Zibo guansheng chemical co. LTD
Contact: manager gao
Contact number: 86-0533-5887828
Fax number: 86-0533-5887829
Mobile phone number: 13581018111
Web site: www.chinaguansheng.cn
Company address: longquan industrial park, zibo city, shandong province, China
Zibo guansheng chemical co., ltd. introduces to you the classification knowledge of water loss reducing agents such as N, N '-2-cyclohexyl carbon diimine (DCC) :
Modified natural products as water loss reducer
Modified cellulose is a kind of water loss reducing agent widely used in water-soluble natural products. CMC (carboxymethyl cellulose), HEC (hydroxyethyl cellulose), CMHEC (carboxymethyl hydroxyethyl cellulose), etc. CMC produces flocculation in cement slurry with strong retarding property, which is no longer used. The comprehensive performance of HEC is satisfactory with a few applications. CMHEC is widely used in foreign countries, but its domestic production is rare, and no application has been reported. The common disadvantages of modified cellulose are poor water solubility, high viscosity, poor temperature resistance and delayed development of cement strength. Chemical grafting copolymerization of cellulose with other functional monomers is a good way to improve the properties of cellulose.
2. Polymer water loss reducer
There are many kinds and excellent properties of synthetic polymer water-loss reducers, which are incomparable to some natural products.
1) nonionic polymer
PVA (polyvinyl alcohol) system is a kind of nonionic water-loss reducing agent widely used in China, with unique advantages. Typical products include the G60S of tianjin zhongyou boxing company. The system using temperature is 95 ℃, higher than the temperature after crosslinking keys are destroyed, fluid loss performance becomes poor. In addition, the system has poor NaCl resistance, which is usually less than 5%. In order to improve the poor temperature and salt resistance of the PVA system, chemical cross-linking can be used to modify the PVA. For example, the alcohol group of the PVA can be condensation reaction by using the condensation mixture such as aldehydes or acids to obtain partially cross-linked PVA. Chemical crosslinking of PVA used alone, do not need borax crosslinking agent, such as heat resistance up to 120 ℃, salt can reach 8%, the filtration volume can be controlled under 50 ml.
2) anionic polymer
Anionic polymer is one of the most widely studied and most product-type water loss reducer at home and abroad. Its copolymer monomers include non - ionic and anionic monomers. Non-ionic monomers mainly include AM (acrylamide), NVP (n-ethylene-pyrrolidone), NNDMA (N, n-dimethylacrylamide), St (styrene), VI (ethylene-imidazole), VFA (ethylene-formamide), VP (ethylene-pyridine), VMAA (n-methylene-n-ethylene-acetamide), etc. Among these monomers, AM is easy to hydrolyze, so the content in the copolymer cannot be too much. NNDMA introduces hydrolytic groups which are difficult to be hydrolyzed, and its high temperature resistance is obviously enhanced. Anionic monomers mainly include two types: one is sulfonate monomers, such as AMPS (2-acrylamide -2-methyl-propionic acid), SS (styrene sulfonate), VS (ethylene sulfonate), PS (propylene sulfonate); The other is carboxylate monomers, such as AA (acrylic acid), MAA (methacrylic acid), HEA (hydroxyethyl acrylic acid), IA (iaconic acid), etc. AMPS has strong temperature and salt resistance, high polymerization activity, and has been widely used in China.
3. Environment-friendly water-loss agent
With people's increasing attention to environmental protection, foreign researchers have increased the research and development of environment-friendly water-loss agent in recent years. The so-called environmental water-loss agent refers to the product with better biodegradability. At present, the main ways to develop environment-friendly water loss reducer are as follows :(1) develop natural products with the function of water loss reduction; (2) modify the existing natural product dehydrating agent to broaden its application range; (3) develop water loss reducer that is stable in strong alkaline environment but degraded in neutral water medium; (4) low molecular weight macromolecules were crosslinked with degradable crosslinkers to obtain high molecular weight water loss reducer; (5) the degradable synthetic polymer is modified to have the function of reducing filtration loss; (6) the development of synthetic macromolecular water-loss reducer with structure similar to natural products and biodegradable by microorganisms.