Application of alkenylsuccinic anhydride
ASA is composed of unsaturated alkene skeleton linked with succinic anhydride. It is usually produced in two steps: first, unsaturated straight chain or branched olefins (a-olefins) are isomerized by double bond shift, that is, a-olefins are isomerized to endoolefins. The ASA thus produced is liquid at room temperature. This is an important condition for emulsifying sizing agent in paper mill. In the second step, the isomerized olefin mixture reacts with maleic anhydride to obtain ASA raw material through addition reaction and corresponding refining under certain temperature, pressure and catalyst.
This product is a highly reactive sizing agent. The hydrolysis rate and activity half-life are very short. With the help of charge adjustment and bridging of emulsifier, stabilizer, accelerator and retention aid, ASA can coagulate and flocculate, thus showing good retention on the fiber. The commonly used supporting agents are quaternary ammonium cationic starch (1%), polyacrylamide (0.02%) and methylene dithiocyanate (3%) × 10) Cationic polymer containing polyamines (0.2% promoter). The dosage of ASA was 1%.