In the chemical dissolution test, the dissolution characteristics of different chemical reagents on different fibers at different temperatures are used to identify the types of fibers.This method is applicable to the identification of various fibers and the quantitative analysis of the blending ratio of blended products.
Three kinds of chemical reagents need to be prepared to test the solubility of fibers: hydrochloric acid (36%~38%), sulfuric acid (70%), sodium hydroxide (5%). Observe the dissolution of the fibers in the three reagents.
Cotton： Insoluble in room temperature hydrochloric acid, partially dissolve in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Linen：Insoluble in room temperature hydrochloric acid, partially dissolve in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide , insoluble in boiling sodium hydroxide.
Silk：Partially dissolve in room temperature hydrochloric acid, dissolve in boiling hydrochloric acid. Dissolve instantly in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide , dissolve instantly in boiling sodium hydroxide.
Wool：Insoluble in room temperature hydrochloric acid, partially dissolve in boiling hydrochloric acid. Insoluble in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide , dissolve instantly in boiling sodium hydroxide.
Viscose：Dissolve in room temperature hydrochloric acid, dissolve instantly in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Polyester：Insoluble in room temperature hydrochloric acid, dissolve instantly in boiling hydrochloric acid. Insoluble in room temperature sulfuric acid , partially dissolve in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide , dissolve instantly in boiling sodium hydroxide.
Nylon：Dissolve instantly in room temperature hydrochloric acid, dissolve instantly in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Acrylic： Insoluble in room temperature hydrochloric acid, insoluble in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Vinylon：Dissolve instantly in room temperature hydrochloric acid, dissolve instantly in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve instantly in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Spandex： Insoluble in room temperature hydrochloric acid, insoluble in boiling hydrochloric acid. Dissolve in room temperature sulfuric acid , dissolve in boiling sulfuric acid. Insoluble in room temperature sodium hydroxide, insoluble in boiling sodium hydroxide.
Because the concentration and temperature of chemical reagents have obvious effects on the fiber dissolving properties, the experimental conditions should be strictly controlled when using this method.
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