Copolymerization Of Monomers Research Articles

Electrical investigation on thiophene–indole conducting copolymers as-synthesized through in situ chemical copolymerization route

In this communication, a series of thiophene–indole conducting copolymers are successfully synthesized via in situ chemical oxidative copolymerization of thiophene and indole monomers using anhydrous FeCl3 as an oxidant. Fourier-transform infrared spectroscopy studies depict the structural confirmation. X-ray diffraction profile indicates the amorphous nature of the as-synthesized copolymeric samples. The electrical conductivity, dielectric properties and relaxation model are indeed studied using AC impedance spectroscopy technique in the frequency and temperature ranges 20 Hz–1 MHz and 303–393 K, respectively. The temperature dependence of electrical conductivity of as-prepared copolymeric samples followed the Arrhenius relation. The variation of AC conductivity with frequency obeys the Jonscher’s power law. The electric modulus spectra showed the non-Debye nature of the studied copolymeric materials. Schematic for in situ synthesis of thiophene–indole conducting copolymer through chemical oxidative copolymerization route

Modified supramolecular carboxylated chitosan as hydrogel electrolyte for quasi-solid-state supercapacitors

Hydrogel-based electrolytes are becoming generally more preferred for electrolyte materials for quasi-solid-state/flexible supercapacitors due to their shape-controlled, high ionic conductivity, no liquid leakage, certain mechanical strength, and flexibility. Here, we develop a modified supramolecular carboxylated chitosan hydrogel electrolyte (CYCTS-g-PAM-Li2SO4) synthesized through a free radical graft copolymerization of acrylamide monomers and chemical crosslinking. Compared with PAM-based hydrogel electrolyte (PAM-Li2SO4), the modified hydrogel electrolyte of CYCTS-g-PAM-Li2SO4 exhibits better performance including higher ionic conductivity (1.74 × 10−2 S cm−1), better electrolyte absorbability (280%) as well as improved mechanical properties (2.25 MPa). A symmetric quasi-solid-state EDLC (electronic double layer capacitor) by sandwiching activated carbon film electrodes with CYCTS-g-PAM-Li2SO4 as the electrolyte and carbon cloths as the current collectors. Notably, the device shows a wide potential window of 0–1.4 V and delivers a high energy density of 8.7 Wh kg−1 at a power density of 350.3 W kg−1. Interestingly, two devices connected in series can light an LED lamp. To our knowledge, this is the first time that reported the modified carboxylated chitosan hydrogel electrolyte for quasi-solid-state supercapacitors, which has application potentials for the modified carboxylated chitosan as hydrogel electrolyte for quasi-solid-state, flexible, and portable energy storage devices.

Fabrication of Tough Hydrogel Composites from Photoresponsive Polymers to Show Double-Network Effect.

Inspired by the toughening mechanism of double-network (DN) gels, tough hydrogel composites with a sandwich structure were fabricated from photoresponsive polymers. By copolymerization of hydrophilic monomers, 2-ureidoethyl methacrylate (UM), and photoresponsive hydrophobic monomers, (2-nitrobenzyloxycarbonylaminoethyl methacrylate (NBOC)) at high concentrations, physical hydrogels that are soft and highly stretchable are formed due to the hydrophobic associations of NBOC, serving as dynamic crosslinkers. By UV irradiation, the physical crosslinking switches into chemical crosslinking, and the soft physical hydrogels transform into rigid and less stretchable chemical hydrogels. By UV curing the surface layers of the physical hydrogels, we prepared hydrogel composites having a sandwiched structure with two rigid outer layers and a soft inner layer. The molecular-level continuous interfaces and matched swelling ratios between the layers ensure the macroscale hydrogel composites' high strength and toughness with a DN gel effect. The outer layers fracture preferentially at deformation, playing a role like the first network of a DN gel, while the inner layer maintains the integrity, playing a role resembling the second network. The evolution of the fracture morphology of the rigid layers gives useful insight into the internal fracture process of DN gels.

Enhanced swelling ratio and water retention capacity for novel super-absorbent hydrogel

Super-absorbent hydrogels (SAH) have become the focus of attention due to their broadly applications in many areas like agriculture, wastewater treatment and hygienic products. Swelling ratio (SR), swelling rate and water retention capacity are the three most key parameters for SAHs. However, SR is commonly opposite to water retention capability. High SR usually means poor water retention capacity, and vice versa. High SR over 2000 g/g along with excellent water retention capacity for SAH is rarely reported so far. In this work, a novel SAH achieving high SR over 5500 g/g along with excellent water retention capability is obtained by co-polymerization of AA monomer and AM monomer. Particularly, water retention ratio (WRR) still remains over 60% after keeping the swollen hydrogel sample in the open air for 3 days at 298 K with humidity only around 40%, indicating its' excellent water retention capability. Furthermore, in 0.5–20 wt% urea water solution, SR is also high up to 1790–3210 g/g, implying its' excellent water absorbency in urea solution. Additionally, such SAH sample also shows good water absorbing behavior in salt solution including 0.9 wt% NaCl and 0.9 wt% KCl, and even this SAH sample displays excellent adsorption performance for removing methylene blue (MB) dye with the maximal adsorption capacity of 856 mg/g. This work open a new way to design and develop novel SAH with significantly improved swelling ratio and water retention capability for many potential applications.

IPN structured UV-induced peelable adhesive tape prepared by isocyanate terminated urethane oligomer crosslinked acrylic copolymer and photo-crosslinkable trifunctional acrylic monomer

In this paper, a linear isocyanate terminated urethane oligomer, polyethylene glycol modified isophorone diisocyanate oligomer (PEG-IPDI), was prepared by the reaction of polyethylene glycol and isophorone diisocyanate. It is mixed as a cross-linking agent with an acrylic copolymer composed of 2-ethylhexyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl acrylate and acrylic acid to form a network pressure sensitive adhesive (PSA) through the reaction of isocyanate groups in PEG-IPDI with hydroxyl and carboxyl groups in acrylic copolymer chains. By blending this network PSA with a photo-initiator and a trifunctional acrylic monomer in a certain ratio, the UV-curable PSA was obtained. After uniformly coating it on the treated polyethylene terephthalate film, a UV-induced peelable PSA tape for a silicon wafer dicing process was prepared. The PSA network formed before UV irradiation was held together with another network produced by UV irradiation of the trifunctional acrylate monomer to give an interpenetrating network (IPN) structure. The results showed that this novel UV-curable PSA tape with IPN structure had strong peel strength before UV irradiation, and could meet the fixed requirements of silicon wafer cutting process. After UV curing, the peel strength was remarkably lowered due to the formation of IPN structure. Compared to those semi-IPN structured PSA tapes prepared with traditional multi-functional urethane acrylate oligomers, the adhesion performances of IPN structured UV peelable PSA tape prepared in this work were similar, but the remaining adhesive on the wafer after the release of the UV cured tape was greatly reduced.

Copolymerization of Azobenzene-bearing Monomer and 3,4-Ethylenedioxythiophene (EDOT): Improved Electrochemical Performance for Electrochromic Device Applications

In this study, novel electrochromic copolymers of 3,4-ethylenedioxythiophene (EDOT) and (E)-1,2-bis(2-fluoro-4-(4-hexylthiophen-2- yl)phenyl)diazene (M1) with different monomer feed ratios were designed and synthesized electrochemically. Electrochemical and spectroelectrochemical characterizations were performed using voltammetry and UV-Vis-NIR spectrophotometry techniques to test the applicability of copolymers for electrochromic applications. In terms of electrochemical behaviors, addition of an electron-rich EDOT unit into the azobenzenecontaining copolymer increased the electron density on the polymer chain and afforded copolymers with very low oxidation potentials at around 0.30 V. While the homopolymers (P1 and PEDOT) exhibited neutral state absorptions centered at 510 and 583 nm, EDOT-bearing copolymers showed red shifted absorptions compared to those of P1 with narrower optical band gaps. In addition, the poor optical contrast and switching times of azobenzene-bearing homopolymer were significantly improved with EDOT addition into the copolymer chain. As a result of the promising electrochromic and kinetic preperties, CoP1.5-bearing single layer electrochromic device that works between purple and light greenish blue colors was constructed and characterized.

Study of Alkaline Durability and Anion Conductivity Using New Expanded Pyridinium Polymer with Self-Assembly Ability

Polymer electrolyte fuel cells (PEFCs) are promising for practical use as the next generation clean power source. Since the anion exchange membrane fuel cell (AEMFC) operates in a basic environment, cost reduction is possible because non-platinum catalysts such as iron can be used. In addition, since the activation overpotential of oxygen reduction is smaller than that of a proton exchange membrane fuel cell (PEMFC), it is attracting attention as an alternative to PEMFC [1]. However, for practical use, further improvement of the anion conductivity and alkaline durability of the anion exchange membrane (AEM), in which a hydroxide ion (OH-) acts as an anion conductor is required. General strategy to promote anion conduction has been to move cation side chain freely, however problem is that the decomposition reaction occurs due to the attack from the OH-. In this research, a new strategy of “self-organizing cation units to form channel structure” is studied to improve alkaline durability and anion conductivity at the same time. It is considered that this self-assembly strategy can achieve both the low mobility of cation to suppress from OH- attack and the anion conduction path. To realize this concept, an extended pyridinium monomer was newly designed with reference to extended pyridinium, one of the heteropolycyclic aromatic cation. Since strong π-π interactions have been reported between extended pyridiniums, introducing an extended pyridinium into the polymer will suppress the molecular motion of the anion conduction site and will induce the formation of self-assembled channels. A new extended pyridinium monomer (TVP) was synthesized according to the synthesis method of the extended pyridinium salt of Katrizky et al [2]. Synthesized TVP was obtained as a pale yellow powder. From the 1H-NMR spectrum, vinyl group and aromatic peaks were observed, and it was confirmed that the monomer possessed high purity. The homopolymer (PTVP) was synthesized by free radical solution polymerization of TVP. Synthesized PTVP was obtained as a yellow solid. In 1H-NMR measurement, vinyl peaks were disappeared and the broadening of aromatic ring peaks were observed, suggesting that the free radical polymerization was taken place. Since PTVP is brittle and difficult to use as a film probably due to its rigid molecular structure, the introduction of a copolymer monomer was examined. When styrene and isoprene reported as an anion exchange membrane were examined as a copolymerization monomer, copolymer of PTVP-styrene and PTVP-isoprene were obtained, respectively. Although a PTVP-styrene copolymer film was brittle, a PTVP-isoprene copolymer film was obtained as a free standing film. Alkaline stability and anion conductivity of the films will be discussed. [1] G. Merle; M. Wessling; K. Nijmeijer, J. Membr. Sci, 2011, 377, 1-35. [2] A. R. Katritzky; Z. Zakarial; E. Lunt; P. G. Jones; O. Kennard, J. Chem. Soc., Chem. Commun., 1979, 6, 268-269.

Adsorption Studies of Zn (II) onto Nano- Biomaterials from Aqueous Media

Hydroxyapatite and β-tricalcium phosphate as a porous composites were prepared by a sol-gel process. We got a solid powder form composites as small particles. Mixed powder by ultrasonically dispersed throughout the aqueous solution containing an optimum amount of Ring-opening- polymerization was used for the preparation of a poly(d,l-lactide-co-glycolide Acid hydrogel polymer -functionalized polymer to appropriate for solid-phase extraction of metal ions from aqueous solutions. Resins were prepared by the copolymerization of the efficacious monomer. After the sol-gel process. Then, the nano-compound materials were used as absorbents to remove zinc ions from the aqueous solutions. The adsorption behaviors of nano-composites had been studied also. Experimental results revealed that the n-HAP/PLGA-β-TCP had greater adsorption capacity than nHAP/ β-TCP , and poly(d,l-lactide-co-glycolide Acid played vital role for the adsorption of Zinc ions. Moreover, the adsorption isotherms were applied by the two models Langmuir and Freundlich , The adsorption of metal ions can be explained the effect of composites recycle on the adsorption process on the cations by the Langmuir and Freundlich models effect and show the fitting of Zn(II) adsorption of correlation coefficient the Freundlich model is the best than Langmuir model

Toward Biodegradable Chain-Growth Polymers and Polymer Particles: Re-Evaluation of Reactivity Ratios in Copolymerization of Vinyl Monomers with Cyclic Ketene Acetal Using Nonlinear Regression with Proper Error Analysis

Recycling and biodegradability of chain-growth polymers is an important and growing topic. Introducing ester bonds in polymers via cyclic ketene acetals (CKAs) is an interesting route to create (bi...

Research on self-degradation of RGO/TiO2-P(AM-DAC) organic-inorganic composite flocculant prepared by surface initiated polymerization and its flocculation mechanism of oil sand tailings

In recent years, compared to commercial flocculants, organic-inorganic composite flocculants exhibit unique advantages in the field of oil sand tail flocculation, instilling technical strength of the new era into the traditional petrochemical industry. However, there are also defects in organic-inorganic composite flocculants, such as insufficient adsorption of tailings particles by polymers, and weak interface bonding between inorganic particles and polymers. In addition, the residual macromolecule in the solution after flocculation causes serious harm to the environment. In order to solve the above problems, the free radicals generated by RGO/TiO2 inorganic particles under illumination are used to initiate the copolymerization of AM and DAC monomers, which enables the copolymer P(AM-DAC) to grow in situ on the surface of inorganic particles, thereby preparing organic-inorganic composite flocculant that is closely bonded at the interfaces and able to electrostatically adsorb oil sand tailings particles. In this paper, the structure of the product is characterized by infrared spectrum, thermal analysis and XPS. The bonding of organic and inorganic interfaces is observed by TEM. The zeta potential is used to study the charged properties of the material. In addition, the simulated oil sand tailings are used to evaluate the effect of the proportion of cationic monomer on the flocculation, and the self-degradation performance of the material is tested under illumination as well as the degradation mechanism is analyzed by infrared spectroscopy with different illumination time. The results found that method can copolymerize both monomers in situ on the surface of the inorganic particles to form a copolymer and the organic-inorganic two-phase interface is tightly combined. The introduction of the cationic monomer (DAC) increases the flocculant cationicity and zeta potential. When the content of the cations is 30%, the flocculation effect reaches the highest. The photo-degradation test shows that the RGO/TiO2-P(AM-DAC) flocculant is capable of self-degradation under illumination conditions. After 8 h of illumination, the degradation rate is 26.1%. The work provides a theoretical basis and technical prototype for the development of polymerization technology and the design of a new generation of dedicated flocculant for oil sand tailings.

Olefins and Vinyl Polar Monomers: Bridging the Gap for Next Generation Materials.

The inherent differences in reactivity between activated and non-activated alkenes prevents copolymerization using established polymer synthesis techniques. Research over the past 20 years has greatly advanced the copolymerization of polar vinyl monomers and olefins. This Review highlights the challenges associated with conventional polymerization systems and evaluates the most relevant methods which have been developed to "bridge the gap" between polar vinyl monomers and olefins. We discuss advancements in heteroatom tolerant coordination-insertion polymerizations, methods of controlling radical polymerizations to incorporate olefinic monomers, as well as combined approaches employing sequential polymerizations. Finally, we discuss state-of-the-art stimuli-responsive systems capable of facile switching between catalytic pathways and provide an outlook towards applications in which tailored copolymers are ideally suited.

Electrochemically initiated co-polymerization of monomers of different oxidation potentials for molecular imprinting of electroactive analyte

Herein, we report an electrochemically initiated co-polymerization of two electroactive monomers of different oxidation potentials. The molar ratio of low oxidation potential monomer in the solution for electropolymerization was optimized to find condition suitable for co-polymerization of high-oxidation potential monomer effectively at lower oxidation potential. The XPS analysis confirmed successful co-polymerization. This co-polymerization condition was further used in imprinting of melatonin, an electroactive compound. Entrapment of melatonin in the polymer matrix was confirmed by measuring electroactivity of melatonin in the 0.1 M KCl−HCl solution (pH 1.6). This MIP based electrochemical sensor determined melatonin in the linear dynamic concentration range 10–80 μM. Detectability of proposed chemosensor was 0.14 μM (S/N = 3). The mean RSD for the concentration range studied was ∼20%. Selectivity of the chemosensor was satisfactory towards common structural analogues and biomolecules. Furthermore, the chemosensor was successfully used to determine melatonin in real samples. The sensitivity in the presence of matrix components and that for the KCl−HCl solution were quite similar. The results obtained indicate the suitability of the devised chemosensor for practical applications.

Microstructure and sulfonation of dual monomer‐grafted polypropylene nonwoven fabrics

ABSTRACTThe sulfonation of styrenic polymers often needs harsh reaction conditions, such as concentrated sulfuric acid and elevated temperature. The awkward situation is handled by grafting copolymerization of polar and nonpolar monomers, and essentially the surface wettability between sulfonating agent and matrix polymer is circumvented in the study. Two pairs of dual monomers, glycidyl methacrylate (GMA)‐acrylic acid (AA), styrene (St)‐acrylic acid (AA), were grafted onto polypropylene nonwoven fabrics (PP) using thermal polymerization, and the resulted fabrics were further sulfonated using sodium sulfite and sulfuric acid, respectively. The microstructure of the modified fabrics was characterized by infrared spectroscopy and scanning electron microscopy. The ion exchange property was verified by copper (II) removal from aqueous solution, and its reutilization was carried out in electrochemical desorption process. The results show that hydrophilic and active monomer AA speeds grafting and sulfonation, but overload of AA will deteriorate copolymerization of GMA, and switch copolymerization chain component due to acylation with benzene ring. Although interfacial compatilizer promotes dual grafting, its overdosing may intensify microphase segregation of the grafting polymers owing to emulsification. The resultant granular polymers will be drained off during functionalization and reutilization processes. The ion exchange fabrics can be applied for treatment of metal ion wastewaters with unique electrochemical desorption feature. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48300.

Aggregation-Caused Quenching-Type Naphthalimide Fluorophores Grafted and Ionized in a 3D Polymeric Hydrogel Network for Highly Fluorescent and Locally Tunable Emission

Polymer hydrogels with intense yet tunable fluorescence are of great research interest due to their wide potential use in biological imaging, sensing, information storage, etc. However, the conventional fluorophores such as naphthalimide and its derivatives are usually not recommended to prepare highly fluorescent hydrogels because of their aggregation-caused quenching (ACQ) nature and spontaneous tendency to undergo fluorescence self-quenching in quasi-solid-state hydrogel systems. Additionally, local regulation over fluorescent behavior of hydrogels, despite being important, still remains underdeveloped. Herein, we report highly fluorescent polymeric hydrogels based on conventional ACQ-type naphthalimide fluorophores, followed by spatial and temporal control of their fluorescent behavior. The hydrogels were prepared by one-pot radical copolymerization of naphthalimide-containing monomer and acrylamide in chitosan-acetic acid solution. Their intense emission comes from synergetic anchoring and diluting effect of the protonated naphthalimide moieties grafted on polymer chains, which result in the electrostatic repulsion among ACQ luminogens and reduced PET (photoinduced electron transfer) effect from adjacent dimethylamine groups to naphthalimide fluorophores. After being deprotonated in alkaline conditions, both PET and the ACQ effect work again to greatly quench fluorescence, endowing the hydrogels with pH-sensitive emission behavior. These properties encourage us to develop a diffusion-reaction (D-R) method to spatially and temporally control their fluorescent behavior. Based on these results, the ion-transfer-printing-assisted D-R method was further developed to fabricate many high-precision and meaningful fluorescent patterns on hydrogels. These fluorescent patterns are invisible under daylight but become vivid under specific UV light illumination, suggesting their wide potential applications in information security and transmission.

Fabrication of novel magnetic graphene oxide nanocomposites for selective adsorption of mercury from aqueous solutions.

In this work, a novel functionalized graphene oxide (GO) was used as an effective and selective adsorbent for removal of mercury (Hg2+). The magnetic nanocomposite adsorbent (MNA) based on GO was prepared through surface reversible addition-fragmentation chain transfer copolymerization of acrylic monomers and then the formation of Fe3O4 nanoparticles. The structure of MNAs was characterized by using FTIR, SEM, TEM, VSM, XRD, and nitrogen adsorption/desorption isotherms. The results of ion adsorption of MNAs demonstrated high selectivity and adsorption efficiency for Hg2+ in the presence of competing ions. Furthermore, the removal of Hg2+ obeyed a pseudo-second-order model and fitted well to the Langmuir isotherm model with the maximum Hg2+ uptake of 389 mg g-1. The MNA was also confirmed as good materials for re-use and maintained 86% of its initial adsorption capacity for mercury after the fifth regeneration cycles. Finally, the experimental results demonstrated that the solution pH, ion concentration, and temperature had a major impact on Hg(II) adsorption capacity. The results indicate that the MNAs with high adsorption abilities could be very promising adsorbents for the selective recovery of ions in wastewater treatment process. Graphical abstract.

Emulsion copolymerization of vinyl monomers from soybean and olive oil: Effect of counterpart aqueous solubility

Highly hydrophobic vinyl monomers from soybean (SBM) and olive (OVM) oil with different amounts of unsaturation were copolymerized in emulsion with significantly more soluble in water comonomers, methyl methacrylate (MMA), vinyl acetate (VA), and methyl acrylate (MA). Our intention was to demonstrate that higher aqueous solubility of the comonomer impacts the mechanism of the emulsion process by balancing latex particle homogeneous and heterogeneous (micellar) nucleation.Using an experimental method based on water insoluble dye Blue 70, it is shown that particle nucleation indeed depends to a great extent on aqueous solubility of the comonomer, along with the plant oil-based monomer (POBM) content in the feed. Upon addition of POBM into the monomer mixture with MMA (aq.solubility 1.5 wt%), the latex polymer particles originating from micellar nucleation essentially increased. In copolymerization of POBM with MA (aqueous solubility 4.9 wt%), this effect is even more pronounced. Those findings clearly indicate that copolymerization loci change when monomer feed hydrophobicity increases, and the magnitude of this effect is dependent on the comonomer aqueous solubility.Experimentally determined changes in reaction order with respect to emulsifier and initiator upon addition of POBM confirm that kinetics of emulsion copolymerization is impacted by comonomer aqueous solubility. The latter finding can be indicative of changing latex particle nucleation mode when monomer feed hydrophobicity changes.Overall, the portion of latex particles originating through micellar nucleation is higher in the copolymerization of more unsaturated SBM (with both MMA and MA) in comparison to OVM. No impact of POBM content on the reaction kinetics was observed in copolymerization with VA (aq. solubility 2.5 wt%). Here, high reactivity of growing PVA radicals in chain transfer reactions makes the presence of POBM in monomer feed kinetically irrelevant.

A new ferrocene/disulfide-containing methacrylate monomer: Synthesis, ATRP and nanocomposite

A new methacrylate monomer containing ferrocene unit and disulfide bond, 2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate (FcMAss), was prepared by subsequent esterification reaction with bis(2-hydroxyethyl) disulfide and methacryloyl chloride using ferrocenecarboxylic acid as starting material. A series of well-defined poly(2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate) (PFcMAss) homopolymers with narrow molecular weight distributions (Mw/Mn < 1.30) was then obtained by atom transfer radical polymerization (ATRP) of FcMAss monomer in toluene. Block copolymerization of FcMAss monomer was initiated by PEG-Br macroinitiator in THF to afford a poly(ethylene glycol)-b-poly(2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate) (PEG-b-PFcMAss) diblock copolymer with a relatively low dispersity (Mw/Mn = 1.34). Graphene oxide (GO)-based nanocomposite, GO-PFcMAss, was prepared by surface-initiated ATRP of FcMAss via the grafting-from strategy, using GO-based macroinitiator obtained by treating tris(hydroxymethyl) aminomethane (TRIS)-modified GO with 2-bromo-2-methylpropionyl bromide. The nanocomposite was characterized by FT-IR and XPS, and showed excellent dispersibility and colloidal stability.

Overcoming Kinetic Trapping for Morphology Evolution during Polymerization‐Induced Self‐Assembly

Polymerization-induced self-assembly (PISA) is a powerful technique to synthesize assemblies with various morphologies. However, PISA mediated by long, stabilizing chains usually produces kinetically trapped spheres; thus, the morphology evolution remains a challenge. Here, a convenient and general strategy for facilitating the morphological evolution by the copolymerization of solvophilic monomers is reported. With the incorporation of only 7% (molar ratio) solvophilic 3-(triethoxysilyl)propyl methacrylate (TESPMA) into poly(N,N-dimethylaminoethyl methacrylate)-b-poly(benzyl methacrylate) (PDMA-b-PBzMA) spheres, PDMA-b-P(BzMA-co-TESPMA) assemblies evolve from spheres to worms, octopi-like and jellyfish-like structures, vesicles, and large compound vesicles. This non-specific effect is further confirmed by the copolymerization of BzMA with other solvophilic monomers, including N,N-dimethylaminoethyl methacrylate (DMA), N,N-diethylaminoethyl methacrylate (DEA), and 2-hydroxypropyl methacrylate (HPMA). This work provides a convenient approach to promote morphology evolution and develops the formulations design of PISA.

Bis-N,N-aminophosphine (PNP) crosslinked poly(p-tert-butyl styrene) particles: A new support for heterogeneous palladium catalysts for Suzuki coupling reactions

Crosslinked polymer particles carrying hemilabile bis-N,N-aminophosphine (PNP) moieties are obtained by the copolymerization of a PNP-derived monomer bearing four vinyl fragments as cross-linkers, with para-tert-butylstyrene and divinylbenzene, using free radical copolymerization in presence of AIBN, performed in aqueous dispersed medium. This new support was characterized by thermogravimetric analysis, elemental analysis, laser diffraction, solid state NMR. The PNP moiety could allow monochelation to palladium. The resulting insoluble Pd-catalyst revealed to be very active for Suzuki cross-coupling with several substrates, allowing separation of the product from the catalyst by filtration. The final palladium PS-PNP catalyst could be reused for several catalytic cycles.

Synthesis and radical copolymerization of novel propyl cyanoacrylate monomers

Novel phenyl-trisubstituted propyl 3-(R-phenyl)-2-cyanoacrylates (where R is 2,4,5-trimethyl, 2,4,6-trimethyl, 2,3-dimethyl-4-methoxy, 2,5-dimethyl-4-methoxy, 2,4-dimethoxy-3-methyl, 2,4-dimethoxy-6-methyl, 4-hydoxy-3,5-dimethyl, 2,3,4-trimethoxy, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3,4,5-trimethoxy) were prepared using piperidine-catalyzed condensation of substituted benzoic aldehydes and propyl ester of cyanoacetic acid with good yields (72–97 wt%). The ethenylbenzene copolymerization of cyanoacrylates (at 3/1 mol feed ratio) in solution with radical initiation at 70 °C resulted in formation of copolymers having MW 3.9 to 27.8 kD and 8.4–25.8 mol% of cyanoacrylate. FTIR, 1H and 13C NMR were used to analyze the structure. Thermal behavior of the copolymers was analyzed by DSC, Tg (81–129 °C) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500 °C range with residue (0.5–7.3 wt%)and then in the 500–800 °C range.