Vacuum weight ratio

A solution of sodium cyanide [143-33-9] (ca 25%) in water is heated to 65—70°C in a stainless steel reaction vessel. An aqueous solution of sodium chloroacetate [3926-62-3] is then added slowly with stirring. The temperature must not exceed 90°C. Stirring is maintained at this temperature for one hour. Particular care must be taken to ensure that the hydrogen cyanide, which is formed continuously in small amounts, is trapped and neutrali2ed. The solution of sodium cyanoacetate [1071 -36-9] is concentrated by evaporation under vacuum and then transferred to a glass-lined reaction vessel for hydrolysis of the cyano group and esterification. The alcohol and mineral acid (weight ratio 1 2 to 1 3) are introduced in such a manner that the temperature does not rise above 60—80°C. For each mole of ester, ca 1.2 moles of alcohol are added. 

The materials were dried in a vacuum oven at 115°C for 24 h. They were then melt blended by using a domestic twin-screw extruder ( 35) [screw diameter = 35 mm]. The weight ratios of PES-TLCP were 90 10 and 70 30, respectively [12]. 

The TLCP used was a widely investigated one, Vectra A950, manufactured by Hoechst-Celanese. The PC was produced by Enichem under the tradename Sinvet 303. Table 3 lists the main properties of these materials according to the manufacturers. The materials were dried in a vacuum oven at 120°C for 4 h before processing. Prior to injection molding of the composite samples, two components were melt mixed by a ZSK, W P, Stuttgart, extruder with a constant weight ratio of PC-TLCP = 80 20 [23]. 

All polyimide alloys were solution blended at a 50/50 weight ratio by codissolving the polymer pairs in a common solvent, such as methylene chloride (MeCl2) or a mixture of MeCl2 and hexafluoroisopropanol (HFIP), co-precipi-tating in methanol and then drying overnight under vacuum at 100 °C. 

Description EB is dehydrogenated to styrene over potassium promoted iron-oxide catalyst in the presence of steam. The endothermic reaction is done under vacuum conditions and high temperature. At 1.0 weight ratio of steam to EB feed and a moderate EB conversion, reaction selectivity to styrene is over 97%. Byproducts, benzene and toluene, are recovered via distillation with the benzene fraction being recycled to the EB unit. 

To prepare the K salt, NbgOs and KOH (mole ratio 1 20, weight ratio 4 17) are heated in a silver or alumina crucible until a clear melt is obtained. The melt is cooled, ground and dissolved in H3O. The solution is decanted to remove any insoluble matter which may be present, then concentrated in vacuum over cone. HaSO until formation of crystals. These are washed with some water and dried on filter paper. 

In addition, we prepared the set of films on the base of PLA with same thickness 40 pm and MW = 67 (defined as PLA 70), MW = 150 and 400 kDa. Along with them, we obtained the blend PHB/PLA with weight ratio 1 1 and MW = 950 kDa for PHB, and MW = 67 kDa for PLA (defined as PHB + PLA blend). Both components mixed and dissolved in common solvent, chloroform, and then cast conventionally on die glass plate. All films were thoroughly vacuum processed for removing of solvent at 40°C. 

Mt and e-caprolactam were well mixed in a mortar in a weight ratio of 1 4, and they were then dried and dehydrated for 12 hours in a vacuum desiccator containing phosphorous pentoxide. These specimens were left in a temperature-controlled bath kept at 100 °C for one hour to cause the e-caprolactam substances to sweU. They were subjected to X-ray diffraction measurements at 25 °C and 100 °C. It was found that two distinct sizes were present at the different temperatures 3.15 nm (25 °C) and 3.87 nm (100 °C) and that the one processed at 100 °C had caprolactam molecules intercalated between the layers. 

The use of 1 1 ratios gave, with both isopropyl and ethyl alcohol, some gel formation in conjunction with the adduct. The unreacted alcohol was removed by vacuum (weight loss equal to the excess alcohol added) and I R was used to identify the resulting adduct. 

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