What is the basic structure of polyester and how to clean polyester fabric correctly

Polyester fabric is a common textile fabric used in daily life. From the perspective of its molecular composition, polyester fabric is composed of short aliphatic hydrocarbon chains, ester groups, benzene rings and alcohol-terminated hydroxyl groups. These structures will lead to its high crystallinity and orientation, so polyester fabric has good wrinkle resistance. Because polyester fabric is not easy to deform, so when cleaning, hand wash, machine wash, dry cleaning can be done, next let's learn about it.

What is the basic structure of polyester

1. Chemical structure

The basic composition of polyester is polyethylene terephthalate, the molecular formula [-OC-ph-Cooch2CH2O -]n, so it is also called polyester fiber (PET), the chemical structure of its long chain molecules is H(OCH2CCOCO)NOCH2CH2OH, the relative molecular weight is generally about 18000~25000. In fact, small amounts of monomers and oligomers are present. These oligomers have a low degree of polymerization and exist in a circular form. Polyethylene terephthalate (PTA) and ethylene glycol (EG) were synthesized by direct esterification and condensation of ethylene terephthalate 9BHET.

From the perspective of polyester molecular composition, it is composed of short aliphatic hydrocarbon chain, ester group, benzene ring, alcohol hydroxyl group. In addition to the existence of two alcohol hydroxyl groups, there is no other polar groups, polyester fiber hydrophilicity is very poor. The polyester molecule contains about 46% ester group, which can be hydrolyzed and pyrolyzed at high temperature, and soaplyzed when encountering alkali, which reduces the degree of polymerization. Polyester molecules also contain aliphatic hydrocarbon chains, which can make polyester molecules have a certain flexibility, but because there are benzene rings in polyester molecules that cannot rotate internally, polyester macromolecules are basically rigid molecules, and the molecular chains are easy to keep linear. Therefore, dacron macromolecules are easy to crystallize under this condition, so dacron has higher crystallinity and orientation.

2. Physical structure

The polyester fiber produced by melt spinning method has circular cross section and no special longitudinal structure observed in microscope. The filamentous fibrillar tissue can be observed under the electron microscope. The special-shaped fiber can change the elasticity of the fiber, make the fiber have special luster and bulk property, and improve the fiber's gripping performance and covering ability, as well as anti-pilling, reducing static electricity and other properties. For example, triangular fibers have flash effect. Five - leafed fibers have a fatty luster, feel good, and resistance to pilling. Hollow fiber due to internal cavity, low density, good heat preservation.

3. Aggregation structure

Measured by electron diffraction, the thickness of dacron folded chain wafer is about 10NM, and the length of dacron single base is 1.075NM. Therefore, it can be considered that the wafer thickness is equivalent to the length of nine dacron molecules single base. However, the chain length of dacron macromolecular chain is about 1.075*130 (average degree of polymerization) =140NM, so it can be seen that dacron macromolecular chain must be folded chain structure. Folding is likely to occur at the -CH2-CH2- segment because the chain here is more flexible and easy to bend. In addition, because dacron macromolecules can also form straight chain crystals (fibrillated crystals). It can be seen that folded chain crystals and fibril crystals coexist in dacron. The proportions of the two kinds of crystals vary with the tensile ratio and thermal setting conditions.

How to clean polyester properly

Polyester fabric is not easy to deform, so hand wash, machine wash, dry cleaning can be done, if there are special washing instructions, should be washed according to the requirements. When washing polyester fabrics by hand, the washing temperature should be below 45 degrees Celsius, soaked in cold water for 15 minutes, and then washed with common synthetic detergent, such as laundry detergent, soap, detergent, etc. Cleaning, in the collar, cuffs and other dirty parts available brush wash. After washing, rinse with clean water, can be lightly twisted, put in a cool ventilated place to dry, can not be exposed to the sun, should not be dried, so as to avoid wrinkles after heat. Machine washing, pay attention to use about 30 degrees of warm water wash, after washing in a cool place to dry.