增塑剂环己烷-1,2-二甲酸酯的绿色合成及性能研究

采用硫酸氢盐/金属单质复合催化剂,以环己烷-1,2-二甲酸酐(HHPA)和正丁醇为原料,合成了增塑剂环己烷-1,2-二甲酸二丁酯(DBCH).最佳工艺条件为:以NaHSO4·H2O/Fe为催化剂,醇酐物质的量比2.5:1,催化剂用量为醇酐总质量的3‰,催化剂粒径为150μm(100目),反应温度155～160℃,反应时间4 h,酯化率可达99.78％,纯度>99％.复合催化剂催化活性高,可回收,安全、经济且环境友好.考察了DBCH对聚氯乙烯制品脆化温度、力学性能、挥发性和耐迁移性能的影响,与纯的PVC树脂相比较,DBCH具有较好的增塑性能.     

基于倾斜摄影技术的输电线路走廊三维场景重建方法的研究与应用

在技术不断发展的过程中,输电线路验收、设计与运维的工作方式也有所改变.在输电线路走廊三维场景重建中使用倾斜摄影技术,实践结果显示,倾斜摄影技术在数据处理自动化程度、地形地貌还原精度和三维建模工作效率方面具有明显优势,此技术能够应用到输电线路走廊三维重建中.     

Toward Largely Enhanced Toughness and Balanced Strength in PA1012/EPDM Blends via Synergistic Effect of Sacrificial Bonds and Network Structure

Here, zinc-neutralized ethylene propylene diene monomer (EPDM) ionomers with different neutralization levels are prepared through melt blending, and are then incorporated with polyamide 1012 (PA1012) to fabricate PA1012/EPDM ionomer blends. Interestingly, complex crosslinking networks are formed in the blends due to the construction of sacrificial bonds (Zn²⁺-carboxyl, Zn²⁺-amide). The as-formed network structure and sacrificial bond endow the PA/EPDM blends with largely enhanced toughness (16 times higher than that of neat PA), as well as balanced strength and stiffness. Meanwhile, the rheological behaviors of PA1012/EPDM ionomer blends indicate their relative low melting viscosity, which can avoid the processing shortcomings of plastics toughened with rubber. Moreover, PA1012/EPDM ionomer blends show obvious gelation behavior, and a maximum notched Izod impact strength exhibited at the gel point, in which unique double network structure can be observed obviously, indicating that there is a corresponding correlation between the rheological and mechanical parameters. Furthermore, the supper-toughening mechanism of PA1012/EPDM ionomer blends at gel point is explored, which origins from the large deformation and cavitation of rubber particles and the destruction of special double network morphologies. This study provides a novel and effective strategy to fabricate PA materials with outstanding toughness and excellent strength simultaneously.     

饰品金合金微量添加元素研究现状

从提高强度、防止氧化、提高铸造性能以及细化晶粒几个方面综述了饰品金合金中微量添加元素的一些研究现状。对不同微量添加元素对饰品金合金性能的影响、相应的副作用,作用机理以及加入量的确定等方面进行了综合评述。并对饰品金合金微量添加元素的发展进行了展望。     

应用有限元方法对高速电主轴的优化设计

介绍了高速电主轴的结构特点，应用有限元分析软件ANSYS以刚度为目标对高速电主轴进行了优化设计，并对优化后的结构进行了热态校核。     

二元稀土镁合金Mg-La和Mg-Nd的组织和性能

系统研究了二元稀土镁合金Mg-2%La(L2)和Mg-2%Nd(N2)的铸态显微组织、拉伸性能和抗蠕变性能.通过研究发现,L2铸态组织中有大量网状的Mg-Mg17La2的共晶相析出;而N2则以Mg12Nd离异共晶析出,析出物的数量少得多.N2合金在室温或者175℃条件下,强度和塑性都优于L2合金.N2合金的抗蠕变性能在175℃、70 MPa条件下比L2低近3个数量级.通过计算两种合金的应力指数和蠕变激活能,L2合金的蠕变机制是受晶界滑动控制的,而N2合金为位错攀移机制控制.     

Thermal decomposition kinetics and lifetime of the complex of Tb2（BA）6（PHEN）2

The thermal behavior of Tb2(BA)6(PHEN)2 (BA: benzoate, and PHEN: 1,10-phenanthroline) in a static air atmospbere was investigated by TG-DTG, SEM and IR techniques. By the kinetic method of processing thermal analysis data put forward by Malek et al., it is defined that the kinetic model for the first-step thermal decomposition is SB(m, n). The activation energy E for this step reaction is 99.07 kJ/mol, the entropy of activation ΔS^≠ is -84.72 J/mol, the enthalpy of activation ΔH^≠ is 94.26 kJ/mol, the free energy of activation ΔG^≠ is 144.77 kJ/mol and the pre-exponential factor lnA is 20.93.The lifetime equation at mass-loss of 10% was deduced as lnτ = -29.0312 19760.83/T by isothermal thermogravimetric analysis.     

Relating the molecular structure and crystallization behavior of polypropylene

The crystallization behavior of two polypropylene (PP) resins as used for biaxially oriented polypropylene (BOPP) and general injection mold applications, respectively, has been intensively investigated and compared by means of polarized light optical micrography (POM), differential scanning calorimetry (DSC), conventional transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). It is found that both molecular weight distribution and isotacticity of polypropylene strongly affect its crystallization characteristics, e.g., the number of crystal nuclei at the initial stage, crystallization dynamics, the morphology, size and perfection of crystals in the final product, and so on. The results indicate an appropriate molecular structure is vital in producing high‐quality BOPP film. Polym. Eng. Sci. 44:1749–1754, 2004. © 2004 Society of Plastics Engineers.     

超长余辉蓄能发光涂料的制备

通过选用透明度高、太阳能吸收率高的丙烯酸树脂和高亮度、长余辉时间的镝和铕稀土离子共掺杂的稀土硅酸盐光致发光粉末材料aCaO·bZnO·cBaO·dMgO·nSiO2:Eu,Dy,制备出了具有较强的蓄光能力和较长发光时间的夜光涂料,并论述了其制备方法和特性。     

粉煤灰在煤矿防灭火中的应用

近几年来,随着煤矿对井下防灭火工作力度的加大,新的科研成果不断涌现。其中,粉煤灰在我国各地的煤矿防灭火工作中发挥了越来越大的作用。这里谨以兖州矿区的几项研究成果为例,说明粉煤灰在煤矿防灭火工作应用中的良好前景。1粉煤灰胶体综合防灭火系统兖州矿业(集团)公司鲍店煤