Urethanes and polyurethanes bearing furan moieties

Summary In view of a study on the preparation and properties of polyurethanes containing furan rings, it was deemed necessary to carry out a preliminary investigation on the synthesis and characterization of simple furanic urethanes given the paucity of information available on this family of compounds. Three types of combinations were tested, viz; (i) furanic alcohols plus non-furanic isocyanates; (ii) non-furanic alcohols plus furanic isocyanates; (iii) furanic alcohols plus furanic isocyanates. The 21 urethanes thus obtained were fully characterized: they are stable (with one exception) and their synthesis is not marred by secondary reactions, ie the furan ring does not introduce side effects.The financial assistance of the Agence Française pour la Maîtrise de l'Energie is gratefully aknowledged.     

Polymeric schiff bases bearing furan moieties 2. Polyazines and polyazomethines

Several furanic polyazines and polyazomethines were prepared by solution condensation of 2,5-furandicarboxaldehyde (FDC) with hydrazine, 1,4-phenylene diamine and O-O′(bis-2-aminopropyl)polyethylene oxide (Jeffamine) and thoroughly characterized. Their thermal and photochemical properties were also studied. Model compounds were used in order to prove the feasibility of the reaction and facilitate the characterization of the polymers. An improvement in the solubility of these furanic poly-Schiff bases could be achieved by the use of oligomeric intermediates or furanic polyketazines.     

Polyamide-imides bearing furan moieties. 1. Solution polycondensation of aromatic dianhydrydes with 2-furoic acid dihydrazides

Novel polyamide-imides containing flexible segments were synthesized from aromatic dianhydrides and various furan dihydrazides by a two-steps procedure that included ring opening polyaddition to give polyhydrazide-acids, followed by thermal or chemical cyclodehydration. The polyhydrazide-acids had inherent viscosities ranging from 0.045 to 0.11 l/g. The polyamide-imides showed good solubility in aprotic polar solvents and had inherent viscosities up to 0.070 l/g, glass transition temperatures close to 250 °C and good thermal stability up to 350 °C.     

Induced transparency in polythiophene bearing azobenzene moieties

The nonlinear absorption of poly[2-[ethyl-[4-(4-nitro-phenylazo)-phenyl]-amino]-ethane(3-thienyl)ethanoate], PAzT, was investigated using single pulse and pulse train open aperture Z-scan techniques to discriminate between fast and accumulative nonlinearities. We observed an induced transparency for excitation with picosecond laser pulses at resonant conditions, which was attributed to the azobenzene moieties attached to the polymer backbone. The fast transparency is caused mainly by the build up of molecules in the first excited state that have a negligible absorption cross-section compared to the ground state. When using pulse trains, the nonlinear response is mainly due to the accumulation of molecules in the cis configuration, which presents a ground state cross-section slightly smaller than that of trans. The cumulative effect arises from a combination of the less intense excitation and longer lifetime of the cis population. We believe that the process observed here makes PAzT an attractive polymer for photonics applications, such as optical switches and storage devices.     

Polyamides incorporating furan moieties. 5. Synthesis and characterisation of furan-aromatic homologues

2,2′-Bis (5-chloroformyl 2-furyl) propane and various aromatic diamines were used as monomers in the study of their interfacial polycondensation and the properties of the ensuing furanic-aromatic polyamides. The effects of such variables as the nature of the organic phase, the temperature, the reaction time, and the type and concentration of the catalyst were investigated as well as the properties of the polyamides in terms of structure, average chain length, T_g, T_m and thermal stability.     

Synthesis and characterization of novel polyarylates bearing NLO moieties

A series of thermally stable second‐order nonlinear optical polyarylates containing azo side‐chain groups have been obtained by interfacial polycondensation. Theoretical calculations of the static hyperpolarizabilities, first‐ and second‐order hyperpolarizability, were carried out. The structures of the obtained monomers and polymers were confirmed by infrared, ¹H NMR and ultraviolet spectroscopies. Thermal and optical properties of the obtained polymers were evaluated. The investigations show that some of the new polymers obtained in this study may find use in optical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2195–2201, 2006     

Polyesters based on two silarylene or germarylene moieties: Synthesis under phase‐transfer conditions

Polyesters (PEs) containing two heteroatoms (Si and/or Ge) in the main chain, derived from the acid dichlorides bis(4‐chloroformylphenyl) ethylmethylsilane, bis(4‐chloroformylphenyl) diethylsilane, bis(4‐chloroformylphenyl) diethylgermane, and bis(4‐chloroformylphenyl) di‐ⁿbutylgermane and from the diphenols bis(4‐hydroxyphenyl) ethylmethylsilane, bis(4‐hydroxyphenyl) diethylsilane, bis(4‐hydroxyphenyl) diethylgermane, and bis(4‐hydroxyphenyl) di‐ⁿbutylgermane, were synthesized under phase‐transfer conditions with three quaternary ammonium salts as phase‐transfer catalysts and three NaOH concentrations in the aqueous phase. PEs were characterized with IR and NMR spectroscopy, including ²⁹Si‐NMR. In general, the yields and intrinsic viscosities were low, and in some cases, an increase in these parameters was shown as a result of the catalyst effect. An increase in the NaOH concentration caused a decrease in the yields because of a hydrolytic process. PEs with Si were thermally more stable than those with Ge. The glass‐transition temperatures decreased when the side chains bonded to the heteroatoms were longer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and properties of one epoxy system bearing fluorene moieties

Diglycidyl ether of bisphenol fluorene (DGEBF) and 9,9‐bis(4‐aminophenyl) fluorene (BPF) were synthesized to introduce more aromatic structures into an epoxy system, and their chemical structures were characterized with Fourier transform infrared spectroscopy, NMR, and mass spectrometric analysis. The dynamic curing behavior of the DGEBF/BPF system was investigated with differential scanning calorimetry. DGEBF was cured with BPF, diaminodiphenylsulfone (DDS), and diaminodiphenylmethane (DDM), and E‐44 (bisphenol A epoxide) was also cured with BPF for comparison. The thermal properties of the obtained polymers were evaluated with dynamic mechanical thermal analysis and thermogravimetric analysis. The cured DGEBF/BPF system showed a remarkably higher glass‐transition temperature, better thermal stability and lower moisture absorption in comparison with the general bisphenol A epoxy resin/BPF system but approximated the heat resistance of the DGEBF/DDS and DGEBF/DDM systems. Such properties make this epoxy system very promising for heat‐resistant applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polymeric photoinitiators bearing side-chain benzoyldiphenylphosphinoxide moieties for UV curable coatings

Polymeric photoinitiators bearing side-chain benzoyldiphenylphosphinoxide moieties have been prepared by reacting poly(4-vinylbenzoic acid) or 4-vinylbenzoic acid/methyl methacrylate copolymers with thionyl chloride followed by methoxydiphenylphosphine. The activity of the above polymeric systems has been checked in the UV curing of the acrylic clear-coating formulation HDDA/BA and compared with that of the low molecular weight model 4-isoprophylbenzoyldiphenylphosphinoxide. The stability to light and to hydrolytic conditions of the polymeric photoinitiators with respect ot the model has also been tested. The results obtained are discussed in terms of composition and structural features of these systems. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of polymer brushes bearing ionic liquid moieties

Poly(1-ethyl 3-(2-methacryloyloxy ethyl) imidazolium chloride) (PEMEIm-Cl) brushes were grafted onto Au surface via surface initiated atom transfer radical polymerization (ATRP). The swelling/collapsed behavior of the brushes was characterized by AFM in different electrolyte solutions. These 15 nm ultrathin polyelectrolyte brushes can be used to modulate the interfacial resistance via conformational changes triggered by external electrolytes and solvent. The interfacial resistance was characterized using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) using [Fe(CN)₆]^3−/4− as the redox probe. The effects of electrolytes, the concentration and type of electrolytes and temperature are investigated in more detail.     

Polymeric photoinitiators bearing side-chain acyldiphenylphosphinoxide moieties for uv surface coatings

Polymeric photoinitiators bearing side-chain acyldiphenylphosphinoxide moieties have been prepared by reacting poly(methacryloyl chloride) and methacryloyl chloride/methyl methacrylate copolymers with methoxydiphenylphosphine. The activity of the above polymeric systems has been checked in the UV curing of both clear and pigmented coating formulations and compared with that of the low molecular weight analog pivaloyldiphenyl-phosphinoxide. The stability to light and to different hydrolitic conditions of the polymeric photoinitiators with respect to pivaloyldiphenylphosphinoxide has also been tested. The data concerning activity and stability are discussed in terms of structural features of the above systems. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of oligo(heteroarylene vinylene)s incorporating furan and thiophene moieties

This article describes the synthesis and characterization of a series of homologous conjugated dimers and trimers bearing alkenyl moieties between furan and/or thiophene heterocycles, linked through their 2,5- positions, and a terminal aldehyde group. A tetramer was also isolated and characterized. These oligomers constitute:

1. useful model compounds for the corresponding conjugated homo- and co-polymers,

2. interesting molecular structures for electroluminescence and other optoelectronic applications, and

3. potential precursors to more specific compounds (e.g. liquid crystals or photosensitive species) thanks to the terminal aldehyde function.

Synthesis and characterization of n-type conjugated copolymers bearing perylene diimide moieties

Three electron-deficient conjugated polymers based on perylene diimide (PDI) units, namely, poly[(N,N′-didodecyl-3,4,9,10-perylene diimide-1,7-diyl)-alt-(9,9-dihexylfluorene-2,7-diyl)] (PPDIF), poly{(N,N′-didodecyl-3,4,9,10-perylene diimide-1,7-diyl)-alt-[N-(2-ethylhexyl) carbazole-3, 6-diyl]} (PPDIC) and poly{(N,N′-didodecyl-3,4,9,10-perylene diimide-1,7-diyl)-co-[N-(2-ethylhexyl) carbazole-3,6-diyl]-co-(9,9-dihexylfluorene-2,7-diyl)} (PPDICF) have been synthesized via Suzuki coupling reaction, and their chemical structures are confirmed by ¹H NMR, ¹³C NMR and FT-IR. All these polymers show broad absorption bands in 250–700 nm, and their optical band gaps are calculated to be ~1.7 eV. Cyclic voltammetry results confirm that the objective macromolecules possess high electron affinity of ~3.9 eV. By employing poly-3-hexylthiophene (P3HT) as electron donor and PPDIC as electron acceptor, all polymer solar cells (aPSCs) with bulky heterojunction structure have been fabricated, preliminary results indicate they have one of the most highest open-circuit voltage (V _oc) (0.86 V) reported so far in aPSCs with PDI-based polymers as electron acceptor.     

Synthesis and photophysical properties of novel organo-soluble polyarylates bearing triphenylamine moieties

Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4′-dicarboxytriphenylamine and 4,4′-dicarboxy-4″-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high T _g values (186–264 °C) and thermal stability. In THF solution, these triphenylamine-containing polyarylates showed UV-Vis absorption bands at 359–365 nm and photoluminescence peaks around 427–451 nm in the blue region. Figure Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4’-dicarboxytriphenylamine and 4,4’-dicarboxy-4”-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high Tg values (186-264 oC) and thermal stability. All the PL spectra of these polymers showed a blue shift when the solvent was changed from NMP to THF or chloroform. Solvation should increase the interaction between polymer chain and solvent, which may consume certain excitation energy and lead to increase on the emission wavelength.     

Polyamides incorporating furan moieties: 4. Synthesis,characterisation and properties of a homologous series

Interfacial polycondensation of 2,2′‐bis[2‐(5‐chloroformylfuryl)]propane with various diamines gave high yields of a novel series of furanic polyamides with high inherent viscosities. The properties of these polymers (T_g, surface energy, crystallinity, thermal stability) were assessed and examined in terms of the role of the specific structure of the bridging group borne by the diamines. Only three polyamides were partially crystalline, whereas all the others were amorphous. Thermogravimetric analysis revealed that thermal decomposition began above 300 °C in all instances. © 2001 Society of Chemical Industry     

Vinyl monomers bearing chromophore moieties and their polymers. VII. Synthesis,photochemical, and initiation behavior of acrylic monomers bearing phenothiazine oxide moieties and their polymers

Four acrylic monomers bearing phenothiazine oxide moieties, that is, N-acryloyl-phenothiazine-5-oxide (APTO), N-acryloyl-2-chlorophenothiazine-5-oxide (ACPTO), N-acryloyl-phenothiazine-5,5-dioxide (APTDO), and N-acryloyl-2-chlorophenothiazine-5,5-dioxide (ACPTDO) were synthesized by oxidation of corresponding N-acryloyl-phenothiazine (APT) and N-acryloyl-2-chlorophenothiazine (ACPT) using sodium perborate as an oxidant. These monomers could easily be polymerized by initiation of AIBN. The emission fluorescence spectra of the monomers and their polymers were recorded, and the results indicated that these 4 new monomers possess a fluorescence structural self-quenching effect (SSQE), as we have reported previously. Moreover, with the change of the electronic structure of sulfur atom in the phenothiazine chromophore, that is, from sulfide to sulfoxide and sulfone groups, the tendency of SSQE of these monomers is in the order of APT > APTO > APTDO. This would be ascribed mainly to the decrease of electron-donating abilities of monomers in a sequence of sulfide, sulfoxide, and sulfone groups; that is, at the sulfur atom of these monomers, APT has 2 lone-pair electrons, APTO has 1 lone-pair electrons, and APTDO completely loses its lone-pair electrons. Based on the exciplex formation, the monomers APTO, APTDO, ACPO, and ACPTDO could act as sensitizers for the photopolymerization of acrylonitrile (AN). The combination of APTO or ACPTO with organic peroxides such as BPO could also initiate the polymerization of vinyl monomers, such as AN, by redox nature. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1191–1199, 1998     

Synthesis and characterization of poly(tetramethylsilarylenesiloxane) derivatives bearing benzodithiophene moieties

Poly(tetramethylsilarylenesiloxane) derivatives bearing benzo[1,2-b;4,5-b′]dithiophene (P1) and benzo[2,1-b;3,4-b′]dithiophene (P2) moieties were prepared via polycondensation of the corresponding disilanol monomers, that is, 2,6-bis(dimethylhydroxysilyl)benzo[1,2-b;4,5-b′]dithiophene (M1) and 2,7-bis(dimethylhydroxysilyl)benzo[2,1-b;3,4-b′]dithiophene (M2), respectively. It was deduced that P1 is a crystalline polymer while P2 is an amorphous one from the results of differential scanning calorimetry (DSC). Bathochromic and hyperchromic effects were observed in the absorption and fluorescence spectra when dimethylsilyl substituents were introduced on the benzo[1,2-b;4,5-b′]dithiophene and benzo[2,1-b;3,4-b′]dithiophene skeletons. The fluorescence quantum yields (Φ_Fs) were not improved by the introduction of dimethylsilyl groups onto the benzo[1,2-b;4,5-b′]dithiophene and benzo[2,1-b;3,4-b′]dithiophene skeletons, whereas the improvement in the Φ_Fs was remarkable in the case of poly(tetramethylsilarylenesiloxane) derivatives that possessed the corresponding fused benzene ring systems, i.e., poly(tetramethyl-2,6-silanthrylenesiloxane) and poly(tetramethyl-1,8-silphenanthrylenesiloxane).     

Flame retardancy and hydrolysis resistance of waterborne polyurethane bearing organophosphate moieties lateral chain

A novel halogen-free flame retardant diol bearing pendant organophosphate group, 2-ethyl-2-(2-oxo-5,5-dimethyl-1,3,2-dioxaphosphorinanyl-2-methylene)-1,3-propanediol (EPPD), was designed and synthesized, and then covalently conjugated into polyurethane as chain extender to prepare a series of phosphorus-containing flame retardant waterborne polyurethanes (PWPU). The chemical structures of the resultant EPPD and PWPU were confirmed by FTIR, ¹H and ³¹P NMR, respectively. Simultaneously, the flammability and thermal behavior of PWPU films were systematically investigated by limiting oxygen index (LOI) test, UL-94 vertical burning experiment and thermogravimetric (TG) as well as residual char analysis. An LOI value of 26.6% and a UL-94 V-0 rating can be achieved when the PWPU sample conjugated with 12 wt% EPPD, showing good inherent flame retardancy. TGA and residual char analysis indicate that the incorporation of EPPD induces a slight decrease of the thermal stability due to the relatively weaker bond energy of OPO, whereas the formed phosphoric and polyphosphoric acid during combustion can impart PWPU with nonflammability owing to the promoting of rugged carbonaceous char in the condensed phase which shields the underlying polyurethane from further attacking of heat flux. Meanwhile, hydrolytic stability study demonstrates that PWPU with organophosphate moieties linking in the side-chain exhibits better hydrolysis resistance than that with phosphoester bond conjugated in the backbone.     

Synthesis and photoisomerization behavior of polyamide-phenyleneethynylenes bearing azobenzene moieties in the main chain

Polymer Bulletin - Novel azobenzene-containing optically active polyamide-phenyleneethynylenes, poly(2–3ap)–poly(2–3bm) were synthesized by the Sonogashira–Hagihara coupling...     

Poly(N-propargylamide)s bearing cholesteryl moieties: Preparation and optical activity

We synthesized a novel chiral cholesteryl-based N-propargylamide (M_ch, HCCCH₂NHCOCH₂CH₂COOch, ch = cholesteryl) from which homopolymers [P(M_ch)] with different molecular weights (number-average molecular weight: 8600, 14100 and 30000) were prepared. The polymers formed helical structures with a preferential helicity. The three polymers increased in both helix content and specific rotation as the molecular weight increased. P(M_ch)-8600 was studied in detail as the model polymer. P(M_ch)-8600 adopted helical conformations in toluene, THF, CHCl₃ and CH₂Cl₂, exhibited thermal stability with a decomposition temperature of 273 °C and formed a lyotropic liquid crystal under the studied conditions. Copolymers of different compositions of M_ch and an achiral monomer (M_et) were prepared. The copolymers formed helices to different degrees depending on the specific composition, indicating an effective approach for controlling the formation of helices in synthetic helical polymers.