Study On Preparation Of Rosin Ester And Its Emulsion

In this dissertation, rosin esters, new rosin-based emulsifiers, rosin ester emulsions were made from rosin. The optimum synthesis conditions were obtained and the properties of the products were tested.An efficient and rapid method of synthesizing rosin pentaerythritol ester is described under microwave conditions in a closed system. This unprecedented synthesis both significantly improves the performance of the products and reduces reaction times, compared to conventional conditions. Furthermore, an orthogonal test of L9(34) was also designed in order to study factors affecting the color and acid value of the products. The optimum reaction conditions are the amount of catalyst R-1 0.15% and pentaerythritol 12% of the refined rosin, respectively, the reaction time 40 min, the microwave power 220W. Under these conditions, the product which has Gardner color 4, acid value 12.7mg/g, softening point 102℃is produced.Maleic rosin pentaerythritol ester of light color and high softening point was made from refined rosin, maleic anhydride and pentaerythritol. The effects of reducing agents, catalysts, color-lighting agents, raw material ratios and reaction time on product performance were emphatically investigated. At the same time, the optimal condition was obtained through the experiments. The amount of maleic anhydride, reducing agent SHHP, catalyst R-1and color-lighting agent M-6 are 13%, 0.3‰, 3‰and 3‰of the refined rosin, respectively. The addition time is 60min; the esterification time is 150min. Under this condition, the product which has Gardner color 3, acid value 9.8 mg/g, softening point 159℃is produced.During the preparation of rosin-based emulsifier, the effects of type and amount of polyol and phosphating agent dosage were emphatically discussed. The results show that with zinc oxide as esterification catalyst whose dosage is 0.4% of rosin acrylic, the molecular weight of polyglycerin 10, 000 and its volume 15%, polyol consumption nOH / nCOOH 0.5, phosphating agent dosage nAPA : nP 3.2:1, a new rosin-based emulsifier with critical micelle concentration 1.2×10-6mol/L, surface tension 28.1mN/m, lime soap dispersing power 4.8%, Krafft point less than 0℃, emulsifying properties more than 7 days is obtained.Finally, the rosin eaters of different softening points were made into emulsions, with self-made emulsifier RH-1. The effects of emulsifier dosages and its addition methods, operating conditions and other factors were investigated and the optimum conditions were determined. Compared RH-1 with commercial emulsifiers, it is concluded that RH-1 is better than commercial emulsifiers, obviously. RH-1 could make rosin esters of different softening points into emulsions whose solid content are greater than 50%. The emulsions obtained also have good low-temperature storage stability, room temperature storage stability and thermal storage stability. Adding the emulsion into PSA, it could made the initial adhesion and 180°peel strength improved greatly.