What is fiber acetate (and what are its advantages)

“From nature, but also return to nature”

Cellulose acetate, the English name is cellulose acetate, referred to as CA. Acetate fiber is divided into diacetate fiber and triacetate fiber, which is a type of man-made fiber. Chemical fibers are made from cellulose as raw material and converted into cellulose acetate through chemical synthesis. First prepared in 1865, it is an acetate ester of cellulose. A thermoplastic resin obtained by esterifying cellulose with acetic acid or acetic anhydride under the action of a catalyst. It is a chemically modified natural polymer obtained by esterifying the hydroxyl groups in the cellulose molecule with acetic acid. Its properties depend on the degree of acetylation.

01

Classification of acetate

According to the degree of substitution of hydroxyl groups by acetyl groups in cellulose, it can be divided into diacetate fiber and triacetate fiber fiber.

Diacetate is a type of acetate formed after partial hydrolysis, and its degree of esterification is lower than that of triacetate. Therefore, the heating performance is not as good as that of trivinegar, the dyeing performance is better than that of trivinegar, and the moisture absorption rate is higher than that of trivinegar.

Triacetate is a type of acetate that does not undergo hydrolysis and has a high degree of esterification. Therefore, it has strong light and heat resistance, poor dyeing performance, and low moisture absorption rate (also called moisture regain).

In the molecular structure of cellulose acetate, the hydroxyl group on the glucose ring of cellulose is replaced by an acetyl group to form an ester bond. The fiber is less esterified than triacetate due to hydrolysis. The supramolecular structure of diacetate fiber has a larger amorphous area, while triacetate fiber has a certain crystalline structure, and the symmetry, regularity, and crystallinity of the fiber macromolecules are higher than those of diacetate fiber.

02

The structure of acetate fiber

The longitudinal fiber surface is smooth, relatively uniform, and has obvious grooves; due to its cross-sectional shape It can be seen that the fiber has no skin-core structure and is in the shape of a clover leaf. The periphery is smooth and has few shallow serrations.

03

Acetate fiber performance

Chemical Properties

1. Alkali resistance

Weak alkaline alkali agent basically does not cause damage to acetate fiber, and the fiber weight loss rate is very small. After encountering strong alkali, especially diacetate fiber, it is prone to deacetylation, resulting in weight loss, strength and modulus. Therefore, the pH value of the solution used to treat cellulose acetate should not exceed 7.0. Under standard washing conditions, it has strong resistance to chlorine bleaching and can also be used for dry cleaning with perchlorethylene.

2. Resistance to organic solvents

Cellulose acetate is completely soluble in acetone, DMF, and glacial acetic acid, but insoluble in ethanol and perchlorethylene. Based on these characteristics, acetone can be used as a spinning solvent for acetate fiber, and tetrachlorethylene can be used for dry cleaning of acetate fiber fabric.

3. Acid resistance

Acetate fiber has good acid resistance and stability. Common sulfuric acid, hydrochloric acid, and nitric acid will not affect the strength, gloss, and elongation of the fiber within a certain concentration range; but it can be dissolved in Concentrated sulfuric acid, concentrated hydrochloric acid, concentrated nitric acid

4. Dyeing properties

Although cellulose acetate is derived from cellulose, during the esterification process, a large part of the polar hydroxyl groups on the glucose ring of cellulose are replaced by acetyl groups to form esters , Therefore, the dyes commonly used for dyeing cellulose fibers have almost no affinity for acetate fiber and are difficult to dye. The most suitable dyes for acetate fibers are disperse dyes with low molecular weight and similar dye uptake rates.

The acetate fiber or fabric dyed with disperse dyes has bright and bright colors, good level dyeing effect, high dye absorption rate, high color fastness, and complete chromatography.

Physical properties

1. Acetate fiber not only has a certain degree of water absorption, but also has the ability to be quickly removed after absorbing water

2. The thermal stability of acetate fiber is good. The glass transition temperature of the fiber is around 185 ℃, and the melting termination temperature is around 310 ℃. At the end of the heating, the weight loss rate of the fiber is 90.78 %; the breaking strength of fiber acetate is 1.29 cN/dtex, and the strain is 31.44%.

3. Density ratio of fiber acetate Viscose fiber is smaller and closer to polyester; its strength is the lowest among the three fibers.

4. Acetate fiber The elasticity is relatively good, similar to silk and wool

5. The shrinkage rate of boiling water is low, but high-temperature treatment will cause damage to the fiber. Strength and gloss will be affected, so the temperature should not exceed 85 ℃

Is acetate fabric comfortable to wear?

1. Divinegar has good breathability and antistatic properties

In an environment with a relative humidity of 65%, diacetyl vinegar has the same hygroscopicity as cotton and better quick-drying performance than cotton. Therefore, it can absorb the evaporated water vapor of the human body well and at the same time Drain out. Thus making people feel comfortable. At the same time, good moisture absorption properties can reduce the accumulation of static electricity and make it less likely to produce static electricity.

2. Second vinegar has a soft touch

Initial modulus diagram of △ fiber

The initial modulus is low, and the fiber is weakly rigid and easy to bend under a slight load, showing a soft character, thus giving the skin a smooth, soft and comfortable feel. But if the initial modulus is too low, it will appear weak.

The initial modulus is high, and the fiber has strong rigidity and is not easy to bend under a small load, showing a stiff character.

3. Divinegar has outstanding deodorizing performance

△Comparison chart of deodorizing performance of diacetyl vinegar, cupro, cotton and polyester

△Diacetate, copper Comparison of deodorizing performance of ammonia, cotton and polyester (2)

Why does acetate fabric have a good appearance?

1. Divinegar has a pearl-like soft luster

△The structure of mulberry silk, acetate fiber and polyester

Mulberry silk has an irregular triangular cross-section, and acetate fiber has irregular concave and convex cross-sections. Both have longitudinal stripes on their longitudinal sections. Its horizontal light is diffuse reflection, and its longitudinal light is also diffuse reflection. The refractive index is lower, 1.48. Therefore, mulberry silk has a pearl-like soft luster.

2. Acetate fiber has excellent drapeability

Fiber initial modulus 30-45cn /dtex has weak rigidity, irregular concave and convex cross-section, soft fabric and good drape

3. Darkmode has bright and bright colors and color fastness

△Color fastness comparison chart (level) of each fiber when saturated with color

Fiber acetate color has a complete color spectrum, full and pure color, and excellent color fastness.

4. Acetate fiber has good dimensional stability

The expansion of acetate fiber to moisture It has low sex resistance, so it has good dimensional stability after being made into fabrics and maintains its beauty when wearing.

5. Divinegar has relatively balanced antifouling properties

For dust, water-based, Oily stains with these three ingredients are difficult to stain and easy to clean