甲基丙烯酸镁增强EVM硫化胶的结构与性能

将甲基丙烯酸镁(MDMA)直接与乙烯-乙酸乙烯共聚物(EVM)共混，并用过氧化物硫化，研究了过氧化二异丙苯(DCP)和MDMA用量对EVM硫化胶物理机械性能和交联结构的影响。结果表明，DCP用量为4．0份时硫化胶的性能较好；MDMA能明显地提高硫化胶的邵尔A型硬度和拉伸强度，同时保持较高的扯断伸长率，以MDMA用量为30-50份最佳。交联结构分析结果表明，硫化胶中离子键随着DCP和MDMA用量的增加而提高。动态力学分析结果表明，在硫化过程中MDMA发生反应使玻璃化转变温度移向低温区。傅里叶变换红外光谱分析表明，在硫化过程中，MDMA与EVM发生了接枝反应，形成了离子交联键。     

甲基丙烯酸镁纳米增强EVM硫化胶

将甲基丙烯酸镁（MDMA）直接添加到乙烯－乙酸乙烯酯共聚物（EVM）中，研究了MDMA对EVM硫化胶力学性能和微观结构的影响。结果表明，MDMA显著提高了硫化胶的拉伸强度和邵尔A型硬度，同时保持较高的扯断伸长率；电镜分析表明，在交联过程中，甲基丙烯酸镁能够原位生成纳米粒子（聚甲基丙烯酸镁），从而对橡胶产生优异的纳米增强效果。     

原位生成甲基丙烯酸钠增强EVM硫化胶的性能

通过氢氧化钠（NaOH)和甲基丙烯酸（MAA）的中和反应，在乙烯－乙酸乙烯酯橡胶（EVM）中原位生成甲基丙烯酸钠（NaMAA)，研究了NaMAA原位增强EVM的流变特性，应力软化和应力松弛以及老化前后的力学性能，并与炭黑（N330）增强的硫化胶进行对比，结果表明：NaMAA的引入对EVM混炼胶的门尼粘度几乎没有影响，但在硫化过程中提高了混炼胶的硫化速度，缩短了焦烧时间，与HAF相比，NaMAA对EVM硫化胶具有更好的增强效果，较好的耐老化性能，NaMAA增强的EVM硫化胶具有更明显的应力软化效应，应力松弛程度更大。     

甲基丙烯酸钠原位增强EVM硫化胶研究

通过氢氧化钠和甲基丙烯酸的中和反应,在乙烯-乙酸乙烯共聚物中原位生成甲基丙烯酸钠(NaMAA)增强EVM.研究了该硫化胶的物理机械性能,并用扫描电镜分析了填充和未填充硫化胶的撕裂断面.研究结果表明,NaMAA增强的EVM硫化胶具有高的拉伸强度、撕裂强度和扯断伸长率.NaMAA的加入使EVM硫化胶的撕裂方向偏移,提高了硫化胶的抗撕裂性能.     

甲基丙烯酸镁补强EVM的硫化反应动力学

在过氧化物硫化体系作用下，甲基丙烯酸镁（MDMA）对乙烯－乙酸乙烯共聚物（EVM）具有较好的补强作用。通过差示扫描量热（DSC）分析研究MDMA补强EVM混炼胶的硫化反应动力学，并分别采用Ozawa法和Kissinger法计算硫化反应动力学参数。结果表明，MDMA补强的EVM硫化过程遵循一级反应，采用Ozawa法和Kissinger法计算的硫化反应活化能具有较好的一致性，分别为127.0,126.3kJ/mol。     

无卤阻燃EVM/EPDM并用胶的性能研究

试验研究乙烯-乙酸乙烯酯橡胶（EVM）/EPDM并用胶的性能。结果表明,随着EPDM用量的增大,EVM/EPDM并用胶的物理性能变化不大,热空气老化后并用胶的邵尔A型硬度和拉伸强度增大,拉断伸长率减小,耐低温性能提高；EVM或EVM/EPDM并用胶的阻燃性能明显优于EPDM；添加阻燃剂和增塑剂的EVM/EPDM并用胶的相容性较未添加阻燃剂和增塑剂的并用胶有所改善。     

转子转速对乙烯-乙酸乙烯酯共聚物/三元共聚尼龙热塑性硫化胶性能的影响

使用密炼机,采用动态硫化工艺制备了乙烯-乙酸乙烯酯共聚物/三元共聚尼龙热塑性硫化胶（EVM/tPA TPV）和乙烯-乙酸乙烯酯-甲基丙烯酸缩水甘油酯共聚物/三元共聚尼龙热塑性硫化胶（EVM-GMA/tPA TPV）,研究了转子转速对两种热塑性弹性体体力学性能和耐热油等性能的影响。结果表明,在一定范围内提高转子转速,热塑性弹性体的力学性能呈上升趋势,当转子转速为80 r/min时,两种热塑性弹性体的综合力学性能最佳;当转子转速达到60 r/min以上时,两种热塑性弹性体的耐热油性能良好;随着转子转速的增加,两种热塑性弹性体的弹性得到改善;在相同转子转速条件下,EVM-GMA/tPA TPV比EVM/tPA TPV具有更好的力学性能、弹性和耐热油性能。     

甲基丙烯酸钠和高耐磨炭黑增强乙烯-乙酸乙烯酯橡胶的断裂行为

研究了甲基丙烯酸钠（NaMAA）和高耐磨炭黑（HAF）增强乙烯一乙酸乙烯酯橡胶（EVM）的断裂行为,采用Griffith能量平衡理论计算了引发硫化胶破坏的裂纹尺寸,并与扫描电子显微镜测得的裂纹尺寸进行了比较。结果表明,NaMAA和HAF填充EVM硫化胶的理论裂纹尺寸均明显小于纯EVM硫化胶;实际测得的裂纹尺寸小于理论裂纹尺寸;NaMAA增强EVM硫化胶的撕裂断面呈现黏滑式撕裂,而HAF增强EVM硫化胶的撕裂断面较平整,存在直的撕裂线。     

硫化特性匹配对混炼型聚氨酯橡胶/丁腈橡胶共混胶性能的影响

考察了混炼型聚氨酯橡胶（MPU）和丁腈橡胶（NBR）硫化特性匹配对MPU/NBR共混胶性能的影响。结果表明,对MPU进行130 ℃热处理后再进行混炼,可缩短硫化诱导期,使其硫化特性与NBR接近,可减小硫化体系的相间偏析,从而增强MPU/NBR共混胶的硫化程度,提高共混胶的物理机械性能。当热处理时间为8 min时,MPU/NBR共混胶的拉伸强度提高37%,耐热油老化性能得到明显改善。     

复合型增强剂对氢化丁腈橡胶/氟橡胶复合材料性能的影响

将炭黑（CB）、氢氧化单甲基丙烯酸锌（HZMMA）和碳纳米管（CNTs）进行复配，以改性氢化丁腈橡胶（HNBR）/氟橡胶（FKM）共混胶，制备了HNBR/FKM复合材料，研究了复合型增强剂对HNBR/FKM共混胶硫化特性、硫化胶的物理机械性能、动态力学性能和耐热氧老化性能的影响。结果表明，当加入HZMMA和CNTs后，HNBR/FKM复合材料的硫化速率加快且交联程度提高；在HZMMA和CNTs的协同作用下，HNBR/FKM复合材料的物理机械性能明显提高；与纯CB增强的相比，加入3份（质量）CNTs的HZMMA增强的HNBR/FKM复合材料热氧老化后扯断伸长率的保持率最高，与此同时硬度变化率最低；随着CNTs添加量的增加，HNBR/FKM复合材料的玻璃化转变温度向低温方向移动，同时损耗因子呈逐渐下降的趋势。     

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。     

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.     

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。     

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。     

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。     

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.     

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.     

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.     

对苯二甲酸乙二酯/聚乙二醇共聚醚酯的热性能研究

将含有磺酸盐基团化合物及不同添加量的聚乙二醇(PEG)与对苯二甲酸乙二酯共聚合成共聚醚酯(COPEET),利用差示扫描量热分析法(DSC)研究了一系列COPEET的玻璃化转变温度、结晶温度以及熔融温度等的变化规律。结果表明:随PEG添加量的增加,COPEET的玻璃化转变温度有规律地下降;PEG质量分数小于30%时,有利于冷结晶、结晶度下降;继续增加PEG则COPEET变得难于结晶;PEG质量分数小于40%时,热结晶容易,但结晶度下降;PEG添加量更高时,熔融结晶变得困难了;添加PEG会降低COPEET的熔点。