α-sulfonated fatty acid esters: II. Solution behavior of α-sulfonated fatty acid polyethylene glycol esters

Sodium α-sulfonated, fatty acid polyethylene glycol monoesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n H] and diesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n COCH(SO₃Na)C _m H_2m+1], wherem=10–16 andn=1–35, were prepared by esterification of α-sulfonated, fatty acids with polyethylene glycols, followed by neutralization with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic solution behavior of these α-sulfonated fatty acid esters was, examined, and the following features were observed. All monoesters prepared in this work had Krafft points below 0°C and also possessed good calcium stabilities. Critical micelle concentrations of the monoesters increased monotonously, as a rule, with an increase in the number of oxyethylene units. These results suggest that the polyethylene glycol residue of the monoester behaves as a hydrophile. On the other hand, diesters possessed high water solubility, low foamability, and critical micelle concentrations that were lower by a factor of ten compared to those of the monoesters.     

充气条件下多层桨悬浮颗粒的临界转速

在直径为386 mm 的通气多层桨搅拌釜中,实验考察了下层搅拌桨型、挡板和气体分布器等对颗粒悬浮临界搅拌转速的影响,这对工业过程的设计和放大具有一定的指导意义.     

Synthesis and surface properties of chemodegradable anionic surfactants: Diastereomeric (2-n-alkyl-1,3-dioxan-5-yl) sulfates with monovalent counter-ions

Sodium, potassium and ammonium cis- and trans-(2-n-alkyl-1,3-dioxan-5-yl) sulfates 6–8 (alkyl: n-C₉H₁₉, 6a–8a, and n-C₁₁H₂₃, 6b–8b) were synthesized in a reaction of aliphatic aldehydes 1a,b with glycerol 2 followed by separation in high yields of individual geometric isomers of cis-and trans-2-n-alkyl-5-hydroxy-1,3-dioxanes, cis-3a,b and trans-3a,b, followed by sulfation with sulfur trioxide-pyridine complex, and finally neutralization with NaOH, KOH, and NH₄OH, respectively. Physical data of the compounds and some surface properties of 2-n-nonyl derivatives, such as critical micelle concentration (CMC), effectiveness of aqueous surface tension reduction (Π_CMC), surface excess concentration Γ_CMC, and the surface area demand per molecule (A_CMC), were determined. It was shown that the surface activity of these compounds is influenced both by their geometric structure and by the monovalent counter-ion.     

复合材料叠层曲板在轴压位移下的非线性稳定特性研究

本文采用动态松弛法（ＤＲ法）研究了正交铺设复合叠怪曲板在单向均匀轴压位移作用下的非线性稳定特性，给出了不对称正交叠层圆柱曲板在两种简支边界条件下的边界应力和板中心无量纲挠度的数值结果，讨论了铺层顺序、层数、曲率等因素对其稳定特性的影响。针对ＤＲ法计算中影响数值收敛性和稳定性的差分网络效应问题，推广应用了Ｒｉｃｈａｒｄｓｏｎ外推法。     

渗透变形的防治及其工程应用

在讨论渗流的基本规律和渗透变形的基本型式的基础上,论述了工程上常用的防渗措施.同时,结合新沂河大小陆湖段原状土的渗透变形试验和防渗处理,论述了土工膜的防渗效用,并指出了河流整治过程中的注意事项.