A kind of modified guar gum and preparation method thereof

Abstract

A modified guar gum and a preparation method thereof relate to the field of vegetable gum modification. Aiming at the defects in the prior art, a modified guar gum with high yield and a preparation method thereof is provided without high temperature and strong alkali conditions. In the method, guar gum is added to the mixed solution of organic matter-water, and then polymerizable functional monomers and initiators are added therein to undergo a heterogeneous reaction to obtain modified guar gum; the functional monomers include N-ethylene 2-pyrrolidone and N-alkylsulfonated acrylamide, and the characteristic functional groups include but not limited to sulfonic acid groups and heterocyclic groups. The method has mild conditions, does not require alkalization, and the reaction does not need to be carried out under a nitrogen atmosphere; the yield of the obtained modified guar gum can reach 100%, and it has high-efficiency viscosity-increasing and temperature-resistant properties. The mass concentration of 0.1% can make the viscosity When it reaches 40mP·s and the mass concentration is 0.3%, its viscosity remains above 70mP·s in the temperature range of 20-80°C.

Description

technical field [0001] The invention relates to the field of vegetable gum modification, in particular to a preparation method of modified guar gum. Background technique [0002] Plant gums such as guar gum have good water solubility, cross-linking, suspension and thickening effects, and are biodegradable. They are environmentally friendly substances and will not pollute the surrounding environment. They have a wide range of applications. For example, it can be used as ice cream emulsification stabilizer and water-retaining agent for cans in the food industry, as a fracturing fluid thickener and drilling fluid suspension agent in the petroleum industry, as a printing paste in the textile industry, and as a drug carrier in the pharmaceutical industry, etc. , In addition, it is widely used in many industries such as papermaking, printing, explosives, fire extinguishing agents, pesticides, cosmetics, etc. [0003] However, plant gums, such as guar gum, also have some disadvant...

AI Technical Summary

Problems solved by technology

However, the alkali resistance and temperature resistance of plant gums are generally poor. For example, guar gum is prone to degradation and loses its proper properties when it is above 80°C. Many chemical reaction processes, such as etherification and grafting, must be A certain yield can only be ensured at a higher temperature, so this method is easy to destroy the molecular structure of vegetable gum

Grafting modification is a new modification method in recent years. Because functional monomers can be prepared separately, and then interact with vegetable gums under mild conditions, it avoids the exposure of vegetable gums to adverse environments such as strong alkalinity and high temperature. , however, the yield of the graft modification method is extremely low, and it is mainly used for laboratory theoretical research at present, and it is difficult for large-scale industrial production

The reason is that this modification method uses a homogeneous reaction, which is only suitable for grafting between small molecular compounds. Due to the high-efficiency viscosity-increasing characteristics of vegetable glue, a very small amount of vegetable glue can form a very high viscosity in water , so that the system is difficult to flow, so that the graft modification is difficult to carry out, and it is not suitable for the reaction between natural macromolecules and small molecules. Therefore, the usual graft copolymerization method controls the concentration of vegetable gum in the aqueous solution to a very low range. (such as less than 1%), and nitrogen protection is required, which directly leads to low yield and high production cost

Images