| The current situation of the research, development and application, together with the development trend of paper intensifiers technique both at home and abroad were summarized in this paper. According to the characteristics and in view of the insufficiency of polyaminoamide-ephichlorohydrin resin (PAE), which was used as one of paper wet strengthening agent, PAE with high solid content is prepared. Also, a series of polyaminoamide-ephichlorohydrin resin (PAE)-styrene(St) graft copolymers such as PS, MPS were prepared by emulsion copolymerization of PAE and St. Further more, the process of preparation and application of them were discussed as well. Concrete work and major achievements included were as follows.1. Initiated by catalyzer, the PPC was synthesized by adipic acid and diethylenetriamine as raw materials. Then with PPC and EPI, the PAE resin with a solid content of 35% was synthesized through condensation polymerizations. After that step, a study to determine the factors influencing the synthesis of PAE was discussed. Afterwards, to further study, the application process of PAE with high solid content was explored. The results showed that the optimum reaction conditions was as follows: the mass ratio of diethylenetriamine to adipic acid, EPI to PPC were 1.5 : 1, 1.1:1 respectively, dosage of initiating agents was 1.0%, temperature of heat preservation was 170℃, temperature of condensation reaction was 60℃. While applied in softwood pulp, when the beating degree was 35-45°SR, pH value was 6-8 and the dosage of PAE was 1.0%, the wet strength agent provided the satisfactory effect.2. Initiated by Ammonium persulfate - sodium bisulfite((NH4)2S2O8-NaHSO3), the PS emulsion was synthesized by PAE and styrene as raw materials. Then the preparation conditions of PS were discussed in detail, and the effects of the PS emulsion on the intensity of paper sheets were investigated as well. The results revealed that when the pH value of reaction system was around 8,heat preservation time was 3h, the dosage of initiator was 0.7%,the dosage of acrylic was 8% to total amount of reactants and the mass ratio of St to PAE was 2:1, the PS emulsion as strengthening agents achieved a very good effect on the reused board pulp and bleached softwood pulp.3. Initiated by catalyzer, the PPC was synthesized by adipic acid and diethylenetriamine as raw materials. Then with PPC and ethyl hexyl acrylate, the modified polyamine MPPC was synthesized through polymerizations/. After that, MPAE resins were synthesized with MPPC and EPI (ephichlorohydrin). And then MPS was prepared through graft copolymerization with MPAE and St as the required two reactants. Various reaction conditions affecting the properties and the applications of MPAE and MPS were researched in detail, furthermore, applications of MPS on different pulps were studied. As it turned out, the MPS resins performed well when the pH value of graft reaction system, heat preservation time, the initiator dosage, the mass ratio of styrene to PAE and the dosage of MPS resins in reused board pulp and bleached softwood pulp were around 8, 3h, 0.7%, 2:1, 1.0% and 0.8% (based on oven dry pulp) , respectively.4. Mechanisms of PS emulsion and MPS emulsion as reinforcing agents of paper was discussed.
|
PDF Full Text Request