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Cationic polyester

Time:2019-06-23 Hits:


Cationic polyester

Cationic dyeable polyester, chemical name: polybutylene terephthalate (elastic polyester); English name: cationic dyed polyester; abbreviation: PBT, also used in the factory CD. Cationic polyester belongs to denatured/modified polyester and can be dyed with cationic dyes at 110 C.

Modification of Cationic Polyester Fiber

Cationic dyeable polyester is modified by copolymerization of polyester dyeable modifier, such as dimethyl isophthalate-5-sodium sulfonate (commonly known as trimer, English abbreviation SIPM) with polyester. Sulfonic acid group is introduced into the polyester molecular chain after copolymerization, which can be dyed with cationic dyes. The dyed fabric has bright colour, high dye exhaustion rate, greatly reducing the discharge of printing and dyeing wastewater, and copolyester. Chips can also increase antistatic, pilling and moisture absorption properties, which is one of the main methods to improve the dyeing properties of polyester fibers in recent years. The blend spinning of 4 cationic dyeable polyesters containing sulfonated isophthalate units and 1 block copolymer of ethylene glycol/polyethylene glycol/sulfonated sodium isophthalate/terephthalic acid by Yonigika Company of Japan can produce ultrafine fibers with high dyeing depth. Cationic activator and a small amount of modifier are added to BHET before or during spinning. Hydroxyethyl Acids) Copolymerization. The spinnability of the copolymers is improved after they are made into random linear copolymers. The modified polyester not only can be dyed with cationic dyes, but also has anti-pilling property and improved wrinkle recovery.

Cationic Polyester Properties

The melting point of cationic polyester prepared by SIPM copolymerization is lower than that of ordinary polyester, and its crystallinity is lower than that of ordinary polyester, which makes dye molecules permeable easily, makes the fibers easy to dye, improves the absorptivity and improves the hygroscopicity.

The molecular weight, crystallinity and strength of cationic polyester fibers are lower than those of ordinary polyester fibers, and the pilling resistance of cationic polyester fabrics is better than that of ordinary polyester fibers. The Young's modulus of cationic polyester is 10%~30% lower than that of ordinary polyester, so the fabric of cationic polyester is also softer than that of ordinary polyester.

In addition, the alkaline hydrolysis rate of cationic polyester is much faster than that of ordinary polyester. Therefore, the alkali reduction rate of cationic polyester fabric is much higher than that of ordinary polyester fabric at the same temperature.

Cationic polyester not only guarantees cationic dyeability, but also increases the micropore of the fibers, improves the dyeing rate, permeability and moisture absorption of the fibers, thus further adapting to the silking simulation of polyester fibers; through silking simulation, the fabric can be soft, breathable, comfortable, antistatic, dyeable at room temperature and atmospheric pressure; through cationic modification, the multi-functional wool imitation can make the fabric soft, antistatic and dyeable. Anti-pilling, co-dyeing with wool at room temperature and pressure.

Fabrics made of cationic modified fibers have the following characteristics when dyed with cationic dyes:

1. Bright tone, good deep dyeing;

2. High hygroscopicity;

3. Good light fastness and fading fastness;

4. The compatibility of dyes is good when dyeing with color combination.

5. In high temperature dyeing bath, the stability is good.

6. It has little contamination to other fibers, including ordinary polyester fibers.

7. The diffusion rate to the fibers is fast and there is no ring dyeing phenomenon.

8. When the pH value changes in the dyeing bath, the dye has high stability.

Cationic modified polyester filament and polyester filament can not be distinguished, if you want to distinguish, you can only use dyeing method! Cationic raw materials are generally dark!

The following picture shows the contrast between cations and glossy polyester fibers. In fact, it is very difficult to distinguish with the naked eye.

Cationic fabric

Cationic fabrics are cationic yarns with special treatment, such as cationic polyester yarn or cationic nylon yarn.

One of the characteristics of cationic fabrics is the two-color effect, which can be used to replace some color-woven double-color fabrics to reduce the cost of fabrics. This is the characteristic of cationic fabrics, but it also limits its characteristics. In the face of multi-color fabrics, cationic fabrics can only be replaced by cationic fabrics.

Cationic fabrics have bright colors and are suitable for use as artificial fibers, but they have poor color fastness to light and washing of natural cellulose and protein fabrics.

The wear resistance of cationic fabrics is also very good. After adding some artificial fibers such as polyester and spandex, the strength and elasticity of cationic fabrics are higher, and the wear resistance of cationic fabrics is second only to nylon.

Cationic fabrics have some chemical properties, such as corrosion resistance, alkali resistance, bleaching resistance, oxidants, hydrocarbons, ketones, petroleum products and inorganic acids, as well as some physical properties, such as ultraviolet resistance.


Sources: Encyclopedia of Chemical Fibers, Baidu Library, Causes and Control of Dyeable Cationic Polyester Uneven Dyeing, by Wu Danfeng

Edited by Dr. Sai Shangfang Bu