Search results for "Polyamide"

1986

The kinetics of polyamidation was investigated for the reaction of diphenyl terephthalate as activated diester with trimethylhexamethylenediamine (1 : 1 mixture of 2,2,4- and 2,4,4-trimethyl isomers) in dimethyl sulfoxide. The good solubility of the resulting polyamide (Trogamid®(poly(iminoterephthaloylimino-x,y,z-trimethylhexamethylene))) assured a reaction in which all reactants, especially the polyamide, were soluble. The conversion was followed by analysis of the phenol set free and by measuring the number-average degree of polymerization Pn of the polyamide. The reaction obeyed an overall second order with the principle of equal reactivity of functional groups fulfilled for Pn ≿ 16. De…

Synthesis of AB and ABA block copolymers as compatibilizers in nylon 6/polycarbonate blends

1996

Nylon 6 (Ny6) and Bisphenol A polycarbonate (PC) are immiscible and form biphasic blends. To improve the compatibility of Ny6 and PC several ABA and AB Ny6/PC block copolymers were synthesized, and their compatibilizing behavior on the blends were tested. Block copolymers were prepared by reacting monoamino- or diamino-terminated Ny6 homopolymers with high molecular weight PC at 130°C in anhydrous DMSO. The reaction of diamino- and monoamino-terminated Ny6 with polycarbonate produces block copolymers of the type PC-Ny6-PC (ABA) and PC-Ny6 (AB), respectively, plus a certain amount of unconverted PC degradated to lower molecular weights. To separate the block copolymer from the unconverted PC…

Filmability and properties of compatibilized PA6/LDPE blends

2005

Blends of low density polyethylene (LDPE) and polyamide 6 (PA6), compatibilized with an ethylene-acrylic acid copolymer (EAA), either alone or combined with a low molar mass bis-oxazoline compound (PBO), have been processed in film blowing operations and the properties of the films have been investigated. Without of compatibilization, the filmability of the blend was very poor and no significant specimen was collected. As a result of the reactive compatibilization, the blends with EAA and even more with the EAA-PBO, were processed successfully in film blowing. The films of the quaternary blends were shown to possess satisfactory mechanical properties as a result of fine and stable morpholog…

1983

PYROLYSIS-MASS SPECTROMETRY OF TRUXILLIC AND TRUXINIC POLYAMIDES AND RELATED COPOLYAMIDES

1977

1982

The polyamides 3–5 were synthesized from α,ω-diamino-substituted oligo(oxyethylene)s (1) and bis-chlorides of dicarboxylic acids (2). As copolymers with defined sequences they contain up to five oxyethylene units per repeating unit. Hereby properties like solubility, thermal stability and complexing ability towards alkali metal cations are influenced.

Ein optisch aktives Polyamid mit atropisomeren Binaphthyl-Grundbausteinen

1968

Zur Darstellung eines optisch aktiven Polyamids mit atropisomeren Grundbausteinen in der Hauptkette wurde (+)-2.2′-Diamino-binaphthyl-(1.1′) (II) hergestellt. Die Drehwerte in einigen Losungsmitteln sowie optische Rotationsdispersion (ORD), Circulardichroismus (CD) und UV-Spektrum werden angegeben. Durch Grenzflachenpolykondensation von II mit Terephthaloylchlorid wurde ein optisch aktives Polyamid (III) erhalten. Drehwerte, ORD und CD von III werden gemessen und mit denen des als Modellsubstanz dargestellten (+)-2.2′-Dibenzamido-binaphthyls-(1.1′) (IV) verglichen. Beide Substanzen zeigen mehrere COTTON-Effekte, die hinsichtlich ihres Vorzeichens ubereinstimmen. In ihrer Lage sind jedoch di…

1988

Structure et proprietes thermodynamiques de polyamides rigides portant ces groupes lateraux flexibles

An experimental methodology to study polymer crystallization under processing conditions. The influence of high cooling rates

2002

Abstract A new experimental route for investigating polymer crystallization under very high cooling rates (up to 2000°C/s) is described. A complete and exhaustive description of the apparatus employed for preparing thin quenched samples (100– 200 μm thick) is reported, the cooling mechanism and the temperature distribution across sample thickness is also analysed, showing that the final structure is determined only by the thermal history imposed by the fast quench apparatus. Details concerning the characterization techniques used to probe the final structure are reported, including density measurements and wide angle X-ray diffraction patterns. Experimental results concerning isotactic poly…

Polyamide-Based Fibers Containing Microwave-Exfoliated Graphite Nanoplatelets

2016

Exfoliated Graphite NanoPlatelets (GNP) have been obtained from Graphite Intercalation Compounds (GIC) subjected to thermal and microwave treatments. Accurate morphological and structural characterization of obtained GNP, performed to compare the degree of exfoliation, show that microwave-treated GNP, exhibit well-exfoliated structure, without any reduction in dimensions compared with the native GIC, differently to the thermal-treated ones. Microwave-treated GNP have been introduced in polyamide (PA) through melt-mixing to obtain nanocomposite that has been subjected to elongational flow, with the aim to improve the nanofiller dispersion and induce GNP orientation along the fiber direction.…