摘要:

AbstractThe particle nucleation processes involved in the microemulsion polymerizations of styrene and methyl methacrylate have been investigated using pyrene fluorescence intensity measurements as a function of conversion. Very distinctive differences were observed between the results for the two different monomers. The styrene fluorescence results were consistent with nucleation occurring within the microemulsion droplets, followed by the subsequent heterocoagulation of the nucleated particles with remaining droplets. The very different methyl methacrylate data were consistent with a homogeneous nucleation mechanism.

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171201

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe monomer 2,5‐diaminobenzenesulfonic acid has been polymerized to a high molecular weight, conjugated main chain azo polymer. The presence of the azo group in the polymer was confirmed using Raman spectroscopy. The polymer is highly soluble in water over a wide pH range. It is also soluble in common polar organic solvents such asN,N‐dimethylformamide, dimethyl sulfoxide andN‐methyl‐2‐py

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171202

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThis report describes the synthesis of a water soluble polyaniline through a biochemical synthetic route. The oxidative free radical coupling mechanism for the synthesis of poly(p‐aminobenzoic acid) is catalyzed by horseradish peroxidase in the presence of hydrogen peroxide. The resulting polymer is electrochemically active and undergoes reversible redox reactions. The polymer as synthesized is self doped and undergoes undoping in alkaline or ammonia solution

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171203

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractLiving ring‐opening polymerization of the cyclic carbonate 1,3‐dioxepan‐2‐one was achieved by using the cationic zirconocene complex [Cp2ZrMe]+[B(C6F5)4]−as catalyst at room temperature. A linear relation between conversion and molecular weight of the obtained polymer was observed. Furthermore, block copolymerization of the cyclic carbonate and ε‐caprolactone was successful

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171204

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe catalytic activity of bovine serum albumin (BSA) modified physically by molecular imprinting using transition‐state analogue (TSA) as a template molecule was studied. The resultant imprinted serum albumin (Imp‐BSA) showed the rate acceleration of dehydrofluorination reaction from (4R,4S)‐4‐fluoro‐4‐(4‐nitrophenyl)butan‐2‐one (1) and followed the type of Michaelis‐Menten reaction in ethyl acetate solution. The enzymatic activity of Imp‐BSA was competitively inhibited by (4R,4S)‐4‐hydroxy‐4‐(

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171205

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractCore‐shell latexes with a core of poly(buty1 acrylate) (PBuA) and a shell of poly(methyl methacrylate) were studied by solid‐state nuclear magnetic resonance (NMR) methods at different temperatures.13C cross polarization/magic angle spinning spectra show differences in mobility in the mobile PBuA phase. In spin‐diffusion experiments the sensitivity of the NMR parameters towards the interphase structure and towards the entire core‐shell structure changes with varying temperature. For an efficient characterization of interphase structures in core‐shell systems the measuring temperature has to be optimized, i.e. the mobility gradient between the two phases within the particle must be sufficiently high to allow for effective selection by the dipolar filter. Yet, the spin diffusion coefficient of the mobile component should be high enough to allow quantitative evaluation of length scales. It is shown that a measuring temperature of about 60–70 K above the glass transition temperature of the mobile component represents an optimum for fulfilling the different requirements sim

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171206

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractMethacryloyl endfunctionalized oligostyrene macromonomers were characterized by matrix assisted laser desorption ionization/time of flight (MALDI‐TOF) spectroscopy and by isocratic and gradient high performance liquid chromatography (HPLC). The molar mass distribution derived by the different techniques coincide for the investigated oligomers. Mixing experiments revealed that the MALDI‐TOF peak areas do not necessarily represent the mixing ratio of the components. Combination of gradient HPLC and MALDI‐TOF has resolved the chemical composition of the coupling products formed by reaction of the living anion with o

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171207

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractAromatic polyamides were prepared by an AlCl3or HCl‐catalyzed polymerization of toluene diisocyanate or methylenebis(phenyl isocyanate) with adipic acid at low temperatures (≤100°C) in a short reaction time (3–4 h). The intrinsic viscosity of the polymers was approximately 1.1 dL/g as determined at 25°C withm‐cresol as solvent, indicating that the polyamides obtained by this method have relatively high molecular weights. The polymers exhibit high glass transition temperatures and good thermal

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171208

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractSoluble poly(2,5‐dialkoxy‐1,4‐phenylenevinylene) has been preparedviaStille coupling reaction between 2,5‐dialkoxy‐1,4‐diiodobenzene andE‐1,2‐bis(tributylstannyl)‐ethene in the presence of palladium complexes. Characterization of this material by means of1H and13C nuclear magnetic resonance (NMR), ultraviolet/visible (UV/VIS) and infrared (IR) spectra is described. Molecular weights, determined by means of gelpermeation chromatography (GPC) analysis and referred to standard polystyrene, were in the range number‐average molecular weightsMn= 2061–2544 and weight‐average molecular weightsMw= 3347–3878. X‐ray diffraction (XRD) analysis of the polymer showed semicrystalline structure.Tg= 57°C, transition to a stable smectic mesophase at 115°C and clearing point at 210°C were revealed by differential scanning calorimetry analysis, optical microscopy observation a

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171209

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

ISSN:1022-1336    

DOI:10.1002/marc.1996.030171210

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY