摘要:

AbstractDental cement compositions made by mixing poly(acrylic acid‐co‐acrylamide) and mixtures of zinc oxide and cryolite (Na3AIF6) in various proportions of 10–50 wt.‐% (w/w) were cured at room temperature. From thermogravimetric analyses of the samples, the integral procedural decomposition temperatures (IPDT), maximum decomposition temperatures, activation energies and frequency factors were evaluated. The cured cement sample containing 20 wt.‐% cryolite in the filler mixture is thermally ve

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240111

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractStarting from 2,4,6‐triiodophenol, 2,3,5‐triiodobenzoic acid and 3,5‐bis(acetylamino)‐2,4,6‐triiodobenzoic acid, polymerizable methacrylates were synthesized and characterized by elemental analyses, IR,1H‐NMR and13C‐NMR spectroscopy. The iodine‐containing methacrylates show a different radical polymerization behaviour. 2,4,6‐Triiodophenyl methacrylate gives only oligomeric products in the presence of azoisobutyronitrile (AIBN), whereas 2‐methacryloyloxyethyl 2,3,5‐triiodobenzoate yields polymers. On the basis of mixtures of isomeric 1,3‐dimethacryloyloxy‐2‐ and 1,2‐dimethacryloyloxy‐3‐(2,3,5‐triiodobenzoyloxy)propane with usual crosslinking monomers,

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240112

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractDie radikalische Addition von 1‐Octanthiol oder 3‐(Trimethoxysily)‐1‐propanthiol an die 1,2‐ bzw. 1,4‐cis‐Doppelbindungen des Polybutadiens erfolgt redox‐induziert mit Dibenzoylperoxid (DBPO) bei Raumtemperatur ohne nachweisbare Nebenreaktionen. Trans‐konfigurierte Doppelbindungen reagieren unter gleichen Bedingungen nicht. Die Molmassenverteilung der Additionsprodukte ist ähnlich eng wie die des re

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240113

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractWater soluble aromatic diazonium double salts, p‐diazodiphenylamine chloride zinc chloride (DZS‐1) and p‐diazoanisol chloride zinc chloride (DZS‐2), have been evaluated as photobleachable dyes for contrast enhancement lithography. After testing the bleaching characteristics, aqueous solutions of DZS‐1 and poly(vinyl alcohol) were used as a contrast enhancement material. Thermal stability, resist contrast, exposure parameters and other bleaching characteristics of the photobleachable membranes were investigated. A. commercial i‐line photoresist was used to evaluate the contrast ratio of the DZS‐1/PVA CEL layer. The contrast ratio obtained in this investig

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240114

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractBlock copolymers of styrene and methyl methacrylate (MMA) were prepared in a two‐stage free‐radical polymerization by means of an azo‐acyloxime ester (AOE) initiator. In the first stage, photosensitive styrene prepolymers were synthesized by using AOE initiator. These polymers were photolysed in the presence of MMA in the second stage to form block copolymers. The block copolymer structure was elucidated by means of extraction by appropriate solvents, GPC analysis and IR and NMR spectral measure

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240115

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractNew poly(oxyethylene) derivatives (S‐betaine) having a zwitterionic structure of ammoniumsulfonate were prepared by the reaction of oxirane (EO) adducts of stearylamine with sodium chloromethanesulfonate and examined as blending antistatic modifiers for poly(ethylene terephthalate) (PET) and polyamide 6 (PA6) fibers. The blend PET and PA6 fibers containing 2.0 wt.‐% of S‐betaine exhibited a decreased half‐life time of leakage of electrostatic charge (t1/2) and a surface area resistivity (Rs) compared with those of the control PET and PA6 fibers. However, their antistatic properties were almost lost after repeated washings, because of the extraction of the agents. To increase the resistivity to washing, copolyester‐type modifiers comprising both S‐betaine and poly(ethylene glycol) were synthesized and incorporated into PET fibers. It was found that the antistatic properties of the blend PET fibers obtained can be retained even after dyeing and repeat

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240116

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractMethylene‐4,4′‐diphenyldiisocyanate and two different bisoxazolines were used for coupling reactions in carboxy‐terminated liquid crystalline poly(ethylene terephthalate‐co‐oxybenzoate). In order to guarantee defined conditions, copolyesters with different carboxylic group concentrations were synthesized. The determination of the carboxylic group content is described.The coupling behaviour of both types of chain extenders has been compared. It was evidenced that the bisoxazolines reacted significantly faster than the diisocyanate. A slight excess of bisoxazoline in the reaction mixture prevented thermomechanical degradation. Depending on the amount of coupling agent added, an oxazoline termination of the copolyester was observed. Additionally, probable crosslinking reactions and the thermal stability have bee

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240117

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe mechanical degradation by high‐speed stirring of cellulose in dilute n‐butanol suspensions was investigated on six different samples with degrees of polymerization (DP) between 300 and 7500. The degrees of polymerization were determined viscosimetrically in CuEn (copper ethylendiamine complex) at different times of mechanical action. The distributions of the DP were measured on the polymer‐analogous nitrates by size exclusion chromatography (HPSEC) in THF.The investigations reveal that only high‐molecular‐weight cellulose undergoes degradation, whereas celluloses with a starting DP0<3000 remain undegraded. In the case of degradation the decrease of the DP with time is exponential, reaching a “limiting” DP (DP∞) of about 3200 which does not diminish further.The narrowing with degradation time of the distributions of DP of the degraded samples allows to assume that the bonds splitting by the action of mechanical forces are the so‐called “weak links” present in high‐molecular‐weight cellulose. The course of the nonuniformity U with decreasing DP, could be confirmed by mathematical derivation of the relationship between U and the degree of degradation DP0/DPt, considering the scis

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240118

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractBei flüssigkristallinen Hauptkettenpolyestern aus Hydrochinon‐ und Terephthalsäurederivaten lassen sich die Schmelztemperaturen durch “Anheften” von flexiblen Seitenketten und raumfüllenden Gruppen stark absenken. Poly(2′‐phenyl‐1′,4′‐phenylen‐2,5‐dihexyloxyterephthalat) liegt im festen Zustand sogar amorph vor; die Glasübergangstemperatur beträgt 47°C, der Phasenübergang zur isotropen Schmelze erfolgt bei 184°C. Neben tiefen Phasenübergangstemperaturen zeichnet sich dieser Polyester durch eine gute Löslichkeit in Toluol und THF aus. Bis zu 40 mol‐% der 2,5‐Dihexyloxyterephthalsäre lassen sich durch unsubstituierte Terephthalsäure ersetzen, ohne die Phasenübergangstemperaturen und die Löslichkeit des Polyesters wesentlich zu beeinflussen. Der Copolyester mit 40 mol‐% Terephthalsäure zeigt im Zugversuch

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240119

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0003-3146    

DOI:10.1002/apmc.1995.052240120

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY