Copyright 2005 American Association of Textile Chemists and Colorists 122TM 89-2003AATCC Technical Manual/2006 Developed in 1958 by AATCC Commit- tee RA66; editorially revised 1974, 1984, 1986, 1988, 1990, 1992; reaf- firmed 1974, 1977, 1980, 1989, 1998, 2003; editorially revised and reaffirmed 1985, 1994. 1. Purpose and Scope 1.1 This test method provides a method for the determination of the presence of mercerization in dyed and undyed cotton yarns and fabrics. In addition, the test will give an indication of the complete- ness of the reaction between the cotton and the mercerization bath. 2. Principle 2.1 Carefully scoured specimens of the cotton to be tested and unmercerized cot- ton are immersed in separate baths of bar- ium hydroxide solution for a definite time period. Aliquot portions of each soaking bath and of fresh barium hydroxide solu- tion are then titrated with hydrochloric acid. 2.2 The ratio of the amount of barium hydroxide absorbed by the mercerized specimen to that absorbed by the unmer- cerized specimen multiplied by 100 gives the barium activity number. 3. Terminology 3.1 mercerization, n.a process for irreversibly altering the physical charac- teristics and appearance of natural cellu- losic fibers by swelling in strong alkali. 4. Safety Precautions NOTE: These safety precautions are for information purposes only. The pre- cautions are ancillary to the testing proce- dures and are not intended to be all inclu- sive. It is the users responsibility to use safe and proper techniques in handling materials in this test method. Manufac- turers MUST be consulted for specific details such as material safety data sheets and other manufacturers recommenda- tions. All OSHA standards and rules must also be consulted and followed. 4.1 Good laboratory practices should be followed. Wear safety glasses in all laboratory areas. 4.2 All chemicals should be handled with care. 4.3 Use chemical goggles or face shield, impervious gloves and an imper- vious apron during dispensing and mix- ing of barium hydroxide, sodium carbon- ate and hydrochloric acid. Concentrated acids should be handled only in an adequately ventilated laboratory hood. CAUTION: Always add acid to water. 4.4 Petroleum solvent can be a com- bustible or flammable liquid, depending on which solvent is used, and presents a hazard. Ethanol and methanol are flam- mable liquids. Flammable liquids should be stored in the laboratory only in small containers away from heat, open flame and sparks. These chemicals should not be used near an open flame. 4.4.1 Carry out reflux procedure in a well ventilated hood with an electrical heating mantle or a water bath as the heat source. 4.4.2 Use chemical goggles or face shield, impervious gloves and an imper- vious apron when handling organic sol- vents. 4.5 An eyewash/safety shower should be located nearby and an organic vapor respirator and a self-contained breathing apparatus should be readily available for emergency use. 4.6 Exposure to chemicals used in this procedure must be controlled at or below levels set by governmental authorities e.g., Occupational Safety and Health Administrations (OSHA) permissible exposure limits (PEL) as found in 29 CFR 1910.1000 of January 1, 1989. In addition, the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) comprised of time weighted averages (TLV-TWA), short term exposure limits (TLV-STEL) and ceiling limits (TLV-C) are recommended as a general guide for air contaminant exposure which should be met (see 13.7). 5. Limitations 5.1 The test cannot be used satisfacto- rily if durable finishes or fibers other than cotton are present. 6. Apparatus 6.1 Burette (preferably automatic) (see 13.4). 6.2 Flask, Erlenmeyer, with reflux tube. 6.3 Flasks, glass-stoppered, 250 mL. 6.4 Flasks, Erlenmeyer, 125 mL. 6.5 Bottles, storage, 250-500 mL. 6.6 Beaker, 1500 mL. 6.7 Pipette, 10 mL. 6.8 Drying oven. 7. Reagents and Materials 7.1 Hydrochloric acid (HCl) standard- ized approx. 0.1N. 7.2 Barium hydroxide reagent Ba(OH)2 approximately 0.25N (see 13.1). 7.3 Phenolphthalein. 7.4 Petroleum solvent BP 30-60C (86-140F). 7.5 Alcohol (95% ethanol or anhy- drous methanol). 7.6 Enzyme, starch-solubilizing. 7.7 Soap, neutral, granular (see 13.2). 7.8 Water, distilled. 7.9 Cotton yarn, unmercerized for ref- erence (standard cotton) (see 13.3). 8. Test Specimens 8.1 A minimum of 5 g of each sample and of the unmercerized standards are scoured as directed after which a 2 g specimen of each scoured sample is weighed and placed in clean, dry glass- stoppered flasks. 9. Procedure 9.1 Scouring. The purpose of the scouring operation is to remove all extra- neous matter, leaving the cotton cellulose in as pure a form as possible and without changing it chemically. 9.1.1 The samples to be tested (at least 5 g each), together with the standard un- mercerized cotton, are refluxed together successively for 1 h with petroleum sol- vent boiling p