Dogs
In the community , the dog will use the rarest way to greet a parked private car - lifting its legs to pee. Many people know that the pH value of dog urine is between 5.4-8.4, so some people ask, will dog urine corrode tires? And because driving safety is directly related to our lives, many people have begun to worry that the dogs in the community will one day send them to meet the Buddha. So, is there any scientific basis for the statement that dog urine can cause tire blowouts? We might as well do an in-depth study.
In fact, the substances contained in dog urine neither react with rubber, nor are its pH levels sufficient to corrode rubber, and the aging effect is almost negligible. The rubber on the surface of the tire mainly plays the role of wear resistance and shock absorption. What really plays a decisive role in the strength is the reinforcing fiber fabric inside the carcass, etc., which will not cause a puncture due to the aging of the outer rubber. In addition, since the surface of car wheels has undergone anti-corrosion treatment and has a certain resistance to strong acids and alkali, we do not need to react too much to the dog’s enclosure behavior.
Rubber tires resist aging
There are many types of rubber, from natural rubber (mainly polyisoprene) to various synthetic rubbers (such as styrene-butadiene) Rubber, butadiene rubber, isoprene rubber, etc.), almost all can be used in the production of rubber tires. Before rubber is made into tires, it has to go through a process of joining (also called vulcanization) - simply put, it uses chemical bonds to connect long-chain molecules of rubber so that it can be regarded as a large unit from a macro perspective. molecular. This process makes the chemical properties of rubber tires very stable, with high strength, elasticity, wear resistance and anti-aging properties.
Naturally, rubber molecules are not diamond, and the chemical bonds within them are not brittle and indestructible. For rubber, what is really lethal are some energy-laden rays, such as ultraviolet rays. Ultraviolet rays can break molecular chains, reducing the strength of rubber, and the aging of rubber is also mainly caused by this.
In order to delay the occurrence of aging, the rubber materials used in tires will add additives such as carbon black (so the tires are all black) to absorb ultraviolet rays. At the same time, carbon black can also serve as reinforcement Efficiency, so that the tire has sufficient hardness for use. Because the core of dog urine obviously does not contain high-energy rays, compared with ultraviolet rays, dog urine has no effect on the aging of tires.
Rubber tire corrosion resistance
In addition to anti-aging, tires also have excellent corrosion resistance - rubber itself is particularly resistant to corrosion. For example, in industrial production, pickling production lines often With rubber lining, protective gloves used for strong acid and alkali operations are also rubber.
Strong acid and alkali rubber protective gloves
Although there is no direct answer to this question Corrosion resistance tests on tire rubber, but some people have done such research on sealing rubber. The researchers used three types of sealing rubber (hydrogenated nitrile rubber) and soaked them in 30% ammonia water at 23°C for 28 days. They then found that their fracture elongation rates (a measure of material toughness) were the highest. It dropped by 18% (the genial performance balance of these three types of rubber is as high as 400%, and it is still as high as more than 300% after dropping by 18%); and soaked in sulfuric acid with a concentration of 3% at 70°C for 28 days, its fracture elongation rate is the highest A decrease of only 17% proves their strong resistance to chemical corrosion. It is generally believed that the quality of tire rubber is closer than sealing rubber, and its resistance to chemical corrosion will be stronger than the rubber used in the study.
The most important ingredient in dog urine is water, and there is also a small amount of uric acid and urea, making the pH value of dog urine generally between 5.4-8.4 (the pH value is used to express the pH value in aqueous solution hydrogen ion concentration). The hydrogen ion concentration of the 3% sulfuric acid used in the above experiment is about 0.6 mol/L, which is at least 150,000 times that of dog urine; and the pH of 30% ammonia is about 11, which is hundreds of times more alkaline than dog urine. It seems that the corrosive ability of dog urine is so negligible for tire rubber.
In addition to the low pH, how long does it take for dog urine to stay on the tire surface? It is also very short, and the amount that can be effectively retained is even less - even if the concentration of water evaporates slightly increases, in front of the dense and safe molecules of rubber, its effect is almost negligible.
There was a hidden reason behind the flat tire
Rumors mention that the side of the tire is the most vulnerable place, and dogs happen to urinate here. It is very likely that the tire will burst due to dog urine while driving, threatening life safety. There is such a speculation, which proves that the initiator does not know much about tires.
Typical tire outer structure
As can be seen in the picture, The rubber layer on the side is indeed relatively thin, but this is not the Achilles heel of the tire. The puncture has nothing to do with side corrosion.
In essence, the relationship between tire puncture and tire inner tube (some integrated tires do not have a separate inner tube, but the inner tube and outer tire are combined together). The function of the inner tube is to provide gas with a certain pressure and protect the gas from being leaked during use to achieve a shock-absorbing effect. Butyl rubber and chloroprene rubber with good air tightness are often used. However, inner tubes are generally soft and have low strength. They are easy to tear and cause punctures when stress occurs, so they must be protected by outer tires.
The strength of the tire that provides protection is provided by the belt layer and the ply (generally composed of high-strength polymer fiber fabrics or even steel wires). The main function of the outer layer of rubber is wear resistance. Therefore, the outer tire of the tire is equipped with a wear line to remind the wear status and prevent excessive wear from damaging the inner tube and causing bursting.
As for the side of the tire, since it does not contact the ground, the risk of wear and tear has nothing to do with a puncture. In addition, the possibility of dog urine not penetrating into the inner tube will not cause a tire burst due to direct contact with the inner tube.
Compared with excessive wear and tear, tire punctures caused by under-pressure are more likely to be ignored, and they are more likely to look for dog urine as the cause because they do not understand the cause of such punctures. When the tire is under-inflated but is running at high speed, a large amount of heat will be generated inside the rubber, causing the tire temperature to rise. At high temperatures, the mechanical properties of the rubber will drop sharply and its strength will decrease, leading to a tire blowout. Frequently checking the tire pressure and tire wear, inflating and replacing tires in time are the most effective ways to prevent tire blowouts, which is much more meaningful than paying attention to dog urine.
Specially talk about wheel hubs
According to the logic of rumors, the main reason for the corrosion of wheel hubs is that dog urine is a liquid containing ions, and metal in ions Corrosion of the battery will occur in the liquid. If corrosion occurs and continues, it will only be a matter of time before the efficiency leads to structural damage, vehicle crashes, and death.
I am very sorry that the above description is appalling. temporary carThe standard methods for measuring metal corrosion resistance in the industry include GB/T 10125-1997 "Man-made Air Corrosion Test-Salt Spray Test", etc. However, because corrosion mainly occurs on the surface, it is difficult to have an effect on the structure, so these standards do not address it. How much corruption can change the strength of a material. In fact, under the protection of rare anti-corrosion methods such as alloying, electroplating and coating, even corrosion is difficult to occur. The use of these methods in wheel hubs is already very familiar, and there is no need to worry about surface corrosion in normal use. .
To sum up, car owners can rest assured that dogs’ urine is not as strong as you think. To avoid the occurrence of tire blowouts, it is better to give them love regularly. Check the car. Of course, pet owners should not stop their dogs from peeing randomly just because dog urine will not corrode the feces. Since they live in the same community, everyone must be responsible and ethical residents, be civilized, and The ability to establish new trends makes everyone's life better.
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