In the days when Mommy is not around, does your wardrobe also have the same “beating when mom sees it” scene?
The result of random stacking is that each piece of clothing is as wrinkled as the waste paper you throw into the trash can.
If you want to be lazy, you can stroke or pull it with your hands, but the pleats will not move at all without any shame. You must use an iron to tame them.
Why do clothes wrinkle so easily?
Moreover, compared to polyester (polyester fiber), nylon (nylon, polyamide fiber) and other synthetic fiber clothing, as well as wool, silk clothing ,Cotton and linen clothes are more likely to wrinkle.
Cotton and linen come from the villi of the seeds of the Gossypium plant (left) and the stems of flax (right) respectively | Source: Wikipedia
Synthetic fibers are mostly polymerized from petrochemical raw materials; the main component of wool and silk is protein; while the main component of cotton and linen is plant cellulose.
Cellulose molecular structure (part) | Source: Wikipedia
Each Cellulose molecules are long-chain polymers composed ofhundreds or thousands of glucose units linked hand in hand. The glucose units in cellulose like to make friends around them and formhydrogen bonds with other glucose units.
Each long cellulose molecule contains a crystalline region and Amorphous region (amorphous region). Although the crystalline regions of cellulose are tightly arranged, limiting their freedom of movement, thenon-crystalline regions between cellulose are loosely bonded, and hydrogen bonds are easily broken.
Schematic diagram of cellulose microstructure | Source: Chengjun Zhou & Qinglin Wu (2012)
Hydrogen bond is a secondary bond formed between a hydrogen atom and a highly electronegative atom (such as oxygen, nitrogen, fluorine). The force is stronger than the van der Waals force between molecules, but far less reliable than intramolecular chemical bonds (such as covalent bonds).
Hydrogen bonds between water molecules | Source: Min Lamb
Pressure Under slight “coercion” by external factors such as temperature and temperature, the boat of friendship can capsize at any time, and the fragile hydrogen bonds can be broken at any time, and then the cellulose molecules go to “hook up” other friends.
If it is only wrinkled for a short time, it is still good to pull it back, but if it is kept in the closet for a long time, Cellulose will have enough time to form more hydrogen bonds with its surrounding partnersAfter the structure stabilizes, it cannot easily return to its original state.
When washing clothes, in addition to the mechanical force that will distort the clothes, water molecules will also jump into the cellulose, disrupting their original order and causing the fibers to The element slides to a greater extent and forms new hydrogen bonds.
Especially for natural fabrics with strong water absorption, if you do not shake them flat and then dry them, the clothes will definitely become more “pretty” after drying, and they will be “pretty” enough to wear. 100% return rate when you go out.
The wet paper becomes wrinkled after it dries, which is also due to the “chaotic confusion” between water molecules and hydrogen bonds.
The clothes are wrinkled like this, so the only way to fix them is with an electric iron. The hot steam released by the iron willbreak the hydrogen bonds of the cellulose in the folds, while applying pressure to force the molecules into their proper positions, restore their formation, and reconnect the hydrogen bonds.
If you can’t find the iron at the moment, you can also try washing it again.clothes, then straighten them out and hang them to dry.
For those in the late stage of lazy cancer, who really don’t even want to bother with ironing, it is recommended to choosesynthetic fibers or blends of synthetic fibers and natural fibers. clothing, but at the same time, you have to give up the comfort and breathability of pure cotton and linen clothing.
A more thorough way to be lazy is to strangle wrinkles in the cradle.
A traditional anti-wrinkle method is to use starch to “size” the clothes, and then they can be fried.There are Many branchescan form hydrogen bondswith cellulose molecules, binding the cellulose.
Source: “Working Cells”
But starch is soluble, The anti-wrinkle effect disappears after just one wash.
If you want to fight wrinkles for a long time, you still have to do something serious – Replace the hydrogen bonds between cellulose molecules with strong covalent bonds.
In the early 20th century, people began to use urea and formaldehyde to treat cotton fabrics, allowing them to enter the gaps between cellulose and interact with them. The cellulose reacts to form a strong covalent bond to “tether” the cellulose. This reaction process is called “Cross-linking“, and the chemical substance that acts as a cross-linking agent is called across-linking agent or anti- Wrinkle finishing agent.
Urea, yes, it is the metabolic waste in urine, and it is also the nitrogen fertilizer that nourishes plants; FormaldehydeFormalin, which is often used to soak animal specimens, is a formaldehyde aqueous solution with a concentration of about 37%. It has the functions of fixing (cross-linking) macromolecules (such as proteins) and antiseptic and sterilizing, and has a pungent smell. , those who “smell” it cry; everyone is more familiar with its status as a carcinogen. After the home is decorated, you have to wait for it to dissipate before you can move in.
The formalin used to soak animal specimens is a formaldehyde aqueous solution
Can As you can imagine, the clothes treated in this way will smell bad, and they may also irritate the skin, threaten health, easily turn yellow, and damage fabrics.
In the 1950s, the American chemist and inventor Ruth Logan Benellito was known as the “Queen of Cotton” strong>(Ruth Rogan Benerito) invented an anti-wrinkle technology while working in the United States Department of Agriculture (USDA) laboratory: treating cotton fabrics with maleic acid (maleic acid), when the temperature reaches At temperatures above 160°C, this acid is catalyzed by sodium hypophosphite to cross-link with cellulose to achieve an anti-wrinkle effect.
Ruth Logan Benellito holds 55 invention patents | Source: Wikipedia
In the era of the rise of synthetic fibers with better anti-wrinkle properties, Benellito’s anti-wrinkle treatment technology is considered to have saved the cotton industry.
In the 1960s and 1970s, a new anti-wrinkle finishing agent – DMDHEU (dimethylol dihydroxyethylene Urea resin, referred to as 2D resin) was developed. Because of its low price and good effect, it is naturally favored by the textile industry.
DMDHEU (red) cross-linked cellulose molecules (blue) | Source: c&en
But the synthesis of DMDHEU is also inseparable from urea and formaldehyde. Clothes treated with it will still release free formaldehyde and damage the fabric. When natural fabrics are treated in this way, their texture becomes more like synthetic fibers.
Later, people made some improvements to the anti-wrinkle treatment technology using DMDHEU, such as using titanium dioxide catalyst during cross-linking. Reducing the production of formaldehyde can also reduce the loss of color and wear resistance of fabrics. In addition, the etherification treatment of DMDHEU can also reduce the amount of formaldehyde released.
To this day, DMDHEU is still one of the most commonly used anti-wrinkle finishing agents.
The textile industry is also developing formaldehyde-free anti-wrinkle finishing agents, such as BTCA (1,2,3,4-butane tetrahydrofuran) Carboxylic acid), it not only can give cotton fabrics a good anti-wrinkle effect, but combined with a catalyst, it will also cause less damage to the wear resistance and other aspects of clothing.
The molecular structure of BTCA, which combines with cellulose through esterification reaction | Source: pubchem
But the problem is that BTCA is expensive, its cost is 10 times that of DMDHEU, and the catalyst it requires – sodium hypophosphite is a phosphorus-containing compound , will lead to eutrophication of water bodies, and toxic phosphine compounds are also easily generated during the reaction.
Citric acid, chitosan and other natural anti-wrinkle finishing agents are non-toxic, harmless and inexpensive, and have anti-wrinkle effects. Not ideal.
So when it comes to anti-wrinkle clothing, you can’t have your cake and eat it too, so let’s learn how to fold and iron clothes from Mom first╮(╯ ▽╰)╭.
Mama: How come your clothes are wrinkled like this?
Me: Mom, please listen to my explanation, this is due to hydrogen bonding.
left;”>But the problem is that BTCA is expensive. Its cost is 10 times that of DMDHEU, and the catalyst it requires – sodium hypophosphite is a phosphorus-containing compound. It will lead to eutrophication of water bodies, and toxic phosphine compounds are easily generated during the reaction.
Citric acid, shell Polysaccharideand other natural anti-wrinkle finishing agents are non-toxic, harmless and not expensive, but the anti-wrinkle effect is not very satisfactory.
So in clothing In terms of anti-wrinkle, you can’t have your cake and eat it too, so let’s learn how to fold and iron clothes from Mama first╮(╯▽╰)╭.
Mama: How come your clothes are wrinkled like this?
Me: Mom, listen to my explanation. Blame hydrogen bonding.
