Synthesis and characterization of new imidazole and fluorene–bisphenol based polyamides: Thermal,photophysical and antibacterial properties

A new para-linked diether-diamine, 9,9-bis{4-[2-(4,5-diphenylimidazol-2-yl)-4-aminophenoxy] phenyl}fluorene (III), bearing fluorene–bisphenol and two ortho-linked diaryl-substituted imidazole rings were synthesized by the catalytic reduction of the nitro groups of compound (II), 9,9-bis{4-[2-(4,5-diphenylimidazol-2-yl)-4-nitrophenoxy]phenyl}fluorene, by using hydrazine monohydrate in the presence of Pd/C. Compound (II) was synthesized by the nucleophilic chloro displacement reaction of the synthesized 2-(2-chloro-5-nitrophenyl)-4,5-diphenyl-1H-imidazole with 9,9-bis(4-hydroxyphenyl)fluorene in refluxing DMAc in the presence of potassium carbonate. This diamine was condensed directly with aliphatic and aromatic diacids via the Yamazaki–Higashi phosphorylation method in the presence of triphenylphosphite (TPP), pyridine (Py) and halide salt to give high molecular polyamides (PAs). The synthesized PAs were obtained in quantitative yields with inherent viscosities between 0.51 and 0.76 dL g^?1. The structures of diamine and PAs were characterized by elemental analysis, FT-IR and NMR spectroscopy, and properties of PAs were investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and UV–visible and fluorescence spectroscopy. The PAs showed good solubility in aprotic and polar organic solvents, with high thermal stability exhibiting the glass transition temperatures (T_gs) and 10% weight loss temperatures (T_10%) in the range of 226–330 °C and 400–466 °C in air, respectively, and fluorescence emission with maximum wavelengths (λ_em) in the range of 417–473 nm with quantum yields (Φ_f) of 9–35%. Two of these polymers together with compounds (II) and (III) were also screened for antibacterial activity against Gram positive and Gram negative bacteria.     

Synthesis,Characterization and Anti-Breast Cancer Activity of New 4-Aminoantipyrine-Based Heterocycles

4-Aminoantipyrine was utilized as key intermediate for the synthesis of pyrazolone derivatives bearing biologically active moieties. The newly synthesized compounds were characterized by IR, ¹H- and ¹³C-NMR spectral and microanalytical studies. The compounds were screened as anticancer agents against a human tumor breast cancer cell line MCF7, and the results showed that (Z)-4-((3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-ylidene)methylamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 5, 3-(4-bromophenyl) -1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 13, 1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1-Hpyrazol- 4-yl)-3-(4-iodophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 14, 3,3′-(4,4′-sulfonylbis(4,1-phenylene))bis(1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) 16, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-hydrazono-4-oxo-3-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 17, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-3-phenyl-2-(2-phenylhydrazono)-1,2,3,4-tetrahydro pyrimidine-5-carbonitrile 18, and (Z)-4-(3-amino-6-hydrazono-7-phenyl-6,7-dihydro pyrazolo[3,4-d]pyrimidin-5-yl)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 19 were the most active compounds with IC₅₀ values ranging from 30.68 to 60.72 μM compared with Doxorubicin as positive control with the IC₅₀ value 71.8 μM.     

Synthesis and properties of new poly(amide‐imide)s based on 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane and aromatic diamines

Six new poly(amide‐imide)s 8a–f containing trimethylene moiety in the main chain were synthesized by the polycondensation reactions of 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 with six different aromatic diamines 7a–f in a medium constituting N‐methyl‐2‐pyrrolidone, triphenylphosphite, CaCl₂, and pyridine as condensing agents. The polycondensation reaction produced a series of novel poly(amide‐imide)s 8a–f in high yields with inherent viscosities between 0.35 and 0.63 dL/g. The resulting poly(amide‐imide)s were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility tests, and FTIR spectroscopy. 1,3‐Bis[4,4'‐(trimellitimido) phenoxy] propane 6 as a new monomer containing trimethylene moiety was synthesized using a three‐step reaction. At first 1,3‐bis[4,4'‐nitrophenoxy] propane 3 was prepared by the reaction of 4‐nitrophenol 1 with 1,3‐dibromo propane 2 in DMF solution . Then, dinitro 3 was reduced to 1,3‐bis[4,4'‐aminophenoxy] propane 4 by using a solution of sodium sulfite in ethanol. Finally, 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 was prepared by the reaction of one equivalent diamine 4 with two equivalents of trimellitic anhydride 5 in a mixture of acetic acid‐pyridine (3 : 2). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Anionic synthesis of aromatic carboxyl functionalized polymers. Chain-end functionalization of poly(styryl)lithium with 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl] oxazole

The novel syntheses of 4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)benzophenone, 1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylethanol and 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) are described. ω-Oxazolyl polystyrene ( 2 ) was synthesized in quantitative yields by the reaction of poly(styryl)lithium with stoichiometric amounts of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) in toluene/tetrahydrofuran (4 : 1 v/v) at −78°C. Deblocking of the oxazoline protecting group by acid hydrolysis followed by saponification quantitatively provides the corresponding aromatic carboxyl chain-end functionalized polystyrene ( 3 ). The functionalization agent and functionalized polymers were characterized by HPLC, thin layer chromatography, size exclusion chromatography, vapor phase osmometry, spectroscopy (¹H NMR, ¹³C NMR and FTIR), potentiometry and elemental analysis.     

Synthesis,characterization, and gas transport properties of new semifluorinated poly(ether imide)s containing cardo moiety

A series of new semifluorinated poly(ether imide)s (PEI)s was synthesized from a diamine monomer, 9,9‐bis ‐[3‐phenyl‐4‐{2′‐trifluoromethyl‐4′‐(4′′‐aminophenyl)phenoxy} phenyl]fluorene on reaction with three different aromatic dianhydrides namely, 4,4′‐(4,4′‐isopropylidenediphenoxy)bis (phthalic anhydride), 4,4'‐(hexafluoro‐isopropylidene)diphthalic anhydride, and 4,4'‐oxydiphthalic anhydride. The PEIs were well characterized by elemental analysis, spectroscopic, thermal, mechanical, electrical, and optical techniques. The synthesized PEIs showed high glass transition temperature (T_g up to 288 °C) and high thermal stability (T_{d ,10} up to 521 °C under synthetic air), high tensile strength, up to 76 MPa and low dielectric constant (?) (2.35–2.61 at 1 MHz). The membranes prepared from these polymers were studied for their gas permeability for four different gases CO₂, O₂, N₂, and CH₄. The PEI membranes showed high gas permeability (P _CO2 up to 70.3 and P _O2 up to 16.7 Barrer) and high permselectivity (P _CO2/P _CH4 up to 73.6 and P _O2/P _N2 up to 13.4); for the O₂/N₂ gas pair the PEIs surpassed the present upper boundary limit of 2008 drawn by Robeson. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45213.     

Synthesis and Characterisation of Polyamides and Polyimides from Amino/Methylene bis[Benzenamine] Styryl Pyridines

Polyamides and polyimides containing diamines, with potential non-linear optical characteristics, were prepared using (E)-4,4′-[[[2-(4-pyridinyl)ethenyl]phenyl]amino]bis[benzenamine] and (E)-4-4′-[[[2-(4-pyridinyl)ethenyl]2-methyl phenyl]amino]bis[benzenamine] condensed with pyromellitic dianhydride to obtain poly(amic acid)s. The poly(amic acid)s were soluble in polar aprotic solvents, such as dimethylformamide, dimethylsulphoxide and dimethylacetamide, and could be cast into transparent, tough, flexible films. Amorphous thermally stable polyimides were formed by cyclodehydration. Similarly, (E)-4,4′-[[[2-(4-pyridinyl)ethenyl]phenyl]methylene]bis[benzenamine] and (E)-4,4′-[[[2-(4-pyridinyl)ethenyl]phenyl]methylene]bis[N-ethylbenzenamine] were condensed with 3-methyladipoyl chloride to obtain other new polyamides. Characterisation using infra-red and nuclear magnetic resonance spectroscopy, X-ray diffraction and thermogravimetric analysis are reported. © 1997 SCI.     

Ligand-bridged bicobaloximes synthesized by ligand replacement: Synthesis,structure and characterization

Two ligand-bridged bicobaloximes, formed by replacement of pyridine (py) in monocobaloximes, [MeCo(dmgH)₂(py)] (Me = methyl, dmgH = dimethylglyoxime) and MeCo(dpgH)₂(py) (dpgH = diphenylglyoxime), by 4,4′-bipyridine and 2,4-di(1H-imidazol-1-yl)-6-methoxy-1,3,5-triazine, respectively, are reported. The crystal structures of the ligand-bridged bicobaloximes so obtained are described.     

Synthesis and characterization of poly(urethanes) containing sulfone and silarylene or germarylene moieties

4,4′-Sulfonyldianiline (SDA) is reacted with 4,4′-(R₁R₂-silylene)bis(phenyl chloroformates) or 4,4′-(R₁R₂-germylene)bis(phenyl chloroformates) (where R₁ and R₂ are Me, Et, Ph combinations) in solution yielding poly(urethanes) (PUs) of moderate molecular weight containing silarylene, germarylene and sulfone moieties. DSC and TGA analyses were carried out. The highest glass temperatures (Tg) were obtained when one or two Ph groups were bonded to a heteroatom. However, these values were always low due to the flexibility gained by the chain due to the incorporation of the sulfone function. No-significant differences in Tg were observed when silicon was replaced by germanium in the main chain. All polymers were stable up to 200–220 °C and underwent a complex decomposition process with a higher rate for PUs with side aliphatic groups. The thermal decomposition temperature (TDT) (10 wt%) for PUs based on Ph–Si–Ph moiety were higher than those obtained from germarylene-containing polymers.     

Syntheses and Characterization of Three Coordination Polymers of Zinc(II) and Cadmium(II) with Dicarboxylates and Bis(thiabendazole) Ligands

Three d ¹⁰ coordination polymers formulated as [Zn(L1)₂(mip)] _n (1), [Zn(L1)(2,6-ndc)] _n (2) and [Cd(L2)_0.5(bpdc)] _n (3) (L1 = 1,1′-(1,3-propanediyl)bis(thiabendazole), L2 = 1,1′-(1,6-hexanediyl)bis(thiabendazole), H₂mip = 5-methylisophthalic acid, 2,6-H₂ndc = 2,6-naphthalenedicarboxylic acid, H₂bpdc = 4,4′-biphenyldicarboxylic acid) were hydrothermally synthesized. Complexes 1–3 were characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction analysis, and single crystal X-ray diffraction. Complexes 1 and 2 present different chain structures, both of them are extended into 2D supramolecular architectures via C–H···O hydrogen bonds, while 3 is a three-fold interpenetrating three-dimensional framework with binodal 4,4-connected mog topology. The thermal stability, UV–visible spectroscopy and luminescence properties of complexes 1–3 were also examined. Furthermore, complex 3 exhibits relatively positive catalytic activity towards the degradation of methyl orange in a Fenton-like process.     

Highly optical transparency and thermally stable polyimides containing pyridine and phenyl pendant

In order to obtain highly optical transparency polyimides, two novel aromatic diamine monomers containing pyridine and kinky structures, 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]diphenylmethane (BAPDBP) and 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]-1-phenylethane (BAPDAP), were designed and synthesized. Polyimides based on BAPDBP, BAPDAP, 2,2-bis[4-(5-amino-2-pyridinoxy)phenyl]propane (BAPDP) with various commercial dianhydrides were prepared for comparison and structure-property relationships study. The structures of the polyimides were characterized by Fourier transform infrared (FT-IR) spectrometer, wide-angle X-ray diffractograms (XRD) and elemental analysis. Film properties including solubility, optical transparency, water uptake, thermal and mechanical properties were also evaluated. The introduction of pyridine and kinky structure into the backbones that polyimides presented good optical properties with 91–97% transparent at 500 nm and a low cut-off wavelength at 353–398 nm. Moreover, phenyl pendant groups of the polyimides showed high glass transition temperatures (T_g) in the range of 257–281 °C. These results suggest that the incorporating pyridine, kinky and bulky substituents to polymer backbone can improve the optical transparency effectively without sacrificing the thermal properties.     

Synthesis of phenanthroline derivative by Suzuki coupling reaction and the use of its ruthenium complex as an optical pH sensor

A phenanthroline derivative, which has an aniline group, was synthesized by palladium catalyzed Suzuki cross coupling reactions. The aryl phosphine ligand, PPh_3, showed higher activity than the alkyl phosphines, P(^tBu)₃ and PCy_3, in the Suzuki couplings and provided the coupled product, 4-phenyl-7-(4′-amino-biphenyl-4-yl)-[1,10]phenanthroline (5), with 73% yield. Its ruthenium complex, bis(4,7-diphenyl-[1,10]phenanthroline){4-phenyl-7-(4′-amino-biphenyl-4-yl)-[1,10]phenanthroline} ruthenium(II) bis(hexafluorophosphate) (8), was synthesized under mild conditions. This complex showed a linear fluorescence intensity response between pH 3.5 and pH 8.5.     

Poly(N-phenylmaleimides) bearing chiral oxazolinyl pendant: Supramolecular aggregation and enantioselectivity in fluorescence response

N-Phenylmaleimide derivatives bearing a chiral oxazoline substituent at the benzene ring (N-[o-(4,5-dihydro-1,3-oxazol-2-yl)phenyl]maleimides, OPMIs) were polymerized using a binary initiating system composed of Et₂Zn and n-BuLi to in situ produce the zinc complexes of optically active poly(OPMI)s. The significant changes in chiroptical and fluorescent properties were observed for these polymers upon complexation with metal ions due to the formation of supramolecular structure, evidenced by circular dichroism, fluorescence spectrum and atomic force microscopy. The fluorescence spectra of poly(OPMI)/Zn^II complexes in the presence of (R)/(S)-1,1′-bi-2-naphthol (BINOL) and (R)/(S)-2-amino-1-propanol were studied in THF media. It was found that the fluorescence intensity of the complexes responded differently to both enantiomers of BINOL and the amino alcohol in a quenching and enhancement fashion, respectively. Furthermore, the enantioselective fluorescence response was strongly dependent on the amount of incorporated zinc in polymer matrices.     

Effective aminolytic depolymerization of poly(ethylene terephthalate) waste and synthesis of bisoxazoline therefrom

Aminolytic depolymerization of postconsumer poly(ethylene terephthalate) (PET) bottle waste with 2-amino-2-methyl-1-propanol and 1-amino-2-propanol under atmospheric condition was investigated in the presence of catalysts zinc acetate or sodium acetate. The virtual products obtained in pure form were, respectively, bis(1-hydroxy-2-methylpropan-2-yl)terephthalamide and bis(2-hydroxypropyl)terephthalamide. The latter was taken for further studies because of its higher yield and subjected to cyclization using thionyl chloride under low-temperature conditions to get 1,4-bis(5-methyl-4,5-dihydrooxazol-2-yl)benzene, which is used as chain extender in polyester and nylon compositions and as a crosslinking agent in powder paint compositions. The products obtained from depolymerization were characterized by TLC, melting point, IR spectroscopy, ¹H-NMR, ¹³C-NMR, and DSC. We have shown that it is possible to synthesize new utility products by recycling of PET waste. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Two structural analogous TbIII-indazole-radical complexes with different dynamic magnetic behaviors

The combination of Tb^III ion with two different indazole nitronyl nitroxide radicals resulted in two novel 2p-4f compounds, namely, [Tb(hfac)₃(5-IndazoleNIT)]₂ (1) (hfac = hexafluoroacetylacetone; 5-IndazoleNIT = 5-(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl- 4,5-hydro-1H-imidazol-2-yl)-1H-indazole) and [Tb(hfac)₃(6-IndazoleNIT)]₂ (2) (6-IndazoleNIT = 6-(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl- 4,5-hydro-1H-imidazol-2-yl)-1H-indazole). Single crystal X-ray diffraction studies revealed that compound 1 was binuclear complex, in which each 5-IndazoleNIT molecular acted as a bridging ligand linking two Ln^III ions through its oxygen atom of the NO group and nitrogen atom of the indazole ring to form a cyclic four-spin system. Complex 2 exhibited analogous binuclear cyclic four-spin systems with different space group. Compound 1 was found to take on slow relaxation of the magnetization, suggesting single-molecule magnet (SMM) behavior, while no ac signal is noticed for compound 2. The different magnetic relaxation behaviors between 1 and 2 are due to the different location of the radical in the indazole ring. It is demonstrated that the location of the radical in the indazole ring played an important role in determining the spin dynamic for the lanthanide-radical system.     

Synthesis and characterization of polyimides from 4,4′-(3-(<Emphasis Type="Italic">tert</Emphasis>-butyl)-4-aminophenoxy)diphenyl ether

A novel diamine 4,4′-(3-(tert-butyl)-4-aminophenoxy)diphenyl ether (4) was synthesized from 2-tert-butylaniline and 4,4′-oxydiphenol through iodination, acetyl protection, coupling reaction and deacetylation protection. Then some polyimides (PIs) were obtained by one-pot polycondensation of diamne 4 with several commercial aromatic dianhydrides respectively. They all exhibit enhanced solubility in organic solvents (such as NMP, DMF, THF and CHCl₃ etc.) at room temperature. Their number-average molecular weights are in the range of (2.1–3.7)?×?10⁴ g/mol with PDI from 2.25 to 2.74 by GPC. They can form transparent, tough and flexible films by solution-casting. The light transparency of them is higher than 90% in the visible light range from 400 nm to 760 nm and the cut-off wavelengths of UV–vis absorption are below 370 nm. They also display the outstanding thermal stability with the 5% weight loss temperature from 525 °C to 529 °C in nitrogen atmosphere. The glass transition temperatures (T _g s) are higher than 264 °C by DSC. XRD results demonstrate that these PIs are amorphous polymers with the lower water absorption (<0.66%). In summary, the incorporation of tert-butyl groups and multiple phenoxy units into the rigid PI backbones can endow them excellent solubility and transparency with relatively high T _g s.     

An insight on the effect of rubbing textile fiber on morphology of some semi-alicyclic polyimides for liquid crystal orientation

Two semi-alicyclic PIs were prepared from bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BOCA) and the aromatic diamines: 4,4′-oxydianiline (ODA) or 4-(4-{[4-(4-aminophenoxy)phenyl]sulfonyl}phenoxy)aniline (pBAPS). The obtained films are transparent in visible domain, having a cut-off wavelength of 294 nm for poly(BOCA–ODA) and 264 nm for poly(BOCA– p BAPS), respectively. Atomic force microscopy images indicate a better surface organization after rubbing with cotton velvet (V_C) comparatively with cellulose diacetate (V_CD). Contact angle measurements reveal a slight increase of hydrophobicity after patterning as a result of dipolar forces intensification and geometrical constraints of the macromolecular chains. The alignment properties of both PIs, tested with N-(4-methoxybenzylidene)-4-butylaniline, are more obviously for processing with V_C. Also, the contrast between the dark and bright states is higher for poly(BOCA– p BAPS)/V_C comparatively with poly(BOCA–ODA)/V_CD, since its larger surface malleability generates deeper microgrooves.     

Synthesis and memory characteristics of polyimides containing noncoplanar aryl pendant groups

A series of soluble aromatic polyimides were prepared from 2,2′-diphenyl-4,4′-biphenyl diamine (DPBD), 2,2′-bis(biphenyl)-4,4′-biphenyl diamine (BBPBD), 2,2′-bis[4-(naphthalen-1-yl)phenyl]-4,4′-biphenyl diamine (BNPBD) and 2,2′-bis(3,5-dimethoxyphenyl)-4,4′-biphenyl diamine (BMPBD) by polycondensation with 2,2′-bis[4′-(3′′,4′′,5′′-trifluorophenyl)phenyl]-4,4′,5,5′-biphenyl tetracarboxylic dianhydride via a two-step procedure. The resulting polymers were fully characterized and they exhibited excellent organosolubility, high thermal and dimensional stability. Resistive switching devices with the configuration of Al/polymer/ITO were constructed from these polyimides by using conventional solution coating process. Devices with the active layer based on DPBD, BBPBD and BNPBD exhibited nonvolatile and rewritable flash type memory characteristics with the turn-on voltage at ?2.0 to ?3.0 V and the turn-off voltage at 2.0–3.0 V. Whereas, device based on BMPBD demonstrated a bipolar write-once read-many times (WORM) memory capability with the writing voltage around ±3.0 V. The ON/OFF current ratio of these devices was of about 10⁶ and the retention times can be as long as 10⁴ s.     

pH responsive “off–on–off” luminescent switch of a novel ruthenium(II) complex [Ru(bpy)2(pipipH2)]2+

A novel ruthenium(II) complex, [Ru(bpy)₂(pipipH₂)](ClO₄)₂ · H₂O (1) (pipipH₂ = 2-(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)-1H- imidazo[4,5-f][1,10] phenanthroline, bpy = 2,2^′-bipyridine) has been found to act as a luminescent pH switch with extraordinary sensitivity through protonation and deprotonation of the bis-imidazole-containing ligand pipipH₂ in aqueous solution at room temperature.     

Investigation of the curing mechanism and properties of bismaleimide-triazine resins containing phenolphthalein and cyano group

A series of bismaleimide-triazine (BT) resins with and without O, O′-diallyl bisphenol A (DABPA) were produced by mixing 2, 2-bis (4-cyanatophenyl) propane (BADCy) and MCBMI (2,6-bis(4-(1-(4-(4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)phenoxy)-3-methylphenyl)-3-oxo-1,3-dihydroisobenzofuran-1-yl)-2-methylphenoxy)benzonitrile). The resins show just one glass-transition temperature (T _g) and enhanced flexural properties as well as superior fracture toughness compared with commercial BDM/BADCy system, in which BDM is (N,N′-bismaleimido-4,4′-diphenylmethane). Introduction of DABPA can decrease the curing temperature of bismaleimide-triazine (BT) resins but increase its impact strength. When the mole of DABPA reach up to 1.2, the impact strength was increased by 1.34 times in comparison with BDM/ BADCy system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 136, 47420.     

Synthesis and polymerization of novel <Emphasis Type="Italic">N</Emphasis>-substituted maleimides containing an oxazoline group

Summary A novel type of maleimide-based monomers, N-[o-(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl]maleimide (DMOPMI), ()-N-[o-(4-ethyl-4,5-dihydro-1,3-oxazol-2-yl)phenyllmaleimide (()-EOPMI), and (R)-N-[o-(4-ethyl-4,5-dihydro-l,3-oxazol-2-yl)phenyllmaleimide ((R)-EOPMI), were synthesized for the first time. Their polymerization behavior was studied briefly by both radical and anionic initiating mechanisms. The results indicated that the addition polymerization takes place mainly in the vinylene group without appreciable side reactions. The polymerization in low polar media tended to increase molecular weights or optical activity of the obtained polymers.