Synthesis and properties of poly(arylene ether phenyl-s-triazine)s

A series of new poly(arylene ether phenyl-s-triazine)s was prepared by the nucleophilic aromatic substitution polymerization of the potassium salt of bisphenols with 2,4-bis (halophenyl)-6-phenyl-s-triazine in N-methyl-2-pyrrolidone at elevated temperature. The polymers with inherent viscosities exceeding 0.5 were obtained after polymerization for 1 h using 2,4-bis(fluorophenyl)-6-phenyl-s-triazine as a monomer. The glass transition temperatures of the resulting polymers ranged from 200 to 260°C depending on the bisphenol used in the polymer synthesis. The poly(arylene ether phenyl-s-triazine)s demonstrated excellent thermal stabilities in excess of 490°C (5% weight loss in air). The isothermal TGA measurements (400°C under air or nitrogen atmosphere) revealed that the 4,4'-biphenol- and hydroquinone-based poly(arylene ether phenyl-s-triazine)s belong to the most superior class of heat resistant polymers, such as polyimide Kapton?. The mechanical properties of these polymers are also described. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of poly(arylene ether imide ketone)s

Poly(arylene ether ketone)s containing imide units were prepared by the aromatic nucleophilic displacement reaction of the potassium salts of bisphenols with bis(4-fluorobenzoyl)phthalimides in N-methyl-2-pyrrolidone at elevated temperature. The polymers having inherent viscosities of 0.34–0.77 dL/g were obtained in 2 h. The polymers exhibited glass transition temperatures ranging from 216 to 268°C and decomposition temperatures (5% weight loss under air atmosphere) ranging from 450–570°C mainly depending on the bisphenols used in the polymer synthesis. The isothermal TGA measurements (400°C under air or nitrogen atmosphere) revealed that the 4,4'-biphenol- and hydroquinone-based poly(arylene ether ketone imide)s belong to a superior class of heat resistant polymers. The mechanical properties of these polymers are also described. © 1994 John Wiley & Sons, Inc.     

Synthesis and characterization of new fluorescent poly(arylene ether)s

The poly(arylene ether)s were prepared by the nucleophillic aromatic substitution polymerization of phenolphthalin and its derivatives with activated aromatic difluorides. The polymers had glass transition temperatures ranging from 210 to 240°C. Though the monomers have no fluorescence, the resulting polymers fluoresced a light green color in solid and solution states. The maximum excitation and emission wavelengths are 420 nm and 470 nm, respectively. In the polymer solutions, the fluorescence intensity decreased gradually, but the intensity was recovered by heating the polymer at 220°C for a few minutes. The fluorescent polymer had a stable radical. A model compound having the same repeating unit of the polymer was also prepared. The fluorescence properties of this model were almost the same as those of the polymers. © 1994 John Wiley & Sons, Inc.     

A novel benzimidazole moiety‐containing benzoxazine: Synthesis,polymerization, and thermal properties

A novel benzoxazine‐containing benzimidazole moiety (P‐PABZ) was synthesized from 2‐(4‐aminophenyl)‐1H‐benzimidazole‐5‐amine and characterized. With the aid of differential scanning calorimetry and in situ Fourier transform infrared, we found the thermal polymerization of P‐PABZ in bulk started around 140 °C and its favored polymerization pathway. Compared to the benzoxazine derived from 4,4′‐diamine diphenyl methane (P‐MDA), P‐PABZ exhibited lower processing temperature, and the corresponding polymers had higher glass transition temperature and enhanced thermal stability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis, structure and reactivity of new yttrium bis(dimethylsilyl)amido and bis(trimethylsilyl)methyl complexes of a tetradentate bis(phenoxide) ligand

The reactions of a bulky amino-methoxy bis(phenolate) ligand H₂L with Y(CH₂SiMe₃)₃(THF)₂ and Y[N(SiHMe₂)₂]₃(THF)₂ under mild condition leads to the selective formation of the thermally stable complexes [L]Y(CH₂SiMe₃)(THF) (1) and [L]Y[N(SiHMe₂)₂](THF) (2). The X-ray structures revealed very similar binding of the [ONOO] ligand core to the metal for both complexes, which feature an octahedral geometry involving coordination of the methoxy side-arm of the ligand and of a remaining THF molecule. ¹H-NMR spectroscopy indicates that the solid state structure of 1 and 2 is retained in hydrocarbon solutions with THF coordinated to yttrium. Alkyl complex 1 showed no activity in ethylene polymerization, presumably due to the presence of coordinated THF. The amido complex 2 catalyzed sluggishly the polymerization of methyl methacrylate to give isotactic-rich PMMA but is very active for the ring-opening polymerization of ε-caprolactone.     

Exhaustive and partial alkoxylation of polymethylhydrosiloxane by copper‐catalyzed dehydrocoupling with alcohols: Synthesis,crosslinking behavior,and thermal properties of the products

Polymethylhydrosiloxane (PMHS) reacts with aliphatic and aromatic alcohols at room temperature in the presence of [CuH(PPh₃)]₆ complex catalyst to give poly[(methyl) (alkoxy)siloxane]s in high yields. Reactivity of alcohols decreases in the order of p‐methoxyphenol > p‐cresol > phenol > benzyl alcohol > allyl alcohol > ethanol > isopropanol > tert‐butyl alcohol. Partially p‐cresylated polymers, which still retain unreacted Si? H bonds, react further with ethylene glycol or water to form cross‐linked polymers, which, depending on the extent of cross linking, gelate during the cross‐linking process. Propargyl alcohol reacts with PMHS very rapidly to give exhaustively and partially propargyloxylated PMHS. Resulting polymers, upon heating, undergo crosslinking. Partially propargyloxylated polymers display high thermal stability [T_d5 (temperature of 5% weight loss) > 500 °C] as compared with starting PMHS (243 °C) and exhaustively propargyloxylated one (414 °C). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Metal-complex-bearing star polymers by metal-catalyzed living radical polymerization: Synthesis and characterization of poly(methyl methacrylate) star polymers with Ru(II)-embedded microgel cores

One-pot, spontaneous, and in-situ incorporation of Ru(II) complexes into a microgel (solubilized nanometer-scale network) has been achieved in near quantitative efficiency by a polymer-linking reaction of linear living poly(methyl methacrylate) (PMMA) with a bifunctional methacrylate (ethylene glycol dimethacrylate or bisphenol A dimethacrylate; linking agent) and a phosphine-ligand monomer [diphenyl-4-styryl-phosphine ( 3 ); i.e., CH₂CH C₆H₄ p-PPh₂] in the RuCl₂(PPh₃)₃-catalyzed living radical polymerization. The products were Ru-bearing. PMMA-armed star polymers with a microgel-core that consisted of a copolymer network of the linking agent and 3 . Upon the network formation, the phosphine ligands efficiently encapsulated RuCl₂(PPh₃)₃, thus achieving a polymer catalyst directly from a polymerization catalyst. Colored dark brown-red, the star polymers exhibited UV-vis absorptions originating from the entrapped complex (3.1–7.4 × 10⁻⁵ mol Ru/g of polymer), the incorporation efficiency being close to 100% with respect to the original polymerization-catalyst. Detailed spectroscopic characterization showed the following: an absolute molecular weight of 1.7 × 10⁵ to 1.7 × 10⁶, an arm number of 11–92 arms/polymer, and a radius of gyration of 8–19 nm (in DMF). Direct observation of the individual star molecules in solid state was achieved by transmission electron microscopy (unstained; 2–3 nm dark dots for the core) and atomic force microscopy (semi-circular images). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4966–4980, 2006     

Linear diacetylene polymers containing bis(dimethylsilyl) phenyl and/or bis-(tetramethyldisiloxane) carborane residues: Their synthesis,characterization and thermal and oxidative properties

A series of inorganic-organic linear diacetylenic hybrid polymers ( 5a–e ) were prepared by the polycondensation reaction of 1,4-dilithiobutadiyne with 1,4-bis(dimethylchlorosilyl)benzene and/or 1,7-bis(tetramethylchlorodisiloxane)-m-carborane. Their structures were characterized using FTIR, and ¹³C and ¹H NMR spectroscopies, and their thermal and oxidative properties were evaluated by DSC and TGA analyses. The hybrid polymers exhibited solubility in common organic solvents and were viscous liquids or low melting solids at room temperature. Broad prominent exotherms, attributed to reaction of the diacetylenic units, were observed by DSC in the 306°C to 354°C temperature range. When 5a–e were analyzed by TGA to 1000°C under nitrogen, weight retention between 79 and 86% were obtained. Ageing studies, performed at elevated temperatures in air on a thermoset and a ceramic obtained from polymer 5b , showed this system to have excellent thermal and oxidative stability. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2387–2391, 1997     

Synthesis of bis(2,2′:6′,2″-terpyridine)-terminated telechelic polymers by RAFT polymerization and ruthenium-polymer complexation thereof

Well-defined polystyrenes and poly(n-butyl acrylate)s of the two ends being functionalized with terpyridine groups were synthesized via addition-fragmentation chain transfer (RAFT) polymerization using a symmetric bisterpyridine-functionalized trithiocarbonate as a chain transfer agent (CTA). Kinetic studies on RAFT mediated thermal polymerization of styrene indicated the controlled polymerization. Corresponding triblock copolymers of styrene and n-butyl acrylate were obtained by utilizing the bisterpyridine-functionalized homopolymers as the macro-CTAs. Supramolecular metallo-polystyrenes with different repeat blocks were prepared by the chelating interaction between the terpyridine ends and Ru(II) ions. The formation of the metallo-polymers was proven by UV-vis spectra and dynamic light scattering (DLS).     

Energy-efficient manufacturing of polymers with tunable mechanical properties by frontal ring-opening metathesis polymerization

Frontal polymerization (FP) is a process in which the heat generated by the self-reaction transforms monomers to cured polymers. Here, in order to improve the flexibility of polydicyclopentadiene, comonomers (norbornene-terminated polyether, ND-230,400,2000) are designed and synthesized, which can copolymerize with dicyclopentadiene (DCPD) by FP. The polymers (ND) prepared by ND-2000 and DCPD have tunable mechanical properties, from thermosets to elastomers. Specifically, the breaking elongation of the polymers can be varied 69-fold, from 6.1% to 423.4% by controlling the proportion of ND-2000. Among them, ND polymer with 50 wt% ND-2000 has good elastic behavior without yield. And, the reaction mixture solutions of DCPD and ND-2000 have the characteristics of controllable gel time and shear thinning, which make it have the potential of application in additive manufacturing.     

Synthesis,polymerization, and thermal properties of benzoxazine based on bisphenol‐S and allylamine

A bifunctional benzoxazine monomer, 6,6′‐bis(3‐allyl‐3,4‐dihydro‐2H‐benzo[e][1,3]oxazinyl) sulfone (BS‐ala), was synthesized from bisphenol‐S, allylamine and formaldehyde via a solution method. The chemical structure of BS‐ala was confirmed by ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The polymerization behavior of BS‐ala was investigated by FTIR, solid‐state ¹³C NMR, and differential scanning calorimetry (DSC). The oxazine ring opening polymerization is prior to the addition polymerization of allyl group, and the exothermic peaks corresponding to the two reactions appear partially overlapped in the DSC curve. The storage modulus of the resultant polybenzoxazine at 25°C is about 3.9 GPa, and the glass transition temperature is 254°C. The 5% and 10% weight loss temperatures of the polybenzoxazine are about 335°C and 361°C in both air and nitrogen, respectively. The char yield is about 58% at 800°C in nitrogen, whereas almost no residue is remained at 700°C in air. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and properties of new crystalline poly(arylene ether nitriles)

Crystalline poly(arylene ether nitrile) could be prepared by the polycondensation of 2,6-dihalobenzonitrile with resorcinol at 200°C in N-methylpyrrolidone in the presence of sodium carbonate. A reaction temperature of at least 200°C was necessary to attain high molecular weight polymer. Spectral data indicated that the polymer had the structure of a poly(meta-phenylene ether) with pendent nitrile groups on every other phenylene unit. Despite this structure, the crystallinity and the crystallization rate of the polymer were greater than those of the corresponding polymer with a para-linked structure. The glass transition temperature and the melting temperature of the polymer were almost the same as those of poly(etheretherketone) (PEEK^TM). A series of other new poly(arylene ether nitriles) were also examined. The polymers derived from 4,4′-biphenol, dihydroxytetra-phenylmethane, dihydroxydiphenylsulfone, and 1,5-isoquinolinediol had high glass transition temperatures. The poly(arylene ether nitriles) exhibited excellent tensile strength compared with the corresponding ketone- or sulfone-containing polymers. Comparing the three different kinds of polymers containing the same bisphenol units, the order of glass transition temperature was found to be sulfone- > nitrile- > ketone-containing polymers, while the order of tensile strength was nitrile- > ketone- > sulfone-containing polymers. The excellent mechanical properties are attributable to dipole-dipole interactions of nitrile groups. © 1993 John Wiley & Sons, Inc.     

Synthesis, characterization, and thermal stability of star-shaped poly(ε-caprolactone) with phosphazene core

Hexakis[p-(hydroxylmethyl)phenoxy]cyclotriphosphazene was synthesized by the reaction of hexachlorocyclotriphosphazene with the sodium salt of 4-hydroxybenzaldehyde and subsequent reduction of aldehyde groups to alcohol groups by using sodium borohydride. This compound was employed in initiating the ring-opening polymerization of ε-caprolactone. The resulting polymers were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). The characterization data indicated the star-shaped PCL with phosphazene core were successfully synthesized with narrow molecular weight distribution and high yields. ¹H-NMR analysis was used to calculate the number-average molecular weight. The calculated result from NMR was closer to the theoretical data than that from GPC analysis. Polarizing optical microscopy (POM) combined with differential scanning calorimetry (DSC) was used to study the crystallization behavior of the star-shaped PCL. The result indicated that the highly branched architecture of star-shaped PCL resulted in interrupted crystallization form and subsequently lower melting temperature. Thermogravimetric analysis (TGA) carried out on the star-shaped PCL suggested that introduction of phosphazene rings strengthen the thermal stability of the resulting polymers.     

An effect of polymers on thermal stability of bitumens

Results of studies dealing with an effect of polymers (selected kinds) and plasticizer on thermal stability of coal-tar pitch were presented. Factors being decisive in miscibility of composition constituents and instability of bitumen-polymer-plasyticizer mixtures were determined.     

The thermal polymerization of amino acids revisited; Synthesis and structural characterization of hyperbranched polymers from L‐lysine

This contribution reports on the synthesis of hyperbranched polylysines via thermal polymerization of L ‐lysine hydrochloride. Polymerization of L ‐lysine hydrochloride in the presence of one equivalent KOH at 150 °C resulted in polymers with a number‐average molecular weight of 4600 g/mol and a polydispersity of 2.6 after 48 h. The rate of polymerization could be significantly enhanced and the polymer molecular weight improved by carrying out the polymerization with 3 mol % of an amidation catalyst. Among the different catalysts that were investigated Zr(OⁿBu)₄ was found to be the most effective. Unequivocal support for the branched architecture of the polymers was obtained from ¹H NMR spectroscopy, which allowed the identification and quantification of the four different structural units that constitute the polymer, viz. N^α and N^ε linked linear units, dendritic units and terminal units. The structure of the polymers was found to be relatively independent of the reaction conditions. The degree of branching and the average number of branches varied between 0.35–0.45 and 0.15–0.25, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5494–5508, 2007     

Synthesis of asymmetric star-branched polymers consisting of three or four different segments in composition by means of living anionic polymerization with a new dual-functionalized 1,1-bis(3-chloromethylphenyl)ethylene

A series of four-armed A₂BC, AB₂C, and ABC₂ asymmetric star-branched polymers with a three-component system, the A, B, and C segments of which are polystyrene, polyisoprene, and poly(4-trimethylsilylstyrene), respectively, have been successfully synthesized with a methodology based on living anionic polymerization with dual-functionalized 1,1-bis(3-chloromethylphenyl)ethylene ( 1 ). These star-branched polymers have well-defined architectures and precisely controlled chain lengths, as confirmed by size exclusion chromatography, ¹H and ¹³C NMR, vapor pressure osmometry, and static light scattering analyses. A simple and convenient one-pot process for star-branched polymer synthesis is an additional advantage of this methodology. One problem to be solved is that the synthetic route is limited in some cases by the inherently low reactivity of polyisoprenyllithium toward the 1,1-diphenylethylene functionality of in-chain-functionalized polymers. A new four-armed ABCD star-branched polymer, the A, B, C, and D segments of which are polyisoprene, poly(4-methoxystyrene), polystyrene, and poly(4-trimethylsilylstyrene), could also be synthesized through the extension of the methodology using 1 to a four-component system. The successful results strongly demonstrate the synthetic versatility and potential of this methodology for a wide variety of well-defined asymmetric star-branched polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4535–4547, 2004     

Synthesis and characterization of copoly(arylene sulfide)s

Copolymerizations of p-dichlorobenzene (DCB)/4-bromophenyl ether (BPE), DCB/4,4′-dibromobiphenyl (DBB), and DBB/BPE pairs with sodium sulfide under high temperature (270–290°C) utilizing N-methyl-2-pyrrolidinone (NMP) as solvent were carried out to give C(DCB/BPE), C(DCB/DBB), and C(DBB/BPE) copolymers, respectively. The reactivity of dihaloaromatic monomers toward thiolate anion in the polycondensation reaction followed the order DBB > DCB > BPE. The reactivity gap between DBB and DCB toward thiolate anion seemed to be smaller than that between BPE and DCB, resulting in both high yield and high molecular weight in the C(DCB/DBB) copolymers compared to C(DCB/BPE) copolymers. The copolymerization of DBB/BPE pair with sodium sulfide, which has larger reactivity gap than the DCB/DBB or DCB/BPE pair, gave mixtures of PBS and PPSE homopolymers especially in the range of 50–80 mol % BPE in the feed. The C(DCB/DBB) and C(DCB/BPE) copolymers, however, exhibited random copolymer character in all comonomer ratios in the feed as evidenced by copolymer composition and DSC data. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2311–2317, 1999