Macromolecular Chemistry and Physics

Transcription

1 Contents 2383 Macromolecular Chemistry and Physics Articles published on the web will appear several weeks before the print edition. They are available through: Cover: Surface-constrained foaming of poly(ferrocenylsilane) ceramic precursor films with supercritical CO 2 yields tunable microcellular foams that exhibit conventional isotropic pore cells (inset), as well as anisotropic pore cells that elongate and orient along preferred diffusion pathways. Further details can be found in the Full Paper by D. J. Frankowski, S. Fournier-Bidoz, I. Manners,* G. A. Ozin, S. A. Khan, and R. J. Spontak* on page Full Paper: Cyclodi(ethylene succinate) (C2) was reacted with poly(ethylene terephthalate) (PET) in the molten state, yielding high molar mass random or block PET-copoly(ethylene succinate). These copolyesters exhibit higher melting temperatures and crystallinity than conventional PET-aliphatic polyester copolymers. The method provides a way of chemically recycling PET into degradable aliphatic-aromatic polyesters. Synthesis of Aliphatic-Aromatic Copolyesters by a High Temperature Bulk Reaction Between Poly(ethylene terephthalate) and Cyclodi(ethylene succinate) S. Salhi, M. Tessier, J.-C. Blais, R. El Gharbi, A. Fradet* Macromol. Chem. Phys. 2004, 205, Full Paper: Exposure of poly(ferrocenylsilane)s, organometallic ceramic precursors, to supercritical CO 2 under surface constraints yields microcellular polymeric foams with submicron cell sizes. Curvature in the films and inherent surface roughness create paths that facilitate CO 2 diffusion, resulting in the formation of highly elongated or V-directional cells oriented obliquely to the film surface (see Figure). These results are prerequisite for the production of magnetically-active porous ceramics from pyrolyzed poly(ferrocenylsilane) foams. Tunable Microcellular Morphologies from Poly(ferrocenylsilane) Ceramic Precursors Foamed in Supercritical CO 2 D. J. Frankowski, S. Fournier-Bidoz, I. Manners,* G. A. Ozin, S. A. Khan, R. J. Spontak* Macromol. Chem. Phys. 2004, 205,

2 2384 Contents Full Paper: Reverse-selective polymer membranes exhibiting high CO 2 affinity can be used for purification of H 2 in industrial gasification processes. In this work, the physical properties of CO 2 -selective membranes composed of various poly(ethylene glycol) diacrylate (PEGda) compositions containing nanocomposites are reported. PEGda oligomers were exposed to CO 2 at different pressures to elucidate the roles of CO 2 pressure, network topology and nanoparticle aggregation on molecular transport and solubility. Results from swelling and sorption kinetics confirm that both penetrant diffusivity and solubility increase with increasing PEGda chain length and decreasing network density. Effects of Pressure and Nanoparticle Functionality on CO 2 -Selective Nanocomposites Derived from Crosslinked Poly(ethylene glycol) N. P. Patel, J. M. Zielinski, J. Samseth, R. J. Spontak* Macromol. Chem. Phys. 2004, 205, Full Paper: New thermoplastic elastomers (TPE) were prepared by a two step polycondensation reaction between a,o-dichlorosilane fluorinated polyimides and a,odisilanol-polyhybridsiloxanes. This method of polymerization leads to the preparation of high molecular weight alternating block copolymers. The surface tension of the resulting copolymers depends exclusively on the content of the siloxane moiety. The thermomechanical analyses showed three different behaviors depending on the molecular weight of each precursor: a partial miscibility of the siloxane group into the imide block, a totally miscible phase and a behavior of the TPE block, where the difference between the lower and upper T g reaches 320 8C. This difference leads to a high temperature range of use for these new materials. The thermal stability of all the block copolymers is very good both in air and in nitrogen. A weight loss of 10% is observed at 400 8C in nitrogen. New Fluorinated Thermoplastic Elastomers, 4 Synthesis and Characterization of Alternating Fluorinated Polyimide- Polyhybridsiloxane Block Copolymers Prepared via Polycondensation S. Andre, F. Guida-Pietrasanta, A. Rousseau,* B. Boutevin, G. Caporiccio Macromol. Chem. Phys. 2004, 205, Full Paper: Random copolymers containingmethylmethacrylate, butylmethacrylate and allyl methacrylate were synthesized via atom transfer radical polymerization. The random copolymers obtained are linear and soluble in organic solvents. They were characterized by means of NMR and GPC (see Figure) and were crosslinked photochemically. Kinetic studies have shown that with increasing temperature, conversion, and content of allyl methacrylate an increase of side reactions is observed. ATRP of Allyl Methacrylate with Alkyl Methacrylates Crosslinking of Poly(methacrylate)s with Allyl Ester Side Groups M. Mennicken, R. Nagelsdiek, H. Keul,* H. Höcker Macromol. Chem. Phys. 2004, 205,

3 Contents 2385 Full Paper: The first completely linear unsaturated polyamides are synthesized in which there are no aromatic or pendant groups present to produce the double bonds. These nylons contain an extremely low amide density compared to those commercially available. The Figure shows DSC heating and cooling thermograms for nylons 6 u18 and 18 u18. Linear Unsaturated Polyamides: Nylons 6 u18 and 18 u18 C. Bennett, L. J. Mathias* Macromol. Chem. Phys. 2004, 205, Full Paper: Polymer brushes have been formed at the mica-toluene interface by self-assembly of polystyrene chains with sulfozwitterionic end-groups that are physically attracted to the interface. We vary the number of such groups on the end of each chain, and use the surface force balance (SFB) to examine the effect on the brush. Interactions Between Polymer Brushes: Varying the Number of End-Attaching Groups I. E. Dunlop, W. H. Briscoe, S. Titmuss, G. Sakellariou, N. Hadjichristidis, J. Klein* Macromol. Chem. Phys. 2004, 205, Full Paper: A new kind of degradable gel was synthesized by the copolymerization of vinyl sorbate (VS) with molecular oxygen via a conventional radical copolymerization process. A soluble polymer was produced at a low conversion, and the ratio of gel fraction increased with an increase in the conversion. The degree of crosslinking as well as the degradation behavior was easily controlled by a change in the monomer concentration. Thermal degradation properties of the gels and the other kinds of degradation by various stimuli were investigated. Facile Synthesis of a Degradable Gel by Radical Copolymerization of Vinyl Sorbate and Molecular Oxygen S. Taketani, A. Matsumoto* Macromol. Chem. Phys. 2004, 205, Full Paper: Amphiphilic AB, ABA and BAB block copolymers, in which thermo-responsive poly(methyl vinyl ether) has been combined with poly(isobutyl vinyl ether) or poly(octadecyl vinyl ether), show high stabilization activity for aqueous dispersions of the hydrophobic organic pigments copper phthalocyanine and carbon black. The optimal colloidal stabilization with the BAB copolymers is ascribed to the formation of a stable bilayer structure (see Figure). The stabilizing properties are lost above the phase demixing temperature of the PMVE-blocks, which opens possibilities for the design of colloidal systems with temperature-adjustable stability and wetting properties. Block Copolymers of Vinyl Ethers as Thermo-Responsive Colloidal Stabilizers of Organic Pigments in Aqueous Media N. A. Bulychev, I. A. Arutunov, V. P. Zubov, B. Verdonck, T. Zhang, E. J. Goethals, F. E. Du Prez* Macromol. Chem. Phys. 2004, 205,

4 2386 Contents Full Paper: Solution properties and interpolyelectrolyte complex formation ability of a series of alternating polyampholytes based on N,N-dimethyldiallylammonium chloride are reported. The copolymers exhibit ampholytic, polyelectrolytic, and amphiphilic character as a function of copolymer composition, ph, ionic strength, water ethanol mixture composition (see Scheme), and hydrophobicity of the acid monomer. Replacement of the intraionic contacts by interionic ones is responsible for formation of water-soluble complex particles between polyampholytes and anionic polyelectrolytes including surfactant. Solution Properties and Complexation of Polyampholytes based on N,N-Dimethyldiallylammonium Chloride and Maleic Acid or Alkyl (Aryl) Derivatives of Maleamic Acids Z. E. Ibraeva, M. Hahn, W. Jaeger, L. A. Bimendina, S. E. Kudaibergenov* Macromol. Chem. Phys. 2004, 205, Full Paper: The thermal behaviour of poly(propylene terephthalate) (PPT) modified with 2,2-bis[4-(ethylenoxy)-1,4-phenylene]propane terephthalate) (BHEEBT) units was investigated by thermogravimetric analysis, differential scanning calorimetry and optical microscopy. The presence of BHEEBT units along the PPT chain was found to significantlyaffectitsthermalproperties.inparticular, the glass transition temperature showed a monotonic increment, the overall crystallisation rate decreased and the interphase fraction increased as the amount of BHEEBT units was increased. The Figure shows calorimetric curves of PPT, PBHEEBT homopolymers and their random copolymers after melt quenching. Poly(propylene terephthalate) Modified with 2,2-Bis[4-(ethylenoxy)-1,4-phenylene] propane terephthalate) Units: Thermal Behaviour, Crystallisation Kinetics and Morphology C. Berti, M. Colonna, L. Finelli, C. Lorenzetti, N. Lotti,* M. Vannini Macromol. Chem. Phys. 2004, 205, Full Paper: The crystallization process of PET in PET/PC block copolymers is analyzed as a function of the PET block length. The copolymers present slow crystallization rate, that relatively increases with the molecular weight of the PET blocks. It is noteworthy that the analogous PET homopolymers, instead, show a maximum in the crystallization rate as a function of the molecular weight. This different behavior is particularly interesting and is attributed to the presence of PC in copolymers and to the potential miscibility between PETand PC. It is shown that the block length and the miscibility between PETand PC are key parameters to understand the crystallization process in PET/PC copolymers. Crystallization of Poly(ethylene terephthalate) in Poly(ethylene terephthalate)/bisphenol A Polycarbonate Block Copolymers: Influence of Block Length and Role of the Rubbery Amorphous Component A. Celli,* P. Marchese Macromol. Chem. Phys. 2004, 205, Macromolecular News: Short Portrait of Prof. Dr. Oskar Nuyken on the Occasion of his 65 th Birthday Macromol. Chem. Phys. 2004, 205, Book Review Macromol. Chem. Phys. 2004, 205, 2499 Author Index 2004, 205 Macromol. Chem. Phys. 2004, 205,

5 Contents 2387 Author Index Andre, S Arutunov, I. A Bennett, C Berti, C Bimendina, L. A Blais, J.-C Boutevin, B Briscoe, W. H Bulychev, N. A Caporiccio, G Celli, A Colonna, M Du Prez, F. E Dunlop, I. E El Gharbi, R Finelli, L Fournier-Bidoz, S Fradet, A Frankowski, D. J Fraser, C. L Goethals, E. J Guida-Pietrasanta, F Höcker, H Hadjichristidis, N Hahn, M Ibraeva, Z. E Jaeger, W Keul, H Khan, S. A Klein, J Kudaibergenov, S. E Lorenzetti, C Lotti, N Manners, I Marchese, P Mathias, L. J Matsumoto, A Mennicken, M Nagelsdiek, R Ozin, G. A Patel, N. P Rousseau, A Sakellariou, G Salhi, S Samseth, J Spontak, R. J , 2409 Taketani, S Tessier, M Titmuss, S Vannini, M Verdonck, B Voit, B. I Zhang, T Zielinski, J. M Zubov, V. P Access Macromolecular Chemistry and Physics from your desktop. The journal is available through Wiley InterScience at Articles are published online days or even weeks before the printed issues are mailed, through Wiley InterScience s EarlyView 1 service. A full rate subscription entitles users to online access to full text plus access to the tables of contents and abstracts of hundreds of other Wiley journals. Speak to your librarian or visit the site for full details. Society members, please contact your society about online access to the journal.