The significance of promoting the use of polycarboxylate superplasticizer monomers
(1) Save energy and resources
At present, China is in a period of rapid development and construction, and the relative shortage of energy resources is an important issue that restricts rapid development. On the one hand, polycarboxylate superplasticizer monomers have good compatibility with admixtures, promoting the application of industrial by-products. On the other hand, with their high water reduction rate, they can save a large amount of cement. This means that a project can save thousands of tons of cement, alleviate the current shortage of resources and energy, and play an important role in reducing environmental pollution caused by clinker burning, which is in line with the development direction of green building materials.
(2) Low environmental load promotes the development of green building materials
Formaldehyde is a highly toxic substance and ranks second on the priority control list of toxic chemicals in China. Formaldehyde has been identified by the World Health Organization as a carcinogenic and teratogenic substance, a recognized source of allergic reactions, and one of the potential strong mutagens. Research has shown that formaldehyde has strong carcinogenic and pro carcinogenic effects. The impact of formaldehyde on human health mainly manifests in olfactory abnormalities, irritation, allergies, lung dysfunction, liver dysfunction, and immune dysfunction.
Naphthalene based water reducing agent is a naphthalene sulfonic acid formaldehyde condensate. Industrial naphthalene is sulfonated with concentrated sulfuric acid, and then a certain amount of formaldehyde reacts with naphthalene sulfonic acid to form formaldehyde condensate. Finally, it is neutralized with alkali to obtain a mixture of sodium salt and sodium sulfate of naphthalene sulfonated formaldehyde condensate, which is called naphthalene based water reducing agent. Synthesis is divided into four reaction steps, namely sulfonation reaction, hydrolysis reaction, condensation reaction, and neutralization reaction. The condensation reaction requires a large amount of formaldehyde, which causes pollution to the environment. If the synthesis process is not properly controlled during production, the product is easily contaminated with a large amount of free formaldehyde, causing secondary pollution to the environment during transportation and use.
In order to further control indoor environmental pollution and improve the indoor environmental quality of civil construction projects, the Ministry of Construction and relevant departments have proposed to strengthen the control of formaldehyde pollution in concrete admixtures. They have proposed to control the ammonia pollution in concrete admixtures while also controlling the formaldehyde pollution in concrete admixtures, effectively avoiding excessive formaldehyde in the indoor air of bare houses. The synthesis of polycarboxylate superplasticizer adopts aqueous solution free radical polymerization, and the entire process is free of formaldehyde and other harmful emissions, with no wastewater or exhaust gas emissions, which is in line with the development direction of green building materials.
Meanwhile, the use of polycarboxylate superplasticizers is beneficial for alleviating the greenhouse effect of CO2. In 2008, China's cement production was 1.39 billion tons, and its CO2 emissions were 6.2 billion tons, surpassing the United States and ranking first in the world. Polycarboxylate water reducer, with its high water reduction rate, can reduce cement by 10-15% and reduce CO2 emissions by 100-200 million tons.
