How were the goblins able to escape from the plastic products inside the car? أداة الاختبار –

How were goblins able to escape from plastic products in car interiors

“The air in the car will smell. »

\"Car interior materials will emit small molecules.\"

With media reports and consumers paying more attention to health, the above two phrases are becoming more and more popular. carpets, leather, glue, fabrics, plastic parts, etc., volatile organic compounds and odors in the car increase. With the trend towards lightweighting and increasing requirements for design customization, the use of plastic products in automotive interiors is also increasing, which also leads to an increase in dispersion.

So where do these little elves in plastic products come from?

We know that most plastic products are polymer compounds. These compoundsArtificial substances are mainly synthesized by chemical reactions through small molecular substances extracted from petroleum. The synthesis process is diverse and will introduce all reaction monomers, solvents, catalysts, etc., and if these substances do not react completely, they will follow the polymer in the next steps and eventually end up on the interior parts of the car and will slowly distribute into the interior environment of the car. For example, ABS is commonly used in automobiles, because the reaction solvent is ethylbenzene, a certain amount of ethylbenzene residue will be found during the dispersion test of parts. Is the dispersion of plastic products caused by these residues? Of course not...

Since polymer compounds have long polymer chains, they are sensitive. When affected by high temperature, radiation, oxidation by oxygen, etc., a breakage of the macromolecular chains will also occur. . On the one hand, this breakage will cause changes in physical properties; on the other hand, it is likely to produce low molecular weight organic compounds that volatilize into the environment. Let\'s take two polymers commonly found in car interiors: polypropylene and polycarbonate as examples to see how they evolve.

Polypropylene is a thermoplastic polymer with an olefin chain, which can be seen in many places in our daily lives. However, due to the presence of methyl groups on the polypropylene chain, carbon atoms are easily attacked, leading to degradation reactions:

From the reaction mechanism below above we can see that polypropylene When attacked by free radicals and with the participation of oxygen,beta degradation occurs and further aldehydes (VII) are produced. When this chain break occurs at the end of the chain, acetaldehyde is produced. Acetaldehyde is produced every time this happens. Therefore, the dispersion of acetaldehyde is higher than that of polypropylene in the tests.

In addition to aldehydes, olefin degradation will also produce other volatile organic compounds. We performed GC-MS analysis on common polypropylene alloy products on the market. From the results, we can see that different volatile substances representative of alloy products are also different.

Polycarbonate is also a common engineering plastic that is widely used in various plastic alloys. Polycarbonate is often used in car headlights and even car roofs.

According to the polycarbo synthesis processnate, the residues are mainly halogenated hydrocarbons or phenol. Thermal oxygen degradation of polycarbonate also produces primarily compounds containing benzene rings. However, due to their relatively large molecular weight, they rarely diffuse into the interior environment of the vehicle in the form of volatile organic compounds.

Through the introduction above, I think everyone should better understand how these little goblins came out of Pandora\'s box.

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