不同门尼黏度反式-1，4-聚异戊二烯与炭黑的相互作用及其对硫化胶性能的影响

研究了不同门尼黏度反式-1,4-聚异戊二烯(TPI)与炭黑N 330的相互作用及其对TPI硫化胶物理机械性能和疲劳性能的影响.结果表明,随TPI生胶门尼黏度增大,炭黑结合胶含量减少,炭黑分散性变差,增强作用减弱.未填充炭黑TPI硫化胶的100%定伸应力和拉伸强度随TPI门尼黏度的增大而显著提高;用炭黑增强后,不同门尼黏度TPI硫化胶的100%定伸应力和拉伸强度差别不大.不同门尼黏度TPI硫化胶的压缩生热和压缩永久变形在填充炭黑后均增大,其中低门尼黏度的增加幅度显著大于高门尼黏度者;不同门尼黏度TPI硫化胶压缩生热的变化主要由炭黑与橡胶之间的作用引起.生胶门尼黏度为50～80的TPI硫化胶的动态疲劳性能较好.     

充油对反式-1,4-聚异戊二烯及其与丁苯橡胶并用胶性能的影响

采用干法充油工艺,将门尼黏度为120的反式-1,4-聚异戊二烯(TPI)充芳烃油37.5份制备充油反式-1,4-聚异戊二烯(OETPI).对TPI、OETPI的生胶、硫化胶及其与丁苯橡胶(SBR)并用硫化胶的性能进行了对比.结果表明,OETPI生胶的硬度、门尼黏度、物理机械性能都比TPI的低;OETPI混炼胶的硫化速率比TPI混炼胶的高;OETPI硫化胶的100%和300%定伸应力、邵尔A硬度、拉伸强度等物理机械性能与TPI硫化胶的相比有所降低;磨耗、压缩生热、压缩永久变形增大.与TPI/SBR混炼胶相比,OETPI/SBR混炼胶具有更高的炭黑分散度,较高的硫化速率;OETPI/SBR并用硫化胶的抗湿滑性比TPI/SBR并用硫化胶明显提高,物理机械性能、滚动阻力和动态生热变化不大,耐屈挠龟裂性能提高.     

拉伸疲劳过程中未填充丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶性能的变化

研究了反式-1,4-聚异戊二烯(TPI)用量不同的未填充丁苯橡胶(SBR)/TPI共混硫化胶的拉伸疲劳性能,考察了TPI用量为20份(质量,下同)的未填充SBR/TPI共混硫化胶在拉伸疲劳过程中动态性能及TPI结晶性能的变化。结果表明,TPI用量为20份或30份时SBR/TPI共混硫化胶的拉伸疲劳性能较好,随TPI用量增加其疲劳断裂表面的撕裂线逐渐增多。X射线衍射分析表明SBR/TPI(质量比为80/20)共混硫化胶的结晶衍射峰强度随着拉伸疲劳次数的增加而不断增强。动态力学分析表明SBR与TPI的相容性良好;随拉伸疲劳次数增加SBR硫化胶损耗因子的峰值不断降低,而TPI用量为20份的SBR/TPI共混硫化胶在拉伸疲劳过程中损耗因子峰值的变化不明显,但损耗因子在40～60℃有较大幅度的下降。     

充油反式-1,4-聚异戊二烯橡胶的研制及性能

采用干法充油工艺,对用负载钛体系催化异戊二烯本体沉淀聚合得到的高门尼粘度反式-1,4-聚异戊二烯(TPI)的充油工艺性能及充油橡胶的性能进行了研究.结果表明,随着充油量的增加,充油生胶的可塑性增大,混炼行为得以改善,但高填充油份数的生胶放置中有喷油现象;充油生胶的屈服强度、拉伸强度、拉断伸长率、定伸应力均下降;充油硫化胶的拉伸强度、拉断伸长率、100%定伸应力及回弹值均下降,撕裂强度在充油量为37.5份时出现极大值,硬度先增大到极大值后又略有减小,磨耗量增大,抗湿滑性提高.综合考虑,高门尼粘度TPI充油量以37.5份左右为宜.     

TPI的门尼粘度对NR/TPI减震制品性能的影响

研究反式异戊橡胶（TPI）的门尼粘度对天然橡胶（NR）/TPI减震性能的影响。结果表明：与NR硫化胶相比,NR/TPI硫化胶的硬度增大,拉伸性能和抗撕裂性能降低,压缩永久变形减小,在－30,23和70 ℃下的耐屈挠龟裂性能提高,但在100 ℃×48 h热老化后23 ℃下的耐屈挠龟裂性能降低;随着TPI门尼粘度的提高,NR/TPI硫化胶的拉伸性能、撕裂强度和回弹值提高,静态压缩永久变形、动静刚度比和损耗因子减小,耐压缩疲劳性能以及在－30,23和70 ℃下的耐屈挠龟裂性能提高;高门尼粘度TPI在橡胶减震制品中的应用性能更优异。     

反式-1,4-聚异戊二烯改性氯丁橡胶的研究

研究了不同门尼粘度的反式-1，4-聚异戊二烯（TPI）与氯丁橡胶（CR）并用胶的性能，并对比了CR／TPI与CR硫化胶的性能。结果表明，CR中并用10份TPI可明显改善开炼机混炼时的粘辊性、胶料在硫化过程中产生气泡等缺陷；并用TPI后。硫化胶的物理机械性能、耐热老化性能和耐臭氧性能有所下降，但当TPI与CR门尼粘度相近时，硫化胶的耐屈挠疲劳性能可提高1倍左右。     

反式-1,4-聚异戊二烯的结晶性对丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶动态力学性能的影响

用动态力学分析仪和差示扫描量热仪研究了丁苯橡胶(SBR)/反式-1,4-聚异戊二烯(TPI)共混硫化胶的动态力学性能和结晶性能。结果表明,SBR与TPI的两相相容性良好。随着TPI用量的增加,SBR/TPI共混硫化胶的玻璃化转变温度向低温方向移动,且损耗因子峰值逐渐降低。用炭黑填充CV体系硫化SBR/TPI共混胶的损耗因子峰值低于相应的未填充胶料;而当TPI晶体熔融后,炭黑填充胶料的损耗因子要大于未填充者。不同硫化体系硫化SBR/TPI共混胶的损耗因子峰值和玻璃化转变温度从大到小的变化依次为CV体系、EV体系和DCP体系。     

国产天然橡胶在低滚动阻力胎面胶中的应用

研究国产天然橡胶（NR）在低滚动阻力胎面胶中的应用。结果表明：与进口NR（20#标准胶）相比,国产NR的生胶门尼粘度较低,塑性初值和塑性保持率较小,加工性能较好;混炼胶的门尼粘度也较低,硫化返原率稍高;硫化胶的拉断伸长率和撕裂强度稍低,60 ℃时的损耗因子稍大,耐老化性能略差。     

树脂206对CM/SBR共混胶力学性能的影响

研究了树脂206对CM/SBR共混胶硫化特性、力学性能和动态力学性能的影响。结果表明,随着树脂206用量的增大,共混胶焦烧时间缩短,正硫化时间延长,门尼粘度升高;撕裂强度、定伸应力和硬度均增大,拉伸强度变化不大,拉断伸长率略有降低。加入树脂206改善了耐热空气老化性能。随着树脂206用量的增大,混炼胶和硫化胶的储能模量均增大;应变较大时,加入树脂206可使硫化胶损耗因子降低。     

充油量对Fe系1,2-聚丁二烯橡胶性能的影响

以芳烃油作填充油，考察了6种充油量时Fe系1，2-聚丁二烯橡胶的加工工艺性能和硫化胶的性能的影响。实验结果表明，随充油量的增加，生胶门尼粘度ML100℃^1＋4值下降，可塑性增加，混炼行为变佳；硫化胶的扯断伸长率、永久变形增大，而拉伸强度和撕裂强度在充油量为20份时出现极大值，300％定伸应力、硬度、生热和磨耗等均降低。综合考虑，充油量为20份为宜。     

Synthesis of dysprosium/Mn–Cu ferrite binary nanocomposite: Analysis of structural,morphological, dielectric,and optomagnetic properties

Manganese–copper ferrite (MCFO) and dysprosium (Dy)-doped manganese–copper ferrite nanocomposites (Mn_0.5Cu_0.5Dy_xFe_2−xO₄) (x = 0, 0.05, 0.10, and 0.15) were synthesized by sonochemical method. Crystal structure and the structural parameters of the MCFO were analyzed based on the doping concentration of Dy ion. It was observed that the average crystalline size of the synthesized nanocomposite decreases when the concentration of Dy increases. The existing spherical surface morphology of the MCFO and Dy-doped MCFO nanocomposites were obtained through scanning electron microscopy. In the UV spectrum, the pristine MCFO sample showed an absorbance peak at 743 nm whereas the absorbance values of Dy-doped ferrite nanocomposite considerably shifted (blue) toward a lower wavelength (231–222 nm). The dielectric parameters of all ferrite nanocomposites were studied in the frequency range of 100 Hz to 5 MHz. The dielectric spectrum revealed that dielectric constant and loss tangent decreased with increased doping concentration of Dy ion. The saturation magnetization also changed with Dy doping in MCFO. The impact of Dy on manganese–copper ferrite changed the optical, dielectric and magnetic properties of the prepared binary ferrite nanocomposite, which can be used for microwave-absorbing material applications.     

核壳型纳米粒子合成方法及其性能的研究进展

核壳纳米粒子作为复合纳米粒子一个重要的分支,由于其光、磁和催化等方面的优异性能,近年来引起了人们广泛的关注.本文主要介绍了核壳纳米粒子的制备方法及诸多性能,并对核壳纳米粒子的发展进行了展望.     

Mechanical Properties of Compression Molded Banana Pseudo-stem Filled Unplasticized Polyvinyl Chloride (UPVC) Composites

Mechanical strengths of a banana pseudo-stem (BPS) fiber and unplasticized polyvinyl chloride (UPVC) composite were evaluated to assess the possibility of using it as a new material in engineering applications. Samples were fabricated by the compression molding process with reference to the effect of filler loading. The samples were submitted to mechanical tests to measure tensile, flexural, and impact properties of the composites. The nature of adhesion between the matrix and the reinforcement and information relating the structure of mechanical properties can be obtained by scanning electron microscopy (SEM) assessment of the composite fracture surface. The mechanical properties show that the composites did not have good adhesion between filler and matrix; on the other hand, the filler insertion improved the flexural modulus and the material rigidity.     

丁腈橡胶的伏安特性与功率特性的研究

本文对乙炔碳黑填充丁腈橡胶（NBR）的伏安特性及其功率特性进行了研究,分析了丁腈橡胶在交、直流电场下的导电机理,并对环境温度变化时的丁腈橡胶的功率及功率与电压的变化规律提出了相应的关系式,同时对导电丁腈橡胶的物理机械性能进行了研究与测定。     

TMPTMA在硅橡胶中的应用研究

研究了助交联剂三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)对硅橡胶硫化性能、力学性能、低温性能和粘接性能的影响。结果表明,加入少量TMPTMA能改善硅橡胶的硫化特性和工艺性,提高硫化胶的硬度,降低硅橡胶的结晶温度,并有效提高硅橡胶与金属的粘接强度;但TMPTMA用量超过一定数值后,由于TMPTMA部分自聚合,在硅橡胶内形成一定的交联网络,造成两相界面粘接力变差,致使硅橡胶的拉伸强度降低。当TMPTMA用量为1份时,硅橡胶具有最佳的综合性能。     

阻隔性PET/PEN共聚酯的性能研究

对共聚型阻隔聚酯PETNx(x为共聚酯中NDA占羧酸总质量的百分比)的热性能、流变性能和阻隔性能进行了研究。结果表明,PETNx体系属于假塑性流体。PETNx的CO2气体阻隔性优于常规PET;随着PETNx中NDA含量的增加,共聚物的玻璃化温度呈线性增高。     

聚氨酯种类对机械性能以及阻尼性能影响研究

分别以聚四氢呋喃醚二醇(PTMEG)、聚氧化丙烯二醇(PPG-1000)为软段,以二苯基甲烷二异氰酸酯(MDI-50、MDI-100LL),以及扩链剂1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)为硬段,采用预聚体法制备了聚氨酯弹性体。并系统研究了聚氨酯体系中各组分的种类对材料机械性能和阻尼性能的影响。     

Study of the Mechanical,Thermal Properties and Morphology of Polypropylene Nanocomposites in the Presence of Compatibilizer

In this work, the mechanical, rheological, and thermal properties and morphology of a polypropylene matrix reinforced with single-walled nanotubes (SWNTs) were investigated. Polypropylene-grafted-maleic acid was used as a compatibilizer to promote SWNTs dispersion. Compared to uncompatibilized nanocomposites, the tensile modulus of the material increased considerably when nanotubes and compatibilizer were employed. The rheological characterization results revealed that addition of SWNTs increased the storage modulus and complex viscosity at low frequencies. SEM revealed that the SWNTs were uniformly distributed when low concentrations of SWNTs were employed. The results of DSC indicated that the addition of SWNTs increased the crystallinity of nanocomposites.     

单向玻璃纤维-铝合金层板的几种力学性能研究

本文用实验方法研究了单向玻璃纤维-铝合金层板的拉伸性能、疲劳性能和冲击性能。利用金属体积分数理论验证了这类层板的拉伸性能。通过对其疲劳性能的实验研究，发现裂纹扩展速率的大小及刚度的下降与加载的最大循环应力密切相关的规律。实验发现该层板具有比铝合金好得多的冲击性能。     

Effects of support and additive on oxidation state and activity of Pt catalyst in propane combustion

The effects of support and additive on the oxidation state and catalytic activity of Pt catalyst in the low temperature propane combustion were systematically investigated on Pt/MgO, Pt/Al₂O₃ and Pt/SiO₂–Al₂O₃. The catalytic activity varied much with both support materials and additives. The catalyst on the more acidic support showed higher activity, and the catalytic activity on every support materials increased as the electronegativity of additives increased, while some additives decreased the activity. The oxidation state of platinum, estimated by white line intensity of Pt L_III-edge XANES spectrum, also varied with the support and additives, and additives with higher electronegativity greatly prevented the platinum from its oxidation under oxidising atmosphere. Among almost all the catalysts with various supports and various additives, a clear relationship was observed between the oxidation state of platinum and the catalytic activity; the more metallic platinum showed higher activity. Thus, it was concluded that the total electrophilic/electrophobic property derived from those of the support and additive controls the oxidation state of platinum, which intensively affects the catalytic activity; i.e. higher electrophilic property provides less oxidised platinum, resulting in high catalytic activity. The mechanism of this effect was also discussed on the basis of thermochemical data, and it was proposed that the electrophobic materials promote the noble metal oxidation since the noble metal oxo-anion such as PtO^δ− is more stabilised with electrophobic cation.