两亲性聚长链α-烯烃共聚物的合成及在柴油乳液中的作用

Synthesis of amphiphilic poly(long chain α-olefin) grafting copolymer and its role in diesel emulsion

用负载型TiCl4/MgCl2催化剂催化1-十八烯(1-oct)与对甲基苯乙烯(pMS)共聚合,得到1-oct与pMS的共聚物[P(1-oct-co-pMS)]。再通过反应性基团功能化法,用HBr/H2O2对P(1-oct-co-pMS)中pMS结构单元上的对位甲基进行选择性溴化,接着用改进的Williamson醚化法将端羟基聚乙二醇(PEG-OH)接枝到P(1-oct-co-pMS)主链上,制备了PEG-OH接枝P(1-oct-co-pMS)[P(1-oct-co-pMS)-g-PEG]的两亲性接枝共聚物,实现了聚长链α-烯烃的功能化。以P(1-oct-co-pMS)-g-PEG为分散剂,山梨糖醇酐油酸酯/失水山梨醇单油酸酯聚氧乙烯醚混合物为表面活性剂,采用高剪切乳化机制备了含水乳化柴油(即柴油乳液),用动态光散射法测定柴油乳液的粒径及其分布。结果表明,含有P(1-oct-co-pMS)-g-PEG的柴油乳液稳定性较好,在室温条件下可以稳定6天以上。

Copolymers of 1-octadecene （1-oct） and para-methylstyrene （pMS） [P （1-oct-co-pMS） ] were synthesized with supported TiCln/MgCI2 catalyst. Subsequently, P （1-oct-co-pMS） copolymers were brominated by HBr/H202 system with high selectivity for the para-methyl group ofpMS unit by means of functionalization of reactive group. Then, poly （ethylene glycol） monomethyl ethers （PEG-OH） were grafted onto the main chain of brominated P （1-oct-co-pMS） by using a modified Williamson ether synthesis, and the amphiphilic copolymers of PEG-OH grafted P （1-oct-co-pMS） [P （1-oct-co-pMS） -g-PEG] were prepared that realized the func- tionlizaion of poly （long chain ct-olefin）. Using P （1-oct-co-pMS）-g-PEG as dispersion agent and Span80/ Tween80 mixture as surfactant, water-in-diesel emulsions were prepared with vigorous stirring by high-shear emulsifier. The particle size and its distribution of the water droplets in diesel emulsion were determined by dy- namic light scattering method. The results showed that the diesel emulsions containing P （1-oct-co-pMS） -g- PEG exhibited excellent stability and could be stored for more than 6 days at ambient temperature.