| In order to develop polyurethane surfactants with higher surface activity and lower critical micelle concentration,polyurethane prepolymer,cetyl alcohol are synthesized from isophorone diisocyanate（IPDI）and N-methyldiethanolamine（MEDA）,cetyl alcohol（CA）and aminoethanesulfonic acid as capping agents,bromoalkanes and epichlorohydrin as quaternization agents.Anionic,reactive cationic and non-reactive cationic polyurethane surface actives are prepared by changing the molar ratio according to the reactivity of the functional groups of each component.The structure characterization and performance study of the prepared surface activity were carried out,and the results showed that:（1）Among the 2LC series surfactants with diamine structure:the Krafft point of the cationic polyurethane surfactant（2LC2-2）terminated with double long-chain alkanols and quaternized with short-chain brominated alkanes is 22.0～23.0,the surface tension is23.6m N/m,the critical micelle concentration is 3.0×10-4mol/L,the emulsion stabilization time to kerosene is 565.0s,and the foam stabilization（5min foam stabilization rate）is 88.0%;The terminal,long-chain brominated alkane quaternized cationic polyurethane surfactant（2LC4-2）has a Krafft point of 41.0,a surface tension of 30.4m N/m,and a critical micelle concentration of 2.5×10-4mol/L,the emulsion stability time is 1940.0s,and the foam stability is 97.7%.（2）Among the 3LC series surfactants with polyamine structure:the Krafft point of 3LC1-1 is 21.0～23.0,the surface tension is 25.5m N/m,and the critical micelle concentration is7.9×10-4mol/L.The emulsion stability time of 3LC2-2 is 23.0s,and the foam stability is 46.9%.The Krafft point of 3LC2-2 is 14.0,the surface tension is 27.6m N/m,and the critical micelle concentration is 5.3×10-4mol/L,the stability time is 16.2s,the foam stability is 41.7%.The Krafft point of 3LC2-3 is 10.5,the surface tension is 29.4m N/m,the critical micelle concentration is 9.2×10-4mol/L,and the emulsion stability time for kerosene is 18.2s,and the foam stability is 25.7%.（3）In the long-chain alkyl single-terminated anionic polyurethane surfactant:the surface tension of LA-10 is 33.4m N/m,the critical micelle concentration is 4.4×10-4mol/L,and the emulsion stability time to kerosene is 7680s,the foam stability is 82.6%;the surface tension of LA-20 is 46.1m N/m,the critical micelle concentration is 3.5×10-4mol/L,the emulsion stability time to kerosene is 108.0s,and the foam stability is 81.5%.Compared with the cationic surfactant 2LC series synthesized in this paper,the surface activity of the LA series anionic surfactant is slightly lower,but its emulsification and foam stabilization performance is better,especially the emulsification performance of LA-10,the emulsification time for kerosene is as high as 7680.0s.（4）Among the BC series surfactants end-capped by silicone and polyether long chain segments:the surface tension of the nonionic polyurethane surfactant BC is 43.1m N/m,and the critical micelle concentration is 7.5×10-4mol/L,the emulsion stability time to kerosene and paraffin is 30.7s and 13.3s,and the foam stability is 84.0%.The critical micelle concentration was 1.1×10-4mol/L,the emulsion stability time of kerosene and paraffin is 42.7s and 14.6s,and the foam stability is 43.8%.The surface tension of RBC-1 with reactive groups is 41.8m N/m,the critical micelle concentration is 9.4×10-5mol/L,and its emulsion stability time to kerosene and paraffin is 49.3s and 16.3s,foamability is 80.7%.Compared with BC and BC0-1.RBC-1have the best surface activity and emulsifying properties.（5）Three structures of 2LC2-2,2LC3-2 and 2LC4-2 are designed based on the polyurethane core 2LC of the diamine structure.The study found that:based on the steric hindrance effect and the difference in the reactivity of the raw materials,the 2LC3-2 system is a mixture of 2LC2-2 and 2LC4-2,that is,the cationic polyurethane surfactant with two heads and three tails cannot be prepared through the core of the diamine structure.（6）When preparing the polyurethane core LA,the molecular weight of its hydrophilic segment should not be too low or too high.If the molecular weight of the hydrophilic segment is too low,the hydrophilicity of the core is poor,which is not conducive to emulsification;if the molecular weight is too high,the association behavior of long hydrophobic chains in the core structure will be restricted and the surface activity will be reduced.（7）For the LA series surfactants with single-end capping of long-chain alkyl groups,they need to be re-capped with aminoethanesulfonic acid in a water bath,and the capping process should be designed in combination with the core structure and the freezing point of the reaction monomer. |
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