The Wet-preparation Of Switterionic Guar Gum And Its Application In Cigarette Paper

Guar gum derivatives because of its combustion without a peculiar smell and no toxic side effects, is widely used in cigarette paper. Cationic guar gum and nonionic guar gum are now commonly used. But in recent years papermaking wet end had a huge change, for example, making an alkaline system instead of an acid system,white water circulation system is highly closed and so on. In order to adapt to these changes, we must adopt a new wet chemical process, so as to ensure the normal running of a paper machine. Compared to the cationic guar gum, amphoteric guar gum charge is nearly neutral, have little effect at the height of closed loop system for wet end, and therefore has better application effect.In this paper a new type, Zwitterionic Guar Gum (ZGG), was prepared by reaction of guar gum and N-(2.3-epihydric propyl)-N-(carboxymethyl)-N, N-dimethylammonium hydroxide (ECDH), the ECDH was prepared in advance by reaction of DMGC and epichlorohydrin. There was a simple study on the viscosity and degree of substitution of the pH of the modified guar gum. DSC was used in the quantative determination of DMGC, and the structure of the ZGG was characterized by IR spectrum. In a single factor experiment to optimize the synthesis of ZGG, the results show that the optimal reaction conditions are: alkali / guar gum mass ratio of 1.25 x 10^-2, reaction temperature of 70℃, reaction time 6h. The guar gum DS can reach 0.43.In a reaction of cationic guar gum with chloroacetic acid, there is synthesis of traditional amphoteric guar gum. The synthetic process are discussed. The results show that: the alkali / guar gum mass ratio of 1 x 10^-2, reaction temperature of 70℃, reaction time of 2h are the optimum reaction condition, the carboxymethyl degree of substitution is 0.343.Study the cationic guar gum, traditional amphoteric guar gum and Zwitterionic Guar Gum addition rate on the Zeta potentials and the paper properties was performed. The experimental results show that: the cationic adding amount will increase pulp Zeta potential and can make it be more positive, and have a bad influence on wet end. On the other hand the addition of amphoteric guar gum will not increase the Zeta potential. By comparison, Zwitterionic Guar Gum has smaller influence than traditional amphoteric guar gum. Addition of Modified guar gum, has small effect on the paper's tensile strength and air permeability, can significantly improve the whiteness of the paper, accelerate the drainage speed, and improve filler retention.The experiment results of modified guar gum used in white water circulation shows that: with an increase in the number of circulation, white water concentration gradually increased; adding cationic guar gum, white water Zeta potential will continue to rise; adding the amphoteric guar gum, white water Zeta potential does not change; Zwitterionic Guar Gum for almost potential changes is not affected; the paper tensile strength and air permeability will have small fluctuations; and the whiteness of the paper will change.