Surface antistatic treatment of polyamide yarns with long-chain quaternary ammonium salts of hydroxymethanesulfonic acid

Conclusions A surface treatment of polyamide yarns in the stages of spinning and stretching has been described, with aqueous solutions of long-chain quaternary ammonium salts of hydroxymethanesulfonic acid, with subsequent heat-setting, as a result of which the yarns acquire long-term antistatic properties.The optimum conditions for surface antistatic treatment of polyamide yarns which have been selected permit one to carry out this process on equipment which is used in the preparation of serially produced complex yarns and fibres.Translated from Khimicheskie Volokna, No. 4, pp. 36–38, July–August, 1987.     

Interaction of humic acid salts with drug preparations

The use of natural polymers that form complexes with drug preparations is promising in the development of drugs of new generation. The possibility of complex formation on the interaction of humic acid salts with papaverine, benzohexonium, and B-group vitamins was demonstrated by calorimetric and potentiometric titration. These interactions can occur between the charged groups of a humic acid macroanion and the positively charged centers of drug molecules. The degree of binding of drug preparations by a natural polymer macromolecule can be determined by the charge and the structure of their molecules.     

Soluble phosphate salts as setting aids for premixed calcium phosphate bone cement pastes

Recently, premixed calcium phosphate cement pastes have been proposed as biomaterials for bone tissue repair and regeneration. Use of premixed pastes saves the time and removes an extra step during a medical operation. α-Tricalcium phosphate (α-TCP) based cements set to form calcium deficient hydroxyapatite which has a moderate bioresorbtion speed. α-TCP cements require a setting aid, usually a sodium or potassium phosphate salt, to speed up the setting process. Within the current research we investigated which setting aid has significant advantage, if α-TCP is used in form of non-aqueous premixed paste. This approach offers the application of simple ingredients to produce a premixed calcium phosphate cement. The following properties of cement formulations were evaluated: cohesion, phase composition, microstructure, pH value of the liquid surrounding the cement, and compressive strength.Compositions using mixture of basic and acidic potassium phosphate salts (KH₂PO₄ and K₂HPO₄) in sufficient amounts give the best overall results (adequate cohesion and pH of the surrounding liquid, hydrolysis of starting materials within 48 h, and compressive strength of 12 ± 3 MPa). Cement prepared with basic sodium phosphate salt (Na₂HPO₄) as setting aid had considerably higher compressive strength 22 ± 1 MPa, but the pH of the surrounding liquid was basic (9.0).     

Use of calcium zirconate as stabilizer when making zircon parts

Conclusions The method of casting from aqueous suspensions using calcium zirconate as a stabilizer was used to make zircon parts close in the nature of the green material, fired material and shrinkage during firing to parts made from prestabilized zirconium dioxide.The operation requires one high-temperature firing and a single grinding for the bulk of the mateial (about 80%).The addition of a calcium zirconate additive makes it possible to cast from acid dross characterized by greater resistance to particle aggregation and demixing of the suspension, and to obtain stronger and easy to process green material which is less liable to deform during firing.The use of calcium zirconate with a synthesizing temperature of 1200° produces good grindability and almost complete stabilization of the zirconium dioxide in the parts.The research was carried out by the Technology of Ceramics and Refractories Department of the Mendeleyev MKHTI in collaboration with the Industrial Silicates Laboratory of the Institute of Silicate Chemistry of the Academy of Sciences of the USSR and with the Podol'sk Refractory plant.     

双三羟甲基丙烷磷酸酯盐织物抗静电剂的合成工艺研究

以三氯氧磷（PO）和双三羟甲基丙烷（DTMP）以及氢氧化钾为原料,合成了织物抗静电整理剂双三羟甲基丙烷双磷酸酯钾盐。主要考察了原料配比、反应温度及反应时间对反应过程的影响,确定了最佳反应条件：n（PO）：n（DTMP）=4：1,反应温度为70℃,反应时间为5h,收率为95．04％。     

Use of the urinary calcium/creatinine ratio as an indicator of the nutritional status of calcium

The relationship between calcium and creatinine in basal urine for evaluating its usefulness as an indicator of calcium nutritional status was evaluated. Samples of basal urine were collected form a group of 5 to 12-year-old school children who followed a three-month program of dietary complementation. The calcium to creatinine ratio showed no correlation with daily total calcium intake. However, a correlation was found when intake was expressed in mg per kg of body weight (r = 0.67) and increased significantly when data were grouped according to growth rate (r = 0.85). On this basis, the Ca/Creat. ratio was analyzed as a function of weight gain (g/kg) for calcium intake: higher and lower than 10 mg/kg/day (4 = 0.82 and 0.89, respectively), the intercept of each line with the Y axis (null weight gain) being 0.096 and 0.068, respectively. These findings indicate the possibility of using the Ca/Creat. ratio in field studies as an indicator of nutritional status of the population in regard to calcium.     

Electrophysical properties of antistatic yarns

The decisive factors in removing static electrical charges are these:

抗静电聚酰胺纤维制备方法

介绍了抗静电聚酰胺纤维的几种制备方法。重点阐述在纤维表面涂覆表面活性剂法 ,亲水性高分子聚合物与聚酰胺 6共混纺丝法 ,导电纤维法。指出采用多种方法配合使用 ,可获得满意的抗静电效果。     

陶土、碳酸钙对抗静电阻燃胶板抗静电性和阻燃性的影响

抗静电阻燃胶板主要用于煤矿、电厂、化工、钢铁等企业,起铺垫、减震或密封等作用。它与普通胶板的不同之处在于有较好的导静电性能和好的阻燃性能,其技术指标必须达到相应的国家标准或行业标准要求。本文通过填充剂的对比试验,来反映陶土、碳酸钙对抗静电阻燃胶板的阻燃、抗静电性能的影响。     

Influence of antistatic agent encapsulated into functionalized mesoporous silica on antistatic properties of polystyrene

Small molecular surfactant (SMS) such as HDC-193 was encapsulated into mesoporous silica SBA-15 and 3-aminopropyltriethoxysilane-modified SBA-15 (mSBA-5) to develop new controlled release SMS system. The diffusion process of HDC-193 from mesoporous silica with different structures and diameters was investigated. Both situations of large pore and organic modification promoted the adsorption and thus a larger load of SMS in mesoporous silica. The results of molecular dynamics simulations and washing durability experiments showed that the lifetime of HDC-193 encapsulated into mSBA-15 in polystyrene blends is five times longer than that of HDC-193/polystyrene. This suggests an efficient strategy for designing permanent antistatic agents.     

Effect of calcium salts on the thermal properties of polyacrylonitrile fibres

Conclusions -- On interaction of CaCl₂ with polyacrylonitrile fibres, strong chemical bonds are formed between the polymer macromolecules.-- The introduction of Ca(II) into the fibre helps reduce polymer deformation up to a temperature of 200°C and helps increase its thermal resistance.Translated from Khimicheskie Volokna, No. 6, pp. 51–52, November–December, 1990.     

抗静电PET树脂的合成及性能研究

采用聚乙二醇、间苯二甲酸双羟二乙酯磺酸钠、无机盐与对苯二甲酸双羟二乙酯共聚合的方法合成了一种新型抗静电聚对苯二甲酸乙二酯(PET)树脂。该树脂的体积电阻率达到10~8Ω·cm数量级,静电半衰期达到0.02s,且不受长时间水洗的影响,其抗静电性能明显优于用共混等其他方法获得的抗静电PET树脂。     

一种新型抗静电剂的制备

以1-甲基-3-羟乙基咪唑氯盐和聚氨酯预聚物(TDI-TMP)为原料合成了一种新型的抗静电剂。结果表明,在反应温度为70℃,反应时间为48 h的反应条件下,所制备的聚合物具有良好导电性能,其表面电阻为1.0×108Ω,产率也较高,高达85%。