Tertiary Amine Methacrylate Research Articles

Stimulus-Responsive Gas Marbles as an Amphibious Carrier for Gaseous Materials.

Gas marbles are a new family of particle-stabilized soft dispersed system with a soap bubble-like air-in-water-in-air structure. Herein, stimulus-responsive character is successfully introduced to a gas marble system for the first time using polymer particles carrying a poly(tertiary amine methacrylate) (pKa ≈7) steric stabilizer on their surfaces as a particulate stabilizer. The gas marbles exhibited long-term stability when transferred onto the planar surface of liquid water, provided that the solution pH of the subphase is basic and neutral. In contrast, the use of acidic solutions led to immediate disintegration of the gas marbles, resulting in release of the inner gas. The critical minimum solution pH required for long-term gas marble stability correlates closely with the known pKa value for the poly(tertiary amine methacrylate) stabilizer. It also demonstrates amphibious motions of the gas marbles.

Responsive tertiary amine methacrylate block copolymers: uncovering temperature-induced shape-shifting behaviour

Responsive polymeric nanoparticles are an exciting field of study, yet little is known about the temperature sensitivity of those based on tertiary amine methacrylate block copolymers.

Investigation of the composite materials photopolymerization efficiency in the hree-dimensional 3D printing objects formation

The development and investigation of photopolymerization composite (PhPC) materials with improved photochemical and physical-mechanical properties, providing the possibility of using them during image formation processes in 3D printing technologies, have been carried out. The effect of the nature and amount the polymerization composition constituents on the photocuring of urethane methacrylate and etheracrylate oligomers with the inclusion of organosilicon modifiers, as well as tertiary aminemethacrylates in the process of their irradiation with LED lamps of different wavelengths in the presence of photoinitiators, has been investigated. The effect of the nature and amount of photoinitiators on the optical and polymerization properties of materials and coatings was studied using a PLAZMON-71 spectrometer. According to the results of the calculated photopolymerization kinetic parameters (rate, induction period), it was found that the composition containing the photoinitiators Irgacure 819 (2%), Darocur 1173 (1%), as well as tertiary aminemethacrylate (5%) provides a high polymerization rate and a slight induction period among the investigated compositions. The surface plasmon resonance method allows to determine and control the rate of composite materials photocuring during forming images in 3D printing technology. The possibility of regulating the photochemical and operational characteristics of the constructed nanocomposite materials with the inclusion of organosilicon modifiers in the composition according to their purpose in technological processes of stereolithographic recording of 3D information during printing volumetric images is demonstrated.

Facile construction of beads-on-a-string complexes of polymeric micelles and DNA via tunable electrostatic interactions

Inspired by the structure of chromatin fibers, the compaction of DNA by cationic nanoparticles has received much attention in the fields of nanomaterials and biotechnology. However, the fabrication of artificial chromatin-biomimetic assemblies of DNA and nanoparticles in biological environments is still a challenge due to their dependence on uncontrollable electrostatic interactions. Herein, block and random copolymerization of 2-(diisopropylamino)ethyl methacrylate (DPA) and 2-(dimethylamino)ethyl methacrylate (DMA) were used to regulate the charge density and distribution of cationic polyethylene glycol-b-poly(tertiary amine methacrylate) micelles, adjusting the electrostatic interaction between the micelles and DNA. We showed that the assembled PEG-b-PDMA-b-PDPA micelle/DNA system exhibited a strong electrostatic interactions between the micelles and DNA, causing uncontrollable intrachain flocculation. However, the assembled PEG-b-P(DMA-r-DPA) micelle/DNA system showed relatively week, tunable electrostatic interactions, leading to an open -chromatin-like structure

Radiation grafting of DMAEMA and DEAEMA-based adsorbents for thorium adsorption

Radiation grafting of two tertiary amine methacrylates; 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) onto polyolefin non-woven fabric (PE/PP-NWF) was comparatively investigated in this study. In addition, the absorbent preparation process, grafting kinetics, and mechanism were investigated. The thermal properties were investigated by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). Fourier transform infrared (FTIR) spectroscopy was performed to confirm the successful grafting and incorporation of the two monomers functional groups onto PE/PP-NWF. X-ray diffraction (XRD) analysis was used to examine the differences between the crystal sizes and structures. Lastly, the adsorption of Th(IV) ion was investigated in batch mode. The results indicate that the radiation grafting of both DMAEMA and DEAEMA onto PE/PP-NWF required high activation energies with increasing temperatures from 313 to 333 K. Furthermore, P-DMAEMA and P-DEAEMA demonstrated different adsorption behaviours towards Th(IV). Results showed that P-DEAEMA exhibited lower Th(IV) adsorption capacity compared to P-DMAEMA, although both contain similar carbonyl and tertiary amino functional groups. These findings indicate that the molecular structure of the adsorbent was responsible. The molecular sizes increased with increasing branched carbon chains from the methyl to ethyl groups. Density functional theory (DFT) analysis indicated that induced steric effect eventually increases the inter-molecular repulsions caused by the additional CH2-groups in the structure, which reduces adsorption capacity.

Tertiary Amine Methacrylate based Polymers as Corrosion Inhibitors in HCl Solution. Part II

In this study, the inhibitive performance of novel synthesised water-soluble of different molecular weight diblock copolymers of derivative methyl methacrylate (VB84, VB206, VB207, VB361, VB371,VB406) on the corrosion behavior of AISI 304 stainless steel in 10–3 M HCl containing various concentrations of polymers was investigated using potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), scanning electron microscopy(SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and inductively coupled plasma optical emmision spectrometry (ICP-OES) methods. Polarisation curves indicated that all studied polymers were acting as mixed type inhibitors. All electrochemical measurements showed that inhibition efficiencies increased with increasing polymer concentration. It was determined that the increase of inhibitor efficiency by concentration resulted from the adsorption of polymers to metal surface, and the adsorption fitted to the Langmuir adsorption equation. The variation in inhibitive efficiency mainly depends on the type and the nature of the substituents present in the polymer molecule and also depends on the molecular weight of the polymer. The best inhibition in 10-3 M HCl shows VB84 homopolymer. Surface images obtained with SEM, EDX, and AFM methods determined by verifying these results that inhibitors decrease the dissolution of metal, prevented the corrosion.

Tertiary Amine Methacrylate based Polymers as Corrosion Inhibitors in Double Distilled Water. Part I

In the current study, the inhibitive performances of tertiary amine methacrylate based water soluble diblock copolymers on the corrosion behavior of AISI 304 stainless steel were investigated in double distilled water (DDW, at pH 7.6) using potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and inductively coupled plasma optical emmision spectrometry (ICP OES) methods. Related diblock copolymers were poly[2-(dimethylamino)ethylmethacrylate] (PDMA), poly[2-(diethylamino)ethylmethacrylate] (PDEA), poly[2-(diisopropylamino)ethylmethacrylate] (PDPA) homopolymers and poly[2-(dimethylamino)ethylmethacrylate]-b-poly[methylmethacrylate] (PDMA-b-PMMA), poly[2-(diethylamino)ethylmethacrylate]-b-poly[methylmethacrylate] (PDEA-b-PDMA) and poly[2-(diisopropylamino)ethylmethacrylate]-b-poly[2-(dimethylamino)ethylmethacrylate] (PDPA-b-PDMA). Diblock copolymers having different molecular weight and different comonomer ratios. Polarisation curves indicated that all the studied polymers were acting as a mixed type inhibitors. All electrochemical measurements showed that inhibition efficiencies increased with an increase in the inhibitor concentration. It was determined that the increase of inhibitor efficiency by concentration resulted from the adsorption of polymers to metal surface, and the adsorption fitted to Langmuir adsorption equation. Adsorption equilibrium constant (Kads) and free energy of adsorption(ΔGads), which were thermodynamic parameters of adsorption were calculated by benefiting from the drawn adsorption isotherms. The variation in inhibitive efficiency mainly depended on the type and the nature of the substituents present in the inhibitor molecule and also depended on the molecular weight of the inhibitors. The best inhibition in DDW showed VB207 diblock copolymer. Surface images obtained with SEM, EDX and AFM methods, determined by verifying these results that inhibitors decreased the dissolution of metal, and prevented the corrosion.

Characterization of tertiary amine methacrylate nanogels for the co-delivery of siRNA and chemotherapeutic agents

Characterization of tertiary amine methacrylate nanogels for the co-delivery of siRNA and chemotherapeutic agents

Self-assembled and Nanostructured Copolymer Aggregations of the Tertiary Amine Methacrylate Based Triblock Copolymers

The micellization behavior of novel tertiary amine methacrylate-based ABA type triblock copolymers formed by poly[2-(dimethylamino)ethyl methacrylate] [PDMA] middle block and poly[2-(diethylamino)ethyl methacrylate] [PDEA] or poly[2-(diisopropylamino)ethyl methacrylate] [PDPA] side blocks, PDPAm-b-PDMAn-b-PDPAl, and PDEAm-b-PDMAn-b-PDEAl was investigated. Both types of triblock copolymers were water-soluble and had potential for various applications due to their self-assembled and the bottom-up nanoscale micellar construction. The micellar aggregations of the triblock copolymers in aqueous solutions with varying comonomer ratios, molecular weights, temperatures, and pH values were investigated by small-angle X-ray scattering and dynamic light scattering. Compact micellar aggregations were obtained as 0.5 weight percent solutions at 20–21°C and pH 8.67 to 9.05, and characterized as polydispersed spherical core-shells. One group of triblock copolymer micelles had PDPA-cores with radii from 18 to 21 Å and PDMA-shell thicknesses of 89–105 Å, whereas the other group had PDEA-core spherical micelles with core radii of 60–62 Å and a PDMA-shell thicknesses of 64–66 Å.

Hydrophobic effects within the dynamic pH-response of polybasic tertiary amine methacrylate brushes.

The solvation and swelling behaviour of three dialkylaminoethyl methacrylate polymer brushes, of varying hydrophobicity, have been investigated using a combination of in situ ellipsometry and a quartz crystal microbalance with dissipation (QCM-D). At low pH the tertiary amine groups of the three polymers are protonated and all three brushes are significantly solvated and swell by adopting an extended conformation. As the pH is increased the weak polybasic brushes become increasingly deprotonated and collapse via solvent expulsion. By employing high temporal resolution measurements we have found that monomer hydrophobicity has a direct influence on the dynamics of this pH-response. The most hydrophobic poly(2-diisopropylamino)ethyl methacrylate (poly(DPA)) brush exhibits the fastest maximum swelling rate. This maximum swelling rate is reduced with decreasing monomer hydrophobicity for the 2-diethylamino, and even further for the 2-dimethylamino analogues. For all three brushes, the corresponding collapse transition is slower and compounded by an induction time that decreases with monomer hydrophobicity. Here also, the maximum collapse rate is greatest for the most hydrophobic polymer. This domination of the pH-response kinetics by monomer hydrophobicity is attributed to attractive hydrophobic forces between polymer segments overcoming the repulsive electrostatic forces between the tertiary amine residues.

Double Responsive Hydrogels based on Tertiary Amine Methacrylate Star Block Copolymers

Abstract Double hydrophilic stimuli-responsive star block copolymers with poly(2-(dimethylamino)ethyl methacrylate) (PDMA) inner blocks and poly(2-(diethylamino)ethyl methacrylate) (PDEA) outer blocks were synthesized using ATRP. Different multifunctional initiators based on sugar scaffolds were employed in a core-first approach with sequential polymerization of both blocks yielding stars with 4 and 6 arms, respectively, and varying length of the PDEA outer block. The star block copolymers show pH- and temperature-responsive aggregation as revealed by dynamic light scattering and turbidimetry. The impact of pH, PDEA block length and arm number on the gelation behavior was investigated by tube inversion and rheology.

Synthesis of pH-responsive tertiary amine methacrylate polymer brushes and their response to acidic vapour

Weak polyelectrolyte brushes exhibit pH-responsive swelling behaviour, tuneable surface energy, and some promise as “smart” responsive coatings. In this paper, we demonstrate the growth of two weak polybase brushes by surface-initiated atom transfer radical polymerisation (SI-ATRP) using electrostatically adsorbed polyelectrolyte macro-initiators. Poly[2-(diethylamino)ethyl methacrylate] (PDEA) and poly[2-(diisopropylamino)ethyl methacrylate] (PDPA) brushes of 150 and 170 nm thickness respectively were grown within 22 h at 20 °C. Using in situellipsometry an acid-induced swelling transition was observed at pH 7.4 for PDEA and pH 6.5 for PDPA, similar to the pKa values reported for the corresponding free polymer chains. The kinetics of brush swelling involves an initially fast regime followed by a subsequent slower regime. Reversible surface energy switching with pH modulation was also demonstrated by contact angle goniometry. Finally, it was demonstrated that PDPA brushes respond to the presence of acidic vapours. On exposure to humid HCl vapour, such brushes become hydrophilic, resulting in water uptake and swelling, producing a visible change in the thin film interference colour.

Synthesis and physical gels of pH- and thermo-responsive tertiary amine methacrylate based ABA triblock copolymers and drug release studies

A series of novel pH-responsive ABA triblock copolymer gelators have been synthesized by using poly[2-(diisopropylamino)ethyl methacrylate] (PDPA) as the A block and poly[2-(dimethylamino)ethyl methacrylate] (PDMA) as the B block via group transfer polymerization. While the PDPA-b-PDMA-b-PDPA triblock copolymers are molecularly soluble in acidic aqueous media due to protonation of all tertiary amine groups, they formed either gels by the chain-end hydrophobic interactions with relatively high polymer concentration (10 wt%) or near monodisperse “flower” micelles with low polymer concentration at neutral and basic aqueous solutions. The hydrophobic model drug release was studied in a sustained manner from the gels at pH 7.4 by varying the polymer concentration, the polymer molecular weight and the temperature of the medium. Preliminary studies indicate that both slow, sustained release and fast, triggered release of a model hydrophobic drug, dipyridamole, can be achieved by tuning the solution pH, polymer concentration, polymer molecular weight and temperature of the gel.

Film-Forming Microgels for pH-Triggered Capture and Release

The pH-responsive behavior for a series of lightly cross-linked, sterically stabilized poly(tertiary amine methacrylate)-based latexes adsorbed onto mica and silica was investigated using in situ tapping mode AFM at room temperature. The adsorbed layer structure was primarily determined by the glass transition temperature, T(g), of the latex: poly[2-(diethylamino)ethyl methacrylate]-based particles coalesced to form relatively featureless uniform thin films, whereas the higher T(g) poly[2-(diisopropylamino)ethyl methacrylate] latexes retained their original particulate character. Adsorption was enhanced by using a cationic poly[2-(dimethylamino)ethyl methacrylate] steric stabilizer, rather than a nonionic poly(ethylene glycol)-based stabilizer, since the former led to stronger electrostatic binding to the oppositely charged substrate. Both types of adsorbed latexes acquired cationic microgel character and swelled appreciably at low pH, even those that had coalesced to form films. Fluorescence spectroscopy was used to study the capture of a model hydrophobic probe, pyrene, by these adsorbed latex layers followed by its subsequent release by lowering the solution pH. The repeated capture and release of pyrene through several pH cycles was also demonstrated. Since these poly(tertiary amine methacrylate) latexes are readily prepared by aqueous emulsion polymerization and adsorption occurs spontaneously from aqueous solution, this may constitute an attractive route for the surface modification of silica, mica and other oxides.

Synthesis of Zwitterionic Diblock Copolymers without Protecting Group Chemistry

A versatile new route to zwitterionic diblock copolymers that avoids protecting group chemistry is reported. Various tertiary amine methacrylates are block copolymerized with 2-hydroxyethyl methacrylate to produce hydroxy-functional diblock precursors via sequential monomer addition. These low-polydispersity precursors are then treated with succinic anhydride under mild conditions to produce a range of new near-monodisperse zwitterionic diblock copolymers in which both blocks are weak polyelectrolytes. Thus, the final copolymers exhibit complex aqueous solution behavior (isoelectric points, schizophrenic micellization behavior, etc.) depending on the solution pH.

A brief review of ‘schizophrenic’ block copolymers

Recent progress in the synthesis of so-called ‘schizophrenic’ water-soluble block copolymers is reviewed. The original report in this new sub-field involved a tertiary amine methacrylate-based AB diblock copolymer synthesized by group transfer polymerization that was both pH- and salt-responsive, allowing the formation of either A-core or B-core micelles in aqueous solution. A second example involved a poly(propylene oxide)-tertiary amine methacrylate diblock copolymer synthesized via atom transfer radical polymerization (ATRP) that exhibited both pH- and thermo-responsive behavior. More recently, several examples of wholly pH-responsive zwitterionic diblock copolymers (prepared via ATRP, usually using protecting group chemistry) have been reported, with their aqueous solution behavior being characterized with varying degrees of precision. The synthesis and characterization of purely thermo-responsive diblock copolymers is also discussed, along with the first example of an ABC triblock copolymer that is capable of forming a ‘trinity’ of micelles in aqueous solution at 20 °C simply by adjusting the solution pH. In this remarkable final example, the cores of the three types of micelles are formed by hydrophobic forces, polyion complexation and hydrogen bonding, respectively.

Biomimetic Stimulus-Responsive Star Diblock Gelators

Novel biomimetic gelators with star diblock copolymer architectures have been synthesized by atom-transfer radical polymerization (ATRP). Two types of trifunctional ATRP initiator were used to polymerize 2-(methacryloyloxy)ethyl phosphorylcholine [MPC] at 20 degrees C, followed by sequential monomer addition of various tertiary amine methacrylates or mixtures thereof. Poor living character was achieved using an amide-based trifunctional initiator, but the analogous triester initiator gave reasonably well-defined thermo-responsive and pH-responsive star diblock copolymers. The most effective thermo-responsive gelators were obtained by the statistical terpolymerization of 2-(dimethylamino)ethyl methacrylate [DMA], 2-(diethylamino)ethyl methacrylate [DEA], and a monomethoxy-capped poly(propylene oxide) methacrylate [PPOMA], whereas pH-responsive gelators were prepared using 2-(diisopropylamino)ethyl methacrylate [DPA] as the second monomer. Star diblock copolymer gelators that were both thermo-responsive and pH-responsive were obtained by the statistical copolymerization of DMA with DPA. Copolymer compositions were assessed by 1H NMR spectroscopy, and the molecular weight distributions of the three-arm star MPC homopolymer precursors were assessed by aqueous gel permeation chromatography. Static light scattering was used to obtain weight-average molecular weights of selected star diblock copolymers and rheological measurements and variable-temperature 1H NMR were used to probe the onset of gelation.

Synthesis of Novel Folic Acid-Functionalized Biocompatible Block Copolymers by Atom Transfer Radical Polymerization for Gene Delivery and Encapsulation of Hydrophobic Drugs

Two synthetic routes to folic acid (FA)-functionalized diblock copolymers based on 2-(methacryloyloxy)ethyl phosphorylcholine [MPC] and either 2-(dimethylamino)ethyl methacrylate [DMA] or 2-(diisopropylamino)ethyl methacrylate [DPA] were explored. The most successful route involved atom transfer radical polymerization (ATRP) of MPC followed by the tertiary amine methacrylate using a 9-fluorenylmethyl chloroformate (Fmoc)-protected ATRP initiator. Deprotection of the Fmoc groups produced terminal primary amine groups, which were conjugated with FA to produce two series of novel FA-functionalized biocompatible block copolymers. Nonfunctionalized MPC-DMA diblock copolymers have been previously shown to be effective synthetic vectors for DNA condensation; thus, these FA-functionalized MPC-DMA diblock copolymers appear to be well suited to gene therapy applications based on cell targeting strategies. In contrast, the FA-MPC-DPA copolymers are currently being evaluated as pH-responsive micellar vehicles for the delivery of highly hydrophobic anticancer drugs.

Interaction between a tertiary amine methacrylate based polyelectrolyte and a sodium montmorillonite dispersion and its rheological and colloidal properties

AbstractThe rheological and colloidal properties of sodium montmorillonite dispersions were investigated in the presence of a special type of cationic polymer [modified poly(ethylene glycol)]. 2‐(Dimethylamino) ethyl methacrylate was polymerized with monomethoxy‐capped oligo(ethylene glycol) via aqueous atom transfer radical polymerization. The tertiary amine residues of the resulting polymer were then quaternized with methyl iodide to obtain a cationic polyelectrolyte. The rheology and ζ‐potential experiments showed that the cationic polymer adsorbed onto the sodium montmorillonite surface strongly. The rheological parameters (plastic viscosity and yield value) were obtained with a rotational low‐shear rheometer. The results indicated a gradual increase in gelation with the addition of the cationic polymer, which reached a maximum at a cationic polymer concentration of 0.4–0.8 g/L. This gel‐like dispersion showed pronounced thixotropy. A further increase in the polymer concentration resulted in a reduction in this gelation. The adsorption of the cationic polymer onto the clay surface reduced the ζ potential to small values, but no isoelectric point was observed. The basal‐spacing measurements showed that the cationic polymer strongly adsorbed onto the sodium montmorillonite instead of entering the montmorillonite layers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 300–306, 2005

Synthesis and characterization of novel pH-responsive microgels based on tertiary amine methacrylates.

Emulsion polymerization of 2-(diethylamino)ethyl methacrylate (DEA) in the presence of a bifunctional cross-linker at pH 8-9 afforded novel pH-responsive microgels of 250-700 nm diameter. Both batch and semicontinuous syntheses were explored using thermal and redox initiators. Various strategies were evaluated for achieving colloidal stability, including charge stabilization, surfactant stabilization, and steric stabilization. The latter proved to be the most convenient and effective, and three types of well-defined reactive macromonomers were examined, namely, monomethoxy-capped poly(ethylene glycol) methacrylate (PEGMA), styrene-capped poly[2-(dimethylamino)ethyl methacrylate] (PDMA50-St), and partially quaternized styrene-capped poly[2-(dimethylamino)ethyl methacrylate] (10qPDMA50-St). The resulting microgels were pH-responsive, as expected. Dynamic light scattering and 1H NMR studies confirmed that reversible swelling occurred at low pH due to protonation of the tertiary amine groups on the DEA residues. The critical pH for this latex-to-microgel transition was around pH 6.5-7.0, which corresponds approximately to the known pKa of 7.0-7.3 for linear PDEA homopolymer. The microgel particles were further characterized by electron microscopy and aqueous electrophoresis studies. Their swelling and deswelling kinetics were investigated by turbidimetry. The PDEA-based microgels were compared to poly[2-(diisopropylamino)ethyl methacrylate] (PDPA) microgels prepared with identical macromonomer stabilizers. These PDPA-based microgels had a lower critical swelling pH of around pH 5.0-5.5, which correlates with the lower pKa of PDPA homopolymer. In addition, the kinetics of swelling for the PDPA microgels was somewhat slower than that observed for PDEA microgels; presumably this is related to the greater hydrophobic character of the former particles.