How to formulate the Polycarboxylate Superplasticizer high performance water reducer?

Introduction 

As the latest generation of high-performance water reducer, polycarboxylic acid water reducer is different from traditional ordinary water reducer. It has strong dispersibility in concrete, high water reduction rate and small slump loss of concrete. It is a major breakthrough in the history of water reducer, so it will become the focus of researchers' in-depth optimization research in the future. In addition to the "molecular design" method in the mother liquor synthesis technology, polycarboxylic acid high-performance water reducer products also use small materials such as retarders, air entraining agents, defoamers, thickeners, and anti-mud agents to adapt to the concrete construction needs of different seasons, different materials and mix ratios, and finally obtain high-performance water reducers with excellent performance.

For polycarboxylic acid manufacturers with mother liquor synthesis technology, it is a must to start with polycarboxylic acid synthesis technology to develop high-quality polycarboxylic acid water reducers required for concrete and obtain different types of functional mother liquors. However, the synthesis and practical application of mother liquors require a period of time, and one type of mother liquor cannot solve the many problems faced by water reducers in engineering applications. Mastering the compounding of mother liquors and the physical compounding of auxiliary small materials is a necessary supplement for the application of polycarboxylic acid water reducers. It is very critical to solve the technical problems faced by engineering sites through the characteristics of mother liquors and the physical compounding of small materials. Therefore, the compounding technology of polycarboxylic acid water reducers is the focus of future researchers.

1. Formulation of mother liquors of polycarboxylic acid water reducers/Polycarboxylate Superplasticizer 

The formulation of mother liquors of polycarboxylic acid water reducers can adjust the molecular side chain density of its products, taking advantage of their strengths and making up for their weaknesses. In many cases, the compounding of mother liquors can achieve the effect of 1+1>2. The effect that a single mother liquor cannot achieve can be achieved by compounding multiple mother liquors. Of course, the prerequisite is to synthesize a variety of monomer mother liquors with excellent quality and different properties. It is worth noting that polycarboxylic acid series cannot be compounded with naphthalene series, melamine series, aminosulfonate, etc.

2. Formulation of polycarboxylic acid water reducer with functional small materials

In order to cope with the problems faced by various projects at the actual construction site, higher requirements are placed on the working performance of concrete. At this time, the compounding of mother liquors alone may not fully meet the requirements. The performance of concrete may be further improved by adding some functional small materials (retarders, air entraining agents, thickeners, etc.). Adding retarders is an important small material to adjust the setting time of water reducers to adapt to different temperature conditions. Sometimes adding certain retarders will help reduce slump loss, but it cannot be used as an effective method to inhibit slump loss. At the same time, in the process of compounding retarders, we should pay attention to the fact that retarders have a certain water-reducing effect, which should be considered in the process of compounding with water reducers. Concrete bleeding is a common problem in engineering, and functional small materials such as air entraining agents and thickeners can play a role at this time. Adding air entraining agents can increase the air content in concrete and improve its bleeding and viscosity. However, it should be noted that the air content of concrete should not be too high, otherwise it will cause the concrete strength to be too low. In the process of compounding polycarboxylic acid water reducer and functional small materials, researchers must make compatibility issues with polycarboxylic acid water reducer in advance. The amount of small materials of functional components needs to be reasonably controlled to avoid side effects as much as possible.

Conclusion and Outlook

⑴ Looking back on the development and promotion of polycarboxylic acid water reducer in China over the past decade, during this period, we have completed the continuous improvement and updating of polycarboxylic acid water reducer, and its performance has become increasingly perfect, and the gap with countries such as Japan has been continuously narrowed. Although there are still some problems with polycarboxylic acid water reducer in concrete engineering and other fields, which to a certain extent limit the wider promotion and application of polycarboxylic acid water reducer, we firmly believe that with the accumulation and deepening of basic theoretical research on polycarboxylic acid water reducer by scientific researchers and the summary and improvement of engineering practice experience, polycarboxylic acid high-efficiency water reducer will definitely be oriented to engineering with better technical and economic performance, thereby promoting the faster development of concrete technology.

⑵ In the future, polycarboxylic acid water reducer will inevitably gradually replace traditional ordinary water reducer and occupy a larger share in the market. Researchers must accelerate the research process of variety series diversification. At present, all the three types of mother liquors on the market, namely ordinary type, slow setting type and early strength type, are far from enough. More functional mother liquors should be developed for compounding or use in other occasions to meet the requirements of engineering for concrete performance.

⑶ The development of polycarboxylic acid water reducers with specific functionality is also a future development direction. With the gradual depletion of natural sand, a large amount of machine-made sand and artificial sand will be used on engineering sites in the future. Sand with high mud content and high stone powder content is bound to affect the performance of concrete. Researchers should increase their efforts to develop anti-mud and anti-stone powder polycarboxylic acid water reducers.