bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and properties of aromatic polyamides from 2,2′‐bis(p‐aminophenoxy) biphenyl or 2,2′‐bis(p‐aminophenoxy)‐1,1′‐binaphthyl and aromatic dicarboxylic acids
Authors: Liou Guey‐Sheng , Maruyama Masaki , Kakimoto Masa‐Aki , Imai Yoshio
Published: April 2003

New aromatic diamines having kink and crank structures, 2,2′‐bis(p‐aminophenoxy)biphenyl and 2,2′‐bis(p‐aminophenoxy)‐1,1′‐binaphthyl, were synthesized by the reaction of p‐fluoronitrobenzene with biphenyl‐2,2′‐diol and 2,2′‐dihydroxy‐1,1′‐binaphthyl, respectively, followed by catalytic reduction. Biphenyl‐2,2′‐diyl‐ and 1,1′‐binaphthyl‐2,2′‐diyl‐containing aromatic polyamides having inherent viscosities of 0.44–1.18 and 0.26–0.88 dL/g, respectively, were obtained either by the direct polycondensation or low‐temperature solution polycondensation of the diamines with aromatic dicarboxylic acids (or diacid chlorides). These polymers were readily soluble in a variety of organic solvents including N,N‐dimethylacetamide (DMAc), N‐methyl‐2‐pyrrolidone (NMP), dimethyl sulfoxide, m‐cresol, and pyridine. Transparent, pale yellow, and flexible films of these polymers could be cast from the DMAc or NMP solutions. These aromatic polyamides containing biphenyl and binaphthyl units had glass transition temperatures in the range of 215–255 and 266–303°C, respectively. They began to lose weight at ca. 380°C, with 10% weight loss being recorded at about 470°C in air. © 1993 John Wiley & Sons, Inc.
Synthesis and thermal properties of poly(cycloalkyl methacrylate)s bearing bridged‐ and fused‐ring structures
Authors: Matsumoto Akikazu , Mizuta Keiichiro , Otsu Takayuki
Published: April 2003

Radical polymerizations of some cycloalkyl methacrylates bearing bridged‐ and fused‐ring structures, i.e., bornyl methacrylate (BoMA), isobornyl methacrylate (IBoMA), 2‐decahydronaphthyl methacrylate (DNMA), and 3‐tetracyclo [4.4.02,5.17,10] dodecyl methacrylate (TCDMA), were carried out. The radical polymerization reactivities of these monomers depended on the structure of the cycloalkyl ester groups in the following order: TCDMA > BoMA > DNMA > CHMA > IBoMA > MMA, where CHMA and MMA are cyclohexyl and methyl methacrylates, respectively. The propagation and termination rate constants of these monomers were evaluated from the polymer radical concentration determined by electron spin resonance spectroscopy. The solubilities and microstructures of the resulting polymers were examined. Thermal properties, i.e., glass transition temperatures and decomposition behaviors, of the polymers were also investigated and related to the structures of the polymer side chain. © 1993 John Wiley & Sons, Inc.
Regioselective hydrosilations. I. The hydrosilation of α,ω‐dihydrogen functional oligopolydimethylsiloxanes with 3‐vinyl‐7‐oxabicyclo[4.1.0]heptane
Authors: Crivello J. V. , Bi Daoshen
Published: April 2003

The hydrosilation of α,ω‐dihydrogen functional oligopolydimethylsiloxanes with epoxy compounds containing vinyl groups has been found to take place regioselectively in such a manner that compounds can be isolated in high yields in which only one SiH group has been reacted. Three different α,ω‐dihydrogen functional oligopolydimethysiloxanes with different chain lengths were monohydrosilated and the resulting epoxide monomers characterized. The rate of hydrosilation at the first SiH functional group has been shown to be considerably faster than at the second site and from these kinetic studies, activation energies for each hydrosilation step were calculated. Mechanisms are considered which offer an explantion for these observations. © 1993 John Wiley & Sons, Inc.
Design of alkaline metal ion conducting polymer electrolytes
Authors: Okamoto Y. , Yeh T. F. , Lee H. S. , Skotheim T. A.
Published: April 2003

Polysiloxanes with covalently attached oligo ethylene oxide and di‐t‐butylphenol (I), naphthol (II), and hexafluoropropanol (III) were synthesized. The crosslinked polymers with a hexamethylene spacer were also prepared. The ion conductivities of the Li, Na, and K salts were measured as a function of temperature. The highest conductivities for K and Na of I at 30°C were 5.5 × 10−5 and 5.0 × 10−5 S/cm, respectively, when the ratio of the ion to ethylene oxide unit was 0.014. On the other hand, Li conductivity was 8.0 × 10−6 S/cm when the ratio between Li and ethylene oxide unit was 0.019. The maximum conductivities of Li ions of II and III were in the order of 10−6 and 10−7 S/cm at 30°C, respectively. When the polymers were crosslinked by a hexamethylene residue, the ion conductivities decreased while the degree of crosslinking increased. The temperature dependence of the cation conductivities of these systems could be described by the Williams‐Landel‐Ferry (WLF) and the Vogel‐Tammann‐Fulcher (VTF) equation. The results demonstrate that ion movement in these polymers is correlated with the polymer segmental motion. The order of ionic conductivity was K+ > Na+ ≫ Li+. This suggests that steric hindrance and π‐electron delocalization of the anions attached to polymer backbone have a large effect on ion‐pair separation and their ionic conductivities. Thermogravimetric analysis of the polymers indicated that the degradation temperature for I and II were about 100°C higher than for poly(siloxane‐g‐ethylene oxide). This is due to the antioxidant properties of sterically hindered phenols and naphthols. © 1993 John Wiley & Sons, Inc.
Synthesis and physical properties of N‐substituted polyimides based on imidazole
Authors: Kim Yang‐Kook , Rasmussen Paul G.
Published: April 2003

AB‐type monomers based on imidazole for the preparation of polyimides were synthesized by carrying out a substitution at the 1‐position of 2‐amino‐4,5‐dicyanoimidazole, followed by hydrolysis. Thus, pendant groups such as hexyl and 2,4‐dinitrophenyl as an aliphatic long chain and an electron‐withdrawing group, respectively, were introduced at the 1‐position of the imidazole monomer. A solid‐state polymerization was employed to prepare the poly(imidazoleimide)s in the form of a film from poly(imidazoleamic acid chloride)s by heating up to 180–200°C. The carbonyl stretching peaks of the imide ring appear at 1808 (sym) cm−1 and 1756 (antisym) cm−1. The effects of monomer structure on reactivity and the degree of imidization were investigated by comparing the viscosity of the resultant polymers and intensity of carbonyl peak at 1808 cm−1. The difference in the hydrolysis rate between polyimides having short or long aliphatic pendant groups at the 1‐position was observed using FT‐IR. The inherent viscosity of the N‐hexyl polyimide was 1.26 dL/g in N‐methyl pyrrolidinone (NMP) and 0.22 dL/g in the case of N‐2,4‐dinitrophenyl poly(amic acid) in methanesulfonic acid at 30°C. The structural, physical, and material properties of the polyimides were characterized by infrared, nuclear magnetic resonance, luminescence, viscosimetric methods, differential scanning calorimetry, thermogravimetric analysis, optical microscopy, and wide angle x‐ray scattering. Solution properties were also investigated by monitoring the viscosity as a function of time at 30°C. Luminescence spectroscopy of the poly(1‐methyl imidazole imide) and poly(1‐methyl imidazoleamic acid) films shows an emission band centered at 535 and 505 nm, respectively. Thermal properties are described comparing the weight loss and decomposition temperature as a function of the polymer structure and the degree of imidization. © 1993 John Wiley & Sons, Inc.
Paracyanogen reexamined
Authors: Maya Leon
Published: April 2003

Samples of paracyanogen were prepared by the pyrolysis of silver cyanide, the photolysis of cyanogen, and by sputtering a carbon electrode in a nitrogen plasma. This work was undertaken to establish whether these materials are alike and to derive structural information on the basis of FT‐IR, 13C‐MAS—NMR, and through temperature‐programmed thermal decomposition. Paracyanogen derived from the above sources is indeed alike spectrally and thermally. Paracyanogen is a polymer that incorporates carbon, mostly sp2, and nitrogen in a disordered structure. Cyanogen is the main volatile component released in the thermal decomposition of paracyanogen. The cyanogen released was identified by FT‐IR and MS. The rate of release reaches a maximum at ca. 700°C. Paracyanogen is not an appropriate carbon nitride precursor because of its limited thermal stability. © 1993 John Wiley & Sons, Inc.
Immobilization of poly(ethylene oxide) on polyethylene using a plasma‐induced graft copolymerization process
Authors: Wang Chee‐Chan , Hsiue Ging‐Ho
Published: April 2003

A radio‐frequency glow discharge induced graft copolymerization process has prepared a PAAc‐grafted PE film in this present study. Poly(ethylene oxide) (PEO) was then covalently immobilized onto PAAc‐grafted PE film by a chemical coupling reaction. Carboxylic groups were introduced onto the surface of PE film by exposing the film to an Ar plasma, and the plasma‐treated film was then next reacted with a 50% acrylic acid aqueous solution. These functional groups were reacted with bisamino PEO by a coupling agent CMC. ESCA, IR, and water contact angle studies were conducted for characterizing the surfaces of these films during the varied stages of the reaction. Increasing the molecular weight of the PEO attached to the PAAc‐grafted PE resulted in an increased wettability of the films. © 1993 John Wiley & Sons, Inc.
Soluble polymers with pendant thionine groups: Synthesis and evaluation as singlet oxygen photosensitizers
Authors: Amat‐Guerri F. , Botija J. M. , Sastre R.
Published: April 2003

Thionine (1) has been covalently bound to linear copoly(styrene‐p‐vinylbenzyl chloride) and to linear copoly(acrylic acid‐2‐ethylhexyl acrylate). The resulting polymeric dyes, purified by ultrafiltration, present quantum yields of singlet oxygen generation in dimethylformamide solution lower than their corresponding low‐molecular‐weight models thionine hydrochloride (1.HCl) and N(3)‐acetylthionine (Ac‐1), the decrease being more pronounced in the case of the polystyrene‐dye photosensitizer. High chromophore concentrations within the volume encompassed by each macromolecule in the solution can explain this fall in efficiency. The free dyes thionine hydrochloride and its hydrolysis products thionoline (2) and thionol (3) behave as good singlet oxygen generators, with quantum yields of 0.71, 0.62, and 0.63, respectively. © 1993 John Wiley & Sons, Inc.
Semi‐interpenetrating polymer networks synthesis by photocrosslinking of acrylic monomers in a polymer matrix
Authors: Moussa K. , Decker C.
Published: April 2003

Semi‐interpenetrating polymer networks have been obtained by UV‐radiation curing of acrylate monomers dispersed in a polymer matrix, using an arylketone as photoinitiator. The polymerization kinetics was studied quantitatively by infrared spectroscopy for the various polymers examined: polyurethane, poly(vinyl chloride), poly(methyl methacrylate). The fastest reaction occurs in PVC films, where UV‐curing develops extensively within a fraction of a second, leading to an insoluble and highly resistant material. The functionality of the acrylic monomer has a strong influence on the formulation reactivity, as well as on the mechanical and chemical properties of the final product. In PMMA, the polymerization was shown to continue to proceed efficiently for a few seconds after the UV exposure, even in the presence of air, due to both the high concentration of initiating radicals generated by the intense irradiation and the slow termination processes in solid media. © 1993 John Wiley & Sons, Inc.
Study of polymer treatment with tetrafluoromethane plasma: Reactivity of fluorinated species on model surfaces
Authors: Poncin‐Epaillard Fabienne , Pomepui Barbara , Brosse Jean‐Claude
Published: April 2003

Polyolefins and their model molecules, some n‐alcanes, have been modified by a tetrafluoromethane microwave plasma. The chosen molecules are high‐density polyethylene (HDPE) and hexatriacontane (HTC), low‐density polyethylene (LDPE) and paraffin, and polycaprolactone (PCL) and octadecyl octadecanoate (ODO). It has been found, except for paraffin, that the model surfaces have the same behavior as the corresponding polymers. Plasma modification is described as the sum of two mechanisms: degradation and fluorination. These reactions seem to be competitive and parallel. Degradation and fluorination rates are dependent on treatment time and are practically independent on substrate position. A domain of fluorination exists near the edge of plasma, whatever the substrate in or outside plasma. © 1993 John Wiley & Sons, Inc.
Synthesis and propeller–propeller transition of optically active poly(diphenyl‐o‐tolylmethyl methacrylate)
Authors: Yu Bin , Ding Mengxian , Wang Yuechuan , Wang Fosong
Published: April 2003

Diphenyl‐o‐tolymethyl methacrylate (DPTMA) was synthesized and polymerized using initiators of organolithium complexes with (+)‐(2S,3S)‐dimethoxy‐1,4‐bis(dimethylamino) butane (DDB) and (−)‐sparteine (Sp) as the chiral ligands. DDB was suitable for its complex effective to prepare optically active poly(diphenyl‐o‐tolylmethyl methacrylate) (PDPTMA) with one‐handed helical conformation, whereas only low‐molecular weight polymer was formed when Sp was used as ligand due to the repulsive hindrance between the triarylmethyl group and the ligand. A new mutarotation propeller–propeller transition, was observed for PDPTMA from the optical rotation curves and CD spectra in THF solution. The equivalent period of PDPTMA was estimated to be 14 Å based on the x‐ray diffraction. © 1993 John Wiley & Sons, Inc.
Synthesis and properties of monodisperse polydimethylsiloxane networks
Authors: Bontems Susan L. , Stein Judith , Zumbrum Michael A.
Published: April 2003

α,ω‐Divinyl‐terminated polydimethylsiloxane polymers with low polydispersivity were synthesized via anionic polymerization of hexamethylcyclotrisiloxane (D3). Five “monodisperse” polymers with different molecular weights were hydrosilylated with tetrakisdimethylsiloxysilane in the presence of platinum catalysts and inhibitors to form crosslinked networks. Control studies to determine the effect of platinum, silicon hydride, and heat were performed to verify that no redistribution occurred during hydrosilylation. The properties of these cured samples were characterized chemically by degradation with trifluoromethanesulfonic acid in the presence of hexamethyldisiloxane, infrared spectroscopy, and nuclear magnetic spectroscopy. Mechanical properties were studied by measurements of Shore A hardness, dynamic shear modulus, and tensile modulus. The relationship between the molecular weight of the vinyl polymer and the final properties of the cured networks was measured. © 1993 John Wiley & Sons, Inc.
Helix‐sense‐selective polymerization of phenyl[bis(2‐pyridyl)]methyl methacrylate and chiral recognition ability of the polymer
Authors: Ren Changyu , Chen Chuanfu , Xi Fu , Nakano Tamaki , Okamoto Yoshio
Published: April 2003

A novel monomer, phenyl[bis(2‐pyridyl)]methyl methacrylate (PB2PyMA), was synthesized. The solvolysis rate of PB2PyMA measured in CDCl3–CD3 OD [1/1 (v/v)] by 1H‐NMR spectroscopy at 35°C was much smaller than those of triphenylmethyl methacrylate (TrMA) and diphenyl‐2‐pyridylmethyl methacrylate (D2PyMA). PB2PyMA was anionically polymerized with the complexes of organolithiums with (−)‐sparteine (Sp), (S,S)‐(+)‐and (R,R)−(‐)‐2,3‐dimethoxy‐1,4‐bis(dimethylamino)butanes[(+)‐and (−) ‐DDB], and (S)‐(+)‐1‐(2‐pyrrolidinylmethyl) pyrrolidine (PMP) in toluene at low temperature. The polymers obtained with Sp and DDB complexes showed low optical activity. PMP complexes, particularly that with N,N′‐diphenylethylenediamine monolithium amide, were effective in synthesizing a polymer of high optical rotation ([α]25365 ∼ +1350°) which was comparable to those of poly(TrMA) and poly(D2PyMA) with one‐handed helical structure. The optical rotation of poly(PB2PyMA) in a mixture of CHCl3 and 2,2,2‐trifluoroethanol (9/1, v/v) slowly decreased with time. Optically active poly(PB2PyMA) coated on macroporous silica gel was able to resolve racemic compounds as a chiral stationary phase for high‐performance liquid chromatography. © 1993 John Wiley & Sons, Inc.
Heat‐resistant thermosetting polymers based on a novel tetrakisaminophenoxycyclotriphosphazene
Authors: Kumar Devendra , Gupta Alka D. , Khullar Mrignaini
Published: April 2003

Two heat‐resistant thermosetting polymers (IX and X) have been developed based on a new cyclotriphosphazene containing tetrakisamine. These polymers were synthesized by the reaction of tetrakisamine (IV) with maleic anhydride followed by in situ cyclodehydration and polymerization of the maleimides (VII and VIII) at 235–240°C for 1.5 h and 290°C for 0.5 h. The thermogravimetric analyses (TGA) of the developed cyclotriphosphazene containing cyclomatrix polymers showed their thermal stability up to 350°C and char yield of 71% in nitrogen at 800°C and 65% in air at 700°C. The monomer, 2,2,4,4‐tetrakis(4′‐aminophenoxy) ‐6,6‐diphenylcyclotriphosphazene (IV), useful for producing a variety of heat‐ and fire‐resistant polymers, has been synthesized in good yield. Its syntheses involve Friedel‐Crafts reaction of hexachlorocyclotriphosphazene (I) with benzene followed by the reaction of 2,2,4,4‐tetrachloro‐6,6‐diphenylcyclotriphosphazene (II) with potassium 4‐nitrophenoxide. The reduction of the obtained 2,2,4,4‐tetrakis(4′‐nitrophenoxy)‐6,6‐diphenylcyclotriphosphazene (III) with molecular hydrogen in presence of PtO2 gave the tetrakisamine (IV). The structure of the synthesized monomer and intermediates were characterized by FT‐IR, 1H‐NMR, 31P‐NMR, mass spectroscopy, differential scanning calorimetry (DSC), and elemental analysis. These resins are potential candidates for the development of heat‐ and fire‐resistant composites, laminates, and adhesives, useful for space, aerospace, and electronic application. © 1993 John Wiley & Sons, Inc.
Molecular composite. I. Novel block copolymers of liquid‐crystalline polyamide and amorphous polyimide: Synthesis and characterization
Authors: Chang Ken‐Yuan , Lee Yu‐Der
Published: April 2003

Two series of PA/PI block copolymers have been prepared from a two‐pot polycondensation reaction. Acid‐terminated poly‐p‐benzamide (PBA) prepolymer, composed of a rigid‐rod structure and lyotropic character, was synthesized by applying the phosphorylation reaction of Yamazaki. On the other hand, two amine‐terminated polyimide prepolymers with an amorphous structure were prepared by a typical low‐temperature condensation reaction from 4,4′‐(hexafluoroisopropylidene)‐bis(phthalic anhydride) (6FDA)/2,2′‐bis‐(4‐aminophenyl)‐hexafluoropropane (BAAF) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA)/2,3,5,6‐tetramethyl‐p‐phenylene diamine (TMPD). The molecular weight of these prepolymers was determined by intrinsic viscosity or GPC. The copolymerization was carried out by mixing two prepolymer solutions. The products were analyzed by extraction, IR, and ηinh so as to confirm that the copolymerization reaction was precisely accomplished. Thermal analysis and lyotropic behavior were studied for these block copolymers and the critical concentration in NMP–LiCl was found to be 6.0% for one among those block copolymers. The copolymers were observed to form anisotropic liquid‐crystalline domains under polarized light once the solutions had been prepared at (and beyond) the critical concentration. © 1993 John Wiley & Sons, Inc.
Wavelength sensitivity of the photoinduced reaction in polycarbonate
Authors: Torikai Ayako , Mitsuoka Takuya , Fueki Kenji
Published: April 2003

Bisphenol A polycarbonate (PC) was irradiated with monochromatic light of wavelengths 260, 280, 300, 320, 340, 400, and 500 nm by use of the Okazaki large spectrograph (OLS). The quantum yield of main‐chain scission (ϕcs), efficiency of photo‐Fries rearrangement (Er), and effects of wavelength on ϕcs and Er were investigated. It was found that photodegradation and photo‐Fries rearrangement of PC took place by the irradiation of 260–300 nm light, but did not by the irradiation at λ ≧ 320 nm. The ϕcs has a maximum value in the case of the irradiation with 260 nm light, while Er was found to have a maximum value by the irradiation of 280 nm light. © 1993 John Wiley & Sons, Inc.
Sequence‐regulated oligomers and polymers by living cationic polymerization. III. Synthesis and reactions of sequence‐regulated oligomers with a polymerizable group
Authors: Minoda Masahiko , Sawamoto Mitsuo , Higashimura Toshinobu
Published: April 2003

New sequence‐regulated macromonomers (3) with a vinyl ether terminal were prepared by the HI/ZnI2‐mediated living cationic polymerization of vinyl ethers: CH3CH(OR1)CH2CH(OR2)C(COOEt)2CH2CH2OCHCH2 (3a: R1 = nBu, R2 = CH2CH2OCOPh; 3b: R1 = iOct, R2 = CH2CH2Cl). The synthesis consisted of three consecutive steps: (i) quantitative addition of hydrogen iodide to the first vinyl ether into an adduct [CH3CH(OR1)l]; (ii) propagation of a second vinyl ether from the adduct in the presence of zinc iodide; and (iii) quenching the resulting AB‐type heterodimeric living intermediate with a carbanion [θC(COOEt)2CH2CH2OCHCH2] carrying a vinyl ether group. The HI/ZnI2‐initiated living cationic polymerization of 3a and 3b yielded narrowly distributed polymers \documentclass{article}\pagestyle{empty}\begin{document}$\left( {\overline {DP}} _{_n } \sim 10 \right)$\end{document} consisting of a poly(vinyl ether) backbone and sequence‐regulated oligomer branches. The terminal vinyl ether function of 3 was also utilized to prepare pentamers and hexamers with controlled sequence of functional vinyl ethers by selective dimerization and chain extension reactions with HI/ZnI2. © 1993 John Wiley & Sons, Inc.
Ionic‐conductivity switching of vinyl malachite green leuconitrile copolymers based on photoinduced carrier generation
Authors: Kimura Keiichi , Kaneshige Masayuki , Tokuhisa Hideo , Yokoyama Masaaki
Published: April 2003

Copolymers of bis[4‐(N,N‐dimethylamino)phenyl]‐4‐vinylphenylmethanenitrile (vinyl Malachite Green leuconitrile) with methyl methacrylate or ω‐methoxyoligo(oxyethylene) methacrylate have been synthesized, aiming at designing one‐component‐type organic polymers for photoswitchable ion‐conducting films. The triphenylmethanenitrile copolymers with ω‐methoxyoligo(oxyethylene) methacrylate were found to undergo ionic‐conductivity switching by turning on and off UV light at ambient temperature, owing to their low glass transition temperature. © 1993 John Wiley & Sons, Inc.
Living carbocationic polymerization of isobutyl vinyl ether and the synthesis of poly[isobutylene‐b‐(isobutyl vinyl ether)]
Authors: Lubnin Alexander V. , Kennedy Joseph P.
Published: April 2003

The MeCH(O‐i‐Bu)Cl/TiCl4/MeCONMe2 initiating system was found to induce the rapid living carbocationic polymerization (LC⊕Pzn) of isobutyl vinyl ether (IBuVE) at −100°C. Degradation by dealcoholation which usually accompanies the polymerization of alkyl vinyl ethers by strong Lewis acids is “frozen out” at this low temperature and poly(isobutyl vinyl ether)s (PIBuVEs) with theoretical molecular weights up to ca. 40,000 g/mol (calculated from the initiator/monomer input) and narrow molecular weight distributions (M̄w/M̄n ≤ 1.2) are readily obtained. According to 13C‐NMR spectroscopy, PIBuVEs prepared by living polymerization at −100°C are not stereoregular. The MeCH(O‐i‐Bu)Cl/TiCl4 combination induces the rapid LC⊕Pzn of IBuVE even in the absence of N,N‐dimethylacetamide (DMA). The addition of the common ion salt, n‐Bu4NCl to the latter system retards the polymerization and meaningful kinetic information can be obtained. The kinetic findings have been explained in terms of TiCl4. IBuVE and TiCl4 · IBuVE and TiCl4 · PIBuVE complexes. The HCl (formal initiator)/TiCl4/DMA combination is the first initiating system that can be regarded to induce the LC⊕Pzn of both isobutylene (IB) and IBuVE. Polyisobutylene (PIB)–PIBuVE diblocks were prepared by sequential monomer addition in “one pot” by the 2‐chloro‐2,4,4‐trimethylpentane (TMP‐Cl)/TiCl4/DMA initiating system. Crossover efficiencies are, however, below 35% because the PIB⊕ + IBuVE → PIB‐b‐PIBuVE⊕ crossover is slow. © 1993 John Wiley & Sons, Inc.
Silanes on magnesium chloride studied by solid‐state 29Si‐NMR spectroscopy
Authors: Clayden Nigel J. , Jones Peter J. V.
Published: April 2003

29Si cross‐polarisation NMR was used to study the interaction between silanes and MgCl2 when co‐milled. Large changes are seen for the 29Si chemical shift of the silane between the silane in solution and in the solid complex. Interpretation of the differences in chemical shift are hindered by the absence of an adequate semi‐empirical theory. The 29Si chemical shift tensors confirm a strong interaction between the silane and MgCl2. © 1993 John Wiley & Sons, Inc.
Synthesis of a polyolefin–polystyrene graft terpolymer
Authors: Deeken John S. , Farona Michael F.
Published: April 2003

A graft polymer was prepared attaching the macromer, polystyrene end‐capped with benzocyclobutene, to the carbon–carbon double bonds in poly‐1‐hexene‐co‐7‐methyl‐1,6‐octadiene through thermally induced Diels–Alder reactions. The branches per backbone were determined by additive molecular weights and NMR spectroscopy to be 0.8, 1.6, and 2.7, for levels of polystyrene of 40, 60, and 80%, respectively. Grafting efficiencies were high, varying from 84–95%. © 1993 John Wiley & Sons, Inc.
Conductivity of crosslinked poly(N‐vinylpyrrolidone) gel film containing surfactant as electrolyte salt
Authors: Tsutsumi Hiromori , Hamamoto Shinji , Matsuda Yoshiharu
Published: April 2003

New polymeric solid electrolyte films, consisting of crosslinked poly(N‐vinylpyrrolidone) (PVPD) as matrix, and surfactant, sodium deoxycholate (NaDC), lithium deoxycholate (LiDC), sodium laulylsulfate (R12OSO3Na), or sodium palmitate (R15COONa) as electrolyte salt, are prepared; their basic structure and conductivity dependence on temperature are reported. The structure of the electrolytes is amorphous. Their conductivity is 3.1 × 10−5 S cm−1 (containing NaDC), 8.42 × 10−6 S cm−1 (LiDC), 2.18 × 10−4 S cm−1 (R12OSO3Na), and 7.27 × 10−5 S cm−1 (R15COONa) at 20°C. Their temperature dependence of the conductivity is similar to that of liquid electrolyte rather than that of usual polymeric solid electrolyte, i.e., the WLF‐type dependence. The values of activation energy of conductivity (Ea) were PVPD, 25.5 kJ mol−1; PVPD/NaDC, 21.4 kJ mol−1; PVPD/LiDC, 25.3 kJ mol−1; PVPD/R12OSO3Na, 17.2 kJ mol−1; PVPD/R15COONa, 18.7 kJ mol−1. © 1993 John Wiley & Sons, Inc.
Enzymatic polyesterification in organic media. II. Enzyme‐catalyzed synthesis of lateral‐substituted aliphatic polyesters and copolyesters
Authors: Knani Dafna , Kohn David H.
Published: April 2003

Enzymatic polymerization of hydroxyesters in organic media has been the subject of a previous and ongoing research in our laboratory. As part of that study, four ϵ‐substituted‐ϵ‐hydroxyesters were synthesized, and then polymerized using crude porcine pancreatic lipase (PPL) in n‐hexane. These lateral‐substituted hydroxyesters polymerized enantioselectively to produce optically active oligomers and a resolved optically active unreacted monomer. It was found that with increasing bulkiness of the lateral substituent, in the order Me >Et >Ph, the enzymatic reaction becomes slower, yet the enantioselectivity is higher. The lateral‐substituted hydroxyesters were also copolymerized enzymatically with the more reactive linear methyl ϵ‐hydroxyhexanoate. Optically active copolymers were obtained, higher in molecular weight than the analogous homopolymers. © 1993 John Wiley & Sons, Inc.
Thermotropic liquid crystalline polyamides from polyethyleneglycol bis(4‐carboxyphenyl)ethers
Authors: Higashi Fukuji , Nakajima Kohji , Watabiki Mamoru , Zhang Wen Xiong
Published: April 2003

New thermotropic liquid crystalline polyamides were prepared from polyethyleneglycol bis(4‐carboxyphenyl)ether (PEGn, n = 2, 3, 4) and aromatic diamines by using triphenyl phosphite in pyridine as the condensing agent. Substituted p‐phenylenediamines and 4,4′‐diaminobiphenyls were successfully used; melting points and isotropization temperatures of the polyamides were changed by the kind and number of the substituents. Copolymerization of long chain aliphatic dicarboxylic acids was carried out at the lower melting point of the copolymer. Kink monomers were also incorporated into the polymer backbone. © 1993 John Wiley & Sons, Inc.
Thermotropic copolyamides from polyethyleneglycol bis(4‐carboxyphenyl)ethers with different oxyethylene units
Authors: Zhang Wen Xiong , Higashi Fukuji
Published: April 2003

Copolymerizations of polyethyleneglycol bis(4‐carboxyphenyl)ethers (PEGn) with different n values were found to significantly lower the anisotropic transition temperature (Tm) of the copolymers produced, and the thermotropic copolyamides of thermally more stable nematic phases were obtained. The effect was investigated in terms of PEGm/PEGn molar ratios, the number of oxyethylene units, and the even—odd character of the flexible segment. Several modes of copolymerization were carried out to investigate the effect of monomer (PEGn sequence on Tm. By these copolymerizations thermally stable copolyamides even from p‐phenylenic diamines such as methyl‐p‐phenylenediamine and p‐phenylenediamine were obtained. © 1993 John Wiley & Sons, Inc.
Synthesis and characterization of polyethylene film grafted with acrylic acid and diethyleneglycol‐dimethacrylate
Authors: Gineste Jean‐Luc , Garaud Jean‐Luc , Pourcelly Gerald
Published: April 2003

Acrylic acid (AA) and diethyleneglycol‐dimethacrylate (DEGDM) are grafted onto 25 μm low‐density radio‐peroxided polyethylene. Monomer content is determined by exchange capacity measurements. Studies of electrical resistance and zero‐current membrane potential allow for the determination of the influence of DEGDM on both the dissociation of grafted AA and the permselectivity of these so‐obtained cation‐exchange membranes. DEGDM, acting as a crosslinking agent, limits the AA degree of grafting, slightly increases the electrical resistance, but contributes to enhance the permselectivity. For example, when these grafted films are immersed in 3M NaCl aqueous solutions, the addition of DEGDM leads to an increase of the transport number of Na+ close to 20%. © 1993 John Wiley & Sons, Inc.
Living cationic polymerization of vinyl ethers by electrophile/lewis acid initiating systems. XII. Phosphoric and phosphinic acids/zinc chloride initiating systems for isobutyl vinyl ether
Authors: Kamigaito Masami , Sawamoto Mitsuo , Higashimura Toshinobu
Published: April 2003

Phosphoric and phosphinic acid derivatives (R1R2PO2H; R1, R2 = OPh, OPh; OnBu, OnBu; Ph, Ph; Ph, H) in conjunction with zinc chloride (ZnCl2) led to living cationic polymerization of isobutyl vinyl ether (IBVE) in toluene below 0°C. The number‐average molecular weights (M̄n) of the polymers (M̄n > 2 × 104) were directly proportional to monomer conversion and in excellent agreement with the calculated values assuming that one polymer chain forms per R1R2PO2H molecule. Throughout the reaction, the molecular weight distributions (MWDs) stayed narrow (M̄w/M̄n ⩽ 1.1). A dibasic acid, PhOP (O) (OH)2, coupled with ZnCl2, also induced living cationic polymerization of IBVE where one molecule of the acid generated two living polymer chains. The polymerization by (PhO)2PO2H/ZnCl2 and its model reactions were directly analyzed by 31P and 1H‐NMR spectroscopy. The analysis showed that the acid initially forms the adduct [CH3CH(OiBu)OP(O)(OPh)2], the phosphate linkage of which is in turn activated by ZnCl2 so as to initiate living propagation. The finding thus indicates that (PhO)2PO2H indeed acts as an initiator in the living polymerization. The NMR analysis also suggested that an exchange reaction occurs between the phosphate group at the polymer terminal and the chlorine in ZnCl2. The occurrence of living IBVE polymerization with these various R1R2PO2H/ZnCl2 systems shows that phosphoric and phosphinic acids are another general class of protonic acids which are effective initiators for the living cationic polymerization assisted by Lewis acids. © 1993 John Wiley & Sons, Inc.
New poly(amide‐imide) syntheses. V. Preparation and properties of poly(amide‐imide)s based on the diimide—diacid condensed from 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane and trimellitic anhydride
Authors: Yang Chin‐Ping , Hsiao Sheng‐Huei , Lin Jiun‐Hung
Published: April 2003

A dicarboxylic acid (1) bearing two pre‐formed imide rings, was prepared from the condensation of 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane and trimellitic anhydride. A new family of poly(amide‐imide)s having inherent viscosities of 0.53–1.68 dL/g was prepared by the triphenyl phosphite activated polycondensation from the diimide—diacid I with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N‐dimethylacetamide. All the soluble poly(amide‐imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these poly(amide‐imide)s were in the range of 237–293°C and the 10% weight loss temperatures were above 508°C in nitrogen. © 1993 John Wiley & Sons, Inc.
Photogeneration of polyfunctional amines and novel thermal curing reactions of epoxy resin and polyurethane oligomer using these amines
Authors: Nishikubo Tadatomi , Takehara Eiji , Kameyama Atsushi
Published: April 2003

Photochemical reactions of various blocked polyfunctional amines such as bis(4‐formylaminophenyl)methane (FAPM), bis(4‐acetylaminophenyl)methane (AAPM), bis(4‐benzoylaminophenyl)methane (BAPM), 2,4‐diformylaminotoluene (DFAT), m‐xylene diformamide, and bis[[(2‐nitrobenzyl)oxy]carbonyl]hexane‐1.6‐diamine were carried out to give the corresponding free amines in THF solution, in epoxy resin, or in polyurethane oligomer with terminal isocyanate groups. Photolysis of FAPM and DFAT to produce the corresponding polyfunctional amines such as 4,4'‐methylenedianiline and 2,4‐diaminotoluene proceeded with 80 and 75% conversions, respectively, in THF solution under UV irradiation at 5 h. AAPM and BAPM also produced the corresponding photo‐Fries rearrangement products with 32 and 38% conversions, respectively, under the same irradiation conditions. The photolysis of those compounds also occurred with similar conversions in the epoxy resin and in the polyurethane oligomer under UV irradiation; and the thermal curing reactions of the epoxy resin and the polyurethane oligomer with photogenerated polyfunctional amines proceeded smoothly after heating at 140°C for 2 hrs. © 1993 John Wiley & Sons, Inc.
Polymeric phosphonium salts as a novel class of cationic biocides. IV. Synthesis and antibacterial activity of polymers with phosphonium salts in the main chain
Authors: Kanazawa Akihiko , Ikeda Tomiki , Endo Takeshi
Published: April 2003

Polymers with phosphonium salts and different alkyl spacers in the main chain were prepared, and their antibacterial activities against Staphylococcus aureus and Escherichia coli were explored by the viable cell counting method in sterile distilled water. The antibacterial activity of the polymers was found to be higher than that of the corresponding model compounds against each strain, and the effect of the molecular weight on the antibacterial activity was also observed for the compounds with the same spacer length. The antibacterial activity of the polymer samples bonded with different spacer lengths was found to increase with increasing the spacer length against both strains. © 1993 John Wiley & Sons, Inc.
Novel polymeric structures via the chlorination of cis‐1,4‐polybutadiene in the presence of aryl nucleophiles
Authors: Hahn Stephen F. , Dreyfuss M. P.
Published: April 2003

The addition chlorination of cis‐1,4‐polybutadiene in the presence of a variety of aryl nucleophiles resulted in the formation of head‐to‐head poly(vinyl chloride) with pendant aromatic functional groups. Chlorination in methylene chloride solution with benzoic acid gave chlorinated polymers with pendant benzoate esters. Chlorination in the presence of phenol and benzhydrol provided polymers with pendent phenyl and diphenyl methyl ethers, respectively. Acetophenone participated during chlorination to affored polymer with pendant α‐chloroether groups, while benzonitrile gave a polymer with pendant imidoyl chlorides. The extent of participation of these nucleophiles was estimated from elemental analysis and NMR spectral data, and the effect of aryl substitution on density, glass transition temperature, and linear coefficient of thermal expansion was determined. © 1993 John Wiley & Sons, Inc.
New poly(amide‐imide)s syntheses. VII. Preparation and properties of poly(amide‐imide)s derived from 1,5‐bis(4‐aminophenoxy) naphthalene, trimellitic anhydride, and various aromatic diamines
Authors: Yang Chin‐ping , Chen Wen‐tung
Published: April 2003

New bis(phenoxy)naphthalene‐containing poly(amide‐imide)s having an inherent viscosity in the range of 0.62–1.09 dL/g were prepared by the direct polycondensation of 1,5‐bis(4‐trimellitimidophenoxy) naphthalene (I) and various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N‐methyl‐2‐pyrrolidone (NMP) in the presence of calcium chloride. The diimide‐diacid (I) was prepared by the condensation of 1,5‐bis(4‐aminophenoxy) naphthalene and trimellitic anhydride. Most of the polymers were soluble in aprotic solvents such as NMP and N,N‐dimethylacetamide (DMAc), and afforded transparent, flexible and tough films upon casting from DMAc solutions. Measurements of wide‐angle X‐ray diffraction revealed that those polymers containing p‐phenylene or oxyphenylene groups were characterized as crystalline polymers. Tensile strength and initial moduli of the polymer films ranged from 61–86 MPa and 1.83–2.21 GPa, respectively. Glass transition temperatures of the polymers were in the range of 231–340°C. The melting points of the crystalline polymers ranged from 375–430°C. The 10% weight loss temperatures were above 512°C in nitrogen and 481°C in air. © 1993 John Wiley & Sons, Inc.
Novel polyaddition catalyzed by transition metals. II. Synthesis of polysulfones using polyaddition of arenedisulfonyl chlorides to diethynyl compounds catalyzed by cuprous chloride
Authors: Lim Jong‐chan , Suzuki Masato , Saegusa Takeo
Published: April 2003

CuCl‐catalyzed polyaddition of arenedisulfonyl chloride to diethynyl compound was performed to produce polysulfones consisting of sulfonyl groups between arenylene and chlorovinylene groups. The polyaddition proceeded via both trans and cis addition, whose proportion was affected by the polarity of the reaction medium, the presence of triethylamine · HCl salt, and the nature of the monomer. © 1993 John Wiley & Sons, Inc.
Regioselective hydrosilations. III. The synthesis and polymerization of ambifunctional silicon‐containing epoxy monomers
Authors: Crivello J. V. , Bi Daoshen
Published: April 2003

Silicon‐containing epoxide compounds bearing Si  H groups can be readily prepared in high yields by the regioselective rhodium‐catalyzed monohydrosilation of α,ω‐dihydrogen functional siloxanes and silanes with vinyl epoxides. The remaining Si  H groups in these compounds can be further selectively hydrosilated with unsaturated epoxides to give a series of unique ambifunctional monomers containing two different epoxide groups in the same molecule. The photopolymerization of these monomers has been studied using analytical techniques including real time infrared spectroscopy and differential scanning photocalorimetry. On photopolymerization, the new monomers yield interesting networks. © 1993 John Wiley & Sons, Inc.
Regioselective hydrosilations. IV. The synthesis and polymerization of monomers containing epoxy and alkoxysilane groups
Authors: Crivello J. V. , Bi Daoshen
Published: April 2003

Using rhodium and platinum catalyzed regioselective hydrosilation, a series of α‐hydrogen‐ω‐epoxy silane and siloxane compounds have been prepared in good yields. These intermediates have been further condensed with vinyltrimethoxysilane in subsequent hydrosilation reactions to prepare an interesting new class of ambifunctional monomers containing both epoxy and trimethoxysilane groups. It was further shown that these same compounds could be synthesized by a simplified “one‐pot” two‐step procedure. An investigation of the simultaneous cationic ring‐opening polymerization of the epoxy groups and the acid‐catalyzed condensation of the trimethoxysilyl groups was carried out. © 1993 John Wiley & Sons, Inc.
Macromolecular synthesis from saccharic lactones. Ring‐opening polyaddition of D‐glucaro‐ and D‐mannaro‐1,4:6,3‐dilactones with alkylenediamines
Authors: Hashimoto Kazuhiko , Wibullucksanakul Sirinat , Matsuura Mitsuyasu , Okada Masahiko
Published: April 2003

Ring‐opening polyaddition of a saccharic acid dilactone prepared from D‐glucose, D‐glucaro‐1,4 : 6,3‐dilactone, with several alkylenediamines proceeded at room temperature with no catalyst. The resulting new polyamides carrying many pendant hydroxyl groups, poly(alkylene D‐glucaramide)s, were more amorphous and hydrophilic than the corresponding nylons having no hydroxyl groups, and were hydrolyzed more easily than the latter in an acidic condition. The ring‐opening ability of D‐mannaro‐1,4:6,3‐dilactone, which was another saccharic acid dilactone obtained from D‐mannitol, was found to be lower than that of the D‐glucaric analogue. © 1993 John Wiley & Sons, Inc.
The synthesis of a precursor of polybenzimidazole (PBI) and blends with polyamic acid (PAA)
Authors: Kim S. H. , Pearce Eli M. , Kwei T. K.
Published: April 2003

The precursor of polybenzimidazole (PBI), poly(3,3′‐diamino‐4,4′‐benzidine isophthalamide) (PDABI), was synthesized from poly(3,3′‐dinitro‐4,4′‐benzidine isophthalamide) (PDNBI) by reduction. With increasing temperature, the NH2 moiety which was protected by SnCl5−1 could cyclize and form PBI. Blends with polyamic acid (LaRC‐TPI) were prepared. Clear blend films were prepared at up to 400°C. The IR spectra displayed shifts in the NH stretching band, thereby providing evidence for specific interactions related to the miscibility of their cured blends. © 1993 John Wiley & Sons, Inc.
Graft copolymerization of methyl acrylate onto potato starch initiated by ceric ammonium nitrate
Authors: Liu Mingzhu , Cheng Rongshi , Wu Jingjia , Ma Cheng
Published: April 2003

A study was made of the ceric ammonium nitrate (CAN) initiated graft copolymerization of methyl acrylate (MA) onto potato starch. The variables affecting the graft were investigated. The optimums have been obtained; they are the concentrations of MA, CAN, and nitric acid (HNO3) (1.08, 5.0 × 10−3, and 0.081 mol/L, respectively). The reaction temperature is ca. 50°C and the reaction time is 2 h. The molecular weight of grafted poly(methylacrylate) has been determined. On the basis of experimental results, the mechanism of grafting has been explored, a new kinetic equation of the graft copolymerization is established: Rp = Kkd [STOH] [Ce4+] + Kkpkd/kt[STOH][M], where K, kd, kp, and kt are constants. The equation fits the results of experiments. © 1993 John Wiley & Sons, Inc.
Study on aqueous polymerizations of vinyl monomers initiated by metal oxidant–chelating agent redox initiators
Authors: Hsu Wen‐Cheng , Kuo Jen‐Feng , Chen Chuh‐Yung
Published: April 2003

In this study, a series of chelating type reductants containing redox pairs were tested as the initiator for aqueous polymerizations. The redox pairs consist of Ce(IV) or several first‐row transition metals coupled with chelating agents of amino acids, dibasic acids, or diamine. The initial rates and limiting conversions of acrylamide polymerization initiated by those redox pairs were determined. The reductive reactivity of the chelating agents with Ce(IV) and the oxidative half‐wave potential of Ce(III)‐chelating agent/Ce(IV)‐chelating agent were measured to evaluate the feasibility of these redox pairs as initiators. After the evaluation, the redox pairs other than Ce(IV)‐amino acid type chelating agent were precluded to be promising initiators for aqueous polymerizations. Those Ce(IV)‐amino acid type chelating agent redox pairs which could form at least two five‐ or six‐membered rings were found to be potential initiators. The Ce(IV)‐NTA pair was the most promising one. The mechanism of initiation of the redox pairs was proposed and further confirmed by the 13C‐ and 1H‐NMR spectra of NTA‐terminated polyacrylamide. The complex formation constants (K) and disproportionation constants (kd) of the Ce(IV)‐amino acid type chelating agent redox initiators for acrylamide polymerization were evaluated. The factors governing the parameters of chelated complexes and the performance of polymerizations were discussed. These redox pairs were also used as the initiators for aqueous polymerizations of acrylic acid and acrylonitrile. © 1993 John Wiley & Sons, Inc.
Influence of molecular weight on some properties of liquid crystalline polyurethanes
Authors: Szczepaniak Barbara , Frisch Kurt C. , Penczek Piotr , Rudnik Ewa , Cholińska Mariola
Published: April 2003

This investigation extends our previous investigations of liquid crystalline polyurethanes prepared from 4,4′‐bis(2‐hydroxyethoxy)biphenyl (BHBP), 2,4‐tolylene diisocyanate, and poly(oxytetramethylene)diols as the flexible spacers. The influence of molecular weight of investigated polyurethanes on their properties is discussed for two series with the same content of BHBP and different lengths of flexible spacers. The polyurethanes were investigated by means of DSC, polarizing microscopy, x‐ray diffractometry, and IR spectroscopy. The molecular weight distribution was determined by GPC. Morphology was studied by the SALS method. The molecular weight of polyurethanes and the length of flexible spacer influence the phase transition temperature and the range of mesophase occurrence. © 1993 John Wiley & Sons, Inc.
Polymerization of 7‐phenyl‐2,6‐dimethylquinone methide and its derivatives
Authors: Lin Lon‐Tang W. , Bromps William , Ching Ta Yen
Published: April 2003

7‐Phenyl‐, 7‐chlorophenyl‐,7‐methylphenyl‐, and 7‐trifluoromethylphenylquinone methide were synthesized to investigate the anionic polymerization of quinone methide. Novel high molecular weight polymers have been prepared and the substitution effects of the monomers on polymerization kinetics were determined. © 1993 John Wiley & Sons, Inc.
Preparation and properties of aromatic polyamides from 2,2′‐bis(p‐carboxyphenoxy) biphenyl or 2,2′‐bis(p‐carboxyphenoxy)‐1,1′‐binaphthyl and aromatic diamines
Authors: Liou Guey‐Sheng , Kakimoto Masa‐Aki , Imai Yoshio
Published: April 2003

New aromatic dicarboxylic acids having kink and crank structures, 2,2′‐bis(p‐carboxyphenoxy) biphenyl and 2,2′‐bis(p‐carboxyphenoxy)‐1,1′‐binaphthyl, were synthesized by the reaction of p‐fluorobenzonitrile with biphenyl‐2,2′‐diol and 2,2′‐dihydroxy‐1,1′‐binaphthyl, respectively, followed by hydrolysis. Biphenyl‐2,2′‐diyl‐and 1,1′‐binaphthyl‐2,2′‐diyl‐containing aromatic polyamides having inherent viscosities of 0.58–1.46 dL/g and 0.63–1.30 dL/g, respectively, were obtained by the low‐temperature solution polycondensation of the corresponding diacid chlorides with aromatic diamines. These polymers were readily soluble in a variety of organic solvents including N,N‐dimethylacetamide (DMAc), N‐methyl‐2‐pyrrolidone (NMP), dimethyl sulfoxide, m‐cresol, and pyridine. Transparent, pale yellow, and flexible films of these polymers could be cast from the DMAc or NMP solutions. These aromatic polyamides containing biphenyl and binaphthyl units had glass transition temperatures in the range of 210–272 and 260–315°C, respectively. They began to lose weight around 380°C, with 10% weight loss being recorded at about 450°C in air. © 1993 John Wiley & Sons, Inc.