雾化干燥技术纳米氧化锌/天然橡胶复合材料的制备和性能研究

通过雾化干燥法混炼制备纳米氧化锌(ZnO)/天然橡胶复合材料,并对其性能进行研究,同时与传统湿法混炼和传统干法混炼复合材料进行对比。结果表明:与采用传统湿法混炼和传统干法混炼相比,采用雾化干燥法混炼可使纳米ZnO在橡胶基体中分散较均匀,且无明显团聚,硫化胶的交联网络均匀,交联密度较大,物理性能、耐溶剂性能、耐老化性能和导热性能较好;采用雾化干燥法混炼可以减小胶料的纳米ZnO用量,缩短硫化时间,保证硫化胶的各项性能稳定。     

全配方湿法连续混炼工艺的研究

针对炭黑与橡胶混炼难度大以及传统干法混炼工艺繁琐、产生粉尘污染等问题,研究全配方（补强填料包括炭黑和白炭黑）湿法连续混炼工艺。结果表明：全配方湿法连续混炼工艺分为4个阶段,分别为补强填料和小料水分散体的制备、炭黑母胶的制备、白炭黑母胶的制备、连续混炼;全配方湿法连续混炼工艺从初期补强填料和小料水分散体的研磨到后期的连续混炼均促进了炭黑在橡胶基体中的分散,使硫化胶的物理性能和动态力学性能比传统干法混炼工艺硫化胶明显提高,同时避免了干法混炼工艺的粉尘飞扬的问题,可实现胶料的清洁化、连续化生产。     

纳米氧化锌在橡胶中的作用机理及应用

根据无机配合剂在橡胶中的分散形态，研究纳米氧化锌在橡胶中的作用机理及其对胶料性能的影响。在硫化过程中氧化锌作为活性剂与有机促进剂、硬脂酸、硫黄等的反应发生在氧化锌粒子的表面。以纳米氧化锌等量替代普通问接法氧化锌，可提高硫化胶的300％定伸应力和耐磨性，减小压缩永久变形，降低压缩疲劳温升；以纳米氧化锌减量50％替代间接法氧化锌，仍可保证硫化胶的性能要求。     

纳米氧化锌母炼胶对NR性能的影响

将纳米氧化锌制成纳米氧化锌母炼胶，研究纳米氧化锌母炼胶对NR硫化胶物理性能的影响及纳米氧化锌的减量机理。试验结果表明，与加5份普通氧化锌相比，加2份纳米氧化锌母炼胶，硫化胶的拉伸强度提高，其它物理性能相近。透射电镜分析表明，纳米氧化锌母炼胶在NR胶料中不存在团聚现象，其分散性优于普通氧化锌和纳米氧化锌。在热力学理论分析基础上提出了纳米氧化锌在橡胶硫化过程中的作用机理。为纳米氧化锌减量60％替代普通氧化锌提供了理论依据。     

原位生成甲基丙烯酸锌对天然橡胶补强的研究

在天然橡胶(NR)混炼过程中加入氧化锌与甲基丙烯酸(MAA),在橡胶基体中原位生成甲基丙烯酸锌(ZDMA),并在硫化剂过氧化二异丙苯作用下制备NR/ZnO/MAA硫化胶。用扫描电镜、透射电镜研究了硫化胶的形态,并研究了制备条件对硫化胶力学性能的影响,结果表明,在155℃硫化温度,DCP用量为1.5～2 0质量份(phr)条件下,NR硫化胶具有较佳的力学性能。随着ZnO/MAA用量的增加,硫化胶定伸应力、拉伸强度和撕裂强度显著增加,表现出显著的补强作用。     

纳米氧化锌在胶鞋中的应用

介绍纳米氧化锌替代普通氧化锌在胶鞋胶料中的应用情况。应用纳米氧化锌可以改善胶料的硫化特性和混炼特性等加工性能；在胶料含胶率适当降低的条件下，仍可提高大底和围条硫化胶的物理性能；可使海绵中底胶料的发泡率由85％提高至92％，且泡孔结构小而均匀，从而提高胶鞋的质量。     

纳米ZnO在减震器胶料中的应用研究

探讨了纳米氧化锌对减震器胶料硫化特性和力学性能的影响。结果表明,和普通氧化锌在同等用量时,纳米氧化锌可以缩短胶料的硫化时间,提高胶料的力学性能。台架实验证明,纳米氧化锌用量5份时,橡胶减震器寿命提高20%。     

纳米氧化锌在橡胶复合材料中的初步应用

探讨了纳米氧化锌在橡胶复合材料中的初步应用。结果表明 ,在适当范围内 ,随着纳米氧化锌用量的增大 ,复合材料的拉伸强度和定伸应力等力学性能明显提高 ,但用量过大会使复合材料的性能下降 ;加入纳米氧化锌后 ,体系的正硫化时间有所延长。纳米氧化锌在改善橡胶耐磨性方面不如氧化锌晶须显著     

不同种类增塑剂对天然橡胶性能的影响

正橡胶增塑剂通常是一类分子量较低的化合物。加入橡胶后,能够降低橡胶分子链间的作用力,使粉末状配合剂与生胶很好地浸润,从而改善混炼工艺,使配合剂分散均匀,缩短混炼时间,降低耗能,并能减小混炼过程中的生热现象,同时它能增加胶料的可塑性、流动性、黏着性,便于压延、压出和成型等工艺操作。还能改善硫化胶的某些物理机械性能,如降低硫化胶的硬度和定伸应力,赋予硫化胶较高的     

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.     

嵌段型SIBR的制备与性能研究

采用正丁基锂为引发剂，环己烷为溶剂，四氢呋喃为结构调节剂，四氯化锡为偶联剂制备嵌段结构的苯乙烯-异戊二烯-丁二烯共聚橡胶（SIBR），并对其性能进行研究。结果表明，单体配比和结构调节剂加入时间对SIBR硫化胶物理性能有影响，结构调节剂较早加入可提高SIBR硫化胶的物理性能；与溶聚丁苯橡胶（SSBR）／BR／NR并用胶相比，SIBR的玻璃化温度较低，耐低温性能较好，抗湿滑性能优异，滚动阻力相差不大。     

SIBR与NR/SSBR共混物结构与性能的比较

用透射电镜、扫描电镜、动态粘弹谱仪等研究了星形两嵌段SIBR、星形无规SIBR的相态结构、静态力学性能、磨耗性能、动态生热性能及动态粘弹性能,并与40/60（质量比）的NR/SSBR共混物进行了对比。结果表明,星形两嵌段SIBR呈宏观均相、微观分相的特点,其力学和磨耗性能都优于其他两种胶料,而且动态压缩生热也较低,对冰雪、润滑路面的抓着性好,其性能更接近对高性能轮胎胎面胶全面的性能要求。     

Preparation of nano‐zinc oxide/EPDM composites with both good thermal conductivity and mechanical properties

In this article, nano‐zinc oxide (ZnO) filled ethylene propylene diene monomer (EPDM) composites are prepared, and the mechanical (static and dynamic) properties and thermal conductivity are investigated respectively, which are further compared with the traditional reinforcing fillers, such as carbon black and nano‐silica. Furthermore, influence of in‐situ modification (mixing operation assisted by silane at high temperature for a certain time) with the silane‐coupling agent Bis‐(3‐thiethoxy silylpropyl)‐tetrasufide (Si69) on the nano‐ZnO filled composites is as well investigated. The results indicate that this novel reinforcing filler nano‐ZnO can not only perform well in reinforcing EPDM but can also improve the thermal conductivity significantly. In‐situ modification with Si69 can enhance the interfacial interaction between nano‐ZnO particles and rubber matrix remarkably, and therefore contribute to the better dispersion of filler. As a result, the mechanical properties and the dynamic heat build‐up of the nano‐ZnO filled composites are improved obviously by in‐situ modification, without influencing the thermal conductivity. In comparison with traditioanl reinforcing fillers, in‐situ modified nano‐ZnO filled composites exhibit the excellent performance in both mechanical (static and dynamic) properties and better thermal conductivity. In general, our work indicates that nano‐ZnO, as the novel thermal conductive reinforcing filler, is suitable to prepare elastomer products serving in dynamic conditions, with the longer expected service life. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

双相填充配方的不同加油温度混炼技术研究

介绍啮合式密炼机混炼双相填充配方不同加油温度混炼技术的研究。研究结果显示啮合式密炼机采用高温加油混炼工艺混炼的双相填充基部胶配方,对降低基部胶配方的生热及改善胶料的分散性能均有明显优势;使用新混炼技术混炼的基部胶配方物理机械性能改善明显,成品轮胎的台架性能得到进一步优化,其它性能符合国家标准要求。     

国产集成橡胶SIBR基本性能的研究

研究了国产集成橡胶(SIBR)的基本性能,结果表明:SIBR与乳聚丁苯橡胶物理机械性能相当;其动态力学性能与通用乳聚丁苯橡胶相比,SIBR在0℃具有更高的tanδ值,在60℃具有更低的tanδ值,说明SIBR具有高抗湿滑性和低滚动阻力;压缩疲劳温升实验结果表明SIBR比丁苯橡胶压缩疲劳温升低,压缩永久变形率更小。实验证明SIBR是一种良好的轮胎胎面用橡胶。     

Reinforcement of polymethyl methacrylate with silane-treated zinc oxide nanoparticles: fire retardancy,electrical and mechanical properties

Polymethyl methacrylate (PMMA)/zinc oxide (ZnO) composites were prepared using melt mixing process. A nano ZnO-treated with aminopropyl triethoxysilane (APTS) was used as reinforcing particles. PMMA composites were obtained with different ZnO loadings of 0, 0.5, 1 and 2 parts by weight. This research was focused on determination of the influence of different loadings of silane-treated ZnO particles on the morphology, electrical, mechanical and flammable properties of the PMMA composites. Addition of ZnO to the PMMA composite was observed to enhance the thermal properties and char formation. The results from cone calorimeter showed 21% reduction in the peak heat release rate for the composite loaded with 1.5 wt% of ZnO as compared to that of neat PMMA. The surface resistivity, volume resistivity and EMI shielding properties of the composites as a function of ZnO loading were estimated. The results showed that the surface and volume resistivity of the composites reinforced with ZnO particles decreased and the EMI shielding increased almost linearly with increasing ZnO volume content. However, the tensile strength of the composites showed a slight decrease with increase in ZnO content. The SEM micrographs and AFM images showed dispersion of ZnO particles in the PMMA matrix. The nanoparticles were distributed evenly on the surface. Nevertheless the pockets of agglomerates could be seen at higher ZnO loading level.     

星形苯乙烯-异戊二烯-丁二烯嵌段共聚物结构与性能的关系

以环己烷为溶剂,苯乙烯(St)、丁二烯(Bd)、异戊二烯(Ip)为单体,正丁基锂为引发剂,采用负离子聚合法合成了集成橡胶———星形苯乙烯-异戊二烯-丁二烯嵌段共聚物(SIBR),考察了星形SIBR的相对分子质量、侧基含量、嵌段比(即Ip的均聚物链段与St-Bd的无规共聚物链段的质量比)与其性能的关系。结果表明,在考察范围内,星形SIBR的拉伸强度和撕裂强度随着其相对分子质量的增加而增大。随着1,2-和3,4-结构含量之和的增加,0℃和60℃时的损耗因子均有所增大。固定St/Bd(质量比)为1/3,随着嵌段比的逐渐降低,所得星形SIBR的门尼黏度逐渐增大;嵌段比为20/80时所得星形SIBR具有较好的力学性能与动态力学性能,且与溶聚丁苯橡胶2300、2305以及天然橡胶相比,具有更好的抗湿滑性和滚动阻力的平衡。     

Preparation and properties of poly(propylene carbonate) and nanosized ZnO composite films for packaging applications

A series of polypropylene carbonate (PPC)/ZnO nanocomposite films with different ZnO contents were prepared via a solution blending method. The morphological structures, thermal properties, oxygen permeability, water sorption, and antibacterial properties of the films were investigated as a function of ZnO concentration. While all of the composite films with less than 5 wt % ZnO exhibited good dispersion of ZnO in the PPC matrix, FTIR and SEM results revealed that solution blending did not lead to a strong interaction between PPC and unmodified ZnO. As such, poor dispersion was induced in the composite films with a high ZnO content. By incorporating inorganic ZnO filler nanoparticles, the diffusion coefficient, water uptake in equilibrium, and oxygen permeability decreased as the content of ZnO increased. The PPC/ZnO nanocomposite films also displayed a good inhibitory effect on the growth of bacteria in the antimicrobial analysis. The enhancement in the physical properties achieved by incorporating ZnO is advantageous in packaging applications, where antimicrobial and environmental‐friendly properties, as well as good water and oxygen barrier characteristics are required. Furthermore, UV light below ～ 350 nm can be efficiently absorbed by incorporating ZnO nanoparticles into a PPC matrix. ZnO nanoparticles can also improve the weatherability of a PPC film. In future research, the compatibility and dispersion of the PPC matrix polymer and the inorganic ZnO filler nanoparticles should be increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

SIBR生胶门尼粘度对胶料性能的影响

研究不同门尼粘度的集成橡胶(SIBR)混炼胶和硫化胶的各项性能,并与溶聚丁苯橡胶(SSBR1204)进行对比.结果表明,适当提高SIBR生胶的门尼粘度,可以在不影响胶料加工性能的前提下,提高混炼胶强度,同时硫化胶的物理性能和动态力学性能也普遍得到改善.高门尼粘度的SIBR综合性能较理想,与SSBR1204相比并无显著差异.     

Effects of particle type on thermal and mechanical properties of polyoxymethylene nanocomposites

The effects of particle size of titanium dioxide (TiO₂) on mechanical, thermal, and morphological properties of pure polyoxymethylene (POM) and POM/TiO₂ nanocomposites were investigated and compared with the results for nanoparticle ZnO in the same matrix, reported in a previous paper. POM/TiO₂ nanocomposites with varying concentration of TiO₂ were prepared by the melt mixing technique in a twin screw extruder, the same method that used for blending the homogeneous ZnO nanocomposites. The dispersion of TiO₂ particles in POM nanocomposites was studied by scanning electron microscopy (SEM). The agglomeration, as observed by the mechanical properties of TiO₂ particles in the polymer matrix, increased with increasing TiO₂ content, a result not found for ZnO even at lower particle sizes. Increasing the filler content of POM/TD32.4 and POM/TD130 (130 nm) nanocomposites resulted in a decrease in tensile strength. The Young modulus, stress at break and impact strength of TiO₂ nanocomposite did not improve with increasing filler contents, in opposition to the better agglomeration conditions of ZnO nanocomposite even at lower particle sizes. Because of agglomeration, the POM/TD32.4 nanocomposites had lower mechanical properties and lower degradation temperature than the POM/TD130 ones. The sizes of nanoparticles determined the agglomeration, but however, the agglomeration also depended on the type of nanoparticles, even when using the same matrix (POM) and the same mixing method. TiO₂ nanoparticles were more difficult to mix and were more agglomerated in the POM matrix as compared to ZnO nanoparticles, regardless of the size of the nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012