Dodecyl Methacrylate Research Articles

Photo-induced electron transfer in a pyrenylcarbazole containing polymer–multiwalled carbon nanotube composite

A polymer incorporated with a pyrenylcarbazole pendant poly(12-(3-(pyren-1-yl)-carbazol-9-yl)dodecyl methacrylate, denoted as PCP) was synthesized and applied in the functionalization of multi-walled carbon nanotubes (MWCNTs) by noncovalent π–π interaction. The PCP–MWCNT hybrids were isolated and characterized by SEM, TEM, and UV-visible absorption and emission spectroscopies. The strong interaction between PCP and the MWCNT in a 1,1,2,2-tetrachloroethane (TCE) solution was studied. It demonstrated an effective quenching effect on emission from PCP by the MWCNTs. DFT calculations showed electron delocalization between the pyrene and carbazole moieties. The LUMO of PCP is mainly located on the pyrene moiety while the LUMO + 1 is predominantly positioned on the carbazole moiety. Femtosecond transient absorption (TA) experiments determined the characteristic TA peaks of the excited states, which have contributions from both the pyrene and carbazole moieties. The excited state lifetime of the polymer PCP was measured to be 659 ps and the photo-excited electrons were injected into the MWCNTs very effectively on a time scale of 420 fs.

Improvement in Oil Absorbency by Using Modified Carbon Nanotubes in Preparation of Oil Sorbents

ABSTRACTThis article reports the first oil‐absorbent cross‐linked copolymer consisting of modified multiwalled carbon nanotube (MWCNT) and showing high oil absorbency. Also, to investigate and evaluate the effective parameters on oil absorbency, cross‐linked dodecyl methacrylate (DDMA)–diphenylacrylamide (DPAA) and DDMA–butyl acrylate (BA) copolymers were synthesized. DDMA was copolymerized with different mol% of DPAA or BA and cross‐linked using azobisisobutyronitrile as the initiator and various weight percentages of 1,4‐butandiol dimethacrylate, methylene bisacrylamide, or vinyl group–modified MWCNT cross‐linkers. The effects of monomer feed composition, cross‐linker concentration, and the hydrophobicity of the copolymer units on swelling properties of the cross‐linked copolymers were studied through the oil‐absorbency tests. It was found that in the reactions used vinyl group–modified MWCNTs act as cross‐linking agents for the free radical polymerization, carbon nanotubes (CNT) played the other roles, that is, as a comonomer and an adsorbent. The oil absorbents containing CNTs showed the highest oil absorbency (toluene, 42.6 g; crude oil, 36.0 g/g oil absorbent). Therefore, CNT‐based oil absorbent can be introduced as a promising candidate for environmental protection and oil recovery. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 2013, 32, 21332; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21332

Ultrathin, Oil-Compatible, Lubricious Polymer Coatings: A Comparison of Grafting-To and Grafting-From Strategies

A grafting-to approach is described as a means of fabricating ultrathin, oil-compatible, friction-reducing coatings. The tribological properties of grafted-to coatings of poly(dodecyl methacrylate) (P12MA), prepared by means of a photoactivated perfluorophenylazide adhesion promoter, were compared with those of grafted-from coatings of the same polymer of comparable molecular weight, prepared via surface-initiated, atom-transfer radical polymerisation. It was shown that in a sub-hydrodynamic regime (i.e. boundary/brush lubrication), both coating types can be equivalently effective, exhibiting very low friction coefficients (0.02) against a bare silica countersurface with no detectable wear over the duration of the test (around 1,000 cycles, and maximal Hertzian contact pressure ca 170 MPa as calculated for a bare–bare configuration), providing that sufficiently viscous base lubricants are employed.

Polymer-Brush Lubrication in Oil: Sliding Beyond the Stribeck Curve

We report a highly effective macroscopic, non-aqueous lubrication strategy, employing polymer-brush-based surface modification. Poly(alkyl methacrylates) with hexyl, dodecyl and octadecyl side chains have been prepared on both silicon and iron substrates by means of surface-initiated atom-transfer radical polymerisation. Frictional properties of the three polymers have been evaluated in hexadecane, ethanol and toluene. For the case of the poly(dodecyl methacrylate), the study additionally involved nine base lubricating fluids of different chemical natures, with viscosities ranging from 4 to 2,200 cSt at 20 °C. By constructing a set of Stribeck curves at low values of speed × viscosity (at constant load), it was possible to identify an extended hydrodynamic lubrication regime and, for P12MA-based coatings, a low-friction, brush-lubrication regime, reinforced by time-dependant effects, which appeared to replace the mixed and boundary regimes observed for conventional lubricants. Self-mated poly(dodecyl methacrylate) brushes maintained low coefficient-of-friction values (e.g. 0.012 in hexadecane) over thousands of reciprocating cycles (>100 m total distance) under low speed × viscosity conditions (0.1 cm/s and 4 cSt).

Novel polyelectrolyte gels as absorbent polymers for nonpolar organic solvents based on polymerizable ionic liquids

Novel class of polyelectrolyte gels based on the copolymer of vinylimidazolium-typed ionic liquid monomer and Dodecyl methacrylate was prepared by free radical polymerization. A small amount of 3-n-Dodecyl-1-vinylimidazolium tetrafluoroborate is incorporated into crosslinked polyacrylates to provide new lipophilic polyelectrolyte gels that evaluated for swelling in less-polar and nonpolar organic solvents. Their swelling degree becomes more than 50 times as much as their dried weights in some organic solvents. By varying the polarity of the neutral monomer in these polyelectrolyte gels, the design of gels that can absorb solvents of nearly any polarity is demonstrated. The present absorbents are expected to find practical applications particularly in the recovery of spilled oils and the treatment of waste water.

Novel carbon‐nanotube‐based organogels as candidates for oil recovery

AbstractA simple method for synthesis of novel organogels based on multiwalled carbon nanotubes (MWCNTs) is reported. Three classes of organogels were synthesized by crosslinking polymerization of dodecyl methacrylate with various weight percentages of 1,4‐butanediol dimethacrylate, vinyl‐group‐modified MWCNTs or pristine MWCNTs in the presence of 2,2‐azoisobutyronitrile as initiator. In this reaction, the carbon nanotubes (CNTs) served simultaneously as an adsorbent, a comonomer and a crosslinking agent. The oil‐absorbent containing CNTs showed much higher swelling capacity in oil and organic solvents compared with that without CNTs. Therefore, CNT‐based organogels can be introduced as a promising candidate for environmental protection and oil recovery. © 2012 Society of Chemical Industry

Microwave Irradiation Syntheses of Poly Dodecyl Methacrylate- Methacrylate- 2-EthylHexyl Resin and Application in Pesticide

Resin was synthesized by microwave irradiation. The effects of cross-linker dose， initiator dose, and dispersant dose , as well as synthesis reaction temperature on the synthesized resin adsorption of oil were investigated. Morphologies and textural properties of the synthesized resins were characterized by using Scanning Electron Microscopy (SEM). The results showed: In comparison with synthesis method of traditional water-bath heating, the use of microwave irradiation can make the synthesis time shorter, and 10% increase in oil capacity than traditional water-bath heating. The resin had release function, so it can be made wettable powder or granules, which provided another alternative to cream formulations new way.

SP-PLP-EPR Measurement of ATRP Deactivation Rate

The ATRP deactivation rate coefficient is measured by applying laser single pulses for radical production in conjunction with subsequent time-resolved detection of the decay of radical concentration. The novel method is illustrated for copper-mediated dodecyl methacrylate (DMA) polymerization with 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) as the ligand in the presence of 15 wt % acetonitrile. The experiment consists of two parts: measurement of chain-length-dependent termination on the copper-free monomer system followed by monitoring the decay of propagating radicals after laser pulsing applied to the copper–HMTETA system. The rate coefficient of deactivation by the CuII complex is about 2 orders of magnitude below the one of termination of two small propagating DMA-type radicals, which confirms that deactivation is chemically controlled.

Dodecyl methacrylate as a crosslinker in the preparation of tough polyacrylamide hydrogels

Copolymerization of acrylamide with dodecyl methacrylate (C12) solubilized in aqueous micelles of sodium dodecyl sulfate produces tough hydrogels exhibiting moduli of elasticity around 1 kPa. Swelling and gel fraction measurements show that the hydrophobic associations acting as temporary crosslinks are too strong to be destroyed in water during the expansion of the gel network. An order of magnitude larger value of loss factor tan δ of the hydrogels formed using the hydrophobe C12 as compared to the conventional hydrogels indicates the dynamic nature of their crosslink zones. The hydrogels are more homogeneous than the corresponding gels prepared by a chemical crosslinker, as determined by the static light scattering measurements. Mechanical tests indicate that, in addition to the dodecyl domains, permanent crosslinks are also needed to obtain hydrogels that are mechanically stable up to 250% elongation ratios.

Synthesis of methacrylate copolymers and their effects as pour point depressants for lubricant oil

AbstractIn this study, polymethacrylate polymers were synthesized by free‐radical polymerization for use as pour point depressants in lubricant oil, and their low‐temperature properties were investigated. Four methacrylate monomers were synthesized by the esterification of methyl methacrylate (MMA) with four kinds of fatty alcohols. The purification step was performed to prepare the pure monomers. Two polymerization experiments were carried out with four kinds of methacrylate monomers obtained previously and MMA. Copolymers, which were made from one kind of monomer and MMA, and terpolymers, which were made from two kinds of monomers and MMA, were prepared. The molecular structures of the synthesized methacrylate monomers and polymethacrylate polymers were verified by 1H‐NMR, and the molecular weight data were obtained by gel permeation chromatography. The pour points of the base oils containing 0.1 wt % polymethacrylate polymers were measured according to ASTM D 97‐93. The pour points of most base oils containing each polymer decreased compared to that of the pure base oil. Particularly, poly(dodecyl methacrylate‐co‐hexadecyl methacrylate‐co‐methyl methacrylate), made of dodecyl methacrylate, hexadecyl methacrylate, and MMA at a molar ratio of 3.5 : 3.5 : 3, showed the best low‐temperature properties. This terpolymer dropped the pour point of the base oil by as much as 23°C, and its yield was 93.5%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Grafting of iPP powder with methacrylate monomers in water medium

AbstractThe grafting of different methacrylates on iPP in the solid state has been studied under various reaction conditions using a radical initiation. Three peroxides and five grafting agents representing methyl‐, ethyl‐, butyl‐, ethyl hexyl‐, and dodecyl methacrylate were tested. The grafting efficiency (GE) performed in water medium (slurry) as possible heat transfer medium was compared with the GE obtained without using water. The iPP powder was first impregnated with monomer and peroxide initiator and then water solution of NaCl was added. Obtained GEs were much higher for all peroxides and monomers used when compared with GE performed without water. Quantity of grafted monomer was determined by Fourier transform infrared spectroscopy (FTIR). The products were characterized by differential scanning calorimetry (DSC) and surface energies of grafted iPP films were measured. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Propagation and Termination Kinetics of PEGylated Methacrylate Radical Polymerizations

AbstractPropagation and chain‐length averaged termination rate coefficients, kp and <kt>, for radical polymerizations of methacrylates carrying poly(ethylene glycol) (PEG) units are reported. kp derived from pulsed laser initiated polymerizations in bulk, in organic solvents, and in ionic liquids follows the methacrylate‐type family behavior. Contrary, diffusion controlled kt values obtained from chemically initiated polymerizations with in‐line FT‐NIR monitoring of monomer conversion are strongly affected by the PEG units in the ester group. Compared to alkyl methacrylates <kt> is unexpectedly high. Moreover, <kt> of poly(ethylene glycol) ethyl ether methacrylate shows a significant reduction in kt already at 15% conversion, whereas dodecyl methacrylate <kt> is constant up to at least 70% conversion.magnified image

Thermal Stability of Lubricating Oil Additives Based on Styrene and n-Alkyl Methacrylate Terpolymers

In this work the thermal stability of polymeric additives for the improvement of rheological behavior of mineral lubricating oils was investigated. The systems studied comprised methyl methacrylate (MMA)/dodecyl methacrylate (DDMA)/octadecyl methacrylate (ODMA) and styrene (Sty)/DDMA/ODMA terpolymers. The composition of the terpolymers was determined by the 1H nuclear magnetic resonance spectroscopy and molar mass distribution by the size exclusion chromatography. The thermal degradation of terpolymers was studied by the thermogravimetric analysis. Sty/DDMA/ODMA terpolymers exhibited an improved thermal stability in comparison with MMA/DDMA/ODMA terpolymers of the corresponding compositions. Thus, the temperatures of 50% weight loss were found to be 313°C and 363°C for MMA terpolymer and Sty terpolymer, respectively, where x (MMA) = x (Sty) = 30 mol%.

Analysis of DSC curve of dodecyl methacrylate polymerization by two-peak deconvolution method

Free radical polymerization of n-dodecyl methacrylate (DDMA) in bulk has been investigated by differential scanning calorimetry (DSC). Autoacceleration of reaction was observed at the temperatures 70, 80, and 90 °C, with 0.25, 0.5, and 1 wt% of initiator, and was absent at 100 °C. DSC curves obtained at the temperatures below 100 °C were characterized by two maxima. Two-peak deconvolution was used to separate DSC curve into two constitutive unimodal curves, i.e., to calculate the contribution of polydodecyl methacrylate formed before (first maximum) and after (second maximum) the onset of autoacceleration. The share of second maximum decreases as the polymerization temperature and initiator concentration are increased. As the organization of monomer is known to decrease with increasing temperature, it can be expected that the fraction of polymerized disordered phase of monomer (first maximum in DSC curve) is the highest at 90 °C. Our results confirm this prediction and are in good agreement with those observed from conversion versus time curves of DDMA polymerization.

Terpolymerization kinetics of N,N‐dimethylaminoethyl methacrylate/alkyl methacrylate/styrene systems

AbstractLow conversion kinetics of terpolymerization of N,N‐dimethylaminoethyl methacrylate (DMAEM) and dodecyl methacrylate (DDMA) with methyl methacrylate (MMA) or styrene (ST) was investigated. Reactions were performed at 70°C, in toluene solutions, using peroxide initiator. The interdependence between terpolymer and monomer feed composition was successfully described by Alfrey‐Goldfinger equation and the unitary, binary, and ternary azeotropes were calculated. In MMA‐containing system, the wide pseudoazeotropic region with existence of true azeotropic point was observed and experimentally confirmed at the DMAEM:MMA:DDMA molar ratio of 56:41:3. In the ST‐containing system compositional heterogeneity was significant, more than 10 mol%. Required copolymerization reactivity ratios were determined by linear and nonlinear methods. The glass transition temperatures of synthesized terpolymers are found to be between those of the corresponding homopolymers and relative to their content. Increase in the MMA or ST contents and decrease in the DDMA content in terpolymers results in an increase in their glass transition temperatures. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

Role of dispersion stabilizer with hydroxy groups in preparation of monodisperse polylactide microspheres

AbstractMonodisperse poly(D,L‐lactide) (PDLLA) microspheres were prepared by dispersion polymerization of D,L‐lactide in xylene/heptane (1/2, v/v) with poly[(dodecyl methacrylate)‐co‐(2‐hydroxyethyl methacrylate)] (P(DMA‐co‐HEMA)) as a dispersion stabilizer. P(DMA‐co‐HEMA) contains hydroxy groups, which act as an initiation group for pseudoanionic dispersion polymerization. The best coefficient of variation (CV) values concerning particle diameter distribution and the particle diameter of obtained PDLLA microspheres were 3.7% and 5.3 μm, respectively. The particle diameter decreased with increasing concentration of P(DMA‐co‐HEMA) and HEMA maintained low CV (<10%) values. As a result, monodisperse PDLLA microspheres ranging from 1.3 to 5.3 μm were obtained. In addition, it was found that monodisperse PDLLA microspheres were obtained by sufficient capture of growing polymers and monomers in the particle growth stage. Therefore, the HEMA concentration in P(DMA‐co‐HEMA) strongly affecting the capturing capability is the most important factor. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5230–5240, 2009

High-Pressure Phase Behavior for Poly[dodecyl methacrylate] + Supercritical Solvents + Cosolvents and Carbon Dioxide + Dodecyl Methacrylate Mixture

Experimental cloud-point curves for poly(dodecyl methacrylate) [P(DDMA)] + dodecyl methacrylate (DDMA) or dimethyl ether (DME) in supercritical CO2 are reported for the binary and ternary mixtures ...

Viscosity behavior of maleic anhydride and long-chain alkyl methacrylate copolymers in mineral oil solutions

The viscosity behavior of diluted, semidiluted and concentrated solutions of maleic anhydride (MA), dodecyl methacrylate (DDMA), and octadecyl methacrylate (ODMA) terpolymers in mineral oil was investigated. Terpolymers with MA molar ratio of 5 and 10% were synthesized by free radical polymerization in mineral base oil. All the terpolymer solutions in base oil exhibited high kinematic viscosity and values of viscosity index (> 140), proving very high thickening efficiency. Increasing the MA content in terpolymer decreases solution viscosity. Viscosity-concentration dependences of dilute solutions at 40 and 70°C were described by Huggins’ equation, and intermolecular interaction were discussed. In comparison with conventional polymeric viscosity index improvers based on the pure alkyl methacrylates, copolymers of long-chain alkyl methacrylates with small amounts of MA show improved shear and thermal stabilities.

Molecular interaction in some polymeric additive solutions containing styrene-hydrogenated butadiene copolymer

The miscibility of styrene-hydrogenated butadiene copolymer (SHB) with different constituents of polymer additives for lubricating mineral oils was studied in dilute solution regime, using xylene as model solvent, at 30 °C, in a wide range of polymer blend compositions. The systems studied were SHB/poly(ethylene- co-propylene) (EPC), SHB/poly(methyl methacrylate) (PMMA), SHB/poly(dodecyl methacrylate) (PDDMA) and SHB/polystyrene (PS). The viscometric interaction parameters were calculated according to the Krigbaum–Wall and Catsiff–Hewett models of ideal viscometric behavior. Strong repulsive interactions were found in SHB/PMMA and SHB/PDDMA systems pointing to immiscibility. SHB/EPC and SHB/PS deviated much less from ideality. The results were compared to the theoretical estimation of interaction in polymer blends in the absence of solvent, using the Coleman–Graf–Painter approach. No correlation was observed between the interaction in the bulk and in solution.

Multiple Controlled Graft Copolymers by Transition Metal-Catalyzed Living Radical Polymerization

This study is directed to the synthesis of a series of well-defined graft copolymers with the controlled lengths of both the backbone and graft chains by the ruthenium-catalysed living radical polymerisation. The backbone polymer was first synthesised by the ruthenium-catalysed living radical random copolymerisation of methyl methacrylate and 2-(trimethylsilyloxy)ethyl methacrylate followed by the in-situ transformation of the silyloxyl group into the ester with a C-Br bond, which resulted in efficient multifunctional macroinitiators for living radical graft copolymerisation. The methodology led to the novel controlled architectural copolymers, Ax-BAx-type block-graft copolymers, which can function as new building blocks for controlled nanostructures based on microphase separation and is different from that of the conventional ABA triblock copolymers. A series of well-defined Ax-BAx-type block-graft copolymers consisting of soft middle segments (dodecyl methacrylate) and hard outer graft chains (styrene) were synthesised by the ruthenium-catalysed block and graft polymerisations to exhibit characteristics of a thermoplastic elastomer.