Beiträge zum Vernetzungs- und Abbauverhalten von Acrylelastomeren

The aim of this investigation was to obtain additional knowledge of the curing mechanism and the aging properties of acrylic polymers containing active chlorine. These were cured with amine or metal-soap/sulphur combinations. For this purpose, we used sulphur, chlorine, and nitrogen analyses, together with measurements of crosslink density and stress-relaxation. These investigations were partly made with vulcanisates based on technical acrylic polymers, and partly with crosslinked products of homo- and copolymers containing chlorine. Using the amine curing system, the diamine, after vulcanisation, is completely incorporated. Curing with metal-soap/sulphur combinations sulphur crosslinks are formed. The crosslink density is proportional to the concentration of amine or potassium-stearate in the compound. Comparing polyethylacrylate polymers containing vinyl-chlorecetate and 2chloroethyl-vinylether comonomers one always h d s the higher crosslink densities in polyethylacrylat/vinylchloracetat copolymers. We proved by stress relaxation measurements that scission of the network occurs at the crosslinks during air aging. Using amine as the curing agent oxidativedegradation exceeds the thermal one. In case of metal-soap/sulphur curing system thermal degradation exceeds the oxidative portion. Remarkable differences in aging properties between the two types of polymers could not be found. These results fit with our conception of the types of networks built up duringvulcanimtion, based on the other examinations.     

Der Einfluß von Genotyp und Anbauort auf verschiedene Inhaltsstoffe von Samen des Ölkürbis (Cucurbita pepo L.)

Influence of Genotype and Cultivation Place on Various Ingredients of Oil-Gourd Seeds (Cucurbita pepo L.) In the seed of oil pumpkin from an international variety trial several components were analysed. The following results were found: 1. Oil contents were about 49% in mean and were significantly influenced by location, year, variety and by the interaction between location and year. 2. Protein contents laid about 38% in mean and were significantly changed by location. 3. Average crude fibre contents were about 5.17%. The interaction location/year was secured in F-test. 4. Oleic acid contents laid about 27.9% in mean and were influenced by variety, location, year and by the interaction location/year. 5. Average linoleic acid content was about 54.4% of TEA whereby differences within varieties, locations and years as well as interaction location/year were statistically secured. A negative correlation (r=-0.9915) exists between both fatty acids. 6. The tocopherol contents were 437 mg/kg oil in mean and were modificated analogous to oleic- and linoleic acid by variety, location, year and interaction location/year. 7. Average phosphatide contents were about 0.82% and were significantly influenced by variety, location as well as interaction location/year. 8. Mean values of the different minerals were: P = 211 ppm; K = 183 ppm; Mg = 105 ppm; Ca = 26.9 ppm; Na = 3.6 ppm. All elements were significantly depending on location, P and K were depending on variety, too.