Fullerene-containing branched polymethacrylates and polymer networks: Synthesis,structure, and properties

Branched poly(methyl methacrylates) containing covalently and noncovalently attached fullerene C₆₀ are synthesized and characterized by IR and UV spectroscopy. The basic physicochemical characteristics of the branched poly(methyl methacrylate) comprising covalently attached fullerene and the non-functionalized branched polymer of the same composition are compared. The effect of fullerene-containing branched poly(methyl methacrylates) on the kinetics of the crosslinking radical polymerization of 1,6-hexanediol dimethacrylate and on the structural-physical (mechanical, thermomechanical, and diffusion-sorption) properties of the resulting polymers is examined. The role of fullerene attached to the branched poly(methyl methacrylate) as an inhibitor of the crosslinking radical polymerization of dimethacrylate and as a modifier of the structure and properties of the polymers is ascertained.     

Novel acyclic and macrocyclic highly unsaturated silahydrocarbons

Two novel silicon-containing acetylenic synthons, 1-[dimethyl(ethynyl)silyl]-2-[ethynyl(methyl)-(vinyl)silyl]ethyne and bis[(ethynyldimethylsilyl)ethynyl](methyl)vinylsilane, were obtained by the reaction of diethynyl(methyl)vinylsilane with ethylmagnesium bromide and ethynylfluorodimethylsilane. The reaction of magnesium derivatives of the products and diethynyl(methyl)vinylsilane with organylhalosilanes gave macrocyclic polyunsaturated silahydrocarbons containing numerous endo- and exocyclic miltiple bonds.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1612–1616.Original Russian Text Copyright © 2004 by O. Yarosh, Zhilitskaya, N. Yarosh, Istomina, Albanov, Chuvashev, Voronkov.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis and characterization of novel ferrocenyl glycidyl ether polymer,ferrocenyl poly (epichlorohydrin) and ferrocenyl poly (glycidyl azide)

Poly (ferrocenyl glycidyl ether) was synthesized by polymerization of 2-[(4-ferrocenylbutoxy)methyl]oxirane (FcEpo) using toluene solution of methylaluminoxane as the catalyst. Copolymerization of 2-[(4-ferrocenylbutoxy)methyl]oxirane with epichlorohydrin was used for the synthesis of another ferrocenyl based poly (epichlorohydrin). Ferrocenyl based poly (glycidyl azide), GAP, was synthesized by treatment of sodium azide with this copolymer in DMF as solvent at room temperature. The synthesized ferrocenyl based polymers were characterized by FT-IR, ¹HNMR, UV–Vis, TGA, DSC and GPC analysis. The UV–Vis spectra of synthesized polymers show the absorption band of ferrocene moiety at about 450 nm. The TGA and DSC analysis show that poly (ferrocenyl glycidyl ether) has good thermal stability. The TGA analysis shows that the copolymerization of 2-[(4-ferrocenylbutoxy)methyl]oxirane with epichlorohydrin improved the thermal stability of the copolymer. The GPC analysis of poly (ferrocenyl glycidyl ether), ferrocenyl based poly (epichlorohydrin) and Ferrocenyl based poly (glycidyl azide) show the PDI between 1.14–1.17. The electrochemical behavior of synthesized polymers was investigated by cyclic voltammetry (CV) measurements. The CV curves of synthesized polymers show good electrochemical performance and there is one redox system with the single-electron reversible reaction that associated with ferrocene moiety in polymers structure. The anodic and cathodic peak currents increased with scan rate confirmed redox reactions in the system are kinetically fast diffusion-controlled reactions.     

High Performance Poly(ether-amide)s Derived from 1,1-Bis[4-(4-carboxy methylene phenoxy)-3-methyl phenyl] Cyclopentane and Aromatic Diamines

A series of new methyl substituted poly(ether-amide)s were synthesized by using direct Yamazaki’s phosphorylative polycondensation of novel diacid 1,1-bis[4-(4-carboxymethyl phenoxy)-3-methylphenyl] cyclopentane (BCMMP) with various aromatic diamines. These polymers were characterized by FTIR spectroscopy. Inherent viscosities of these polymers were in the range 0.25 to 0.42 dL/g indicating moderate molecular weight built-up. These polymers exhibited excellent solubility in various polar aprotic solvents such as NMP, DMSO, DMAc, DMF, pyridine, and were insoluble in THF, DCM and chloroform. X-Ray diffraction pattern of polymers showed that incorporation of methyl substituent on aromatic backbone and cardo cyclopentylidene moiety containing ether linkage and methylene spacer would disturb the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA showed excellent thermal stability of polymers. The glass transition temperature T_g were in the range 195–210°C. The structure-property correlation among this poly(ether-amide)s was studied, in view of these polymer’s potential applications as high performance polymers.     

Polymerization of adsorbed monolayers. III. Preliminary structure studies in dilute solution of the insertion polymers

Insertion poly(methyl acrylate) and poly(methyl methacrylate) were prepared from monomers adsorbed in monolayers on the surface of montmorillonite clay, both in the presence and in the absence of bifunctional crosslinkers (ethylene glycol dimethacrylate and tetramethylene glycol dimethacrylate). The insertion poly(methyl acrylate) and the crosslinked insertion poly(methyl methacrylate) and dilute-solution properties quite different from conventional polymers of these monomers, the differences including high light-scattering molecular weights combined with low viscosities, low values of the second virial coefficient, unusually large variations of the Huggins' constant k′ with the time-temperature history of the solutions, and low sedimentation velocities. These properties suggest that the insertion polymers have compact structures and are consistent with the postulate of sheetlike macromolecules. The dilute-solution properties of insertion poly(methyl methacrylate) made without crosslinker, unlike those of similarly prepared poly(methyl acrylate), were similar to those of conventional poly(methyl methacrylate). This difference in behavior is attributed to the different tendencies of the two monomers to undergo branching or crosslinking during radical polymerization.     

Graft polymers from poly(vinyl chloride) and chlorinated rubber

Graft polymers from poly(vinyl chloride) (PVC) and chlorinated rubber (CIR) with side chains of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), or poly(ethyl methacrylate) (PEMA) were synthesized. For this purpose, a vinyl monomer was polymerized in the presence of small quantities of PVC or CIR with benzoyl peroxide as catalyst. The graft polymers were separated from both homopolymers by precipitation with methanol from methyl ethyl ketone solutions of the reaction products and the grafting efficiency was calculated. The graft polymers were characterized by infrared spectra, elemental analysis, NMR, and osmometric or light-scattering determinations. From the results it is concluded that the PVC or CIR molecules contain side chains of PMMA, PMA, or PEMA. The graft polymers showed higher molecular weights, and the values of second virial coefficient for these polymers were much different from those of the starting polymers.     

Thermal degradation of bromine-containing polymers: Part 11—Blends of poly(2,3-dibromopropyl methacrylate) and poly(2,3-dibromopropyl acrylate) with poly(methyl methacrylate) and poly(methyl acrylate)

The products of degradation of blends of poly(2,3-dibromopropyl methacrylate) and poly(2,3-dibromopropyl acrylate) with poly(methyl methacrylate) and poly(methyl acrylate) are predominantly those to be expected from the degradation of the individual polymers. However, the appearance of methyl bromide and methanol from all four blends indicates that some interaction does occur across the phase boundary between the two constituent polymers. This is presumed to consist of the reaction of hydrogen bromide, formed by decomposition of the brominated polymers with the methyl groups of the acrylate and methacrylate polymers.     

Interaction of inorganic salts with polar polymers. II. Infrared studies of polymer–inorganic nitrate systems

Certain inorganic nitrate salts are quite soluble in the polymers studied, namely, cellulose acetate, poly(vinyl acetate), poly(vinyl alcohol), poly(methyl methacrylate), and poly(methyl acrylate). Large effects upon the glass-transition temperature were observed in those systems where the transition could be readily measured. Large shifts in the infrared spectra of both the inorganic nitrate salts and in the polymer carbonyl and ester ether frequencies have been observed. These observations have been interpreted in terms of complex formation between these polymers and salts in the solid state. The proposed structure of the complex explains the nature of the infrared shifts both for the nitrate salts and the polymers as well as explaining the concentration effects observed. Effects of the solvating environment upon the salt and polymer spectra remain unexplained. The large glass-transition effects are a result of the degree of solubility of the salts in the polymers and the interactions between them. However, the reason why, in some cases, the change in the transition temperature as a function of concentration goes through a maximum is unclear.     

Sorption and swelling of semicrystalline polymers in supercritical CO2

The equilibrium sorption and swelling behavior of four different polymers—poly(methyl methacrylate), poly(tetrafluoroethylene), poly(vinylidene fluoride), and the random copolymer tetrafluoroethylene–perfluoromethylvinylether–in supercritical CO₂—are studied at different temperatures (from 40 to 80 °C) and pressures (up to 200 bar). Swelling is measured by visualization, and sorption through a gravimetric technique. From these data, the behavior of amorphous and semicrystalline polymers can be compared, particularly in terms of partial molar volume of CO₂ in the polymer matrix. Both poly(methyl methacrylate) and the copolymer of tetrafluoroethylene exhibit a behavior typical of rubbery systems. On the contrary, polymers with a considerable degree of crystallinity, such as poly(tetrafluoroethylene) and poly (vinylidene fluoride), show larger values of partial molar volume. These can be related to the limited mobility of the polymer chains in a semicrystalline matrix, which causes the structure to “freeze” during the sorption process into a nonequilibrium state that can differ significantly from the actual thermodynamic equilibrium. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1531–1546, 2006     

Internal motion in some aromatic polyesters and linear aromatic chains

Low-temperature internal motions of the following polyesters have been investigated by broad line nuclear magnetic resonance: poly(methylene terephthalates) (2–6 methylene groups), poly[1,4-(dimethylene)cyclohexylene terephthalate], poly(diethyleneglycol terephthalate), poly(1,2-propylene terephthalate), poly(1,4-phenylene terephthalate), poly(2,2,3,3,4,4-hexafluoropentamethylene terephthalate), poly[1,4-phenylenebis(dimethyl) siloxane], and poly(2,6-dimethylphenylene oxide). No complex line structure was found for any of the samples. Molecular motions in the polyesters appear to be restricted by polar forces arising from the ester groups. Above—196°C. the line width decreases smoothly with increasing temperatures for all polymers except poly[1,4-(dimethylene)cyclohexylene terephthalate] and poly[1,4-phenylenebis(dimethyl)siloxane]. These two show a definite transition in line width at ?20°C. and +12°C., respectively, caused by the onset of considerable internal motion. At ?196°C. the lattices are rigid except for polymers containing methyl groups: poly(1,2-propylene terephthalate), poly[1,4-phenylenebis(dimethyl) siloxane], and poly(2,6-dimethylphenylene oxide). Internal motion that can be ascribed to be a reorientation of the methyl groups is present at ?196°C. for these three polymers, as is demonstrated by comparison of experimental second moments and those calculated on the basis of various models.     

Polymerization from the surface of single-walled carbon nanotubes - preparation and characterization of nanocomposites

Single-walled carbon nanotubes were functionalized along their sidewalls with phenol groups using the 1,3-dipolar cycloaddition reaction. These phenols could be further derivatized with 2-bromoisobutyryl bromide, resulting in the attachment of atom transfer radical polymerization initiators to the sidewalls of the nanotubes. These initiators were found to be active in the polymerization of methyl methacrylate and tert-butyl acrylate from the surface of the nanotubes. However, the polymerizations were not controlled, leading to the production of high molecular weight polymers with relatively large polydispersities. The resulting polymerized nanotubes were analyzed by IR, Raman spectroscopy, DSC, TEM, and AFM. The nanotubes functionalized with poly(methyl methacrylate) were found to be insoluble, while those functionalized with poly(tert-butyl acrylate) were soluble in a variety of organic solvents. The tert-butyl groups of these appended polymers could also be removed to produce nanotubes functionalized with poly(acrylic acid), resulting in structures that are soluble in aqueous solutions.     

Microhardness measurements of poly(methyl methacrylate) and poly(vinylidene fluoride) polyblends

The preparation of polymer blends of poly(methyl methacrylate) and poly(vinylidene fluoride) in different weight percentages is described. Vickers microhardness measurements have been made to study the effects of load and compositional ratio of the two polymers in polyblend. It is observed that poly(vinylidene fluoride) acts as a plasticizer for poly(methyl methacrylate). Evidence of increasing and decreasing strength of polyblends has been obtained for different compositional ratios of the two polymers.     

Temperature-responsive stationary phase utilizing a polymer of proline derivative for hydrophobic interaction chromatography using an aqueous mobile phase

A new method of chromatography is proposed, utilizing a thermo-responsive polymer carrying an amino acid ester residue for the stationary phase of high-performance liquid chromatography (HPLC). We have been investigating the new concept of chromatography, a temperature-responsive chromatography, using temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm)-modified surface for HPLC with a constant aqueous media as the mobile phase. In this study, we designed and synthesized thermo-responsive poly(acryloyl-L-proline methyl ester) and its copolymer with N-isopropylacrylamide (NIPAAm). Homopolymers of acryloyl-L-proline methyl ester and copolymer were prepared by the reaction of radical telomerization. These polymers underwent a reversible phase transition from water-soluble forms into aggregates by changing the temperature, similar to PNIPAAm. The surface properties and functions of stationary phases modified with poly(acryloyl-L-proline methyl ester) were controlled by the external temperature. In the chromatographic system, we separated steroids and amino acids with a variety of hydrophobicities using a sole aqueous mobile phase. In contrast to a PNIPAAm-modified surface, a poly(acryloyl-L-proline methyl ester)-modified surface showed a greater affinity for hydrophobic amino acids.     

Synthesis of homo- amd block copolymer multi-armed methacrylic star polymers by triisobutylaluminium/tert-butlyllithium initiation

Methacrylate star polymers were prepared using the “arm-first” strategy of star polymer formation by the addition of ethylene glycol dimethacrylate to living linear poly(methacrylate) arms synthesised by a trialkylaluminium/alkyllithium initiating system Control over star molar mass is discussed for poly(methyl methacrylate) armed star polymers as is the preparation of star polymers with block copolymer arms.     

Homogeneous and multiphase poly(methyl methacrylate) graft polymers via the macromonomer method

Anionic and group transfer polymerization processes were used to synthesize controlled molecular weight methacryloyloxy functionalized poly(dimethylsiloxane) and poly(methyl methacrylate) macromonomers having a narrow molecular weight distribution and high percent functionality. These macromonomers were anionically copolymerized with methyl methacrylate (MMA) to afford poly(methyl methacrylate)-graft-poly(methyl methacrylate) (PMMA-g-PMMA) and poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) polymers having not only narrow molecular weight distribution graft parts but also backbone parts. The PMMA-g-PDMS system was fractionated using supercritical chlorodifluoromethane to determine its chemical composition distribution (CCD). The CCD for the PMMA-g-PDMS copolymerized in a living manner was substantially more narrow than the free radically copolymerized material. The PMMA-g-PMMA system was used to study the dilute solution properties of branched homopolymers. The appropriateness of the universal calibration gel permeation chromatography (GPC) method for branched systems exhibiting long chain branching was reaffirmed.     

Solubility of carbon dioxide,methane, and propane in silicone polymers: Effect of polymer side chains

The solubility of methane, carbon dioxide, and propane in five silicone polymers was measured at 10.0, 35.0 and 55.0°C and at pressures up to 26 atm. The polymers were poly(dimethyl siloxane), poly(methyl propyl siloxane), poly(methyl octyl siloxane), poly(trifluoropropyl methyl siloxane), and poly(phenyl methyl siloxane). At a given temperature and pressure, the solubility of the penetrant gases decreases with increasing bulkiness of the polymer side chains, and with decreasing critical temperature of the penetrant. The solubility of carbon dioxide in poly(trifluoropropyl methyl siloxane) appears to be anomalously high, possibly because of specific penetrant/polymer interactions. The temperature and pressure dependence of the solubility coefficients for the penetrant/polymer systems studied are described, and different methods of correlating these coefficients are compared.     

Functionalization of polymers prepared by ATRP using radical addition reactions

Low molecular weight linear poly(methyl acrylate), star and hyperbranched polymers were synthesized using atom transfer radical polymerization (ATRP) and end‐functionalized using radical addition reactions. By adding allyltri‐n‐butylstannane at the end of the polymerization of poly(methyl acrylate), the polymer was terminated by allyl groups. When at high conversions of the acrylate monomer, allyl alcohol or 1,2‐epoxy‐5‐hexene, monomers which are not polymerizable by ATRP, were added, alcohol and epoxy functionalities respectively were incorporated at the polymer chain end. Functionalization by radical addition reactions was demonstrated to be applicable to multi‐functional polymers such as hyperbranched and star polymers.     

聚合温度对聚甲基丙烯酸三丁基锡酯等规度的影响(Ⅰ)

本文测定了0—130℃温度范围内,由~(60)Co-γ射线和两种活性不同的引发剂引发聚合的聚甲基丙烯酸三丁基锡酯的等规度。利用~(13)C-NMR测定聚合物分子链的等规度,如预料的那样,以间同立构为主,并随着聚合温度的升高间同立构等规度降低。作者认为影响聚合物等规度的因素主要是取代基的极性效应。计算出的控制等规度的活化能参数与聚甲基丙烯酸甲酯和聚甲基丙烯酸三甲基锡酯的属同一数量级,可相互比较。     

N‐Bromosuccinimide as a thermal iniferter for radical polymerization

N‐Bromosuccinimide (NBS) was used as a thermal iniferter for the initiation of the bulk polymerizations of methyl methacrylate, methyl acrylate, and styrene. The polymerizations showed the characteristics of a living polymerization: both the yields and the molecular weights of the resultant polymers increased linearly as the reaction time increased. The molecular weight distributions of the polymers were 1.42–1.95 under the studied conditions. The resultant polymers could be used as macroiniferters to reinitiate the polymerization of the second monomer. The copolymers poly(methyl methacrylate)‐b‐polystyrene and polystyrene‐b‐poly(methyl methacrylate) were obtained and characterized. End‐group analysis of the resultant poly(methyl methacrylate), poly(methyl acrylate), and polystyrene confirmed that NBS behaved as a thermal iniferter. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2567–2573, 2005     

An Alkenyl Boronate as a Monomer for Radical Polymerizations: Boron as a Guide for Chain Growth and as a Replaceable Side Chain for Post‐Polymerization Transformation

The ability of isopropenyl boronate pinacol ester to serve as a monomer in radical polymerizations was established and exploited for the synthesis of polymers that are difficult to access using other polymerization techniques. Although the monomer exhibits an α‐methyl‐substituted unconjugated structure, which is usually unfavorable for radical propagation, both free and controlled radical polymerizations smoothly afford the corresponding polymers. A density‐functional‐theory‐based investigation revealed that the boron atom moderately stabilizes the radical species, which leads to the suppression of the degradative chain transfer to the α‐methyl groups, and thus guides the reaction towards the radical polymerization. The boronyl pendants, which are directly attached to the polymer backbone, can be replaced with ‐OH or ‐NH₂ to yield poly(α‐methyl vinyl amine) or poly(α‐methyl vinyl alcohol), which has been inaccessible by conventional synthetic methods.