Abstract: Using lauryl alcohol polyoxyethylene ether (AEO) and isophorone diisocyanate (IPDI) as raw materials,a novel nonionic surfactant AEO-IPDI-AEO (AIA) was synthesized and used for the deinking of recovered waste coated paper.The optimum conditions for synthesis of AIA were examined with whiteness and residual ink concentration as criteria.The structures of the products were characterized by FT-IR and ¹H NMR.The AIA product was blended with other surfactants to examine the deinking effect of blend deinking agent.Results show that the better synthesis conditions of AIA are:n(AEO₇)∶n(IPDI)=2∶1;reaction temperature,(60±2) ℃;reaction time,2 h.The deinking effect of deinking system achieves the best at pH=8.The structural characterization shows that the synthesized product is the target product.Compared with commercial deinking agents,AIA deinking agent displays better deinking effect on coated paper;while for newsprint and typing paper,the deinking effect shows no difference.Test result for blend of AIA and sodium fatty alcohol polyoxyethylene ether sulfate according to the mass ratio of 1∶2 shows that the coated paper whiteness reaches 71.9%,and the concentration of residual ink is only 58.5 mm²/m².Similarly,test result for blend of AIA and nonylphenol polyoxyethylene ether at a mass ratio of 1∶2 shows that the coated paper whiteness reaches 71.3%,and the concentration of residual ink is only 61.4 mm²/m².

Key words: nonionic surfactant, deinking, coated paper, whiteness, residual ink concentration