Preparation method of controlled-release type urea formaldehyde foamed plastic deacidification agent

Abstract

The invention discloses a preparation method of a controlled-release type urea formaldehyde foamed plastic deacidification agent, and relates to a preparation method of the deacidification agent. The method comprises the following steps of: firstly loading an alkaline substance on a carrier with a cellular structure, causing a macromolecule aqueous solution capable of having crosslinking reaction to form a wrapping layer on the surface of the carrier, feeding the resulting carrier into a crosslinking agent solution to cause the macromolecular substance to have crosslinking reaction to form a gel, encapsulating the carrier, and at last carrying out the steps of filtering, separating, drying and the like to obtain the controlled-release type urea formaldehyde foamed plastic deacidification agent. The deacidification agent can effectively solve the problems of the decomposition of a urea formaldehyde resin caused by the acid residue in the urea formaldehyde foamed plastic and the corrosion of an alkaline cement. In addition, the carrier with the cellular structure simultaneously has strengthening and toughening functions, so that the foamed plastic added with the deacidification agent is higher in strength, better in toughness, and improved in the hard while bristle defect and easy crack defect.

Description

technical field [0001] The invention relates to a preparation method of an acid scavenger, in particular to a preparation method of a slow-release urea-formaldehyde foam plastic acid scavenger. Background technique [0002] Foam plastic is a kind of polymer material formed by a large number of gas micropores dispersed in solid plastic. Compared with pure plastic, foam plastic has low density, light weight and high specific strength. Its strength increases with the increase of density. It has the ability to absorb impact load, has excellent cushioning and shock absorption performance, sound insulation and sound absorption performance, low thermal conductivity, good heat insulation performance, excellent electrical insulation performance, and has corrosion resistance and mold resistance. [0003] Urea-formaldehyde foam is a kind of foam plastic, which is a kind of porous rigid foam plastic. It is mainly used as insulation material. characteristics of poison. In developed cou...

AI Technical Summary

Problems solved by technology

The test results show that the pH value of the residual acid in the cured urea-formaldehyde resin foam is about 3.5. This part of the residual acid in the foam has two major adverse effects: 1. Under the joint action of temperature and humidity, the cured urea-formaldehyde resin The lower the pH value of the resin, the higher the degree of hydrolysis of the resin, the greater the amount of formaldehyde produced by the decomposition of the resin, the foam will crack, deform, and even pulverize, and finally the foam will lose its thermal insulation effect

2. When urea-formaldehyde foam is in contact with water vapor or water, the acid remaining in the foam will dissolve in the water. When used as a building insulation material, urea-formaldehyde foam and alkaline cement should be in close contact, but with The acidic solution will continuously corrode the cement, which will make the gap between the foam and the cement bigger and bigger, until delamination and falling off occur, causing casualties and property losses

But adopting this method has the following disadvantages: the first, ammonia gas itself is a kind of gas with strong pungent smell, which affects the health of operators, and ammonia gas is also very easy to leak

Second, the above process must be done during draining, otherwise the ammonia gas will not be able to dissolve in the water to neutralize the residual acid

Third, since the urea-formaldehyde foam is still undergoing a curing reaction during the drainage period, and the curing reaction mainly occurs in the range of pH = 3 to 4, too fast an acid removal rate will affect the curing of the foam. Therefore, it is necessary to find a The operating conditions are mild, and the slow-release acid scavenger that can neutralize after the curing is basically complete has become the goal pursued by people.