Compounded Stock

EVALUATION OF ALKYLLITHIUM INITIATED BUTADIENE-STYRENE RANDOM COPOLYMER (SOLPREN 1204) IN COMPOUNDED STOCK... 

Processing or the working of un-vulcanized compounded stock of rubber to form or build the articles to be vulcanized. 

These are ingredients which when added in very small proportions to the compound stock produce a slight stiffening effect or decrease in plasticity. Benzidine and para amino phenol are examples of... 

The plastic flow of compounded stock of rubber is dependent upon the temperature, force and the rate of force. Obviously these three variables are significant in measuring the processibility of rubber or its compound. After forming the stock to the desired shape, the compounds need to be converted into a strong elastic material. This is... 

We use a 384-pin array to dehver 100 nL of compound to each well (8). The advantage of this approach is that a small volume of compound is used and dilution of compound stock in growth medium is not necessary. The disadvantages of this method include occasional compound precipitation in growth medium and the appearance of a concentration gradient across the monolayer within a well. 

Compounds for testing were dissolved in 10% DMSO and diluted 1/20 in water to give a final stock concentration of 50 pM. A 20-pl aliquot of the compound stock was added to each well in a 96-well plate, followed by 50 pi of the enzyme solution. The reaction was started by adding 30 pi of 166.67 pM UMA to all wells. The final reaction well contained 50 mM Tris, pH 7.7, 20 mM MgCl2, 1.0 mM ATP, 0.4 mM d-G1u, 2.0 mM Lys, 0.05 mM D-Ala-D-Ala, 3 ng/ml MurD, 15 ng/ml MurE, 100 ng/ml MurF, and 100 pg/ml BSA. The 96-well plates were either stacked or covered and incubated for 2 hr at room temperature. The reaction was stopped by adding 20 pi of 250 mM EDTA followed by mixing. 

Compound dilutions should be performed from 10 mM compound stock solutions in DMSO at the day of experiment. Compounds should be taken from micro well plates prepared by the different robot systems dilution is prepared with buffer or intermediate steps (containing DMSO) to avoid precipitation of compounds with low solubility. Final DMSO concentration should not exceed 0.5%. Alternatively, compound dilutions are prepared manually to result in maximal final concentration of DMSO of 0.5 %. 

Cells were seeded at -10,000 per well and cultured in clear 96-well flat bottom TC plates for 24 to 36 hr, followed by treatment with compounds for an additional 20 hr. All compounds (stock solution in DMSO) were diluted in 10% FBS culture medium with a final DMSO concentration of 0.5%. 

FIGURE 12.4 In-house developed, fully automated reformatting system. Compounds stocked in individually barcoded and sealed tubes are transported (A). A robot (B) delivers the tubes in a 96-tube rack to a liquid handler (C), where samples can be added to 96-, 384-, or 1536-well plates. 

STR.TYPE Text Class of compound (Stock or In-house)... 

From 10 mM compound stocks in DMSO prepare twofold dilution series to give compound concentrations over the range 300, 150, 75, 37.5, 18.75, 9.38, and... 

This substance was prepared by K. Suitsxj and K. Okuma who recommended its use as a reagent for magnesium. I. M. Kolt-HOFF 2 demonstrated the acid-base indicator properties of the compound. Stock solutions should contain 0.1% of the sodium salt in water. The color change is from yellow to violet in the pH interval 11.0-13. In strongly alkaline solutions containing magnesium, its color is a corn-flower blue. 

Mill mixing should be completed in 30 minutes. Properly compounded stock may have a Mooney viscosity of about 30 to 35 (MS 1 + 4 at 121 °C MS Mooney viscosity with a small rotor). 

The mixed stock of rubber is called the compound or the compounded stock. The normal sequence of addition is as follows ... 

Tbe whalebone is Ju tbe center, surrounded by the thin strips of rattan, and secured in place by glue. This compound stock U dipped In glue so that every part is permeated by it, and then run through a machine, which winds it with a strong thread from end to end. It is again wound with rope, so that it cannot warp out of shape, and left to diy ... 

The lithium-catalyzed butadiene polymers present an interesting correlation between microstructure and physical test properties. The most outstanding characteristic of the lithium metal-catalyzed butadiene polymers is their excellent low temperature properties. Figure 1 illustrates that, in compounded stocks, lithium-catalyzed polybutadiene reaches a Young s bending modulus of 10,000 pounds per square inch at a temperature 11 °C. below that for emulsion polybutadiene. 

The Young s bending modulus is a measure of the stiffness of a material—a higher value indicates a stiffer material. The sodium polybutadiene is, of course, considerably inferior to both of these polymers in this low temperature test. Table IV similarly illustrates the superiority, in compounded stocks, of lithium polybutadiene in low temperature shear recovery tests, also a measure of cold properties of a rubber. In this test the relative superiority of the lithium polymers to the emulsion and sodium polymer is even greater than that in the former test. 

Physical test properties on some cured rubber stocks prepared from lithium-catalyzed butadiene polymers are listed in Tables V and VI with appropriate controls. The results are only roughly indicative of the potential properties of rubbers made from lithium-catalyzed butadiene polymers because of the limited quantity of polymer available. The tensile data in Table VI indicate that compounded stocks from the lithium polymers are about equal or slightly inferior to the emulsion and sodium polymer controls in regard to these properties however, a hot tensile (lOO C.) on a cured compound from lithium polybutadiene was 325 pounds per square inch compared to 200 to 250 for an emulsion polybutadiene control. The internal friction of cured stocks from the lithium-catalyzed butadiene polymers is similar in magnitude to the emulsion or sodium polymer controls at 50 C. but higher at 100 °C. All lithium polymers, even those with low Mooney viscosities, gave cured compounds with high values of dynamic modulus. 

Accelerator 2, 2 -Dithiobisbenzothiazole Activator Dibutylammonium oleate Antioxidant Phenyl 2-naphthylamine All compounded stocks had approximately this recipe and were given optimum cure at 280° F. 

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