Microwave Synthesis of Copolymers Based on Itaconic Acid Moiety and Their Utility for Scavenging of Copper (II) and Lead (II)

We report here the preparation of the two copolymers, itaconic acid-methyl methacrylate and itaconic acid-acrylamide, in different ratios using microwave irradiation in the presence of azobisisobutyronitrile (AIBN) as initiator and 2-butanone as a solvent. All the prepared copolymers were characterized by different techniques; FT-IR, thermal analysis and elemental microanalysis. The thermal stability property of the prepared copolymers correlated with the changing of the itaconic acid ratio, as the ratio of itaconic acid increased, the crystallinity of the copolymer decreases. The itaconic acid-based copolymers also showed a good scavenging behavior in alkaline media for Cu (II) and Pb (II). The chelation behavior of both Cu (II) and Pb (II) complexes were checked using FT-IR, thermogravimetric analysis (TGA), and differential scanning calorimetery (DSC).     

Polymerization and characterization of novel poly(acrylonitrile‐co‐styrene/pyrrole) nanoparticles: A comparison between microwave and conventional method

In this study, poly(acrylonitrile‐co‐styrene/pyrrole) or poly(AN‐co‐ST/Py) copolymer was successfully synthesized using microwave preparation technique, and its comparison with the conventional heating method is investigated. Different polymerization factors affecting on the preparation conditions and conversion yield such as monomer concentration, comonomers ratio, initiator concentration, cosolvent ratio, cosolvent type, polymerization temperature, and polymerization time have a considerable effect on the conversion yield %, functional groups, and molecular weight. The copolymerization process was approved by Fourier transform infrared, thermogravimetric analysis, ¹H NMR spectroscopy, and gel permeation chromatography. The formation of poly(AN‐co‐ST/Py) nanoparticles was confirmed by SEM, and their possible formation mechanisms were also proposed. The SEM images of poly(AN‐co‐ST/Py) prepared by the microwave method showed that the synthesized copolymer had spikes or rods with spherical structure of the produced copolymers than the poly(AN‐co‐ST/Py) nanoparticles prepared by the conventional heating method. Microwave method showed advantages for the produced copolymers compared to that prepared by conventional method, where it can offer a copolymer in short time, high yield, and more thermally stable copolymers, rather than conventional method.     

A comparative study on the synthesis of 4‐alkyl‐1,3‐diarylpyrazoles using microwave irradiation and conventional thermal methods

A convenient synthesis of 4‐alkyl‐1,3‐diarylpyrazoles ( 2 ) under microwave irradiation as well as conventional thermal method using Vilsmeier cyclization is reported. Microwave irradiation has resulted in the reduction of time from hours to seconds.     

微波辐射用于聚合反应的研究进展

微波辐射在高分子化学研究领域中的应用越来越广泛 ,效果也十分明显 ,与常规加热方式相比 ,微波辐射具有缩短反应时间 ,提高反应产率 ,节省能源损耗 ,制得产物性能好等优点。近年来 ,微波辐射在聚合反应中的应用也越来越多。因此本文对微波辐射在高分子聚合反应中的应用研究进行了综述。     

Electrosyntheses and characterization of a fluorescent conducting copolymer of benzanthrone and thiophene

<正>Poly(benzanthrone-co-thiophene),a new conducting copolymer,was successfully prepared by direct anodic oxidation of benzanthrone and thiophene(Th) in a binary solvent system containing boron trifluoride diethyl etherate (BFEE) and acetonitrile(ACN).The as-formed copolymer film electrodeposited with monomer feed ratio of benzanthrone/Th = 1:1 at the applied potential of 1.3 V versus Ag/AgCl exhibited the advantages of both polybenzanthrone and polythiophene,such as active electrochemical behavior,excellent thermal stability,relatively high electrical conductivity and mechanical properties.UV-Vis spectroscopy,~1H-NMR and SEM were used to characterize and investigate the structures and morphologies of the copolymers.Fluorescence spectroscopy studies revealed that the obtained copolymer films show strong emission at about 525 nm.Moreover,the emitting properties of the copolymers could be tuned by changing some parameters during the electropolymerization process,such as monomer feed ratio.     

Synthesis and characterization of hydrolysable poly(ether-urethane-urea)s derived from l-leucine anhydride cyclopeptide; a green synthetic method for monomer

l-leucine anhydride cyclodipeptide (LAC) was prepared through a green method under microwave irradiation with good yield. Then a new class of hydrolysable poly(ether-urethane-urea)s (PEUUs) was synthesized via two-step polymerization method. In the first step, 4,4′-methylene-bis-(4-phenylisocyanate) (MDI) was reacted with LAC to produce isocyanate-terminated poly(imide-urea) oligomers (hard segment). Reaction of the resulting pre-polymer with different molecular weights (MW) of polyethyleneglycols (PEG)s such as PEG-400, PEG-600, PEG-1000 and PEG-2000 was the second step to furnish a series of new PEUUs. The resulting multiblock copolymers have inherent viscosities in the range of 0.4-1.8 dL/g. These multiblock copolymers are hydrolysable, thermally stable and soluble in amide-type solvents. Polymers containing different molecular weights of PEGs soft segments show different thermal stability, phase separation, hard segment cohesiveness and hydrolysis rate. Some structural characterization and physical properties of these PEUUs are reported.     

Effect of chemical structure on the properties of some hydrogels prepared by using gamma radiation polymerization

Several hydrogels were prepared using radiolytic polymerization of aqueous solutions of acrylamide or acrylamide containing appropriate comonomer such as acrylic acid, maleic acid, itaconic acid, and maleic anhydride. The hydrogels have been prepared at an irradiation dose of 30 kGy. The effects of the chemical structure of the monomer(s) and crosslinking agents on the yield of homopolymer(s) or copolymers have been studied. These crosslinking agents include N, N′‐methylene dimethacrylate (MDA) and N, N′‐methylene bisallyamide (MBA). The hydrogels obtained were characterized using swelling technique, thermal and spectroscopic analysis. The results obtained showed that the prepared samples are able to reject sodium ions and are not able to recover the Basic Blue Dye from their aqueous solution. © 2005 John Wiley & Sons, Ltd.     

Dispersion copolymerization of 2‐ethylhexyl methacrylate and vinylbenzyl chloride and functional group conversions in a fluorinated solvent using microwave heating

Conventional and microwave heating were compared for free radical dispersion polymerizations of crosslinked copolymers of 2‐ethylhexyl methacrylate, vinylbenzyl chloride (VBC), and fluoroalkyl methacryate monomers in the solvent nonafluorobutyl ethyl ether, and for the functional conversion of the VBC units of the copolymer particles with trimethylamine to quaternary ammonium chloride units. By conventional heating, all polymerizations produced foamy coagulated products consisting of primary spherical particles 1–2 μm in diameter. Microwave heating using poly(1H,1H‐dihydroperfluorooctyl acrylate) as a stabilizer gave faster polymerization and stable dispersions of discrete 1 μm particles. Microwave heating also gave faster reactions of the copolymers with trimethylamine to produce quaternary ammonium chloride functionalized colloidal particles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3813–3819, 2008     

Synthesis and characterization of poly (1‐vinyl‐3‐butylimidazolium‐co‐methyl methacrylate) gel polymer electrolytes for dye‐sensitized solar cells: Effect of structure and composition

Herein, three ionic liquid random copolymers (P) containing 1‐vinyl‐3‐butylimidazolium bromide (VBImBr) and methyl methacrylate (MMA) with various molar ratios were prepared using conventional free radical polymerization. Afterward, their corresponding chemically cross‐linked copolymers (XP) were formed similarly in the presence of polyethylene glycol dimethacrylate (PEGDMA). The synthesized copolymers were characterized using FT‐IR, ¹H NMR, and GPC. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results showed that the rigidity and thermal stability of the copolymers depended on the ionic liquid content as well as the degree of cross‐linking. Gel polymer electrolytes were then prepared via obtained copolymers in the presence of a constant amount of synthesized imidazolium‐based ionic liquid. Among the copolymers, the P3 with in feed VBImBr:MMA molar ratio of 70:30 and the cross‐linked 1%‐XP3 copolymer prepared with 1 mol% of PEGDMA exhibited the highest conductivity and diffusion coefficients for I₃^¯ and I^¯. The power conversion efficiency of the optimized linear and cross‐linked copolymers (P3 and 1%‐XP3) under the simulated AM 1.5 solar spectrum irradiation at 100 mW cm^?2 were 3.49 and 4.13% in the fabricated dye‐sensitized solar cells (DSSCs), respectively. The superior long‐term stability and high performance of the gel electrolyte containing 1%‐XP3 suggested it as commercial gel electrolyte for future DSSCs.     

单模微波辐照下壳聚糖-左旋聚乳酸接枝共聚物的酶催化合成

以猪胰脂肪酶(PPL)代替传统的有机金属作为催化剂,在单模微波辐照下利用左旋丙交酯(L-LA)的开环聚合制备壳聚糖-左旋聚乳酸(CS-g-PLLA)接枝共聚物.考察了反应温度及酶用量对接枝率的影响.以此为基础,利用DTG、XRD和3T3成纤维细胞培养对产物的物理性能及细胞相容性进行分析.结果显示,猪胰酶可有效催化接枝反应的进行.反应温度和酶用量对产物的接枝率有较大影响.在单模微波作用下,较低的反应温度(50℃)可获得具有较高接枝率(178.8%)的接枝产物.与纯壳聚糖相比,接枝产物的结晶度和热稳定性降低,说明PLLA的引入破坏了壳聚糖的高结晶性.产物具有良好的细胞相容性,可作为优良的组织工程支架材料.     

Preparation of poly(methyl acrylate‐co‐itaconic anhydride)/SiO2 hybrid materials via the sol–gel process—The effect of the coupling agent,inorganic content,and nature of the catalyst

Transparent poly(methyl acrylate‐co‐itaconic anhydride)/SiO₂ hybrid materials were prepared from methyl acrylate‐itaconic anhydride copolymer and tetraethoxysilane (TEOS) with the coupling agent (3‐aminopropyl)triethoxysilane (APTES) via a sol–gel process. The covalent bonds between the organic and inorganic phases were introduced by the in situ aminolysis of the itaconic anhydride units with APTES forming a copolymer bearing a triethoxysilyl group. These groups subsequently were hydrolyzed with TEOS and allowed to form a network. These reactions were monitored by Fourier transform infrared analysis. The amount of APTES had a dramatic influence on the gel time and sol fraction. The effect of APTES, the inorganic content, and the nature of the catalyst on the thermal properties and morphology of the hybrid materials were studied by differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and atomic force microscopy. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 321–328, 2000     

Miscibility and Thermal Behaviour of Poly(styrene-co-itaconic acid)/Poly(butyl methacrylate-co-4-vinylpyridine) Mixtures. Accessibility and Self-Association Effects

Summary: The miscibility and thermal behaviour of binary mixtures of poly(styrene-co-itaconic acid) containing 11 or 27 mol % of itaconic acid (PSIA-11 or PSIA27) with poly(butyl methacrylate) (PBMA)or poly(butyl methacrylate-co-4-vinylpyridine) containing 10 or 26 mol% of 4-vinylpyridine (PBM4VP-10, PBM4V-P26) were investigated by differential scanning calorimetry, scanning electron microscopy, FTIR spectroscopy and thermogravimetry. The results showed that 11 mol % of itaconic acid and 10 mol % of 4-vinylpyridine respectively introduced within the polystyrene and poly(butyl methacrylate) matrices induced the miscibility of this pair of polymers due to specific interactions of hydrogen bonding type with partial pyridine protonation that occurred between the two copolymers as evidenced by FTIR from the appearance of two new bands at 1607 cm⁻¹ and 1640 cm⁻¹. Increasing itaconic acid content from 11 to 27 mol % led to a decrease of the intensity of the specific interactions within PSIA-27/PBM4VP blends and is attributed to both accessibility and self association effects as evidenced by DSC from the change of the shape of the Tg- composition curves and by FTIR spectroscopy. As shown from the thermogravimetric study, the presence of these specific interactions delayed the anhydride formation and improved the thermal stability of the blends.     

Microwave Effects Due to Anionic or Cationic Initiators in Emulsion Polymerization Reactions

Summary: Emulsion polymerization reactions were performed under microwave irradiation and conventional heating using anionic or cationic initiators and surfactants. Microwave irradiation promoted higher reaction rates for both initiators and surfactants, in comparison with the conventional heating. The effect of high power microwave irradiation was studied using a method of cycles of heating and cooling, where rapid polymerization reactions were obtained. In the reactions with anionic initiator and surfactant, a decrease in the particle diameters was observed with microwave heating, and even smaller particles were obtained using high power microwave irradiation. Moreover, the decrease in the particle size was acompanied by an increase in the polymer molecular weight. On the other hand, these effects were not observed for reactions with cationic initiator and surfactant.     

Photogenerated base in polymer curing and imaging: Design of reactive styrenic copolymers susceptible to a base-catalyzed β-elimination

A novel family of functionalized styrenic copolymers that are susceptible to a base-catalyzed β-elimination reaction is reported. The reactive copolymers, poly-{(2-phenyl-2-cyanoethoxycarbonyloxystyrene)-co-(4-hydroxystyrene)}, are prepared by chemical modification of poly(4-hydroxystyrene) using 2-phenyl-2-cyanoethyl chloroformate. A photoresist material consisting of the copolymer and bis[[(2-nitrobenzyl)-oxy] carbonyl]-4,4′-trimethylenedipiperidine used as an amine photogenerator affords positive tone images by UV irradiation. The effect of copolymer structure and composition on imaging, thermal stability, and the ease of β-elimination reaction is discussed. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3543–3552 1997     

Bioengineering functional copolymers. III. Synthesis of biocompatible poly[(N‐isopropylacrylamide‐co‐maleic anhydride)‐g‐poly(ethylene oxide)]/poly(ethylene imine) macrocomplexes and their thermostabilization effect on the activity of the enzyme penicillin G acylase

Stimuli‐responsive poly[(N‐isopropylacrylamide‐co‐maleic anhydride)‐g‐poly(ethylene oxide)]/poly(ethylene imine) macrobranched macrocomplexes were synthesized by (1) the radical copolymerization of N‐isopropylacrylamide and maleic anhydride with α,α′‐azobisisobutyronitrile as an initiator in 1,4‐dioxane at 65 °C under a nitrogen atmosphere, (2) the polyesterification (grafting) of prepared poly(N‐isopropylacrylamide‐co‐maleic anhydride) containing less than 20 mol % anhydride units with α‐hydroxy‐ω‐methoxy‐poly(ethylene oxide)s having different number‐average molecular weights (M_n = 4000, 10,000, or 20,000), and (3) the incorporation of macrobranched copolymers with poly(ethylene imine) (M_n = 60,000). The composition and structure of the synthesized copolymer systems were determined by Fourier transform infrared, ¹H and ¹³C NMR spectroscopy, and chemical and elemental analyses. The important properties of the copolymer systems (e.g., the viscosity, thermal and pH sensitivities, and lower critical solution temperature behavior) changed with increases in the molecular weight, composition, and length of the macrobranched hydrophobic domains. These copolymers with reactive anhydride and carboxylic groups were used for the stabilization of penicillin G acylase (PGA). The conjugation of the enzyme with the copolymers significantly increased the thermal stability of PGA (three times at 45 °C and two times at 65 °C). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1580–1593, 2003     

Polymeric flocculants processing by accelerated electron beams and microwave heating

Results obtained by accelerated electron beam, microwave and simultaneous microwave and electron beam application in the chemistry of acrylamide and acrylic acid copolymers (polymeric flocculants used for wastewater treatment) are presented. Comparative results concerning the molecular weight and Huggins’ constant for the acrylamide and acrylic acid copolymers obtained by classical heating, microwave heating, electron beam irradiation and simultaneous microwave and electron beam treatment are reported. Microwave heating produces high water solubility of the polymeric flocculants but median molecular weight values. Electron beam irradiation gives high molecular weight values but associated with a cross-linked structure (poor water solubility) while microwave energy addition to electron beam energy gives simultaneously high molecular weight values and high water solubility.     

The influence of chemical modification of unsaturated polyesters on viscoelastic properties and thermal behavior of styrene copolymers

The influence of chemical modification of unsaturated polyesters on viscoelastic properties and thermal behavior of styrene copolymers has been investigated by DMA and TG analyses. Chemical modification of unsaturated polyesters obtained in polycondensation of cyclohex-4-ene-1,2-dicarboxylic anhydride (THPA), maleic anhydride (MA) and suitable glycol: diethylene glycol (DEG) or triethylene glycol (TEG) was performed using 38–40% peracetic acid. It allowed to selective and successful oxidation of carbon-carbon double bonds in unsaturated polyesters giving modified unsaturated polyesters/unsaturated epoxypolyesters/containing both carbon-carbon double bonds in polyester chain and new functional groups-epoxy groups in cycloaliphatic rings. Both unsaturated polyesters and unsaturated epoxypolyesters were used as a component of styrene copolymers cured with different hardeners. It has been demonstrated that the use of modified unsaturated polyesters as a component of styrene copolymers allowed obtaining more stiffness and more cross-linked network structure compared to styrene copolymers based on unmodified polyesters. The higher values of storage modulus, glass transition temperatures and better thermal stability for styrene copolymers based on unsaturated epoxypolyesters were obtained.     

Microwave Assisted Benign Method of Chelating Resin Synthesis Having Different Thermal and Ion Exchange Properties

Summary: Microwave irradiation method was used for synthesis of chelating ion exchange resin derived fom Salicylicacid-Formaldehyde-Resorcinol (SFR-M). The resin was characterized by Elemental analysis, FTIR, TGA and SEM. The Broido and Horowitz-Metzger method were used to calculate the energy of activation (Ea) from TGA. The microwave assisted chelating resin has different thermal behaviour as compared to conventional resin (SFR-C). The sorption capacities of microwave SFR resin for transition metal ions are higher than conventional SFR resin. The separation of binary mixtures [Cu (II) and Zn (II)] in brass and [Ni (II) and Cd (II)] were successfully carried out using Kd value.     

Thermal stability of poly(vinyl bromide) and vinyl bromide-methyl acrylate copolymers. I

The thermal stability of PVB and five VB-MA copolymers with different compositions was studied by thermogravimetric analysis in dynamic nitrogen. The reactivity ratios of the copolymers were determined by using NMR techniques. It was found that r₁(VB) = 0.5 ± 0.1 and r₂(MA) = 7.3 ± 0.3. The stability of VB increases as the MA concentration in the copolymer compositions increases. Apparently, the formation of lactone and anhydride structures has a stabilizing effect. The stability imparted to the degrading copolymers by lactone and anhydride structures is insufficient to produce stability comparable to that of PMA itself.     

Some properties of polyethylene terephthalate-acrylic acid copolymers and ionomers

Acrylic acid has been grafted to polyethylene terephthalate (PET) by mutual irradiation, and the resulting copolymers converted to their sodium, calcium and lead salts. The electrical surface resistance of PET was reduced by grafting, the effect being most pronounced for the copolymer in the form of its sodium salt. The thermal stability of PET was studied by thermogravimetric analysis and differential thermal analysis, and activation energies were derived for the thermal decompositions; similar studies were made for the acidic and ionomeric copolymers. The stability of acidic copolymer was found to be lower than that of ungrafted PET; enhanced thermal stability was obtained only in the metallated copolymers.