Optically transparent and colorless poly(ether-imide)s derived from a phenylhydroquinone bis(ether anhydride) and various trifluoromethyl-substituted bis(ether amine)s

A series of colorless and organosoluble poly(ether-imide)s (PEIs) were prepared from a phenylhydroquinone bis(ether anhydride), i.e., 2,5-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, and seven trifluoromethyl-containing bis(ether amine)s by the conventional two-stage process via the thermal or chemical imidization of the precursor poly(amic acid)s. The fluorinated PEIs prepared via the chemical imidization procedure had inherent viscosities of 0.46–1.27 dL/g and weight-average molecular weights of 68,000–87,500. The PEIs exhibited good solubility in a variety of organic solvents; they were readily soluble in amide-type polar solvents and chlorinated hydrocarbons on a concentration higher than 10%. The solution-cast films showed a high optical transparency and low color intensity, with an ultraviolet-visible absorption edge of 368–375 nm and a yellowness index of 5.9–9.9. These films were flexible and tough with tensile strengths of 89–114 MPa. They exhibited glass-tranisition temperatures of 198–250°C and 10% weight loss temperatures higher than 488°C in air or nitrogen. In addition, these PEI films also displayed low dielectric constants (3.22–3.52 at 1 MHz) and low moisture absorptions (0.22–0.73 wt%).     

Synthesis and characterization of bis (a-methyl-4-nitrobenzyl) peroxide and bis ( a-methyl-4-nitrobenzyl ) ether

以对硝基乙苯为原料,研究了合成标题化合物的方法,并对其进行了结构表征.在合成双-(α-甲基-4-硝基苄基)过氧化物的方法中,使用优选的T(p-OCH3) PPZn作为催化剂,原料的转化率可达16.2％,产物的选择性为44.0％,相应地收率达7.1％.其中以氧气作为氧化剂,使用金属卟啉为催化剂合成对硝基乙苯一步得到双-(α-甲基-4-硝基苄基)过氧化物的方法尚未见文献报道.     

Organosoluble poly(ether imide)s from phthalimidine based and trifluoromethyl substituted bis(ether amine)

A series of new organosoluble and optically transparent poly(ether imide)s (PEIs) were synthesized by the polycondensation of trifluoromethyl substituted and phthalimidine cardo group based bis(ether amine), 3,3‐bis‐[4‐{2′‐trifluoromethyl 4′‐(4″‐aminophenyl)phenoxy}phenyl]‐2‐phenyl‐2, 3‐dihydro‐isoindole‐1‐one with different fluorinated and non‐fluorinated aromatic dianhydrides (2a–e). All the PEIs were well characterized by elemental analysis, NMR, FTIR spectroscopy, and gel permeation chromatography (GPC). The synthesized PEIs showed moderate to high inherent viscosity 0.41–0.61 dL/g and excellent solubility at room temperature in different organic solvents. All the transparent yellow films showed cut‐off length upto 425 nm. They exhibited high tensile strengths upto 98 MPa, excellent thermostability upto 554°C for 5% weight loss, high glass transition temperature upto 327°C, and water uptake value less than 0.6%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Processable and colorless fluorinated poly(ether imide)s based on an isopropylidene‐containing bis(ether anhydride) and various aromatic bis(ether amine)s bearing trifluoromethyl groups

A series of novel organosoluble and light‐colored fluorinated poly(ether imide)s (PEIs) ( IV ) having inherent viscosities of 0.43–0.59 dL/g were prepared from 4,4′‐[1,4‐phenylenbis(isopropylidene‐1,4‐phenyleneoxy)]diphthalic anhydride ( I ) and various trifluoromethyl‐substituted aromatic bis(ether amine)s by a standard two‐step process with thermal and chemical imidization of poly(amic acid) precursors. These PEIs showed excellent solubility in many organic solvents and could be solution‐cast into transparent and tough films. These films were essentially colorless, with an UV–visible absorption edge of 361–375 nm and a very low b* value (a yellowness index) of 15.3–17.0. They also showed good thermal stability with glass‐transition temperature of 191–248°C, 10% weight loss temperature in excess of 494°C, and char yields at 800°C in nitrogen more than 39%. The thermally cured PEI films showed good mechanical properties with tensile strengths of 83–96 MPa, elongations at break of 8–11%, and initial moduli of 1.7–2.0 GPa. They possessed lower dielectric constants of 3.25–3.72 (1 MHz). In comparison with the V series nonfluorinated PEIs, the IV series showed better solubility, lower color intensity, and lower dielectric constants. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 620–628, 2007     

Preparations and reactions of quanternary salts of bis(chloromethyl) ether

The preparation of some novel quaternary salts of bis(chloromethyl) ether are described. The salts derived from trimethylamine are stable in alkali, whereas the ones containing pyridinium groups are unstable in alkali, and are formaldehyde donors and gelatin hardeners. A possible mechanism for the decomposition reaction is proposed.     

双(2-氯乙基)醚的合成新方法

作为冠醚合成的基本原料多甘醇二卤化物,在合成上,均是依照Pedersen C J在1967年及1972年时所提出的方法[1～3],该方法是将相应的多甘醇与氯化亚硫酰在苯中吡啶存在下反应.这个方法适用于二甘醇二氯化物(即双(2-氯乙基)醚,简称二氯乙醚)合成,产率一般较高,但反应进行得很缓慢,操作环境毒性很大,目标产品的分离提纯程序较多.本文提出一种新的合成双(2-氯乙基)醚的方法,使反应时间大大缩短;避免了在毒性很大的环境下操作;反应完全以后的分离提纯简单,目标产品可以直接从反应混合物中减压蒸馏得到;降低了产品的生产成本.     

Highly optically transparent/low color polyimide films prepared from hydroquinone- or resorcinol-based bis(ether anhydride) and trifluoromethyl-containing bis(ether amine)s

Two series of novel polyimides (5a-g and 6a-g) containing flexible ether linkages and pendent trifluoromethyl (CF₃) groups were synthesized from 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride (3a) and 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride (3b) with various CF₃-substituted aromatic bis(ether amine)s (4a-g) via ring-opening polyaddition to poly(amic acid)s, followed by thermal or chemical imidization. These polyimides were readily soluble in a variety of organic solvents and could be solution-cast into flexible and tough films. The cast films exhibited high optical transparency and almost no color, with a UV-vis absorption edge of 368-382 nm and a very low b^∗ value (a yellowness index) of 6.2-15.5. They had good thermal stability with glass-transition temperatures of 186-288 °C, and most of them did not show significant decomposition before 500 °C. Moreover, these polyimide films also possessed low dielectric constants of 2.79-3.49 (at 1 MHz) and low water uptakes (<0.65 wt%).     

Synthesis and stereochemistry of bis(dithiacrown ether) and dodecylthio substituted (E)-thiodesaurines

Reductive dimerization of dodecylthio substituted 1,2-dithiole-3-thiones 6a–b and trithion-dithiacrown ethers 10a–c with triethyl phosphite furnished bis- and tetrakis (dodecylthio), and bis(dithiacrown ether) substituted thiodesaurines (E)- 11a–b and (E)- 12a–c . The stereochemistry of bis(dithia[15]crown-5)-thiodesaurine (E)- 12b has been determined by X-ray crystallographic analysis.     

Synthesis of poly(ether amide)s from p‐xylylene glycol and bis(ether nitrile)s

BACKGROUND: Poly(ether amide)s have been well studied in terms of improving the physical and thermal properties of aromatic polyamides. Poly(ether amide)s of high enough molecular weight to be useful for industrial purposes are generally difficult to prepare. The objective of this project was to introduce a simple and commercially feasible process to prepare poly(ether amide)s by a polymerization reaction at relatively low temperature. RESULTS: A series of poly(ether amide)s were prepared by direct polyamidation of p‐xylylene glycol with bis(ether nitrile)s via the Ritter reaction using concentrated H₂SO₄ in acetic acid. The synthesized poly(ether amide)s showed good solubility in polar aprotic solvents. The resultant poly(ether amide)s had inherent viscosities in the range 0.36–1.03 dL g^?1. The glass transition temperatures of the poly(ether amide)s were determined using differential scanning calorimetry to be in the range 190–258 °C. Thermogravimetric analysis data for these polymers indicated the 10% weight loss temperatures to be in the range 290–390 °C in nitrogen atmosphere. CONCLUSION: The Ritter reaction was applied for the synthesis of a variety of poly(ether amide)s with moderate to high molecular weights. This procedure provides a simple polymerization process for the convenient preparation of poly(ether amide)s in high yield at room temperature. Copyright © 2009 Society of Chemical Industry     

Vinyl polymerization of norbornene with bis(imino)pyridyl nickel(II) complexes

A series of different steric hindrance nickel(II) complexes 1 – 6 bearing 2,6‐bis(imino)pyridine ligands have been synthesized and characterized. The molecular structures of the complexes 3 – 5 were determined by X‐ray diffraction analysis. The coordination geometry around the nickel center of the complexes is either square pyramid for complexes 3 and 4 or trigonal bipyramid for complex 5 . All of the nickel complexes exhibit high catalytic activity for norbornene polymerization in the presence of MAO, although low activity for ethylene oligomerization and polymerization. The effects of the Al/Ni ratio, halogen, monomer concentration, temperature, and reaction time on activity of catalyst for norbornene polymerization and polymer microstructure were investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Living cationic polymerization of isobutyl vinyl ether (II): Photoinduced living cationic polymerization in a mixed solvent of toluene and diethyl ether

A new method of preparation of living cationic polymer of isobutyl vinyl ether via photoinduced polymerization in the presence of diphenyliodonium iodide (DPII, initiator) and zinc iodide in a mixed solvent of toluene/diethyl ether, which was irradiated at ?78°C for short period, was completed within 15 min. The reaction was allowed for further reaction in the dark until monomer was fully consumed. It was found that increase in the conversion of monomer to polymer during the irradiation is very limited. Confirmation of the linear dependence of number‐average molar mass of resulting polymer on % conversion together with the fact that polymerization proceeds until monomer consumption, and controllability of number‐average molar mass of resulting polymer, depending on the molar ratio of monomer and initiator, strongly suggests the living nature of this polymerization, unless reaction temperature becomes higher than 0°C, i.e., the absence of chain breaking process. The narrow molar mass distribution, whose polydispersity index values are less than 1.2, reveals that the rate of initiation where irradiation is usually completed within 15 min is much faster than that of propagation in cationic nature in this system. Effect of some major factors, such as solvent polarity and temperature, on the living nature of the polymerization was also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3581–3586, 2006     

Synthesis and characterization of polyimides based on isopropylidene-containing bis(ether anhydride)s

Two bis(ether anhydride)s, 4,4′-[1,4-phenylenebis(isopropylidene-1,4-phenyleneoxy)]-diphthalic anhydride (IV _a) and 4,4′-[isopropylidenebis(1,4-phenylene)dioxy]diphthalic anhydride (IV _b), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 4-nitrophthalonitrile with α,α ′-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene (I _a) and 4,4′-isopropylidenediphenol (I _b) in N,N-dimethylformamide (DMF) in the presence of potassium carbonate. The bis(ether anhydride)s IV _a and IV _b were polymerized with various aromatic diamines to obtain two series of poly(ether amic acid)s VI _a–g and VII _a–g with inherent viscosities in the range of 0.30∼0.74 and 0.29∼1.01 dL/g, respectively. The poly(ether amic acid)s were converted to poly(ether imide)s VIII _a–g and IX _a–g by thermal cyclodehydration. Most of the poly(ether imide)s could afford flexible and tough films, and they showed high solubility in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, and m-cresol. The obtained poly(ether imide) films had tensile strengths of 45∼83 MPa, elongations-to-break of 6∼27%, and initial modulus of 0.6∼1.7 GPa. The T_gs of poly(ether imide)s VIII _a–g and IX _a–g were in the range of 194∼210 and 204∼243 °C, respectively. Thermogravimetric analysis (TG) showed that 10% weight loss temperatures of all the polymers were above 500 °C in both air and nitrogen atomspheres.     

Poly(ethylene naphthalate) formation 2. polymerization of bis(hydroxyethyl)naphthalate

Bis(hydroxyethyl)naphthalate (BHEN) was polymerized to polyethylenenaphthalate (PEN) in the presence of various metallic catalysts. The influence of the nature and concentration of these catalysts on the rate of polymerization has been investigated. The order of decreasing catalytic influence of various metal ions on the polymerization of BHEN was found to be: Ti > Sb > Zn > Co > Pb > Ni (Mg). The effect of the reaction temperature has also been studied. The optimal concentration of these catalysts and reaction temperature were found to be 30 × 10^–5 (mol/mol B HEN) and 285°-293°C. Because of its insolubility in ordinary solvent, the molecular weight of PEN was measured using the light scattering method.     

Thioetherglycidyl resins. III. Products of condensation of bis(4-mercaptophenyl)ether and bis(4-mercaptophenyl)methane with epichlorohydrin

Thioetherglycidyl resins produced by condensation of bis(4-mercaptophenyl)ether and bis(4-mercaptophenyl) methane with epichlorohydrin were obtained by heterophase alkaline condensation. To define the optimal conditions of condensation, the following factors that influence the process were studied: the kind of organic phase and the mole ratios of epichlorohydrin:mercaptan, alcohol:mercaptan, and alkaline hydroxide:mercaptan. For all syntheses yield and the epoxide content were found. The structure of thioetherglycidyl resins with the highest epoxide content was determined by elementary analysis, infrared IR, and NMR spectra. The physical and chemical properties were also defined. The investigations covered the determination of some properties of resins, cured chemically or thermally with different curatives and thermal and mechanical properties of the cured compounds.     

Poly(aryl ether amides): Self polymerization of an A-B monomer via amide-activated ether synthesis

Summary A synthetic approach for the preparation of poly(aryl ether amides) has been developed where the generation of an aryl ether linkage was the polymer-forming reaction. The amide moiety was found to be sufficiently electron withdrawing to activate halosubstituents, towards nucleophilic aromatic substitution polymerizations, analogous to conventional activating groups (i.e, sulfone, ketone etc.). Several new A-B monomers, 4-fluoro-N-(4-hydroxyphenyl)benzamide, 1, and 4-fluoro-N-(3-hydroxyphenyl)benzamide, 2, which contain both an amide-activated fluoro group and a phenol group were prepared and their self polymerization studied. Compounds 1 and 2 were prepared by the condensation of 4-fluorobenzoyl chloride with either 4-or 3-aminophenol, respectively. The polymerizations were carried out in an N-methyl-2-pyrrolidone (NMP)/N-cyclohexyl-2-pyrrolidone (CHP) solvent mixture in the presence of potassium carbonate. Several new high molecular weight poly(aryl ethers) were prepared by this route with Tg's in the 225 °C range.     

Novel functionalized bis(imino)pyridine cobalt(II) catalysts for ethylene polymerization

This report describes synthesis and ethylene polymerization in the various conditions by two novel 2,6-bis(imino)pyridine (BIMP) catalysts B and C based on cobalt activated by methylaluminoxane (MAO) in a slurry semi-batch reactor. The catalyst activities as well as polymer properties were affected dramatically by electronic effects of the attached substitutions on the para-position of the pyridine ring. Theoretical study exhibited more positive charge on the central metal of the catalyst B resulted in higher activity at the expense of lower thermal stability and lifetime. The polymer obtained using the catalysts exhibited high molecular weight and almost narrow molecular weight distribution (MWD) ranging from 2.35 to 4.10 at the employed polymerization conditions. The highest and lowest molecular weight of the obtained polymers were produced by the catalyst A and C respectively. Hydrogen could slightly increase the catalyst activities with the exception of the catalyst B. The catalyst C bearing electron-donor OMe substitution at the para-position of the pyridine ring, produced PE with narrower PDI relative to the polymer resulted by catalysts A and B.     

Thioether glycidyl resins. II. Products of condensation of bis(4-mercaptomethylphenyl) ether and bis(4-mercaptomethylphenyl)methane with epichlorohydrin

New thioether glycidyl resins produced by condensation of bis(4-mercaptomethylphenyl) ether and bis(4-mercaptomethylphenyl)methane with epichlorohydrin were obtained by heterophase alkaline condensation in water and isopropyl alcohol solution. To define the optimal conditions of condensation, the following factors that influence the process were studied: the mole ratios of epichlorohydrin–mercaptan, alcohol–mercaptan, alkaline hydroxide–mercaptan. For all reaction products, yield, epoxide content, and chlorine content were determined. The structure of thioether glycidyl resins with the highest epoxide content was determined by elemental analysis and infrared and NMR spectra. The physical and chemical properties were defined. Some properties of the resins, cured chemically or thermally with different curatives, and thermal and mechanical properties of the cured compounds were determined.     

Dielectric studies of the polymerization of diethylene glycol bis(allyl carbonate)

Results of dielectric studies are presented for the polymerization of diethylene glycol bis (allyl carbonate). Two transitions are observed in the dielectric spectra, one that can be related to motion of the carbonate unit and another that has been identified as the glass transition. A relation between the glass transition temperature and the level of conversion of double bonds has been established for this system in the 70 to 100% conversion range. While there appears to be a one-to-one relationship between these two parameters, such is not the case for the position of the low-temperature, secondary transition and the level of conversion. This latter result is interpreted in terms of the local free volume available in the crosslinked system.     

Asymmetric polymerization of N-phenylmaleimide

Summary Asymmetric polymerization of N-phenylmaleimide was carried out with the complexes of butyllithium and chiral ligands and optically active polymers were obtained. The optical activity of the polymers should be based on the chiral trans structure of the main chain.A part of this work was reported at The 28th Meeting of Polymer Science (Kobe), July 1982