrile content in the mobile phase. Although the enantioselectivity of our monolithic columns did not meet the level of other reported β-CD monolithic columns, this one-step strategy based on click chemistry still provides an interesting and effective model as it offers the possibility to easily prepare related novel CD methacrylate monoliths through a one-step copolymerization strategy.

Glycosylation of the polypropylene membrane surface via thiol–yne click chemistry for lectin adsorption

Glycosylated membrane, as one of the most important affinity membranes, permits affinity separation/purification of proteins based on carbohydrate–protein interactions. It is an important scientific issue to screen facile method for fabricating the glycosylated membrane surface with high glycosyl density. Such a surface can be fabricated by the direct covalent immobilization of carbohydrate ligands on the surfaces of microporous polypropylene membrane (MPPM). First, alkyne-functionalized membrane surface was fabricated by plasma pretreatment combined with UV-induced graft polymerization of 3-(trimethylsilyl) propargyl methacrylate. Then, the glycosylated membrane surface was directly fabricated with the thiol–yne click reaction to ensure rapid process, improved efficiency, and high glycosyl density. Chemical and physical properties of the membrane surface were characterized by ATR/FT-IR, XPS, FESEM and water contact angle measurement. Static lectin adsorption indicates that the glycosylated membrane can specifically adsorb lectin concanavalin A (Con A) other than peanut agglutinin (PNA). Break through curves from dynamic Con A adsorption show the membrane has unique properties such as strong specificity, high adsorption capacity, and reversible binding capability. We suggest that the prepared glycosylated membrane is of great potentials in affinity membrane chromatography for rapid and high-resolution separation/purification of lectins.

Investigation of Click Reaction at an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers

Cu(I)-catalyzed Huisgen click reactions between lipophilic polymer (tri-arm azidofunctionalized polystyrene) and hydrophilic polymer (copolymer of styrene sulfonate sodium and propargyl methacrylate) were investigated and hollow capsules, consisting of composite polymer nanofilms were obtained in chloroform-water biphasic solution. Since the lipophilic polymer, or hydrophilic polymer and copper catalyst were present in the oil or aqueous phase, respectively, the cross-linking reaction proceeded only at the phase interface. The combination of lipophilic and hydrophilic polymers produced hollow capsules consisting of nanofilms with lipophilic core and hydrophilic shell.

Anchimeric assistance on sequence regulation in partial modification of isotactic poly(propargyl methacrylate) by click reaction

Cu-catalyzed click reaction of highly isotactic poly(propargyl methacrylate) with organic azides with a weakly coordinating monoamine was found to proceed to form blocky segments from 1H NMR observation of monomer-sequence sensitive peak-splittings in the partially modified polymer, while the reaction with a highly coordinative triamine proceeded in a random fashion along the polymer chain.

Precisely controlled copper(0)‐catalyzed one‐pot reaction: Concurrent living radical polymerization and click chemistry

AbstractCopper(0)‐catalyzed one‐pot reaction combining living radical polymerization and “click chemistry” was investigated. By precisely tuning reaction time, three novel well‐defined polymers with different degree of carboxyl substitution, poly(propargyl methacrylate) (PPgMA), poly(1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate) (PCTMMA), and poly(1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate‐co‐propargyl methacrylate) (PCTMMA‐co‐PPgMA) were selectively obtained via Cu(0) powder/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) cocatalyzed LRP and click chemistry. In addition, gel permeation chromatography and 1H NMR analysis in conjunction with FTIR spectroscopy elucidate that one‐pot process undergoes three steps due to a pronounced rate enhancement of click reaction: (1) generating new monomer, 1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate (CTMMA); (2) copolymerization of two monomers (CTMMA and PgMA); (3) building homopolymer PCTMMA. Surprisingly, in contrast to typical Cu(I)‐catalyzed atom transfer radical polymerization (ATRP), copper(0)‐catalyzed one‐pot reaction showed high carboxylic acid group tolerance. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012