Commercial Monomers Research Articles

Effects of quaternization on the morphological stability and antibacterial activity of electrospun poly(DMAEMA-co-AMA) nanofibers

Electrospun nanofibers with antibacterial activity are greatly promising for medical treatment and water purification. Herein we report antibacterial nanofibers electrospun from a series of poly(dimethylamino ethyl methacrylate-co-alkyl methacrylates) (poly(DMAEMA-co-AMA)) and to distinguish the effects of free and cross-linked cations derived from quanternization on the antibacterial activity. Poly(DMAEMA-co-AMA)s are simply synthesized by free radical polymerization from commercial monomers. DSC analysis indicates that they have Tg lower than room temperature and thus the electrospun nanofibers adhere to each other and evenly tend to form films, instead of keeping cylinderic shape. Benzyl chloride (BC) and p-xylylene dichloride (XDC) can quaternize DMAEMA units and to generate cations on the nanofiber surface. XPS analysis and colorimetric assay determine the quaternization degree and the surface accessible quaternary amines (N+), respectively. It is very promising that this quaternization endows the electrospun nanofibers with both stable morphology and antibacterial activity. The BC-quaternized fibers show better antibacterial behavior against Escherichia coli and Staphylococcus aureus than those of the XDC-quaternized/cross-linked ones, because cross-linking suppresses the chain mobility of cations. Our results confirm that antibacterial nanofibers can be facilely prepared and chain mobility of the formed cations is the necessary prerequisite for their antibacterial activity.

A Novel Light-Cured Dental Material Based on Maleic Copolymer Functionalized With Urethane Derivative for Dental Applications

The purpose of this work was to obtain a polymeric material aimed at being easily applied in a thin film on an organic substrate for dental applications. A maleic anhydride copolymer functionalized with a urethane derivative bearing methacrylate groups was synthesized, and by its mixing with commercial dental monomers, two light-curing formulations were prepared and investigated. The surface morphology and physicochemical properties of the obtained materials are affected by their composition. An increase of the diffusion coefficient from 0.38 at 3.58 µm2/s (estimated by fluorescence recovery after photobleaching) could ensure minimal moisture of an organic injectable paste situated under this polymer film.

Molecularly imprinted membrane system for endocrine removal

Molecular imprinting polymer (MIP) technique is well known for creating polymer materials with molecule selectivity in adsorption and separation. MIPs have mostly been prepared by bulk polymerization and grinding the resulting brittle polymer to prepare particles of the desired dimensions. However, this technique also suffered some backdrops such as limitation in its application due to powder shape and limitation in binding ability. To circumvent these problems, we had extended such a technique in the formation of membrane adsorbents using phase inversion imprinting technique. Namely, copolymerization of template-containing monomers with commercial scaffold monomer was achieved in such membranes in order to selectively separate the target molecules. One main feature of this system is the imprinted polymer forming film, which is possible to be used as filtration materials for selective separation. In the present study, we prepared the Bisphenol A (BPA)-imprinted membranes by copolymerization of various cov...

A direct method for preparing ethyldichlorosilane and its comparison with known alternative methods

Various methods, alternative to direct synthesis, for preparing an important commercial organosilicon monomer, ethyldichlorosilane, were studied in detail. The methods, including organomagnesium and organoaluminum procedures, hydrosilylation, and combined methods, were analyzed from the viewpoint of feasibility of laboratory and small-tonnage commercial production, and their advantages and drawbacks were revealed.

Elaboration of novel biosourced AA–BB polyamides with dangling chains from methyl ricinoleate

The existence of entirely biobased AA–BB polyamides is very limited because of the low availability of biosourced diamines. In this work, saturated and unsaturated diamines, with dangling hexyl chain, were successfully synthesized from methyl ricinoleate. These new monomers were reacted with several diacids to prepare novel partially to totally biobased AA–BB polyamides. Linear polyamide analogues were also prepared from commercial monomers. The physico‐chemical properties of the obtained polymers were assessed by DSC and TGA analysis. An auto‐plasticizing effect owing to the dangling chains was evidenced. The new branched monomers and polymers are expected to be used when modification of the properties of existing polyamides are required.Practical applications: The new branched monomers and polymers are expected to be used as green and renewable plasticizers for modification of the properties of existing polyamides. Furthermore, the presence of the carbon–carbon double bonds in the main chains would be beneficial to perform polyamide chemical modifications at the molten state or to achieve cross‐linking reactions suitable for coating applications.Elaboration of new branched renewable polyamides

Synthesis and Characterization of an Experimental Light-Curing Dental Resinous Monomer

2-((phenylcarbamoyl) oxy) ethyl acrylate (Monomer 1) was synthesized based on the raw materials of N-Z-ethanolamine (NSC), acryloyl chloride (AOC), triethylamine (TEA) and dichloromethane (DCM). The chemical structure of Monomer 1 was characterized and confirmed by FTIR and 1H NMR, and the light-curing polymerization behavior was also investigated. Results showed that Monomer 1 had prospective chemical structure. Compared to commercial monomer TEGDMA, Monomer 1 had better reaction speed and conversion rate.

Gelcasting of Alumina with Application of New Monomer Synthesised from Xylitol

Abstract A new monomer for application in the gelcasting process has been designed and synthesized, following the green chemistry trend to use non toxic and renewable compounds. Xylitol was the main substrate for the synthesis that included 3 stages. The final product, named 1-O-acryloylxylitol, was tested regarding its effectiveness as the processing agent for fabrication of alumina elements by gelcasting method. Rheological properties of the ceramic slurries were studied as well as the properties of shaped elements before and after sintering. The results are compared to those obtained by applying commercial monomer 2-hydroxyethyl acrylate.

Synthesis and photopolymerization of novel, highly reactive phosphonated-urea-methacrylates for dental materials

An urea methacrylate (1) and two phosphonated methacrylates (2–3) were synthesized from 2-isocyanatoethyl methacrylate (IEM) and benzyl amine (1), diethyl aminomethylphosphonate (2) and diethyl amino(phenyl)methylphosphonate (3). Their photopolymerization rates are notably higher than commercial monomers, despite the presence of only one double bond. Their polymerization rates follow the order 1∼2>3∼triethylene glycol dimethacrylate (TEGDMA)>2-hydroxyethyl methacrylate (HEMA). A tendency toward high crosslinking density during thermal bulk polymerizations, low oxygen sensitivity and high conversions with benzophenone during photopolymerization indicated the importance of hydrogen abstraction/chain transfer reactions. It was found that the addition of the monomers to HEMA significantly increased its polymerization rate, proving their utility as replacements for TEGDMA as reactive diluents for 2,2-bis[4-(2-hydroxy-3-methacryloyloxy propyloxy) phenyl] propane (Bis-GMA). Copolymer systems containing 2 and 3 showed improved Tg values compared to Bis-GMA/TEGDMA systems.

Solventless synthesis and free-radical photopolymerization of a castor oil-based acrylate oligomer

A simple, low environmental impact procedure for preparing acrylated castor oil (ACO) was developed using a hybrid acrylate isocyanate monomer. The photopolymerization of neat ACO and the co-polymerization of ACO with common low molecular weight acrylate monomers were rapid and reached high conversions, as monitored by real-time FT-IR spectroscopy. The mechanical properties of the ACO polymers and copolymers were determined by dynamic mechanical analysis of the thin polymer films. The resulting copolymers ranged from highly flexible, low glass transition materials to rigid, high glass transition materials depending on the functionality and secondary functional groups of the commercial monomers used. The ACO oligomer was compatible with a variety of acrylate monomers and produced transparent films regardless of co-monomer used. The glass transition temperatures of the copolymers can be coarsely estimated a priori using the Fox correlation. ACO-based materials provide a promising route to introduce renewable materials in many acrylate-based coating applications.

Synthesis and characterization of emulsion polymers using isopropenyl acetate

Abstract Background Isopropenyl acetate (IPA) is one of the monomers from acetate family having an unsaturation with a methyl group attached to the ethylenic carbon. The unsaturation present in the monomer can be utilized for free radical polymerization. Irrespective of this, IPA is not studied much in emulsion polymer synthesis. In the current study, we report the preparation of emulsion polymers using IPA and other acrylic monomers. Terpolymers of butyl acrylate (BA), methyl methacrylate, and IPA were prepared via seeded emulsion polymerization with varying IPA proportions on molar basis. Potassium persulfate was employed as an initiator along with Dowfax 2A1 as surfactant (anionic). Results The emulsions prepared thereof were characterized for particle size, zeta potential and molecular weight using gel permeation chromatography. The emulsion films were evaluated using Fourier transform infrared spectroscopy, as well as their thermal (differential scanning calorimetry, thermo gravimetric analysis) and mechanical properties to study the effect of isopropenyl acetate on their overall properties. Conclusions With increasing proportion of IPA in the formulation, lower conversion was observed which could be due to the lower reactivity of IPA for radical polymerization in the presence of these comonomers. More study for the utilization of IPA in polymer synthesis is needed which, on successful optimization, would give a cost-effective alternative to various commercial acrylic monomers.

Luminescence properties of pHEMA-TiO2 gels based hybrids materials

Photoluminescence (PL) of photochromic pHEMA-TiO2 gels-based hybrids was studied by means of time- and energy-resolved spectroscopy at temperatures between 300K and 10K. The PL band at 485nm is assigned to S0←T1 transition of methoxyphenol (organic molecule added to the commercial monomer hydroxyethyl methacrylate, HEMA and used as an inhibitor of spontaneous polymerisation) in the polymer environment, while the PL band at 600nm is assigned to the self-trapped exciton onto octahedral TiO6 site of the inorganic component. The mechanisms of the excited states population are discussed. In particular it is shown that both singlet-triplet energy transfer in methoxyphenol and methoxyphenol–TiO2 charge transfer are strongly affected by the material composition and temperature. The hypothesis about the photoexcited holes annihilation with the trapped electrons is confirmed to be one of main mechanisms limiting the Ti3+ centres concentration.

Synthesis and polymerizations of phosphonated‐bis(methacrylamide)s for dental applications

AbstractNovel phosphonate and phosphonic acid‐containing bis(methacrylamide)s were synthesized. The phosphonate‐containing monomers (1a and 1b) were synthesized by amidation of 2‐(2‐chlorocarbonyl‐allyloxymethyl)‐acryloylchloride with diethyl 2‐aminoethylphosphonate and diethyl 1‐aminomethylphosphonate. The phosphonic acid‐containing monomers (2a and 2b) were synthesized by hydrolysis of 1a and 1b with trimethylsilyl bromide (TMSBr). All monomers were liquids and dissolved in water and ethanol. Thermal homopolymerization of 1a and 1b in bulk and solution using 2,2′‐azobis(isobutyronitrile) (AIBN) at 80 °C gave crosslinked polymers indicating low cyclization tendencies of these monomers. They were also homopolymerized using photo‐DSC with 2,2′‐dimethoxy‐2‐phenyl acetophenone (DMPA) as photoinitator, and their maximum rates of polymerization were found to be higher than commercial monomers 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyloxy propyloxy) phenyl] propane (Bis‐GMA) and 2‐hydroxyethyl methacrylate (HEMA), indicating their potential as reactive diluents or crosslinkers in dental materials. In fact, copolymerization with monomer 1a resulted in improvements in photopolymerization kinetics of both Bis‐GMA and HEMA. The acidic nature of the aqueous solutions (pH of 2a: 1.42, 2b: 1.53), stability under aqueous conditions after 1 month of study at 37 °C, interaction of 2a with hydroxyapatite (HAP) as representative of both monomers, and copolymerizability of the same with HEMA make these monomers suitable as adhesive monomers in dental adhesives, although their low observed reactivities may present a drawback. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

High throughput atmospheric pressure plasma-induced graft polymerization for identifying protein-resistant surfaces

Three critical aspects of searching for and understanding how to find highly resistant surfaces to protein adhesion are addressed here with specific application to synthetic membrane filtration. They include the (i) discovery of a series of previously unreported monomers from a large library of monomers with high protein resistance and subsequent low fouling characteristics for membrane ultrafiltration of protein-containing fluids, (ii) development of a new approach to investigate protein-resistant mechanisms from structure-property relationships, and (iii) adaptation of a new surface modification method, called atmospheric pressure plasma-induced graft polymerization (APP), together with a high throughput platform (HTP), for low cost vacuum-free synthesis of anti-fouling membranes. Several new high-performing chemistries comprising two polyethylene glycol (PEG), two amines and one zwitterionic monomers were identified from a library (44 commercial monomers) of five different classes of monomers as strong protein-resistant monomers. Combining our analysis here, using the Hansen solubility parameters (HSP) approach, and data from the literature, we conclude that strong interactions with water (hydrogen bonding) and surface flexibility are necessary for producing the highest protein resistance. Superior protein-resistant surfaces and subsequent anti-fouling performance was obtained with the HTP-APP as compared with our earlier HTP-photo graft-induced polymerization (PGP).

A Calorimetric Study of the Self-polymerization of a Commercial Monomer: an Incident Investigation

A Calorimetric Study of the Self-polymerization of a Commercial Monomer: an Incident Investigation

New Dental Composites Containing Multimethacrylate Derivatives of Bile Acids: A Comparative Study with Commercial Monomers

We have prepared multifunctional methacrylate derivatives of bile acids as cross-linkable monomers for use in dental composites. By modifying the chemical structure of the monomers, we were able to vary the viscosity, hydrophobicity, and reactivity and have studied the effect of these parameters on the conversion of the monomers, the shrinkage during polymerization, and the mechanical properties of the resulting polymers and composites. Materials containing these new monomers generally had physical, thermal, and mechanical properties comparable to those containing the commonly used dental monomers BisGMA or UDMA and had lower polymerization shrinkage. The multimethacrylate derivatives of cholic acid, which are known to be less cytotoxic than BisGMA and UDMA, are shown to be promising materials for dental applications.

Development and characterisation of jute reinforced natural matrix composites

The aim of this work is the development of composite materials obtained using as matrix a resin derived from renewable resources. New pre-polymers derived from cardanol, a natural phenol extracted from the shell of the cashew nut, were synthesised. In particular cardanol based novolac-type phenolic resins, capable to form thermoset polymers when blended to commercial epoxy or isocyanate monomers, were successfully developed. Composite laminates obtained using a jute fabric were fabricated and characterised. Jute fabrics were used with and without a surface treatment with NaOH and silane coupling agents. An amount larger than 50% of natural originating materials is present in the laminates.

Gelcasting of alumina suspensions containing nanoparticles with glycerol monoacrylate

An acrylic monomer of low toxicity containing two hydroxyl groups has been synthesized and used for gelcasting in water. The results have been compared to those achieved with the use of a commercially available monomer (2-hydroxyethyl acrylate). Due to the chemical structure of the synthesized monomer, no addition of the crosslinking agent was necessary for gelation and similar results in terms of rheology of suspensions, density and microstructure of the bodies were obtained with respect to those obtained with the commercial monomer. However, higher time for gelation was observed. Two alumina powders with very different particle sizes were used in this study: a commercial submicron-sized powder ( d 50 = 0.35 μm) and a nanometer-sized alumina obtained by freeze-drying from aluminum sulphate solutions. The rheological behavior of concentrated suspensions was studied in order to establish their stability and to analyse the effect of the different monomers used in the process. Once the suspensions were optimized, the influence of the size of the powder on the gelation process was studied. The sintered density of submicrometer-sized alumina was higher (99%) than that measured when the bimodal suspension was used due to the difficulty to obtain highly concentrated suspensions from nanometric powder.

Ring-Opening Copolymerization of 10-Methylene-9,10- Dihydroanthryl-9-Spirophenylcyclopropane via Free Radical and RAFT Processes

A cyclic monomer, 10-methylene-9,10-dihydroanthryl-9-spirophenylcyclopropane (MDS), and styrene (St) were copolymerized by conventional radical polymerization and reversible addition−fragmentation chain transfer (RAFT) polymerization. In both cases, NMR analyses of the resulting copolymers indicated that the ring-opening polymerization proceeded predominantly to give copolymers containing anthracene units in the main chain. The copolymers having relatively high MDS contents with narrow polydispersity (Mw/Mn < 1.2) were obtained by RAFT copolymerization in the presence of suitable chain transfer agents. Free radical copolymerizations of MDS and commercial monomers, such as 4-vinylpyridine (4VP), acrylonitrile, n-butyl acrylate, and methyl methacrylate, were studied using 2,2‘-azobis(isobutyronitrile) as an initiator. The resulting copolymers absorbed light around 260 nm and 330−430 nm, regardless of the nature of the comonomer. Fluorescent peaks of poly(MDS-co-St) were almost the same as those of poly(MDS), whereas poly(MDS-co-4VP) showed an extremely broad peak from 420 to 640 nm with a maximum at 530 nm. These copolymers were thermally stable above 300 °C under nitrogen.

Photo-curing composite paint containing urushi (Oriental lacquer), and wrinkled coating caused by phase separation

To improve the production of traditional lacquerwares by urushi (Oriental lacquerwork) through accelerated drying, we mixed photo-curing monomers with urushi lacquer. We used commercial monomers bearing epoxy, oxetane, or vinyl ether functional groups in conjunction with a photo-cationic initiator [bis(4- tert-butylphenyl)iodonium hexafluorophosphate] and a high-pressure mercury lamp as a UV source. Even in the presence of a large amount of urushi (50 wt% of raw urushi content in the composite paint), photo-cationic polymerization proceeded and gave cured films within a few hours. Photo-differential scanning calorimetry showed negligible retardation of the reaction rate and conversion. Whereas efficient exposure (3.2 J/cm 2) gave cured paint films with glossy smooth surfaces, less exposure unexpectedly gave lusterless surfaces. Microscopy revealed phase separation and wrinkling of the surface with minute ripples, several tens of micrometers in width and height. The outer surface consisted of cross-linked hard polymer, but the inner part under the ripples consisted mainly of monomeric urushi components that solidified slowly. A photo-mask for UV exposure could be used to create a pattern based on variations in the gloss of the paint surface.

Polymer-Stabilized Orthoconic Antiferroelectric Liquid Crystals

Horizontally surface-stabilized orthoconic antiferroelectric liquid crystals (OAFLCs) provide excellent contrast electrooptic switching. However, in very thin cells the bulk relaxation to the anticlinic state tends to be slow because the synclinic state is upheld by the surfaces. In cells thin enough to accomplish a surface-stabilized state of today's short-pitch OAFLC mixtures, the field-induced synclinic (ferroelectric) states often become metastable making the corresponding bright electrooptic state prevail for long times after the electric field is switched off. Fast relaxation is then achieved by specially designed waveforms. By introducing a polymer network formed by in-situ photopolymerization of a small concentration of a commercial reactive monomer dissolved in the OAFLC, we have succeded to drastically reduce the time for relaxation from the synclinic to the anticlinic state after switching off the field down to about 3 milliseconds at room temperature, without the use of any tailored electronic waveforms. The relaxation time of the polymer stabilized OAFLCs (PS-OAFLCs) is thus shorter than in todays nematic liquid crystal displays, which make PS-OAFLCs attractive for use in future high-contrast, blur-free displays.