摘要:

AbstractVon Polyethylenterephthalat (PETP)‐Multifilamentgarnen mit unterschiedlicher thermischer Vorgeschichte wurden Kraft‐Dehnungs‐Kurven mit den Dehngeschwindigkeiten 0,1 bis 100 000%/s ermittelt. Diese lassen sich zu Relaxations‐ und Retardationskurven über sieben Zeitdekaden umrechnen. Durch Superponieren von Relaxationsfunktionen für unterschiedliche Dehnungen bzw. Retardationsfunktionen für unterschiedliche Fadenzugspannungen werden Relaxations‐ und Retardationsfunktionen bis 21 bzw. 13 Zeitdekaden bestimmt, die sich in vier Bereiche unterteilen lassen, denen folgende Strukturveränderungen zugeordnet werden können:Bereich 1: sofort erholbare, quasielastische Deformation mit Relaxationszeiten kleiner 1 bis 10 s,Bereich 2: irreversible Deformation, Verfestigung, mit Relaxationszeiten zwischen 10 und 105s,Bereich 3: elastisches Verhalten des physikalischen Netzwerkes mit Relaxationszeiten zwischen 105und 107s undBereich 4: Umbau und Zerstörung des Netzwerkes mit Relaxationszeiten zwisch

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690101

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractInterferenzmikroskopische Messungen eines PETP‐Monofilamentgarns zeigen, daß die Orientierung des schon hoch vororientierten Materials durch Dehnen und wieder Entspannen abnimmt, langsame Verformung wirkt dabei stärker desorientierend auf das Material als eine schnelle Verformung. Die Packungsdichte nimmt durch Dehnen ab. Die größte Dehngeschwindigkeit bewirkt die größte Abnahme.Ein mit der Dehngeschwindigkeit ϵ = 104%/s gedehntes Monofilament zeigt interferenzmikroskopisch sichtbare „Crazes”︁. Diese „Crazes”︁ sind keine Risse, sondern nur rißförmige Orte verminderter Orientierung. Für kleinere Dehngeschwindigkeiten ist interferenzmikroskopisch Unsymmetrie der Orientierung sichtbar. DTA‐Kurven von PETP‐Fasern zeigen zwischen 30 und 80°C einen exothermen Peak, der spezifischen Strukturen der fehlgeordneten Bereiche zugeordnet werden kann. Bei niedrigen Dehngeschwindigkeiten verlagert sich dieser Peak zu niedrigeren Temperaturen. Durch Lagern des Materials kehrt er zur ursprünglichen Temperaturlage zurück. Für schnell deformiertes Material ändert dieser

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690102

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractMelt rheological studies of nylon 6/polyethylene terephthalate (PETP) blends (PETP content varying from 10 to 50%) were carried out using capillary rheometer in the shear rate range of 58 s−1to 1.15 · 103s−1. With increasing PETP content in the blend a decrease of the melt viscosity as well as non‐Newtonian behaviour was observed. The model equation developed by Uemura and Takayanagi for viscoelastic melt blends has been used to understand the state of dispersion and morphology of a nylon 6/PETP blend system. Further, an inverse relationship between polymer melt viscosity (η) and elastic modulus (E') of fibres was o

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690103

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractThe mechanism of action of an antioxidant, N,N′‐diphenyl‐1,4‐phenylene diamine (I, DPPD)Decoding of abbreviations see p. 48., was investigated under model conditions. After oxidation to a semiquinone radical, phenyl (4‐phenylamino phenyl)aminyl (VIII), or to Wurster's cation phenyl (4‐phenylamino phenyl)ammoniumyl (IX), I reacts with 1‐cyano‐1‐methylethyl (model alkyl) by two routes, both of which are accelerated by weak acids. One of these routes results in alkyl being bound to nitrogen with formation of N,N′‐diphenyl N‐(1‐cyano‐1‐methylethyl)1,4‐phenylene diamine (III). The latter compound is labile, and particularly in the presence of acids readily splits off olefin with regeneration of DPPD. This behaviour is a model of the regeneration mechanism of the stabilizing effect of DPPD, which alternately with its oxidation product (VIII or IX) deactivates the alkylperoxyl and alkyl radicals during the ageing of hydrocarbon substrates under conditions of the relative deficiency of oxygen. The other route leads to binding of the alkyl in the benzene ring with formation of N,N′‐diphenyl 2‐(1‐cyano‐1‐methylethyl) 1,4‐phenylene diamine (IV) and N,N′‐diphenyl 2‐(1‐cyano‐1‐methylethyl) 1,4‐benzoquinone diimine (V), thus modelling the binding of DPPD in the polymer chain, and even the crosslinking of the chain during the ageing of a polymer inhibited with DPPD. Due to the presence of the nitrile group, IV undergoes some further changes, which give rise to the formation of 3,3‐dimethyl 2‐imino‐1‐phenyl 5‐phenylamino indoline (VI)

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690104

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractThe production of unsaturated polyesters based on mixtures of fumaric acid and adipic acid for different proportions without added catalyst was studied. The progress of the polyesterification was followed by determining the amount of water produced during the reaction. The kinetic parameters (reaction order n, activation energy E, frequency factor k0) of the polyesterification were determined and it was found out that n = 3 in all cases, while E and k0increased by increasing amount of fumaric acid in the initial mixture of the reaction. A mathematical model for the polyesterification based on the production parameters (e.g. the heating program) and on the kinetic parameters was used and very good correlation was found between the corresponding pair of curves of water produced during the polyesterification, which were determined experimentally and theoretically (by calculating). With regard to the properties of the final product it was found out that its viscosity and its slight yellow colour increased by increasing the amount of fumaric acid in the initial mixture of raw materials. General prospects for practical application of this method were also discussed.

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690105

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

Abstractp‐Acryloyloxy‐tri‐n‐butyltin benzoate (ABTB) was prepared by the reaction of p‐hydroxy‐tri‐n‐butyltin benzoate and acrylic acid in the presence of dicyclohexylcarbodiimide. The monomer reactivity ratios for the copolymerizations of ABTB (M1) with methyl acrylate (M2), ethyl acrylate (M2), n‐butyl acrylate (M2), methyl methacrylate (M2), styrene (M2) and acrylonitrile (M2) have been found to be r1= 0.080, r2= 1.046; r1= 0.039, r2= 1.585; r1= 0.019, r2= 2.076; r1= 0.150, r2= 1.710; r1= 0.113, r2= 1.339 and r1= 0.007, r2= 2.853, respectively. The Q and e values for the prepared organotin monomer were calculated. Copolymerization reactions were carried out in solution at 70°C using 1 mol‐% azobisisobutyronitrile. The structure of the ABTB monomer and the prepared copolymers was investigated by IR an

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690106

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractUnlösliche sphärische Aluminiumcarboxymethylcellulose‐Xerogelpartikel werden durch partielle Trocknung ionotroper Gele hergestellt, die durch Eintropfen wäßriger Lösungen von Natriumcarboxymethylcellulose in vernetzende Aluminiumsalzlösungen entstehen. Das Quellvermögen der porösen und mechanisch stabilen Trägermaterialien, die von einer dichten Außenschicht umgeben sind, erhöht sich durch partielle Umwandlung von Carboxygruppen in die Natriumsalze; es verringert sich mit zunehmendem Gehalt an freien Säuregruppen und steigender Trocknu

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690107

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractThe electrical properties of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) chelate polymers of terephthalaldehyde bis(S‐benzyldithiocarbazate) (TBDTC) have been studied. Similarly, different concentrations of iodine were doped to these chelate polymers to increase their conductivity for producing a new class of electrical conductive material. The current interest in doping of iodine in chelate polymers is to a great extent due to their possible application in power sources and electrochemical devices. Electrical conductivity of chelate polymers and iodine doped chelate polymers have been studied over a wide range of temperature (∼ 300−450 K). From the electrical conductivity of these polymers activation energies of electrical conduction have been evaluated. A comparison of electrical conductivity and activation energy of electrical conduction of simple and iodine doped polymers has been made and conclusions about the role of iodine in chelate polymers regarding the electrical conductivity have been

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690108

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractModifications of polybutadienes via catalytic and photolytic decomposition of dimethyldiazomalonate (dmdm) are described. This method pertains to the generation of highly reactive carbenes which give rise to the formation of addition and insertion products. Chemical structures of the modified polymers were confirmed by NMR spectroscopy. It was found that carbene dimers were also formed in a significant extent depending on the molecular weight and microstructure of the initial polymers.

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690109

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractGraft copolymerization of N‐methylolacrylamide onto flax/polyester blend fabric using ferrous cellulose thiocarbonate/H2O2redox system was investigated under different conditions including hydrogen peroxide concentration (1−60 mmol/l), ferrous ammonium sulphate concentration (1−50 mmol/l), N‐methylolacrylamide concentration (5−200%, based on weight of sample), polymerization time (10−90 min), temperature (20−50°C), and pH of the medium (1.1−11). The nitrogen content and/or the methylol content were used for calculation of graft yields. Results obtained indicated that graft yields, derived from nitrogen analysis, are higher the greater the H2O2concentration increases till 40 mmol/l, then level off. On the other hand, graft yields derived from methylol content exhibit maximum value at 10 mmol/l H2O2. The results indicate also that grafting was highly favoured when it was carried out using 1 mmol/l ferrous ammonium sulphate and pH 4.4 at 30°C for 60 min. The apparent activation energy of the copolymerization reaction amounts to 9.74 kJ/mol. Furthermore, the graft yield increases by increasing N‐methylolacrylamide concentration within the range studied. The work was further extended to include a comparison between the polymerization efficiencies of the ferrous cellulose thiocarbonate/H2O2redox system and the ferrous/H2O2redox system in inducing grafting of N‐methylolacrylamide onto flax/polyester blend fabric. For this reason, the two systems were studied with respect to graft yield, homopolymer proportion, total conversion, graft efficiency, and h

ISSN:0003-3146    

DOI:10.1002/apmc.1989.051690110

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY