The Preparation Of Modified PFR And The Application Of The Resin In Papermaking Process

It had reported that modified phenol-formaldehyde resin was used in papermaking as retention and drainage aids, however, it hadn't reported that whether the modified phenol-formaldehyde resin could be used in papermaking as intensifier. So, reseaching the characteristics of the phenol-formaldehyde resin with different substituents and the strengthen mechanism of the resin to paper would have great theoretic and guidance significance to produce and use the modified phenol-formaldehyde resin.An anionic phenol-formaldehyde resin which synthesized by phenol, formaldehyde and some amine compound such as diethylamine, triethylamine and diethylene triamine was studied in this paper, and this modified phenol-formaldehyde resin was used in papermaking as an intensifier.In the preparation of modified phenol-formaldehyde resin, the influence was studied on modified phenol-formaldehyde resin with reaction temperature,reaction time,composition of furnish and catalyst. It has shown that the optimum condition to modify phenol-formaldehyde resin were phenol﹕formaldehyde﹕diethylene triamine(molar ratio) 1﹕0.8﹕0.015, reaction temperature 95～105℃and reaction time 2h, when using diethylene triamine as modifying agent. Under this condition, modified phenol-formaldehyde resin was synthesized and analyzed through the IR spectrum.In application of modified phenol-formaldehyde resin in OCC pulp, firstly the application effictiveness of phenol-formaldehyde resin modified by triethylamine and diethylene triamine in OCC pulp was researched, and the optimum application effictiveness was gotten through mon- factor trial. It has shown that the tensile index and ring crush index of handsheets were increased by 15.90% and 9.65%, when phenol-formaldehyde resin modified by diethylene triamine was used in OCC pulp alone (the dosage of resin was 1.0%), and then adding cationic starch to pulp (the dosage of starch was 1.0%), the tensile index and ring crush index of handsheets were increased by 32.81% and 29.29%. Through the optimizing trial, the dosage of modified phenol-formaldehyde resin and cationic starch were gotten, and the optimum dosage of modified phenol-formaldehyde resin and cationic starch were 0.3% and 0.7%, and then, tensile index and ring crush index were increased by 35.28% and 26.50%.There had strength enhancing efficiency when adding modified resin and cationic starch to pulp. Through the optimizing trial, the dosage of phenol-formaldehyde resin modified by triethylamine and cationic starch were gotten, and the optimum dosage of modified phenol-formaldehyde resin and cationic starch were 0.5% and 0.8%, and then, tensile index and ring crush index were increased by 21.83% and 23.52%. Considering the strength enhancing efficiency of phenol-formaldehyde resin modified by triethylamine and diethylene triamine in OCC pulp, the efficiency of phenol-formaldehyde resin modified by diethylene triamine was better than triethylamine. From the crosslinking trial of cationic starch and modified phenol-formaldehyde resin, the tensile index and ring crush index of handsheets were increased by 31.27% and 27.22%, when the mass ratio of cationic starch and modified phenol-formaldehyde resin was 1﹕4,crosslinking temperature was 70℃.In study on strengthen mechanism of modified phenol-formaldehyde resin,through measuring the Zeta potential of pulp with two ways by adding cationic starch alone and adding modified phenol-formaldehyde resin firstly then adding cationic starch, the reason of the influence in Zeta potential of pulp and strength of paper was expounded when adding cationic starch and modified phenol-formaldehyde resin. From the analysis on scanning electronic microscope to the rupture and surface of the paper, cationic starch and modified phenol-formaldehyde resin could increase the combination of fibers.