2021-10-28 Pageview:357
1, It can maintain the “freshness” of furniture and other items because it can inhibit or prevent the growth of odor-causing bacteria and mildew (mold)
2, It can prolong the life of the articles because it can inhibit the growth of bacteria and mold, and can make the articles hygienic and clean
3, Anti-insect
4, The result of the treatment is durable and resistant to repeated cleaning and washing
5, Prevents odors due to other chemical protection properties
6, Good compatibility with substrates and processes within the range of permitted uses.
The proper combination of several polymerization inhibitors can significantly improve the polymerization inhibitory effect. For example, in the presence of sufficient oxygen, the cationization effect of the combination of hydroquinone and diphenylamine or the combination of p-tert-butylcatechol and phenothiazine is about 300 times higher than the effect of any one of them alone. The amount of polymerization inhibitor should be appropriate, too much will cause harmful effects. For example, when the dosage of iodine is 10-+mol/L, it is an effective polymerization inhibitor, but too much dosage will trigger the polymerization reaction; sodium nitrite is an effective ebs wax melting point polymerization inhibitor in the gas phase, but too much dosage will corrode the equipment. Excessive polymerization inhibitor not only increases the cost, but also affects the performance of the product.
The temperature has a great influence on the polymerization inhibition efficiency of the polymerization inhibitor. For example, oxygen is a very effective polymerization inhibitor at room temperature or slightly higher temperature, while at high temperature, oligomers containing peroxy bonds generated by oxygen and free radicals can decompose to form free radicals to initiate polymerization. Another example is hydroquinone monomethyl ether and tert-butyl catechol are effective polymerization inhibitors at low temperatures, but they will decompose at high temperatures and lose their inhibitory effect. Therefore, they are good polymerization inhibitors for monomer storage. It does not need to be removed before polymerization, it can decompose when heated and lose its inhibitory effect.
In addition to the above inhibitory effects, polymerization inhibitors can also be used to determine the initiation rate of the initiator. High-efficiency inhibitors such as DP PH and FeCl can quantitatively and quickly capture free radicals, which can be used to determine the initiation rate. In the process of radical polymerization, the initiation rate is the generation rate of primary radicals.
[R·] is the concentration of free radicals generated by the decomposition of the initiator at time/hour. When adding a polymerization inhibitor, R· is quantitatively captured by the polymerization inhibitor (Z), so
R,_[R.n([Z]一[Z])(4-60)
tt
n is the number of free radicals that can be captured by a molecule of polymerization inhibitor, after the end of the induction period [z]=0, so
n[Z], R=(4-61)
t
In the formula, [Z] is the initial concentration of the polymerization inhibitor, that is, the amount added; t is the time required for the polymerization inhibitor to completely disappear, that is, the induction period. From the above relationship, the initiation rate of the polymerization reaction can be measured, and the initiation efficiency of the initiator can be further determined when the decomposition rate constant of the initiator is known.
Leave a message
We’ll get back to you soon