嵌段聚醚HLB值与分子结构关联的新模型

亲水亲油平衡（HLB）值是表征表面活性剂溶液性质的重要参数。它不仅是亲水、亲油基团数的函数,也与这些基团在分子链中的位置相关。过去基于基团贡献法的HLB值计算模型都忽略了基团所处的位置,而仅仅考虑基团数,且假定贡献度与基团数呈线性关系。本文提出基团贡献非等效的观点,针对由聚氧乙烯（EO）、聚氧丙烯（PO）构成的嵌段聚醚,引入一个同性质重复结构单元段中各链节贡献大小随位置依次递减的函数,从而得到HLB值与EO链节数n和PO链节数m的新的关联式：V_（HLB）=A_0＋f×A_（EO）ln（1＋n）＋f×A_（PO）ln（1＋m）。对一系列由PEO、PPO组成的三嵌段与二嵌段聚醚进行计算,表明该公式比过去的关联式更加准确。

New correlation model for the HLB Values of ethylene oxide and propylene oxide block copolymers

The hydrophile-lipophile balance （HLB） value is a key parameter in determining the solution properties of surfactants. The HLB value is not only a function of the numbers of hydrophilic and lipophilic units, but also depends on their locations on the chain. All the previous correlation models for the HLB values from the group contribution method neglected the locations of units and assumed that the contribution is in proportion with the number of groups. This paper introduces a decay function for the contribution of the sequential units for the block copolyether of ethylene oxide （EO） and propylene oxide （PO）, and developes the following new equation for the relationship between the numbers n of EO unit, m of PO unit and the HLB value VHLB as follows： V_（HLB）=A_0＋f×A_（EO）ln（1＋n）＋f×A_（PO）ln（1＋m） Results of linear regressions for the HLB values on a series of tri-block and bi-block copolyethers of EO and PO indicatedthat this new equation has much better correlation with the experimental data than the previous models reported in the literature.