Angewandte Makromolekulare Chemie最新文献

{"title":"Propylene polymerization with metallocene catalysts in industrial processes","authors":"F. Langhauser, J. Kerth, M. Kersting, Patrick Kölle, D. Lilge, P. Müller","doi":"10.1002/APMC.1994.052230111","DOIUrl":"https://doi.org/10.1002/APMC.1994.052230111","url":null,"abstract":"Product demands for polypropylene polymers cover a wide range of properties. Metallocene catalysts open up the way to influence the molecular properties of polypropylene by altering the ligand system of the metallocene complexes. This leads to new products with application properties which are not available with conventional catalysts. Concept are presented to adapt metallocenes to modern, industrial polymerization processes. Some examples illustrate the particular advantages of this new generation of catalysts","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74652306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymersynthesen durch repetitive N‐alkylierungen","authors":"R. C. Schulz, G. Hochberg, F. Walter","doi":"10.1002/APMC.1994.052230113","DOIUrl":"https://doi.org/10.1002/APMC.1994.052230113","url":null,"abstract":"The repetitive N-alkylation reaction, at first used by Marvel, turned out to be a very versatile method for the synthesis of polycations. Rembaum introduced the name ionenes for this type of polymers. In the first part of the lecture some examples of single-stranded ionenes are described. The second part shows how the repetitive N-alkylation can be used for the synthesis of spiro polymers. In these double-stranded polymers two spiro-conjugated rings of the main chain have a central quaternary nitrogen in common (spiro-ionenes or spiro-azonia polymers)","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88503570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alkane als initiatoren zur radikalischen polymerization","authors":"D. Braun","doi":"10.1002/APMC.1994.052230106","DOIUrl":"https://doi.org/10.1002/APMC.1994.052230106","url":null,"abstract":"Alkanes with highly substituted carbon-carbon bonds can be cleaved in free radicals by homolytic dissociation under the influence of thermal energy. The energy of dissociation is mainly determined by the type and size of the respective substituents. For tetraarylbutane dinitriles the temperatures of decomposition are in the range of other technically used initiators. But nevertheless, these compounds are up to now rather seldom used to initiate free radical polymerizations. This is connected with the special mechanism of initiation: the formed highly substituted alkyl radicals are relatively stable and show only a rather low reactivity against the usually used monomers","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90014697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress in synthesis and application of segmented polymers","authors":"R. Mülhaupt, U. Buchholz, J. Rösch, N. Steinhauser","doi":"10.1002/APMC.1994.052230104","DOIUrl":"https://doi.org/10.1002/APMC.1994.052230104","url":null,"abstract":"Selected examples are presented to illustrate basic concepts and recent development in the synthesis and application of segmented polymers. Segmented reactive liquid rubbers, containing an immiscible silicone segment flanked by two miscible oligo(caprolactone) segments, are efficient epoxy toughening agents. In such nano-phase-separated silicone-modified IPNs impact strength is improved without sacrificing dimensional stability. Compatibilized blends of segmented phenolic polyurethane and nitrile liquid rubbers produce rubber blend microphases diepersed in epoxy prepregs which are used to bond aluminum sheets in structural laminates","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81732365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rôle des pigments dans une réaction de polymérisation sous lumière UV-visible","authors":"L. Catilaz, J. Fouassier","doi":"10.1002/APMC.1994.052180107","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180107","url":null,"abstract":"Ce travail sur le roe des pigments definit le comportement d'un nouveau systeme photosensible qui permet de polymeriser des milieux epais et pigmentes selon un procede en une seule etape. Les differentes interactions presentes en milieu pigmente sont decrites de facon qualitative, et la part de l'intensite lumineuse absorbee par un photo-amorceur dans un systeme pigmente est evaluee. Les proprietes optiques telles que l'absorption et la reflectance des differentes familles chimiques de pigments sont determinees, et, en parallele, les proprietes optiques des differentes sources d'irradiation sont etudiees de maniere a repondre au mieux aux fenetres de transmission des pigments. L'effet photocatalytique de certains pigments est mentionne, ceci afin d'amkliorer la reaction de polymerisation. \u0000 \u0000 \u0000 \u0000Das Verhalten eines neuartigen photoinitiierenden Systems, das die Polymerisation von pigmenthaltigen Schichten groser Dicke in einem Reaktionsschritt gestattet, wird dargestellt. Die verschiedenen Wechselwirkungen, die in einem pigmenthaltigen System auftreten, werden qualitativ beschrieben, und der Anteil der von einem Photoinitiator absorbierten Lichtintensitat wird berechnet. Neben dem Absorptions- und Reflexionsverhalten von verschiedenen Pigmentklassen werden die optischen Eigenschaften verschiedener Strahlungsquellen untersucht, um die Strahlungsbereiche zu finden, die am besten mit den optischen Parametern der Pigmente korrespondieren. Weiterhin wird die Beschleunigung von Polymerisationen durch die photokatalytische Wirkung einiger Pigmente behandelt.","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72731332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of styrene content and ZnO-stearic acid on the mechanical properties of radiation-vulcanized styrene-butadiene rubber (SBR)","authors":"H. A. Youssef, M. Aziz, F. Yoshii, K. Makuuchi, A. A. Miligy","doi":"10.1002/APMC.1994.052180102","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180102","url":null,"abstract":"The effect of styrene content on the properties of electron irradiation-vulcanized SBR loaded with carbon black was pronounced only at low irradiation doses where the crosslinking densities were not so high. At high doses, no effect was observed especially for SBR containing ZnO. It was also observed that ZnO (3 phr) increased the tensile strength of SBR containing 23.5 wt.-% styrene by 20% at 20 kGy irradiation dose, compared to 5% at higher doses for SBR containing 46 wt.-% styrene. However, the increase in tensile strength by ZnO for loaded SBR (23.5%) was almost 17% at all irradiation doses. Besides, tear strength, abrasion resistance and elongation at break were remarkably improved. The high efficiency of ZnO toward SBR (23.5%) may be attributed to the higher butadiene content. The behavior of SBR (46%) at 20 kGy was surprising, since both tensile strength and elongation at break were almost maximum. \u0000 \u0000 \u0000 \u0000Der Einflus des Styrolgehalts auf die Eigenschaften von elektronenstrahlvernetztem, rusgefulltem Styrol-Butadien-Kautschuk (SBR) war nur bei niedrigen Strahlungsdosen, d. h. geringen Vernetzungsgraden, ausgepragt. Bei hohen Dosen wurde kein Effekt beobachtet, insbesondere fur ZnO-enthaltenden SBR. Es wurde auserdem festgestellt, das ZnO (3 phr) die Zugfestigkeit von SBR mit einem Styrolgehalt von 23,5 Gew.-% bei 20 kGy um 20% verbesserte, verglichen mit SBR mit 46 Gew.-% Styrol. Die Zunahme der Zugfestigkeit fur gefullten SBR (23,5%) betrug bei allen Strahlungsdosen nahezu 17%. Daneben waren Reisfestigkeit, Abrasionswiderstand und Bruchdehnung erheblich verbessert. Die hohe Effizienz von ZnO bei SBR (23,5%) konnte auf dessen hoheren Butadiengehalt zuruckzufuhren sein. Das mechanische Verhalten von SBR (46%) bei 20 kGy war uberraschend, da sowohl Zugfestigkeit als auch Bruchdehnung nahezu maximal waren.","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79150271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser‐induced surface grafting of 2‐hydroxyethyl methacrylate and N‐vinyl‐2‐pyrrolidone onto ethylene‐propylene rubber as biocompatible material","authors":"H. Mirzadeh, A. Katbab, M. Khorasani, R. Burford","doi":"10.1002/APMC.1994.052180103","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180103","url":null,"abstract":"Attempts have been made to provide hydrophilic sites onto the surface of ethylene-propylene rubber (EPR) by grafting 2-hydroxyethyl methacrylate (HEMA) and N-vinylpyrrolidone (NVP) onto the surface of this elastomer using CO2-pulsed laser as excitation source. The effect of benzophenone (BZP) and azoisobutyronitrile (AIBN) as photosensitizer upon the graft level has been evaluated. CO2-pulsed laser grafting of HEMA and NVP was found to be dependent upon the wavelength, repetition rate, and fluence of laser. Hydrophilicity of EPR increased upon grafting HEMA and NVP with CO2-pulsed laser. Surface characterization has been carried out using attenuated total reflectance infrared spectroscopy (ATR-IR), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). IR-laser grafting of these monomers is not possible unless the system is irradiated by pulses with the wavelength corresponding to the either maximum absorption of monomer or sensitizer accessible to the laser equipment gain. As the absorption of EPR at these wavelengths is quite low, it is believed that depending upon the wavelength, either photosensitizer and/or monomer molecules are excited through an infrared multiphoton excitation (IRMPE) process above the dissociation energy leading to the decomposition of the excited molecules. Addition of a multifunctional acrylate (MFA) such as 1,1,1-trimethylolpropane-trimethacrylate (TMPTA) to the grafting system enhanced the graft yield. Poly(HEMA) grafted onto the surface of EPR by CO2 pulsed laser tends to form a fractal type of morphology. The shape and size of fractals depends upon both laser parameters and HEMA concentration. EDXA analysis showed the presence of ungrafted (hydrophobic areas) as well as hydrophilic sites (fractals) on the surface of modified samples. Finally, the bulk mechanical properties of EPR after being laser-grafted with HEMA or NVP did not change, as shown by DMTA. \u0000 \u0000 \u0000 \u0000Zur Hydrophilisierung der Oberflache wurde Ethylen-Propylen-Kautschuk (EPR)mit 2-Hydroxyethylmethacrylat (HEMA) und N-Vinylpyrrolidon (NVP) unter Verwendung eines gepulsten CO2,-Lasers als Lichtquelle gepfropft. Der Einflus von Benzophenon (BZP) und Azoisobutyronitril (AIBN) als Photosensibilisatoren auf den Pfropfgrad wurde ermittelt. Der Pfropferfolg hongt von der Wellenlange des Laserlichts, der Pulsrate und dem Laserlichtflus ab. Die gepfropften Oberflachen wurden mittels ATR-Infrarotspektroskopie, Rasterelektronenmikroskopie sowie energiedispersiver Riontgenanalyse (EDXA) charakterisiert. Das Pfropfen dieser Monomeren mit IR-Laserlichtanregung ist nur moglich, wenn bei einer Wellenlange gearbeitet wird, die dem Absorptionsmaximum des Monomeren oder des Photosensibilisators entspricht. Da die Absorption von EPR bei diesen Wellenlangen relativ gering ist, wird vermutet, das - abhangig von der Wellenlange - entweder der Photosensibilisator und/oder das Monomere durch einen Infrarot-Multiphoton-Prozes oberhalb der Dissoziationsenerg","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82882063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emulsion polymerization of butyl acrylate, 3. Effect of initiator type and temperature","authors":"Pavol Potisk, I. Capek","doi":"10.1002/APMC.1994.052180105","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180105","url":null,"abstract":"The emulsion polymerizations of butyl acrylate initiated by water-soluble (ammonium peroxodisulfate, AP) and oil-soluble (dibenzoyl peroxide, DBP) radical initiators were investigated. Polymerizations were found to be faster with AP. The size of polymer particles formed and the molecular weights decreased with increasing temperature and increased with conversion. The number of particles was constant in the conversion range from ca. 30 to 100%. The overall activation energy (E0) was found to be ca. 50–60 kJ · mol-1 which is nearly half of that of the bulk polymerization. The activation energy of the AP-initiated polymerization was found to be independent of conversion while that for the DBP-initiated polymerization decreased with conversion, and the decrease was more pronounced beyond 60% conversion. This behavior was discussed in terms of the emulsion and bulk polymerizations and variations of the activation energy for termination with viscosity of the reaction media. \u0000 \u0000 \u0000 \u0000Die Emulsionspolymerisation von Butylacrylat mit zwei unterschiedlichen radikalischen Initiatoren - wasserloslichem Ammoniumperoxodisulfat (AP) bzw. olloslichem Dibenzoylperoxid (DBP) – wurde untersucht. Die Polymerisation lief mit AP schneller ab als mit DBP. Die Grose der gebildeten Polymerteilchen und die Molekulargewichte nahmen mit steigender Temperatur ab und mit steigendem Umsatz zu; die Teilchenzahl blieb zwischen 30 und 100% Umsatz konstant. Die Bruttoaktivierungsenergie (E0) war mit 50–60 kJ/mol nur etwa halb so hoch wie bei der Massepolymerisation. Wahrend die Aktivierungsenergie bei der Polymerisation mit AP unabhangig vom Umsatz war, nahm sie bei der Polymerisation mit DBP mit dem Umsatz ab; bei uber 60% Umsatz war diese Abnahme besonders deutlich. Dieses Verhalten wird bezuglich der Mechanismen von Emulsions- und Massepolymerisation und der Abhangigkeit der Aktivierungsenergie des Kettenabbruchs von der Viskositat des Reaktionsmediums diskutiert.","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88365935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recycling of egyptian bagasse pith wastes in the synthesis of cationic resins","authors":"M. Metwally, N. Metwally, T. Samy","doi":"10.1002/APMC.1994.052180101","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180101","url":null,"abstract":"A series of sulfonated cationic resins have been prepared and characterized from Egyptian bagasse pith wastes (as a source of cheaper and renewable material) with m-cresol and paraformaldehyde as a crosslinking agent. Reaction conditions for the preparation are presented and properties of the synthesized sulfonated bagasse pith-m-cresol-formaldehyde resins are described and compared with resin not containing bagasse pith. The synthesized resins are stable in water, dilute mineral acids (1 M), organic solvents, and to thermal treatment. The resins having a cation exchange capacity up to 2.91 meq g-1 of dry resin, are being introduced as new exchangers. The synthesized resins are used in the study of the possible separation of some bivalent cations. \u0000 \u0000 \u0000 \u0000Eine Reihe sulfonierter kationischer m-Kresol-Paraformaldehyd-Harze wurden aus dem Mark agyptischer Bagasse hergestellt. Reaktionsbedingungen werden angegeben, und die Eigenschaften der hergestellten Bagassemark/m-Kresol/Formaldehyd-Harze werden mit denen von Harzen ohne Bagassemark verglichen. Die synthetisierten Polymere sind stabil in Wasser, verdunnten Mineralsauren (1 M) und organischen Losungsmitteln sowie gegenuber thermischer Behandlung. Die Harze besitzen Kationenaustauscherkapazitaten von bis zu 2,91 meq/g (bezogen auf trockenes Harz) und werden als Austauschermaterialien fur eine mogliche Trennung zweiwertiger Kationen getestet.","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72813323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpenetrating polymer networks of polyurethane and furfuryl alcohol, IIa. Processability and properties of pultruded fiber-reinforced composites","authors":"C. Ma, D. Goang, J. L. Han, K. Hsieh","doi":"10.1002/APMC.1994.052180104","DOIUrl":"https://doi.org/10.1002/APMC.1994.052180104","url":null,"abstract":"A feasibility study of pultrusion of fiber-reinforced polyurethane/furfuryl alcohol (PU/FA) interpenetrating polymer/network IPN composites has been made. From the viscosity study, it was found that the pot life of the PU/FA IPN prepolymers increased with PU content and showed high reactivity at elevated temperature. It was confirmed from the morphological study that the wetting of fibers by the PU/FA IPN resins was improved with PU content. The appearance of the tensile failure surfaces of the pultruded glass fiber-reinforced PU/FA IPN composites showed “hackle patterns” for PU contents below 15 phr. The mechanical property study shows that the tensile strength of pultruded PU/FA IPN composites is the highest when the PU content is 5 phr. However, the flexural strength, flexural modulus and HDT decreased with PU content. The mechanical properties of various fiber-reinforced (glass, carbon, and Kevlar 49 aramid fiber) pultruded PU/FA IPN composites increased with fiber volume content. \u0000 \u0000 \u0000 \u0000Die Herstellung von faserverstarkten interpenetrierenden Netzwerken (IPN) aus Polyurethan (PU) und Furfurylalkohol (FA) mittels Pultrusion wurde untersucht. Wie Viskositatsmessungen zeigen, nimmt die Topfzeit der PU/FA-IPN-Prapolymeren mit steigendem PU-Gehalt zu, und die Reaktivitat ist hoch bei hoheren Temperaturen. Aus morphologischen Untersuchungen geht hervor, das mit steigendem PU-Gehalt die Benetzung der Fasern mit den PU/FA-Harzen verbessert wird. Die bei Zugversuchen erhaltenen Bruchflachen der glasfaserverstarkten PU/FA-IPNs mit PU-Gehalten unter 15 phr zeigen sogenannte “hackle patterns”. Die Zugfestigkeit der pultrudierten PU/FA-IPN-Composite ist bei einem PU-Gehalt von 5 phr am hochsten; Biegefestig-keit, Biegemodul und Warmeformbestandigkeit nehmen jedoch mit zunehmendem PU-Gehalt ab. Die mechanischen Eigenschaften der mit Glas-, Carbon- oder Aramid- fasern (Kevlar 49) verstarkten pultrudierten Composite nahmen mit steigendem Volumenanteil der Fasern zu.","PeriodicalId":7808,"journal":{"name":"Angewandte Makromolekulare Chemie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73480599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}