SynopsisPure regenerated cellulose fibers and those containing various amounts of phosphorus nitride were pyrolyzed under different conditions in the temperature range of 150-440OC. Easily volatile liquid pyrolysis products, the tar fraction of limited volatility, and the charred residue were determined gravimetrically. The liquid volatiles were analyzed by combined gas chromatography/mass spectrometry for their water content. The tar fraction and the charred residue were inspected by infrared (IR) spectroscopy. The studies revealed that the phosphorus nitride flame retardant enhances the onset of the pyrolytic decompcsition and the release of water at substantially lower temperatures as observed for pure cellulose. The water release favors the carbonization and its extent reduces the formation of levoglucosan as a precursor of easily flammable pyrolysis products. Thus phosphorous nitride must be classified into the water release favoring flame retardants.
The paper describes the effect of styrene on the properties of bis(methacry1oxy) derivatives of epoxy resins (vinyl ester resins). The styrene concentration in the resin was systematically varied between 20 -60 wt.-%. The curing characteristics of vinyl ester resins changed only marginally on dilution with styrene. Dilution with styrene resulted in a decrease in tensile modulus and increase in elongation of neat resin castings and glass fibre reinforced laminates. The glass transition temperature of laminates was determined by dynamic mechanical analysis and was found to decrease with increasing styrene content.
ZUSAMMENFASSUNG:In dieser Arbeit wird der Einflun von Styrol auf die Eigenschaften von Bis(metha-cry1oxy)-Derivaten von Epoxidharzen (Vinylesterharzen) beschrieben. Die Styrolkonzentration im Harz wurde systematisch von 20 -60 Gew.-% geandert. Die Hirtungscharakteristika von Vinylesterharzen inderten sich nur geringfiigig bei der Verdiinnung mit Styrol. Diese Verdiinnung bewirkte eine Abnahme des Zugmoduls und eine Zunahme der Dehnung der unverdiinnten GieBharze und der glasfaserverst&kten Laminate. Die Glasiibergangstemperatur der Laminate wurde durch dynamomechanische Analysen bestimmt. Es wurde gefunden, dal3 diese Temperatur mit steigendem Styrolgehalt sinkt.
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