Synthesis of poly(phenylgermanosilanes) and poly(phenylgermanocarbosilanes)

Phenyl-substituted poly(germanosilanes) and poly(germanocarbosilanes) have been synthesized through the Wurtz-Kipping reaction via dechlorination of mixtures of dichlorophenylsilanes (PhSi(R)Cl₂, where R = H, Ph, or vinyl) with diphenyldichlorogermane in the presence of an ultradisperse sodium suspension. The polymers thus synthesized have been investigated by X-ray fluorescence analysis; FTIR and UV spectroscopy; and ¹H, ¹³C, and ²⁹Si NMR spectroscopy. The peak maxima in the UV spectra of the polymers dissolved in THF are in the wavelength range of 300–375 nm. Under the effect of UV irradiation with a wavelength of 320–380 nm, photoluminescence emission peaking in the range of 380–470 nm is observed. Size exclusion chromatography indicates that all the (co)polymers under examination are characterized by a narrow GPC curve and their polydispersity indexes are no larger than 1.5. According to dynamic TGA data, the weight loss of the polymers reaches 80% even at 500°C. Owing to formation of branched structures in vinyl-substituted copolymers, the GPC curves widen (the polydispersity index is ～6), while the yield of an inorganic residue at 900°C amounts to 40%.     

Synthesis of poly(tert-butoxycarbonyl-p-phenylene): precursor to poly(p-phenylene)

Poly[2-(tert-butoxycarbonyl)-1,4-phenylene] ( 2 ) was prepared by the Ni-catalyzed polymerization of tert-butyl 2,5-dichlorobenzoate ( 1 ). The microstructure of polymer 2 was probably alternating head-to-head and tail-to-tail. This polymer was soluble in dipolar aprotic solvents, chloroform, tetrahydrofuran, and dichloromethane. Polymer 2 was saponified easily by thermal or acid treatment to yield poly[2-carboxy-1,4-phenylene] ( 3 ). Decarboxylation of polymer 3 in quinoline in the presence of copper(II) oxide produced poly(p-phenylene) (PPP) ( 4 ).     

Synthesis and characterization of poly(ethylene glycol) grafted poly(L-lactide)

Poly(ethylene glycol) grafted poly(L -lactide) was prepared by ring opening polymerization of L -lactide and epoxy-terminated poly(ethylene glycol) methyl ether (PEGME). Stannous octoate and Al(Et)₃·0.5 H₂O were tested as polymerization catalysts, and Al(Et)₃·0.5 H₂O was found to be more effective for the ring-opening of the epoxy group of the modified PEGME monomer. The synthesized polymers were characterized by NMR and the efficiency of the incorporation of epoxy-terminated PEGME in the copolymer was determined.     

Synthesis and properties of poly(hydroxamic acid) from crosslinked poly(methacrylate)

Poly(hydroxamic acid) chelating ion-exchange resin was prepared from crosslinked poly(methacrylate) beads. The starting polymer was prepared by a suspension polymerization of methacrylate and divinyl benzene. Conversion of the ester groups into the hydroxamic acid was carried out by treatment with hydroxylamine in an alkaline solution. Hydroxamic acid capacity of the product was 2.71 mmol/g. The resin exhibited high affinity towards Fe(III) and Pb ions and its capacities for Fe(III), Pb, Cu, Ni and Co ions were pH dependent. The ability of the resin to carry out the separation of Fe(III)CuCo/Ni and PbNi ions is also reported.     

Synthesis and characterization of poly(amide-ureas)

Poly(amide-ureas) have been prepared by the action of di-isocyanates generated in situ, a technique so far not used for the preparation of poly(amide-ureas). The polymers were characterized by i.r., X-ray, thermal and viscosity measurements.     

Synthesis of poly(vinyl alcohol-graft-hyperbranched glycerol)

We report the first example of grafting hyperbranched polyglycerol onto poly(vinyl alcohol) via ring-opening polymerisation of glycidol to prepare poly(vinyl alcohol-graft-hyperbranched glycerol) (P[(VA)-g-(hPG)]). The effects of catalyst, molecular weight of PVA, reaction temperature, water content, moles of reagent, and addition time of reagent were also investigated. P[(VA)-g-(hPG)] with various mole fractions of hPG were prepared and the degrees of substitution and branching were determined. P[(VA)-g-(hPG)] displayed decreased degree of crystallinity and also increased solubility in water, compared to PVA. P[(VA)-g-(hPG)] is shown to be a superior hair styling polymer with a curl retention value of 85% after 4 h. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3041–3047     

Synthesis of poly(ester carbonate) copolymers

The synthesis of poly(ester carbonate) copolymers based on bisphenol A, terephthalic acid, and phosgene is reviewed, and a new synthetic route is described leading to polymers which are different from those obtained by methods described in the literature. The most important features of the new method are quantitative incorporation of the dicarboxylic acid into the polymer and absence of undersirable side reactions. Synthesis of the random copolymer in which the dicarboxylic acid and carbonic acid groups are present in about equal molar amounts is discussed. Solution properties, effects of M?_n and copolymer composition on T_g, sequence length distribution, the effect of ester interchange reactions on molecular weight distribution, and effects of monofunctional chain termination on molecular weight of the final product are also discussed.     

Synthesis of a soluble poly(fluorenone)

The synthesis and characterisation of a soluble poly(fluorenone) is presented, a polymer with high electron affinity with potential for use in plastic electronic devices as an n-type material.     

Synthesis of functionalized poly(1,3-dioxolane)

Classical initiation induces polymerization through cyclic tertiary oxonium ions which are responsible for the formation of an important quantity of cyclic oligomers. The activated monomer mechanism, i.e. polymerization in the presence of a diol, has been successful in the case of some substituted oxiranes such as epichlorohydrine and propylene oxide. It has also been used in the case of cyclic acetals [1,3-dioxolane (DXL) and 1,3-dioxepane (DXP)] and allows the preparation of dihydroxylated homopolymers as well as that of triblock copolymers. It was nevertheless shown that transacetalization leads to complications at the onset of the reaction. In order to shed some light on the reactions involved, we used a monoalcohol - methanol - instead of a diol. The products were separated and characterized: a monoadduct (methanol-DXL) was observed, confirming the occurence of the active monomer mechanism, but dimethoxymethane was also observed, evidence of transacetalization between methanol and DXL. It was shown that fast equilibration takes place between the following compounds: (methanol + DXL), (monoadduct of methanol and DXL), (dimethoxymethane + ethyleneglycol). When p-isopropenylbenzyl alcohol was used, it was possible to prepare macromonomers, i.e. poly(DXL) chains carrying polymerizable double bonds at their ends. Nevertheless because of the transacetalization reaction described above, a mixture of products was obtained.     

Synthesis and properties of poly(aniline-co-azidoaniline)

Copolymers of polyaniline and o-azidoaniline were synthesized by chemical oxidative polymerization. The copolymers were characterized by powder X-ray diffraction (XRD) and UV/Vis and FT-IR spectroscopy. Thermal activation of the azido chromophore in the copolymer caused it to react and cross-link into adjacent polymer chains. The cross-linking of the copolymers was indicated by the depletion of the azido band in the FT-IR spectrum. The effects of the cross-linking were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and four-probe conductivity. The TGA showed that the thermal stability of the copolymers is improved due to cross-linking. However, the increased thermal stability is accompanied by a decrease in electrical conductivity due to the loss of conjugation detected by UV/Vis spectroscopy and a loss of crystallinity due to the azido substituents, which was demonstrated by XRD.     

端羟基聚环氧环己烷的合成

端羟基聚环氧环己烷的合成;端羟基聚环氧环己烷;环氧环己烷;阳离子聚合     

Synthesis and characterization of poly(tetrafluoroethyleneperoxides)

Tetrafluoroethylene (TFE) and oxygen react at low temperature in radical conditions to give perfluoropolyether-polyperoxide polymers. This oxypolymerization reaction has been applied on industrial scale for the manufacture of perfluoropolyethers, presently used in many application fields.It is known that highly unstable polymers containing large amounts of peroxidic units -CF₂CF₂OO- can be formed in particular conditions and may represent a potential hazard in the TFE oxypolymerization process. However little has been reported in the literature on the reaction conditions and the characterization of these polymers.In the present paper we describe the synthesis of perfluoropolyether-polyperoxide polymers with high peroxide content up to the nearly pure poly(perfluoroethyleneperoxide). The investigation is particularly focused to elucidate the relationship between reaction conditions, kinetics and polymer structure. The experimental results indicate that the physical chemical properties of these materials are strongly affected by the peroxide content, this latter depending on the reaction conditions, mainly TFE concentration and initiation rate.     

Synthesis and characterization of poly(phosphon acetal) derivatives of poly(vinyl alcohol)

Preparation of poly(phosphonoacetals) (PPA) by transacetalation of poly(vinyl alcohol) with diethyl-phosphonoacetal is described. PPA with a degree of substitution of 60% is an alcoholsoluble polymer with a glass transition temperature (T_g) of 67°C. High resolution ¹H and ¹³C NMR spectra reveal the presence of hemiacetals alongside the six-membered acetal ring with an approximate ratio of 2:8 of these substituents. A possible correlation between the microtacticity of the parent PVA and the structure of PPA is indicated; the syndiotactic and isotactic sequences on the parent polymer controls the relationship between the two pendant groups.     

Synthesis of poly(methyl methacrylate) macromonomer

Anionic polymerization of methyl methacrylate (MMA) was carried out in tetrahydrofuran (THF) or THF/toluene mixture at ?78°C initiated by triphenylmethyl sodium or lithium as initiators. Highly syndiotactic PMMA of low polydispersity (M _w/m _n = 1.11–1.17) could be prepared with triphenylmethyl lithium in THF or THF/toluene mixture at ? 78°C. Moreover, PMMA macromonomer having one vinylbenzyl group per polymer chain was prepared by the couplings of living PMMA initiated by triphenylmethyl lithium with p-chloromethyl styrene (CMS) at ?78°C. The coupling reaction of living PMMA initiated by triphenylmethyl sodium with CMS was scarcely occurred.     

Synthesis and properties of poly(dimethylxylylenylamides)

Poly(dimethylxylylenylamides) were synthesized from six different diphenylenediamenes and two dimethyl-substituted xylylenyldiacid chlorides by solution polycondensation at low temperature. The model compound 2,5-demethyl1,4-benzediacetanilide was synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The polyamides were characterized by IR and viscosity measurements. Some of the polyamides showed crystalline behavior in the x-ray diffractograms. The polyamdes have decomposition temperatures in the range 370–310°C in air and are soluble in all amide solvents. The effects of subsituents on crystallinity, thermal stability, and solubility of the polymides are also discussed.