Preparation method of powder polycarboxylic acids water reducing agent

Abstract

The invention discloses a preparing method of powder polycarboxylic dehydragent, which comprises the following steps: making polycarboxylic dehydragent form droplet in the atomizer; spraying in the drying chamber with the same flowing direction of hot air and material; setting the inlet temperature at 120-200 deg.c and vent temperature at 50-110 deg.c; drying; sedimenting to obtain the product.

Description

technical field [0001] The invention relates to a preparation method of polyacrylic acid dispersant powder, in particular to a preparation method of powder polycarboxylate water reducer. Background technique [0002] Concrete is a commonly used material in bridges, roads, construction and other projects. With the rapid development of construction industry and water conservancy projects, higher requirements are put forward for the performance of concrete. Adding water reducing agent is one of the means to improve the performance of concrete. [0003] The development of water reducing agent has a long history. From the early lignosulfonate to the successful development of β-naphthalenesulfonic acid formaldehyde condensate sodium salt (SNF) and sulfonated melamine formaldehyde condensate (SMF) in the 1960s, two high-efficiency water reducers , so that the development of concrete technology rose to a stage. All three types of superplasticizers are available in powder and liqu...

AI Technical Summary

Problems solved by technology

Due to the characteristics of the process route of this type of water reducer, most of it is supplied in the form of liquid. The supply method of this type of water reducer is widely accepted by customers because of its high performance, but its obvious shortcomings, Because it is supplied in liquid form, its effective content is usually 22% aqueous solution, and the cost of long-distance transportation is very high; in addition, in some application fields, powdered polycarboxylate water reducers are required, such as dry powder mortar, etc.

At present, there are very few powders of polycarboxylate superplasticizers. The main reasons are as follows: First, the water content of polycarboxylate superplasticizers is high due to the aqueous polymerization process, generally at 45%. Between -78%, it requires high energy consumption to prepare it into powder, and the expensive processing cost brings difficulties to the deep processing of such products: the second is that the molecular weight of polycarboxylate water reducer is relatively small , the softening point of the powder after drying is low, and when the processing temperature is higher than the softening point for a long time, the reactive groups of the water reducer may undergo side reactions such as imidization, resulting in yellowing of the product’s appearance, and at the same time, it is harmful to the dispersion of concrete performance degradation