纳米氧化锌对NR胶料性能的影响

研究纳米氧化锌等量或减量替代间接法氧化锌对NR胶料性能的影响。结果表明 ,当纳米氧化锌等量或减量 3 0 %替代间接法氧化锌应用时 ,胶料的焦烧时间和正硫化时间延长 ,抗硫化返原性能提高 ,硫化胶的邵尔A型硬度、3 0 0 %定伸应力和拉伸强度增大 ;当纳米氧化锌减量 60 %～ 80 %使用时 ,胶料的抗硫化返原性能下降 ,硫化胶的拉断伸长率和撕裂强度增大     

抗硫化返原剂WK-901在橡胶隔震支座胶料中的应用

研究抗硫化返原剂WK-901用量对橡胶隔震支座胶料及成品性能的影响。结果表明:抗硫化返原剂WK-901对胶料的t_(10)和t_(90)基本无影响,但对硫化平坦性有显著影响;抗硫化返原剂WK-901对胶料老化前的物理性能有一定影响,对老化后的物理性能有显著影响;随着抗硫化返原剂WK-901用量的增大,成品橡胶隔震支座内层胶的拉伸强度增大,拉断伸长率降低,支座的屈服后刚度和等效水平刚度均增大。     

活性氧化锌和传统氧化锌对天然橡胶胶料性能的影响

活性氧化锌较传统氧化锌有粒径小、比表面积大、具有表面效应和高活性的优点。本研究针对此特点在生胶与添加剂不变的情况下,通过改变氧化锌的种类,来探究活性氧化锌和传统氧化锌对橡胶硫化时间、门尼黏度、拉伸性能、撕裂强度等性能指标的影响。结果表明:与传统氧化锌相比,加入相同份数的活性氧化锌使得胶料拉伸性能、撕裂强度均有所提升,交联密度增大,硫化时间缩短,胶料性能整体得到提升。     

活性氧化锌在全钢子午线轮胎胎面胶中的应用

试验研究活性氧化锌在全钢子午线轮胎胎面胶配方中的应用效果,并与普通氧化锌和纳米氧化锌进行对比.结果表明,活性氧化锌胶料的MH和MH-ML均比普通氧化锌胶料有所增大,t10和t90明显延长,与纳米氧化锌胶料差别不大;活性氧化锌硫化胶的物理性能和耐老化性能均优于普通氧化锌硫化胶,但略低于纳米氧化锌硫化胶;活性氧化锌用量不大于5份时,硫化胶的物理性能变化不明显,加入3份活性氧化锌的硫化胶耐老化性能最优.     

活性氧化锌在普通输送带覆盖胶中的应用

研究了不同用量的活性氧化锌对普通输送带覆盖胶各项性能的影响,并与普通氧化锌、纳米氧化锌进行了对比。实验发现,与普通氧化锌相比,活性氧化锌延长了胶料的tc10和tc90,提高了胶料的加工安全性,与纳米氧化锌相近;加入活性氧化锌的胶料,其拉伸强度、撕裂强度和耐磨耗性能较加入普通氧化锌的胶料略有提高;70℃×168h老化后,性能变化率较普通氧化锌低,与纳米氧化锌相近。活性氧化锌用量减至3份时．其各项性能与5份时相当。     

抗硫化返原剂在全钢子午线轮胎粘合胶中的应用

研究抗硫化返原剂HT918和HTS在全钢子午线轮胎粘合胶中的应用。结果表明：加入抗硫化返原剂后胶料的门尼粘度减小,门尼焦烧时间延长,t90缩短,抗硫化返原性能明显提高,硫化胶的物理性能变化不大,过硫化后的性能保持率明显增大,粘合性能和动态力学性能提高;其中抗硫化返原剂HT918与HTS并用后胶料的抗硫化返原效果最好,抗硫化返原剂HTS胶料的粘合性能最好,抗硫化返原剂HT918胶料的动态力学性能最好;采用抗硫化返原剂HT918制造的成品轮胎的高速和耐久性能提高。     

新型抗硫化返原剂HTR在全钢工程机械子午线轮胎胎面胶中的应用

研究新型抗硫化返原剂HTR在全钢工程机械子午线轮胎胎面胶中的应用。结果表明：在胎面胶中加入2份抗硫化返原剂HTR,胶料的抗硫化返原性能提高,硫化胶老化后的拉伸强度、撕裂强度和回弹值增大,耐磨性能提高,生热降低;成品轮胎的耐久性能提高。     

环保锌在全钢载重子午线轮胎胎面胶和胎侧胶中的应用

研究环保锌在全钢载重子午线轮胎胎面胶和胎侧胶中的应用。结果表明：随着环保锌用量的增大，胶料的交联密度增大，t₉₀延长，抗硫化返原性能提高；采用环保锌等量替代间接法氧化锌，胶料的加工安全性和抗硫化返原性能提高，物理性能良好，同时可降低轮胎使用中的环境污染。     

LSAPZNIC活性氧化锌在橡胶中的应用

基于胶料硫化特性和热空气老化试验前后力学性能对比结果,综合评价了不同用量LSAPZNIC活性氧化锌和间接法氧化锌对橡胶的影响。结果表明,LSAPZNIC活性氧化锌在橡胶中分散效果好;减量使用,可保证硫化胶性能要求;与间接法氧化锌相比,胶料老化性能更加优异。     

抗硫化返原剂BCI对NR胶料性能的影响

将自制的4,4′-N,N′-二苯甲烷双柠康酰亚胺(BCI)用作抗硫化返原剂,研究其对NR胶料性能的影响,并与抗硫化返原剂PK900进行对比。结果表明,BCI具有与PK900相近的抗硫化返原性能,与未加抗硫化返原剂的胶料相比,加入BCI的胶料ML和MH减小,t10和t90变化不大;硫化胶的定伸应力和拉伸强度增大,拉断伸长率减小。裂解气相色谱分析表明,BCI在NR硫化返原过程中形成了新的C—C交联键。     

Sintering of Zinc Oxide Doped with Antimony Oxide and Bismuth Oxide

The phase change, densification, and microstructure development of ZnO doped with both Bi₂O₃ and Sb₂O₃ are studied to better understand the sintering behavior of ZnO varistors. The densification behavior is related to the formation of pyrochlore and liquid phases; the densification is retarded by the former and promoted by the latter. The pyrochlore phase, whose composition is Bi_3/2ZnSb_3/2O₇, appears below 700°C. The formation temperature of the liquid phase depends on the Sb/Bi ratio: about 750°C for Sb/Bi < 1 by the eutectic melting in the system ZnO—Bi₂O₃, and about 1000°C for Sb/Bi > 1 by the reaction of the pyrochlore phase with ZnO. Hence, the densification rate is determined virtually by the Sb/Bi ratio and not by the total amount of additives. The microstructure depends on the sintering temperature. Sintering at 1000°C forms intragrain pyrochlore particles in ZnO grains as well as intergranular layers, but the intragrain particles disappear at 1200°C by the increased amount of liquid phase, which enhances the mobility of the solid second phase.     

Sintering of Zinc Oxide

Sintering studies have been conducted with single crystal spheres of zinc oxide in air at total pressures of 10⁻³ to 1.0 atm over the range 1050° to 1250°C. Quantitative observations were made on the rate of growth of a neck between the spheres. No change in the distance between the geometrical centers of the spheres was observed. An analysis of the kinetic data shows that sintering was predominantly achieved by distillation through the surrounding gas phase. At 1150° the rate of welding was inversely influenced by the total pressure when the latter was changed from 0.003 to 0.75 atm. No conclusion could be reached on the effect of the oxygen partial pressure at constant total pressure. A brief summary of the various sintering mechanisms of zinc oxide from 700° to 1250°C is presented.     

Sintering of Zinc Oxide

The fundamental processes involved in the sintering of ionic solids are highly complex. Of particular significance are the initial stages of sintering during which surface effects are of prime importance. The sintering of zinc oxide has been studied by the method of changes in surface area at temperatures from 300° to 1000°C. and with varying oxygen pressures (from 10^-5 to 760 mm. of Hg). It has been demonstrated that significant sintering occurs at temperatures far below the Tammann temperature. It also has been shown that under specific conditions a very high defect concentration may exist in the surface of the material and that this is closely related to the phenomenon of sintering. Correlation has been made with an electron-microscope investigation. Detailed X-ray studies on single-crystal specimens of zinc oxide have shown that interstitial zinc constitutes the defects. Activation energies have been deduced for the sintering process which suggest that the rate-controlling step is diffusion in the surface zone in the low-temperature region which changes to lattice or complex diffusion and viscous-flow mechanisms about the Tammann temperature.     

Zinc Vanadates in Vanadium Oxide-Doped Zinc Oxide Varistors

Convergent-beam electron diffraction has been used to determine the space groups of β- and γ-Zn₃(VO₄)₂ particles in vanadium oxide-doped zinc oxide varistors. The crystal structure of β-Zn₃(VO₄)₂ has been determined to be monoclinic with space group P 2₁ and lattice parameters of a = 9.80 Å, b = 8.34 Å, c = 10.27 Å, and β= 115.8°, whereas that of γ-Zn₃(VO₄)₂ is monoclinic with space group Cm and a = 10.40 Å, b = 8.59 Å, c = 9.44 Å, and β= 98.8°. Energy-dispersive X-ray microanalysis of these two phases shows significant deviations from their expected stoichiometry. It is apparent that the β-phase is, in fact, the metastable Zn₄V₂O₉ phase, whereas the γ-phase either is a new oxide that consists of zinc, vanadium, and manganese or, more likely, is a zinc vanadate phase with a Zn:V atomic ratio of 1:1 that has the ability to go into solid solution with manganese.     

锌灰制备活性氧化锌工艺

以炼锌厂废锌灰为原料,经硫酸浸取,考察了不同工艺条件对锌的浸出率的影响.实验结果表明:锌灰在50℃下浸取,pH值为1.5时,可使锌灰中锌的溶出率达92.9%.碱式碳酸锌最佳水解温度为40℃,水解时间为2h,pH值为7.5时,溶液中锌含量为10g/L,得到96%以上的水解率.     

利用锌浮渣制备四脚状氧化锌晶须

首次采用锌浮渣为原料,利用平衡气量控制法制备了四脚状氧化锌晶须(T-ZnOw),探讨了原料、反应温度和反应器密封程度等因素对产物ZnO结晶结构和形貌的影响,并采用XRD, FE-SEM、表面能谱(EDS)对其结构和形貌进行了测试表征. 结果表明,具有完整结构的四脚状晶须产品仅由Zn和O组成,O原子数少于化学计量比,且核心部位O含量最低;制备具有规整结构的四脚状氧化锌晶须的最佳反应温度为900℃;以不同锌品位的锌浮渣为原料制备的产品均为具有六方纤锌矿结构的结晶完整的氧化锌,但产品形貌和四脚状晶须的产率受原料中氧化锌含量和Sb含量的影响. 研究表明,制备四脚状氧化锌晶须是锌二次资源回收利用的一条高附加值的途径.     

稀土氧化锌中锌及稀土含量的连续测定法

研究了稀土氧化锌中锌及稀土含量的连续测定方法。用抗坏血酸、磺基水杨酸及硫脲在微酸性介质中分别掩蔽铁、铝及铜离子；在ｐＨ＝５．５的六胺缓冲溶液中用ＥＤＴＡ标准滴定溶液滴定至二甲酚授指示剂变色测定锌及稀土总量：继用氟化铵置换出与稀土元素络合的ＥＤＴＡ，用锌标准溶液测得稀土含量。此方法具有原理可靠、操作简便、测定快速、结果准确等特点。     

Grain Growth of Zinc Oxide During the Sintering of Zinc Oxide—Antimony Oxide Ceramics

Grain growth in a high-purity ZnO with systematic additions of Sb₂O₃ from 0.29 to 2.38 wt% was studied for sintering in air from 1106° to 1400°C. The results are discussed and compared with previous studies of pure ZnO and ZnO with Bi₂O₃ additions in terms of the kinetic grain growth expression: Gⁿ – Gⁿ ₀= K ₀ t exp(— Q/RT ). Additions of Sb₂O₃ inhibited the grain growth of ZnO and increased the grain growth exponent ( n -value) to 6 from 3 for pure ZnO and 5 for the ZnO—Bi₂O₃ ceramic. The apparent activation energy for the grain growth of ZnO also increased to about 600 kJ/mol from 220 kJ/mol for pure ZnO and 150 kJ/mol for the ZnO—Bi₂O₃ ceramics. Both the grain growth exponent and the activation energy were independent of the Sb₂O₃ content. Particles of the Zn₇Sb₂O₁₂ spinel were observed on the grain boundaries and at the grain triple point junctions. It was also observed that the Sb₂O₃ additions caused twin formation in each ZnO grain. It is concluded that both the Zn₇Sb₂O₁₂ particles and the twins are responsible for the ZnO grain growth inhibition by Sb₂O₃.     

用氧化锌矿制备纳米级氧化锌

报道了从氧化锌矿制备纳米级氧化锌的优惠工艺条件,并对所制得的氧化锌产物进行了Ｘ射线衍射分析,证明所得产品为高纯钠米级氧化锌粉。