SU1301821A1 - Foamer for producing heat-insulating cellular concretes - Google Patents

Abstract

The invention relates to building materials, namely to foam formers used to prepare raw material mixtures of heat insulating cellular concrete without self-trenching. The purpose of the invention is to increase the multiplicity and durability of the foam and reduce the coefficient of thermal conductivity. The foaming agent contains, mag.%: Urea-formaldehyde resin 6-8, surfactant 0.2-0.3, oxalic acid 1.2-1.5, polyacetalglycol 0.05-0.2 and water the rest. 4 tab. with (L

Description

. The invention relates to building materials, namely, ENOCORPORATORS used to prepare raw material mixtures of heat-insulating cellular concrete without autoclave processing.

The purpose of the invention is to increase the multiplicity and durability of the foam and reduce the thermal conductivity of concrete

In the proposed foaming agent, the interaction of polyacetal glycol with a urea-formaldehyde resin makes it possible to increase the stability and stability of the foam.

Foam stability is associated with the influence of hydrogen ions and hydroxyl on the interaction of hydrophilic and hydrophobic parts of molecules that shift the equilibrium between the adsorption of the blowing agent and micelle formation. The chemical interaction of the PAG-hydroxyl groups with carbamide-formaldehyde resin hydrocarbon atoms leads to an increase in the length of the hydrocarbon chains with the formation of elastic surface films of foam bubbles, cured with oxalic acid, which increases the viscosity and stability of the foam.

The strength of the films increases, and in their place hydrophobic solid films form, significantly increasing the strength of the foam.

The stable foam frame contributes to less foam destruction during the preparation of the foam concrete mixture, which allows to obtain foam concrete with a lower bulk density. The structure of the foam concrete becomes more homogeneous and finely porous, and the thickness of the cellular partitions from the cement mortar is thinner, which leads to a decrease in the thermal conductivity of the foam concrete compared to foam concrete made on the known foaming agent.

The proposed frother is prepared as follows.

Prepare a 1p% solution of oxalic acid, and then the surfactant is mixed with heated water in a ratio of 1; 1 “After that, the urea-formaldehyde resin of 70% concentration is mixed with polyacetal glycol PAG-1 and a surfactant solution for 1 min. Then the rest of the water is poured in and the foam is stirred in at the speed of rotation of the blades of the foam.

, 15

ten

f5

20

25

thirty

35

40

45

50

55

agitators 250 rpm for 5-7 min. Then, oxalic acid solution is poured in, after which the whole mixture is stirred for 1-1.5 minutes and then the quality of the foam is checked: frequency, draft, after 1 h of liquid and the stability of the foam in the cellular mixture.

Table 1 shows the compositions of the foaming agents, on the basis of which cellular foam concrete mixtures with different bulk density were obtained. According to Table 1, five foaming agent compositions are prepared: compounds 2-4 are within the proposed limits, compounds 1 and 5 are outside, and composition 6 is made on a known frother.

From the analysis of Table 2 it follows that the frother, in which polyacetal glycol was introduced, has a higher foam ratio K and an increased utilization ratio of the foaming agent d, as compared with the known frother. In this case, the foam sediment in the compositions 2-4 is 6-8 mm, and the foam sediment in the composition is 6-13 cm.

On the basis of the obtained frother, mixtures of cellular concrete are prepared, the compositions of which are presented in Table 3.

The data of physicomechanical characteristics, studied by compounds 1-6, are given in Table 4.

Claims (1)

Invention Formula Foaming agent for the manufacture of heat insulating cellular concretes, including carbamide resin, surfactant, oxalic acid and water, characterized in that it contains carbamide-formaldehyde as a carbamide resin to increase the multiplicity and durability of the foam and reduce the thermal conductivity of the foam advanced polyacetalglycol in the following ratio, wt.%: Carb amidoformat - dehydric resin6-8 Surfactant0,2-0,3 Sorrel acid1,2-1,5 Polyacetalgly 11,05-0,2 WaterOstal Urea formaldehyde resin K-FC Ethoxylated apkylphenol (OP-7) Polyacetalglycol (PVH) Oxalic acid Albumin technical Water 0.15 0.20,250,30,3 0.04 0.05 OJ0.20.3 1.16 1.21,351,51,5 93.6592.5592.3090.088.9 Frequency ratio of K 14 foam . 17 Foam Resistance, 83 OL Components Cement 20. 20 25 30 3030 Filler (fly ash) 20 20 25 30 3030 at  Frother1,20,80,50,40,60,4 Water 58,859,249,539,639,439,6 Table 1 4.9 one 4.9 89.2 Table 2 18201815 0,850,870,800,8 Table3 Bulk weight, kg / u Compressive strength MPa Heat conductivity coefficient, W / (m-K) 150 0.3 150 0.5 200 0.7 300 1.0 330 1.0 300 0.6 0.075 0.06 0.07 0.08 0.11 0.1 Tabl4 200 300 330 300 0.7 1.0 1.0 0.6