Organometallic polymers. II. Crosslinking of ferrocenylene–methylene-type polymers

Poly(ferrocenylene-methylmethylene) (PFMM) was prepared and subsequently crosslinked by the aid of either 1,1'-bis(α-hydroxyethyl)ferrocene or polyfunctional ferrocene polymers, containing reactive-CH₂OH or-CH(CH₃)OH groups. The thermal behavior of both the primary polymer and the thermoset was investigated. The solubility parameter of PFMM was determined and the degree of crosslinking was studied by solvent swelling and sol fraction measurements. Various thermosetting structural composites were prepared and subjected to mechanical testing.     

Synthesis and characterization of some 2,4′-dibenzyldiisocyanate ionic polymers. V. Ionene polymers

Cationic polyurethanes containing piperazine rings on the macromolecular chain were synthesized by a Menschutkin reaction. A prepolymer with tertiary dimethylamino end groups and a dihalide were used in the first step, and N,N′-dimethylpiperazine in the second step. The viscometric behaviour of dilute solutions in solvents with high dielectrical constants was studied.     

Synthesis and properties of triptycene-based microporous polymers

A series of star triptycene-based porous polymers (STPs) were synthesized from the palladium-catalyzed C–C coupling polymerization of 2, 6, 14-triiodotriptycene. The porous properties of these STPs including surface area, pore size and gas adsorption can be tuned by varying the strut length from ethynylene to phenylene to phenyleneethynylene. As STP-5, they display the BET surface area of 601 m² g⁻¹, and exhibit excellent adsorption ability to hydrogen (1.0 wt% at 1.0 bar/77 K) and carbon dioxide (9.4 wt% at 1.0 bar/273 K).     

Phosphonitrilic chloride: 27. Synthesis and properties of cyclophosphazene polymers

The products of the reaction between dichlorocyclotriphosphazene, (NPCl₂)₃, and 3,3′-diaminobenzidine, (H₂N)₂C₆H₃C₆H₃(NH₂)₂, in pyridine were shown to be amorphous, black coloured solids and slightly soluble in polar organic solvents, but insoluble in non-polar organic solvents. Measurement of the degree of swelling showed that the products were not crosslinked structures. The products were decomposed by heating at relatively low temperatures and by dilute acids and alkalis.     

Biocidal polymers active by contact. V. Synthesis of polysiloxanes with biocidal activity

Polysiloxanes with 3‐(alkyldimethylammonio)propyl pendant groups were synthesized by quaternization of n‐octyldimethylamine or n‐dodecyldimethylamine with linear polysiloxanes containing 3‐chloropropyl groups and/or 3‐bromopropyl groups attached to silicon atoms. The precursor polysiloxanes, poly[(3‐chloropropyl)methylsiloxane] homopolymer and various copolymers containing (3‐halogenopropyl)methylsiloxane and dimethylsiloxane units, were obtained by equilibrium cationic polymerization of linear and cyclic siloxanes with (3‐halogenopropyl)methylsiloxane units. The polysiloxanes bearing quaternary ammonium salts (QAS) showed bactericidal activity against bacteria such as Escherichia coli and Aeromonas hydrophila when incorporated in a polysiloxane network. The activity was retained after 66 days of immersion in water. The QAS‐containing polysiloxanes are also active in aqueous solution. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1005–1012, 2000     

Synthesis and electrochemical properties of new viologen polymers

New polymeric viologens containing tetra-, tri-, or diethylglycol links as 1,1-substituents has been synthesized by the reaction of tosylated ethylglycols with dipyridine in N, N-dimethylformamide (DMF). Thin films of insoluble hexafluorophosphate salts of these polyviologens were examined using electrochemical technique, electrochemical quartz crystal microbalance (EQMB), and atomic force microscopy (AFM). The cyclovoltammetric results show that the composition of the polyviologen determines the kinetics of the redox reactions and the mode of the charge transport through the film. The charge compensation during the reduction process is accomplished by cation insertion, and vice versa during oxidation. However, the EQMB data indicate that some anion insertion during oxidation also takes place. Water movement during the redox processes was observed.     

Synthesis and properties of carbazole-based hyperbranched conjugated polymers

Carbazole-based novel hyperbranched conjugated polymers linked with triphenylamine and benzene moieties were synthesized by Sonogashira coupling polycondensation of N-octadecyl- and N-octyl-3,6-diethynylcarbazoles with tris(4-iodophenyl)amine and 1,3,5-tribromobenzene. Solvent-soluble polymers with number-average molecular weights in the range of 3500-21,000 were obtained in 48-66% yields. The UV-vis absorption bands of the polymers were red-shifted compared to that of carbazole, indicating the extension of conjugation length. The polymers emitted blue-green fluorescence with high quantum yields up to 67% in CHCl₃. Poly(1/3) containing triphenylamine units emits visible light and shows unique solvatochromism. The polymers were electrochemically redox-active.     

Synthesis and properties of xylenyl ether-dimethylsiloxane triblock polymers

Summary Poly(xylenyl ether-dimethylsiloxane) (PXE-PDMS) triblock polymers were successfully prepared by a hydroxyl-silylamine condensation route as potential modifiers for poly(styrene) (PS) and related materials. This synthesis route affords A-B-A triblock polymers where A represents PXE and B poly(dimethylsiloxane). These new copolymers are more versatile than poly(styrene-dimethylsiloxane) block polymers (as poly(styrene) modifiers) since the PXE is miscible with PS at all molecular weights and compositions. These triblock polymers formed unimodal molecular weight distributions, transparent and tough films, and microphase-separated morphologies as determined by a number of techniques.     

Epoxy polymers. V. Dielectric strength

This report deals with material properties which determine dielectric strength rather than phenomena that occur during breakdown. We propose that the determining factors are the same for liquids and polymers. We report dielectric strengths calculated from measured breakdown potentials and sample thicknesses for liquids, ionic solutions, and epoxy polymers doped with ionizable materials. The breakdown field (in liquids and polymers) is hypothesized to be that which generates some critical current density value in the dielectric. The reasons for this value being critical and characteristic of the material are unknown; however, the ionic current density that the measured breakdown field produces can be calculated from the Onsager theory of high-field electrolytic conduction, and this ionic current density is assumed to be the critical threshold quantity involved. Because of field effects on the dissociative ionization and conductivity of electrolytes in organic systems, the breakdown field varies with concentration and solute species, but the ionic current density associated with the breakdown field is essentially constant for a wide range of species and molar concentrations in a given solvent.     

Synthesis, structure and properties of hydrophobically associating polymers

Hydrophobically modified water-soluble polymers have recently become the subject of extensive research because of their use as aqueous viscosity modifiers in oil recovery and latex paint systems. In this study, poly(acrylamide) samples modified with small amounts of a hydrophobic monomer (ethylphenylacrylamide) have been prepared by free radical copolymerization using an aqueous micellar process in which the use of a surfactant ensures the solubilization of the hydrophobe. The copolymers exhibit improved thickening properties with respect to homopoly(acrylamide) analogs due to intennolecular hydrophobic associations. The aqueous solution-copolymer properties strongly depend on the amount of surfactant used in the synthesis. The differences observed between the samples are directly related to the copolymer microstructure, that is to a more or less block distribution of the hydrophobic units. The interactions in aqueous solution of a surfactant (sodium dodecylsulfate (SDS)) with these copolymers have been examined. A strong increase in viscosity is observed upon the addition of SDS below its critical micelle concentration, owing to the formation of mixed micelles of SDS and hydrophobic monomers. The complex rheological behavior observed is explained in terms of the balance between inter and intrachain liaisons. The effects of hydrolysis on the hydrophobic interactions are also discussed.     

Synthesis,structure and properties of liquid crystalline polymers

The following is an extended abstract of a paper presented at the conference on Liquid Crystalline Polymers in Leeds, 1980, summarising the principles of the synthesis of thermotropic liquid crystalline polymers, their structure dependant phase behaviour and their orientation in electric and magnetic fields.     

Phosphonitrilic chloride: 21. Synthesis of chelating polymers with cyclophosphazene thiocarbamate and the properties of chelating polymers

Chelating polymers containing copper, nickel and cobalt have been formed from cyclophosphazene thiocarbamate trimer and copper, nickel or cobalt ions. These polymers obtained from the reaction are amorphous and the values of electron conductivity are $\text{2·7 × 10}{}^{11}\text{Ω-}\text{cm}$, $\text{3·6 × 10}{}^{13}\text{Ω-}\text{cm}$ and $\text{1·5 × 10}{}^{13}\text{Ω-}\text{cm}$ for the Cu, Ni and Co polymers respectively. The Cu polymer is the most thermally stable on heating to 500°C in air.     

Siloxane zwitterions: Synthesis and surface properties of crosslinked polymers

The aminoalkoxysilanes, γ-aminopropyltriethoxysilane and N-aminoethyl-γ-ainopropyl-trimethoxysilane, were chemically modified by ring-opening addition of γ-propanesultone. Surfaces coated with polymers from these new monomers have, at the surface, zwitterionic functions of sulfobetaines which are attached to the polymeric siloxane backbone. They showed good wettability, with critical surface tensions as high as 50 dynes/cm.     

Synthesis and properties of dimesogenic liquid crystalline side group polymers

Summary Liquid crystalline polymalonates with side groups consisting of two different mesogenic units separated by alkylene spacers from each other and from the polyester backbone have been prepared. According to microscopic observations, DSC measurements and X-ray studies, all polymers display smectic phases.     

Synthesis,properties, and practical application of hyperbranched polymers

The methods of synthesis of hyperbranched polymers are considered and systematized with main attention focused on such modern and promising procedures of crosslinking free-radical polymerization as living chain and intense chain transfer regimes. The synthetic approach to hyperbranched polymers via free-radical oxidative polymerization is the first to be put forth. The main problems concerning these polymers are formulated, and the recent advances in this field are generalized and elucidated.     

Synthesis of statistical networks from liquid polybutadiene. V. Synthesis and adhesive properties of 1,2-polybutadiene networks

A series of 1,2-polybutadiene networks was prepared either by endlinking reaction of telechelic liquid precursors or/and by crosslinking with disilyl compounds. Transparent materials were obtained and used as adhesives in glass assembly mainly. The shear resistance at break was found to be higher compared to conventional vulcanized elastomers.     

Synthesis and properties of sulfonated aromatic fluoro‐polymers

Polycondensation of perfluorobiphenyl with α,α‐bis(4‐hydroxyphenyl)ethylbenzene and/or 9,9‐bis(4‐hydroxyphenyl)fluorene was investigated. The polycondensation of perfluorobiphenyl with α,α‐bis(4‐hydroxyphenyl)ethylbenzene and/or 9,9‐bis(4‐hydroxyphenyl)fluorene proceeded at low‐temperature to a give high‐molecular weight and thermal stable polymers. The ¹⁹F‐NMR spectra of the polymers indicate that the polymers consists of predominantly 1,4‐phenylene structure with respect to the perfluoro‐aromatic compound. The sulfonation of the polymers obtained from the polycondensation occurred at the phenyl groups and fluorenyl side chain. A tough and smooth film was prepared by a casting method from DMF solution of the sulfonated polymer. The films showed hydrolytic and oxidative stabilities, and a high‐proton conductivity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

新型对称性两亲含硅聚合物的合成与界面性能

基于原子转移自由基聚合(ATRP)机理,以二甲基一氯硅烷封端的烯丙基-聚乙二醇为起始剂,甲基丙烯酸乙酯(EMA)为单体,通过控制反应温度,合成了一系列聚合度(DP_(NMR))分别为0. 74,1. 67和3. 07的新型对称性两亲含硅共聚物(PEMA-b-Si-PEG-Si-b-PEMA),并评价了该共聚物在氯仿/水界面的界面活性和吸附行为。结果表明:该类聚合物可以有效降低氯仿/水界面张力,具有最短PEMA链的聚合物可将氯仿/水界面张力从32 m N/m降低至约23 m N/m。动态界面张力分析表明:低浓度的共聚物在吸附的初始阶段符合扩散控制,且较短的PEMA链段有利于产生较快的扩散速率。平衡界面张力分析表明:随着界面浓度的增加,共聚物将表现出多种吸附状态,其吸附状态的数量以及聚合物在界面的偏摩尔面积将随着PEMA链长度的增加而增加。     

Synthesis, characterization, and properties of novel phenylene-silazane-acetylene polymers

New phenylene-silazane-acetylene polymers, P1 and P2, have been synthesized using Sonogashira cross-coupling reactions with a new designed ethynyl-ended silylenediamine, N,N′-bis(4-ethynylphenyl)-1,1-diphenylsilylenediamine (1), as the key monomer. This also represents the first example that construction of polymers containing silazane unit with Sonogashira coupling reaction. The structures of monomer and polymers were well characterized. Their thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Both polymers had good thermal stability with their temperatures at 5% weight loss (T_d5) being higher than 394 °C under nitrogen and higher than 385 °C in air, respectively. Their char yields at 1000 °C under N₂ were above 70%. The fundamental photophysical properties in solution were also investigated. Both polymers showed fluorescence in ultraviolet region with moderate quantum yields. These polymers had potential to be used as high-temperature resistant resins and light-emitting materials with good thermal stability.