摘要:

AbstractImportant advances have been made in controlled radical polymerization, particularly in the application of the new technique for the preparation of novel block copolymers. CO‐copolymers are becoming increasingly popular. Increasing research efforts are also being devoted to discrete supermolecular structures as well as the preparation of nanometer‐size noble metal clusters in polymer matrices. MALDI‐TOF continues its triumph in synthetic polymer chem

ISSN:0323-7648    

DOI:10.1002/actp.1997.010480401

出版商:Akademie Verlag GmbH    

年代:1997

数据来源: WILEY

ISSN:0323-7648    

DOI:10.1002/actp.1997.010480402

出版商:Akademie Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractCrosslinked poly(styrene)‐poly(dimethylsiloxane)‐cyclodextrin systems are a new class of multicomponent polymer networks. They are prepared by swelling a polystyrene gel (PS) with the components of the poly(dimethylsiloxane)‐cyclodextrin network (PDMS(CDX)) and subsequent crosslinking. Electron spectroscopic imaging and elemental mapping are appropriate methods for the investigation of these polymer systems, which contain heteroatoms in one of their components. It is shown that PDMS(CDX) is uniformly distributed within PS. Interpenetration with PS is responsible for the stable anchoring of PDMS(CDX) and prevents phase separ

ISSN:0323-7648    

DOI:10.1002/actp.1997.010480403

出版商:Akademie Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe morphology and electron diffraction patterns of sheared films of a series of aliphatic‐aromatic poly(azomethine ethers) withn= 1,4 and 7–10 CH2units in the aliphatic segment have been characterized by transmission electron microscopy. The films were prepared by shearing in the liquid crystalline (nematic) state. In all cases, lamellae ca. 400 Å thick and more or less perpendicular to the shear direction and perpendicular to the substrate were obtained. Annealing increases the lamellar thickness and overall order. Redrawing of annealed, sheared samples ofn= 10 suggests they consist of chain folded lamellae. Electron diffraction (ED) yieldedh0lsingle crystal patterns in all cases, except forn= 1, which yielded orthorhombic, fiber‐like patterns. Theh0lpatterns suggest a planar, single crystal orientation over the entire sample. Annealing sheared samples above the crystal‐liquid crystal transition temperature resulted in reorientation of the molecules (from parallel to perpendicular) with respect to the substrate. ED patterns changed accordingly fromh0ltohk0. Sheared samples withn= 4 gave both orthorhombic and monoclinic diffraction

ISSN:0323-7648    

DOI:10.1002/actp.1997.010480404

出版商:Akademie Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractPoly(methacrylic acid) (PMA) and poly(acrylamide) (PAAm) with a small mole fraction of naphthol (NpOH) residues were prepared by polymerization of methacrylic acid or acrylamide with three position isomers, methacryloylaminonaphthol. The substituent effect on the apparent pKvalues (pKobsd), determined by spectroscopic pH titrations in aqueous solution, was observed for the NpOH‐labeled PAAm. The electrostatic surface potential (ψ) for PMA was calculated from the difference in the pKobsdvalues for the labeled PMA and PAAm. The obtained ψ value decreased as the spacing between the OH moiety and the polymer main chain increased. This clearly indicates that the ψ value is a sensitive function of the distance from the polyion sur

ISSN:0323-7648    

DOI:10.1002/actp.1997.010480405

出版商:Akademie Verlag GmbH    

年代:1997

数据来源: WILEY