| The concrete mold releasing and curing material is refers to a material that can complete two processes of mold releasing and curing when concrete molding cast. It can not only play the role of mold release agent, but also curing agent, is a new expression in the construction technology. Compared with the traditional process, a lot of manpower and financial resources can be saved by using it. Presently, concrete release agents and curing agents are in a rapid development and application stage, and have shown a various of goods and grown strength situation. However, many problems still exist, such as the product quality varies, no uniform and rigorous test criterion, and products uneven development, lack of high-performance product for plain concrete and reinforced concrete. Therefore, research and development high-performance mold releasing and curing agents become an urgent task to concrete industry development.Konjac glucomanan (KGM) is the main component of konjac tuber, is an excellent natural polymer, and a mixed polysaccharide. KGM has excellent film-forming, adhesion, water retention, hydrophilicity, bio-degradation and so on, so widely used in the chemical, petroleum and food industries. But natural konjac flour generally has some shortcomings, such as greater molecular weight, poor solubility and rheology, hydrosol instability, limiting its application. So, KGM has being a hot spot in recent years, and made great progress. However, these studies mainly involved in food and biomedical materials fields, has not been reported in concrete release agent or curing agent. In this paper, konjac flour was as the raw material, some modification methods were used to prepare concrete mold releasing and curing agent.Main tasks and conclusions were as follows:(1)Ethanol purification and citric acid purification methods were used to konjac flour purification, it showed that:compared with ethanol purification method, citric acid purification KGM has better antimicrobial properties and hydrosol stability. The optimum conditions of citric acid purification were:swelling temperature 60℃, pH=5.0～6.0, swelling time 1h. (2)KGM were modified by chloroacetic acid, NaOH, pyrophosphate, sodium acetate methods, and the film-forming and antibacterial properties were detected to determine the best method to prepare concrete mold releasing and curing integrated material, it showed that: chloroacetic acid modified product when in a alkaline condition had moderate viscosity, good stability, film uniformity and surface smooth, good toughness. (3)Analyzed the factors raw material ratio, pH, time and temperature effecting on the viscosity of modified products, and determined the optimal modification conditions were:when the KGM:chloroacetic acid=1:(0.8 ～0.9), reaction temperature 60℃, pH=8.0～9.0, dissolving time 3h, the sol viscosity 76.23～85.20mPa.s. (4)The integration material was used for concrete mold releasing and curing experimental, it showed that:it meet the concrete industry standard JC901-2002 and JC/949-2005 requirements. It was suitable for steel and wood templates releasing agent, not for plastic template, and more suitable for high-grade concrete mold releasing. (5)FT-IR characterization and thermal analysis were used in modified KGM, it showed that:FT-IR analysis showed the main chain of the modified KGM primary structure has not changed, still the pyranose glucose and pyranose mannose to P-D glycoside linkage formed. Deacetylation reaction occurred in the alkaline condition, the hydroxyl methyl was introducted, increasing the solubility of the molecule. Thermal analysis showed that the thermal stability of the modified products did not change significantly, but the thermal decomposition was higher, more stability. The concrete mold releasing using temperature range was-5～40℃, so it would not affect the thermal stability.
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