Preparation And Application Of PAE Wet-strength Agent For Household Paper

With the improvement of people’s living standard, household paper has becomethe necessity in daily life. At present, the raw material of life paper in the paperindustry has been gradually transformed from native wood pulp to waste paper pulp orthe mixed use of virgin wood pulp and waste paper pulp. However, the application ofPAE is restricted by the toxic byproducts which are hydrolyzed by epichlorohydrin to1,3-dichloro-2-propanol (DCP),3-chloro-1,2-propanediol (CPD) and a small amount ofresidual epichlorohydrin.The wet strength agent used in the household paper must beenvironmental friendly. If PAE were used in the production of household paper, theamount of by-products must be reduced to reach the environmental protectionrequirements. In this paper，a way to reduce the amount of byproducts was studied.Technological conditions of synthetic reaction of PAE and combined withpost-processing was the way to reduce the amount of byproducts. Concrete work andmajor achievements included were as follows.1. The Synthesis of PAE is divided into two steps. Firstly, PPC was synthesizedby adipic acid and diethylenetriamine which was one of the important materials forpreparing PAE. And then, PAE was prepared by epoxidation using PPC and EPI. Astudy to determine the factors influencing the synthesis of PAE, the organic chlorinecontent of it and stability was discussed. The results showed that when the adipic acidand diethylenetriamine as the raw material, the mole ratio of them were1:1.05, theamount of catalyst (mole ratio of the total raw materials) is1%, temperature of heatpreservation was165℃, and the time is4h, EPI to PPC were1.2:1, the temperature ofepoxidation condition is60℃,and the time is4h, then the time of post-processing inorganic amine is6h, the high solid and low chlorine wet strength agent provided thesatisfactory effect.2. The application process of high solid and low chlorine PAE as wet strengthagent was also discussed. The results revealed that the optimum application conditionswas as follows: the ratio of wood pulp and waste pulp is7:3, the beating degree of thepulp is40°SR, the dosage of PAE is1%, the pH of the slurry is7-8which adjusted byadding aluminum sulfate.. Then the paper’s properties are the best. Mechanisms ofPAE as wet strength agent of paper and the structural changes during storage werediscussed.3. The method of repulping wet-strength paper was studied. Using the acid-base method can get better repulp yield.