Boiling water tests

European Norm EN 1087-1, Wood particleboard. Determination of resistance to humidity. Boiling water test, 1997. 

Some applications require materials which are continuously or intermittently in contact with aqueous systems. Therefore, it is desirable to evaluate resins in a simulated test to determine water-extraction resistance (3). A commonly used test is the so-called seven-day boiling water test. Samples of 25-mil thickness were treated with boiling water for four and seven days (water changed daily) and then exposed in a circulating air oven at 125 °C. The relative stabilities are shown in Figure 1. The data... 

Test solution treated with reagent in boiling water Sample added to reagent solution in a test tube and immersed in boiling water Test solution mixed with reagent and warmed in a water bath... 

Fig. 6. Flexural strength of heat-treated and methacrylate coupling agent treated glass-fiber/polyester composites. The 2-h boiling-water test approximates longer-term water exposure (1).

Apparent Specific Gravity. For a porous ceramic, the ratio of the mass to the mass of a quantity of water that, at 4 C, has a volume equal to the apparent SOLID VOLUME (q.v.) of the material at the temperature of measurement. ASTM C20 specifies a boiling water test ASTM C830 a vacuum pressure test. 

Apparent Porosity. The ratio of the open pores to the bulk volume (q.v.), expressed as a percentage. ASTM C830 specifies a vacuum pressure test for refractories ASTM C20 a boiling water test. 

Figures 3.15, 3.16 and 3.17 show two NR compounds, an SBR and an NBR bonded with solvent-borne Chemosils 211/220, a hybrid solvent-borne primer Chemosil 211 with waterborne top coat Chemosil XW7484 and a waterborne system of Chemosil XW1180 primer and XW7484 top coat. Boiling water tests (95 - 98 °C for 2 hours) show 100% rubber retention in all cases (see Figure 3.19).

Trichloroethanoic acid, CCI3COOH. A crystalline solid which rapidly absorbs water vapour m.p. 58°C, b.p. 196-5" C. Manufactured by the action of chlorine on ethanoic acid at 160°C in the presence of red phosphorus, sulphur or iodine. It is decomposed into chloroform and carbon dioxide by boiling water. It is a much stronger acid than either the mono- or the dichloro-acids and has been used to extract alkaloids and ascorbic acid from plant and animal tissues. It is a precipitant for proteins and may be used to test for the presence of albumin in urine. The sodium salt is used as a selective weedkiller. 

If the hydrogencarbonate is in solution and the cation is Ca or Mg. the insoluble carbonate is precipitated this reaction may be used, therefore, to remove hardness in water by precipitation of Ca or Mg ions.) The ease of decomposition of hydrogencar-bonates affords a test to distinguish between a hydrogencarbonate and a carbonate carbon dioxide is evolved by a hydrogencarbonate, but not by a carbonate, if it is heated, either as the solid or in solution, on a boiling water bath. 

Hydrolysis by acids. Sucrose is readily hydrolysed by dilute acids. Dissolve 0 5 g. of sucrose in 5 ml. of water, add 2 ml. of dil. H2SO4 and heat in a boiling water-bath for 5 minutes. Cool and show that the solution has reducing properties, and will form glucosazone. Note that the excess of acid must be neutralised before carrying out the reduction tests. 

Hydrolysis by acids. Place 15 ml. of starch solution in a boiling-tube, add I ml. of cone. HCl, mix well and place in a boiling water-bath for 20 minutes. Cool and add 2 drops of iodine solution to i ml. of the solution no blue coloration is produced. On the remainder, perform tests for glucose in particular show that glucosazone can be formed. Neutralise the excess of acid before carrying out these tests. (Note that a more concentrated acid is required to hydrolyse starch than to hydrolyse the disaccharides, such as sucrose.)... 

Mix 3 g. of starch well with loml. of water in a test-tube and pour the mixture into 90 ml. of boiling water contained in a 300 ml. conical flask, stirring at the same time. Cool to about 70 and then place in a water-bath maintained at 65-70 , but not higher. Now add 2-3 ml. of the malt extract prepared as above, mix well and allow the hydrolysis to proceed. Take a series of test -tubes and in each put 10 ml. of water and 2 drops of a 1 % iodine solution. At intervals of about 4 minutes (depending upon the activity of the enzyme solution), remove 1 ml. of the reaction mixture, cool and add it to one of the test-tubes and note the colour obtained. At the beginning of the experiment the colour will be blue due to the starch alone. As the reaction proceeds, the colour gradually becomes violet, reddish, yellowish and finally colourless. 

Add 1 ml. of the alcohol-free ether to 0-1-0-15 g. of finely-powdered anhydrous zinc chloride and 0 5 g. of pure 3 5-dinitrobenzoyl chloride (Section 111,27,1) contained in a test-tube attach a small water condenser and reflux gently for 1 hour. Treat the reaction product with 10 ml. of 1-5N sodium carbonate solution, heat and stir the mixture for 1 minute upon a boiling water bath, allow to cool, and filter at the pump. Wash the precipitate with 5 ml. of 1 5N sodium carbonate solution and twice with 6 ml. of ether. Dry on a porous tile or upon a pad of filter paper. Transfer the crude ester to a test-tube and boil it with 10 ml. of chloroform or carbon tetrachloride filter the hot solution, if necessary. If the ester does not separate on cooling, evaporate to dryness on a water bath, and recrystallise the residue from 2-3 ml. of either of the above solvents. Determine the melting point of the resulting 3 5 dinitro benzoate (Section 111,27). 

Mix 0-2 g. of 3 5-dinitrobenzoyl chloride, 6 drops of the mercaptan and 1-3 drops of pyridine in a test-tube, and heat the mixture in a beaker of boiling water until fumes of hydrogen chloride cease to appear (15-30 minutes). Add a few drops of water, followed by a drop or two of pyridine to eliminate the excess of the reagent. The product sohdifies upon stirring with a glass rod. Add water, filter, and recrystalUse from dilute alcohol or dilute acetic acid. 

To a mixture of 10 g. of the compound and 3-5 ml. of 33 per cent, sodium hydroxide solution in a test-tube, add 2-5 ml. of 50 per cent, chloroacetic acid solution. If necessary, add a little water to dissolve the sodium salt of the phenol. Stopper the test-tube loosely and heat on agently-boiling water bath for an hour. After cooling, dilute with 10 ml. of water, acidify to Congo red with dilute hydrochloric acid, and extract with 30 ml. of ether. Wash the ethereal extract with 10 ml, of water, and extract the aryloxyacetic acid b shaking with 25 ml. of 5 per cent, sodium carbonate solution. Acidify the sodium carbonate extract (to Congo red) with dilute hydrochloric acid, collect the aryloxyacetic acid which separates, and recrystallise it from hot water. 

Place 10 g. of hquid methyl methacrylate in a test-tube, add 10-20 mg. of benzoyl peroxide (Section IV, 196), stopper the test-tube loosely and heat in a boiling water bath. After 20-25 minutes, the hquid suddenly becomes very viscous and soon sets to a hard, colourless mass of the polymer. 

Reaction with alcoholic silver nitrate. To carry out the test, treat 2 ml. of a 2 per cent, solution of silver nitrate in alcohol with 1 or 2 drops (or 0 05 g.) of the compound. If no appreciable precipitate appears at the laboratory temperature, heat on a boiling water bath for several minutes. Some organic acids give insoluble silver salts, hence it is advisable to add 1 drop of dilute (5 per cent.) nitric acid at the conclusion of the test most silver salts of organic acids are soluble in nitric acid. 

Tested ia water at 93°C after 2 weeks immersion at 93°C. Specimens conditioned 200 h ia boiling water. 

The test colorfastness to potting, ISO 10S-E09, is of importance for dyed wool as potting is one of the processes woven wool fabrics can be given before they are made up iato clothing. The procedure is similar to EOS except that the test conditions are 1 h immersion ia boiling water. 

When you pour boiling water into a cold bottle and discover that the bottom drops out with a smart pop, you have re-invented the standard test for thermal shock resistance. Fracture caused by sudden changes in temperature is a problem with ceramics. But while some (like ordinary glass) will only take a temperature "shock" of 80°C before they break, others (like silicon nitride) will stand a sudden change of 500°C, and this is enough to fit them for use in environments as violent as an internal combustion engine. 

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