Preparation And Application Of CPAM-Hydroxypropyl Chitosan-PAE Composite Strengthening Agent

Using old corrugated paper as one of the main corrugated board material can reduce the using of virgin fiber, and low prices can improve economic value, can protect the environment. But due to the defect of old corrugated paper, the property of products is not good, in order to accommodate the application requirement of paper packaging materials, a novel papermaking agent should be developed.In this paper the composite strengthening agent(CPAM-HPCS-PAE) was prepared with hydroxypropyl chitosan(HPCS), CPAM and PAE resin through the cross-linking reaction. The ratio of three kinds of additives, the dosage of crosslinking agent, reaction time and reaction temperature are considered to improve the reinforcement of CPAM-HPCS-PAE. The results show that when m(HPCS):m(CPAM):m(PAE) is 3:7:5, dosage of crosslinking agent is 4wt%, reaction time is 2.5h and reaction temperature is 45℃, the strengthening effect is maximum.First 11#OCC and domestic waste corrugated paper were sieved by fiber classifier, the paper strength of fiber after sieved and different fiber composition of 11#OCC and domestic waste corrugated paper were examined. Second the composite strengthening agent is used in the preparation of corrugated base paper what is used waste paper fiber as raw material, the effects of strengthening, retention and drainage of pulp was examined, and compared the effects with CPAM/HPCS/PAE mixture and CPAM. The results showed that: the results show that the macrofiber of 11#OCC is more than domestic waste corrugated paper, but fiber fines is less, and the paper strength of 11#OCC is better, when the ratio is 3:7, the tensile index and ring crush index are maximum; when the dosage is 0.5wt%, the sheet ring crush index, tensile index, burst index and fines retention rate reaches maximum, respectively to 9.55 N·m·g-1, 45.3N·m·g-1, 3.21 k Pa·m2·g-1and 95%, The effects are better than CPAM and CPAM/HPCS/PAE mixture. The wet strength of sheet is enhanced and water recycling is better after the composite strengthening agent added.Test methods such as Infrared Spectroscopy(IR), Scanning Electron Microscopy(SEM) and Zeta Potential Analyzer, are applied in this research to investigate the reinforcing mechanism of the CPAM-HPCS-PAE compound reinforcing agent. It is shown that the reinforcing roles of the self-prepared reinforcing agent lie in two main aspects. First, the hydroxyl and amine group in the reinforcing agent can form the hydrogen-bonding with the fibers, which will strength the hydrogen-bonding and also increase the bonding areas between fibers. Second, with the positive charges in the self-prepared reinforcing agent improving the retention of fiber fines, the evenness and ring crush strength of the paper are improved.