纤维素疏水改性及其在稳定油包油Pickering乳液中的应用

Hydrophobic modification of cellulose and its application in stabilizing oil-in-oil pickering emulsion

油包油乳液不仅具有传统水油乳液传质传热方便、聚合效率高的优点,同时其无水条件为水敏感单体、催化剂的反应提供理想场所,在异氰酸酯、酰氯、茂金属催化烯烃聚合领域具有广阔的应用前景.但现阶段油包油乳液的稳定剂不仅种类匮乏,且制备流程复杂,严重制约了该领域的发展.本研究以生物质材料纤维素颗粒作为反应物,采用异氰酸酯偶联法在纤维素颗粒表面通过氨基甲酸酯键接枝长烷基链,实现对纤维素表面润湿性的调控,同时引入极性和非极性链段,并进一步利用烷基链功能化纤维素稳定油包油乳液.研究结果表明,异氰酸酯偶联法成功地在纤维素表面接枝烷基链,纤维素极性的亲水表面变为疏水表面(WCA=142.8°),且功能化纤维素对十二烷包DMF型油包油乳液有很好的稳定作用.最后,在十二烷包DMF乳液中利用异氰酸酯与硫醇反应成功制备了聚硫氨酯微球.本研究的开展为油包油乳液提供一种新型、工艺过程简单、制备方法高效的稳定剂,在一定程度上推动油包油乳液的发展.

The oil-in-oil emulsions not only have the advantages of convenient mass transfer and heat transfer,high polymerization efficiency,but also provide an ideal platform for the reaction of water-sensitive monomers and catalysts.It has promising application prospects in the field of isocyanate,acyl chloride and metallocene-catalyzed olefin polymerization.However,the stabilizers of oil-in-oil emulsion are deficient,and their preparation process is complex,which seriously restricts the development of this field.In this work,biomass cellulose particles were used as reactants,and isocyanate coupling method was used to graft long alkyl chains onto the surface of cellulose particles to regulate of the wettability.Polar and non-polar segments were introduced to the surface of cellulose simultaneously,and further stabilizing the oil-in-oil emulsions.The results showed that alkyl chains were successfully grafted onto cellulose surface by the isocyanate coupling method,and the polar cellulose surface from hydrophilic changed to hydrophobic(WCA=142.8°),and the functional cellulose had a good stabilizing capacity on DMF-in-dodecane emulsion.Finally,the poly(amide-thioether)microspheres were successfully prepared in the DMF-in-dodecane emulsion by using isocyanate and thiol.This approach provides a new type of stabilizer for oil-in-oil emulsions,which is simple in process and efficient in preparation,and promotes the development of oil-in-oil emulsions to a certain extent.