阻燃剂十溴联苯的合成

本文研究了合成+溴联苯的直接溴化法。在三氯化铝的催化作用下,联苯在过量无水溴素中能够顺利实现全环溴化,收率可达98％;副产物以溴化物形式回收,总溴回收率大于90％。此方法亦适合于工业化生产。     

山羊绒制条工艺设计与质量控制

以加工国产44 mm白绒条为例,从工艺流程、原料选配、和绒加油、梳理成条、针梳、精梳几个方面对山羊绒制条工艺进行设计,并提出了生产中质量控制的要点。研究显示:山羊绒长度短、强力低,制条时要合理设计梳理隔距、速比等工艺参数,注重纤维长度的保护,降低纤维损伤;和绒时要注意对水质及和毛油剂的选择,合理的控制精梳落绒率;要合理搭配原料,完成山羊绒原料与最终产品用途相结合,最大限度地提高产品性能指标和外观指标。     

涤纶毛条生产中毛粒的形成原因及其控制措施

讨论了涤纶毛条生产过程中纺丝、拉伸、卷曲、制条等工艺参数及设备条件对毛粒的影响。为了减少毛粒,采用了合理的纺丝和制条工艺,并对后纺设备进行适当改造。涤纶毛条中的毛粒得到了有效控制,从而生产出优质涤纶毛条产品。     

过氧化氢直接氧化法合成2,3,5-三甲基氢醌

以偏三甲苯为原料,H_2O_2-CH_3COOH-H_2SO_4为氧化体系,直接氧化合成2,3,5-三甲基氢醌(TMHQ)。通过正交试验,考察了影响氧化反应的各种因素,确定了氧化反应的最佳条件:反应温度70℃,H_2O_2与偏三甲苯(TMB)的摩尔比为6.5:1,H_2SO_4与TMB的摩尔比为3:1,反应时间3 h。在此条件下,产品纯度达92.13％。     

Relationship between Slivering Point and Gas Generation Rules of 19-Perforation TEGDN Propellants with Different Length/Outside Diameter Ratios and Perforation Diameters

In order to investigate the relationship between the slivering point and burning progressivity, a set of 19-perforation propellants containing triethylene glycol dinitrate (TEGDN) with different lengths/outside diameter ratios and perforation diameters was prepared and tested in a closed vessel. The mass fraction of burnt propellant was derived from the recorded pressure–time history of 19-perforation TEGDN propellants in the closed vessel according to the gas state equation and the form function of tested propellants. Based on the form function calculation and the mass fraction of burnt propellant, instantaneous burning surface area and the burning rate were obtained. The influence of length/outside diameter ratios and perforation diameters on the progressive combustion performance is studied through the dynamic vivacity method. With an increase in the length/outsider diameter, the slivering point occurs earlier and the slivering process lasts longer. Further, the burning progressivity of surface area can be improved. For propellants with same length/outside diameter ratio, with a decreasing of perforation diameter, the slivering point lags behind and the burning progressivity becomes greater. The slivering point corresponds to the instantaneous burning area, which is related to the form function and total burning process as well. However, the total burning progressivity of propellant is a very comprehensive result of propellant under multiple actions, including the mass fraction of burnt propellant, grain size and burning rate at different pressure regions. The correlation between them can boost a better understanding on the interaction between grain size, slivering burning process and burning progressivity.