Study On The Application Of The PAMST Soap-free Emulsion And Its Modified Products In Paper Making

In the paper, in order to develop multi-functional chemicals of recycled papermaking, the deinking properties of AM-ST copolymers (for short PAMST) soap-free emulsion and its modified products on water-based ink printed paper were investigated. In addition, the functions of drainage, retention and paper strength on the recycled corrugated paper pulp also were studies. In the first chapter, a series of PAMST were synthesized by soap-free emulsion copolymerization with acrylamide(AM), styrene(ST), The effects of AM content on the surface tension and the foam height of PAMST soap-free emulsions were discussed; The compatibleness between PAMST soap-free emulsion and low molecular surfactant were studied. In the second chapter, in order to optimize the process of deinking, the effect of pH,pulping time and pulping temperature on the deinking efficiency of water-based ink printed paper were discussed; The deinking efficiency of the complexes of PAMST soap-free emulsion and low molecular surfactant was studied. The results show that the most influence on deinking effect is pulping time. The complexes have the good deinking properties. In the third chapter, the deinking effects of hydrolytic products of PAMST soap-free emulsion on water-based ink printed paper were investigated. The results indicate that the deinking effects decrease with the degrees of hydrolysis of hydrolytic product increase. The complexes of hydrolysis product PAMST-11 and the cationic surfactant CTAB has better deinking effect witch can increase brightness by 5.3%ISO after deinking. In the fourth chapter, the applications of the modified products of PAMST soap-free emulsion in the recycled corrugated paper pulp were discussed. The results show that HC-55 can increase the ring pressure index and the dry tensile index by 36.8% and by 14.4% respectively, at the TX-PAMST dosage of 0.2%. However, HC-73 can increase the ring pressure index by 22.8% and increase the dry tensile index by 24.5%.HC-73 can decrease the degree of beating and turbidity of the white water of pulp by 29.9% and 57.4% respectively, at the TX-PAMST dosage of 0.2%.