Polymerization of perfluorobutadiene

Diisopropyl peroxydicarbonate dissolved in liquid perfluorobutadiene is conducted in a sealed vessel at the autogenous pressure of polymerization. Reaction temperature, ratio of catalyst to monomer, and amount of agitation determine degree of polymerization and product yield

Compatibility testing of spacecraft materials and spacestorable liquid propellants

Compatibility data for aluminum alloy 2219-T87 and titanium alloy Ti-6Al-4V were obtained while these alloys were exposed to both liquid and vapor fluorine and FLOX at -320 F + or -10 F. These data were obtained using a new low cost compatibility method which incorporates totally sealed containers and double dogbone test specimens and propellants in the simultaneous exposure to vapor and liquid phases. The compatibility investigation covered a storage period in excess of one year. Pitting was more severe in the 2219-T87 aluminum alloy than in the Ti-6Al-4V titanium alloy for both fluorine and FLOX exposure. The degree of chemical attack is more severe in the presence of FLOX than in fluorine and phase. The mechanical properties of the two alloys were not affected by storage in either of the two propellants

New polymers of perfluorobutadiene and method of manufacture Patent application

Synthesis of polyfluorobutadiene by polymerization of perfluorobutadiene with diisopropyl peroxydicarbonat

Long term storage test of titanium material with liquid fluorine propellant

The compatibility of 6AL-4V Ti with propellant grade GF2 and LF2 at 77 K for up to 3 years was investigated. Titanium double coupons, annealed or heat treated, with 16 or 64 RMS finishes, were immersed in F2 in individual Pyrex capsules and stored under LN2 for 29 and 39 months. Pre and post immersion tests were performed on the propellant and coupons. Chemical analysis of the propellant did not reveal any significant changes due to titanium corrosion. Gravimetric, visual, microscopic, and metallurgical examination with pitting analysis did not reveal gross corrosion of the titanium although pitting appears to be greater after 39 months exposure. The increase in pit size and number raises the possibility of unpredictable crack propagation instability. Fracture toughness tests are necessary to define this possibility

Reactions of nitroalkenes with nitroalkanes or sulfur ylides catalyzed by amine-thiourea bifunctional polymeric organocatalysts

Non-cross-linked and cross-linked bifunctional polystyrenes bearing both amine and thiourea groups have been synthesized and used as organocatalysts in reactions between nitroalkenes and nitroalkanes or sulfur ylides. Control experiments using monofunctional polymers with only either amine or thiourea groups attached indicated that both functional groups were essential for efficient catalysis of the reactions studied. The non-cross-linked polystyrene was soluble in typical organic solvents and was used as a homogeneous catalyst, while the cross-linked polystyrene was used as a heterogeneous catalyst. © Georg Thieme Verlag Stuttgart · New York.postprin

Rasta resin-DMAP and its use as a recyclable catalyst for the addition of carbon dioxide to epoxides

Rasta resin-DMAP, a new heterogeneous polystyrene-based amine, has been synthesized and used as a catalyst in addition reactions of carbon dioxide to epoxides to afford cyclic carbonate products. This new material was found to be a more efficient catalyst than divinyl benzene cross-linked polystyrene- supported DMAP, and was readily recovered and reused without significant loss of catalytic activity. © Georg Thieme Verlag Stuttgart - New York.postprin

Multifunctional organic polymeric catalysts and reagents

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Notes: Forage Yield, Quality, And Fertility Of Sorghum X Sudan Grass Hybrids In A1 And A3 Cytoplasm

Currently, no information is available comparing the agronomic performance of A1 and A3 cytoplasms in sorghum x sudangrass [Sorghumbi color (L.) Moench] hybrids. The objectives of this study were to compare the effects of A1 and A3 cytoplasm on the maturity, fertility, height, forage yield, and forage quality of sorghum × sudangrass hybrids. In 1989, pollen from a bulk of eight sudangrass populations was used to pollinate four sorghum lines that had been male-sterilized in both A1 and A3 cytoplasm. Hybrids were grown at the Univ. of Nebraska Field Laboratory Ithaca, NE, in 1990 and 1991, in a split-plot design with inbreds (females) treated as whole plots and cytoplasms treated as subplots. The soil was a Sharpsburg silty clay loam (fine montmorillonitic, mesic Typic Agriudoll). Cytoplasm had no effect on days to 50% anthesis, height, forage yield, in vitro dry matter disappearance (IVDMD) or, crude protein. Seed set under selfing bags( fertility restoration) in A3 hybrids was observed, with interaction among A3 cytoplasm sources and lines

Seed Physiology, Production & Technology: Germination, Emergence, and Yield of 20 Plant-Color, Seed-Color Near-Isogenic Lines of Grain Sorghum

Although there is growing demand for sorghum [Sorghum bicolor (L.) Moench] with white seed and tan plant color, there is limited information on the overall agronomic fitness of sorghum with these characters. A set of experiments was conducted to evaluate the combined effects of plant color and seed color on sorghum germination, emergence, and agronomic performance. Twenty near-isogenic lines with red seed/tan plant (RT), red seed/purple plant (RP), white seed/ tan plant (WT), white seed/purple plant (WP) phenotypes were tested under field and laboratory conditions. Plant color X seed color interactions were not significant. Purple plant color phenotypes had higher cold germination, higher germination after accelerated aging, and greater seedling elongation at 10 d than tan plant color phenotypes. Plant color did not influence standard warm germination. No differences in standard warm germination or seed vigor test results were attributable to seed color. Seedling emergence under field conditions was higher for the red seed than the white seed phenotype. Grain yield was higher for the white seed than the red seed phenotype, and higher for the purple plant color than the tan plant color phenotype. Grain test weights from purple plant color lines were higher than those from tan plant color lines. All four phenotypes included relatively high yielding lines. There was considerable overlap between WT, WP, RT, RP lines in yield and other indicators of agronomic performance leading to the conclusion that white seed and tan plant color lines with comparable performance to red seed and purple plant color lines can be selected from segregating breeding populations

Notes: Forage Yield, Quality, And Fertility Of Sorghum X Sudan Grass Hybrids In A1 And A3 Cytoplasm

Currently, no information is available comparing the agronomic performance of A1 and A3 cytoplasms in sorghum x sudangrass [Sorghumbi color (L.) Moench] hybrids. The objectives of this study were to compare the effects of A1 and A3 cytoplasm on the maturity, fertility, height, forage yield, and forage quality of sorghum × sudangrass hybrids. In 1989, pollen from a bulk of eight sudangrass populations was used to pollinate four sorghum lines that had been male-sterilized in both A1 and A3 cytoplasm. Hybrids were grown at the Univ. of Nebraska Field Laboratory Ithaca, NE, in 1990 and 1991, in a split-plot design with inbreds (females) treated as whole plots and cytoplasms treated as subplots. The soil was a Sharpsburg silty clay loam (fine montmorillonitic, mesic Typic Agriudoll). Cytoplasm had no effect on days to 50% anthesis, height, forage yield, in vitro dry matter disappearance (IVDMD) or, crude protein. Seed set under selfing bags( fertility restoration) in A3 hybrids was observed, with interaction among A3 cytoplasm sources and lines