氟橡胶/甲基乙烯基硅橡胶共混胶的性能

研究了氟橡胶(FKM)与甲基乙烯基硅橡胶(MVQ)的共混比、1,4-双叔丁基过氧异丙基苯(BIBP)硫化剂和三烯丙基异三聚氰酸酯(TAIC)助硫化剂用量以及硫化温度对FKM/MVQ共混胶硫化性能和力学性能的影响。结果表明,当FKM/MVQ共混比为50/50、硫化剂BIBP用量为1.0份、助硫化剂TAIC用量为2.5份、硫化温度为160℃时,FKM/MVQ共混胶的硫化性能和力学性能最优,硫化时其最大转矩为19.34 dN·m,拉伸强度为5.29 MPa,扯断伸长率为230.68%。     

玄武岩短纤维/硅橡胶/氟橡胶复合材料制备及表征

以氟橡胶(FMK)和硅橡胶(MVQ)为基体,用玄武岩短纤维作增强相制备了玄武岩短纤维/MVQ/FMK复合材料,研究了MVQ/FMK的最佳并用比,玄武岩短纤维的长径比、用量及表面处理,二段硫化条件对复合材料力学性能的影响,用扫描电镜(SEM)和红外光谱(IR)分析表征了玄武岩短纤维和FMK/MVQ的相容性。结果表明,MVQ/FMK(质量比)为10/90时,并用胶的力学性能最好,使用长径比为1 800的玄武岩短纤维7份时,玄武岩短纤维/MVQ/FMK复合材料的力学性能最佳,最佳的二段硫化条件是200℃×6h。SEM和IR分析得出γ-巯丙基三甲基硅烷(KH-590)、双(γ-三乙氧基硅基丙基)四硫化物(Si69)在玄武岩短纤维表面发生了明显的化学反应,而且KH590处理的玄武岩短纤维与MVQ/FMK的相容性较好。     

动态硫化体系对POE/PP热塑性弹性体性能的影响

研究了不同硫化体系对动态硫化聚烯烃弹性体(POE)/聚丙烯(PP)热塑性弹性体机械性能的影响。结果表明,2,5-二甲基-2,5-双(过氧化叔丁基)(DBPH)作为交联剂最合适,用量为1.56 phr的时候性能最好;三烯丙基异氰酸(TAIC)作为助交联剂最合适,用量为0.195～0.39 phr时最好。     

挤出型镀银铝粉/硅橡胶导电复合材料的制备与性能研究

研究硅烷偶联剂对镀银铝粉的表面改性及镀银铝粉用量对镀银铝粉/硅橡胶导电复合材料性能的影响.结果表明,采用硅烷偶联剂A-171,A-172和A-187对镀银铝粉进行表面改性后复合材料不交联,而采用硅烷偶联剂A-137和A-151对镀银铝粉进行表面改性后复合材料可以硫化,其中硅烷偶联剂A-151的改性效果较好,最佳用量为15份.随着镀银铝粉用量的增大,复合材料的拉伸强度、拉断伸长率和体积电阻率减小,且出现逾渗现象,高导电复合材料镀银铝粉的最佳用量为280份.     

硫化发泡体系对硅橡胶泡沫材料应力松弛性能的影响

考察了过氧化二异丙苯/N,N-二亚硝基五次甲基四胺(DCP/H)、2,5-二甲基-2,5-二叔丁基过氧化己烷/偶氮二甲酰胺(双二五/AC)和过氧化苯甲酰(BPO)/AK 3种硫化发泡体系及助交联剂TAIC对硅橡胶泡沫材料力学性能和压缩应力松弛性能以及泡孔结构的影响。结果表明,DCP/H硫化发泡体系的力学性能和应力松弛性能优于双二五/AC和BPO/AK,添加适量助交联剂TAIC有助于进一步降低硅橡胶泡沫材料的应力松弛性能。扫描电镜(SEM)观察发现,DCP/H硫化发泡体系对应的硅橡胶发泡材料泡孔较小且分布均匀,当加入适量的助交联剂TAIC后,硅橡胶泡沫材料的泡孔更加细小均匀。     

炭黑用量对硅橡胶基力敏复合材料性能的影响

以炭黑为导电功能填料制备炭黑/甲基乙烯基硅橡胶(MVQ)力敏复合材料,研究炭黑用量对复合材料硫化特性、拉伸性能、压缩应力松弛性能、电性能和压阻性能的影响.结果表明:炭黑用量为11～16份时,炭黑/MVQ复合材料电性能达到逾渗阈值.随着炭黑用量的增大,炭黑/MVQ复合材料拉伸强度先增大后减小,最后趋于稳定,而压缩松弛率呈减小趋势.炭黑用量为11份时炭黑/MVQ复合材料的压阻重复性较好.适宜的炭黑用量为10～12份.     

镀镍石墨/硅橡胶导电复合材料的性能研究

以镀镍石墨为导电填料制备镀镍石墨/甲基乙烯基硅橡胶(MVQ)导电复合材料,并对其性能进行研究.结果表明,采用密炼工艺、硫化温度为110℃、偶联剂A-151和硫化剂双24用量分别为6和8份时,所制备的镀镍石墨/MVQ复合材料的导电性能和拉伸性能较好.     

镀银铝粉/硅橡胶高导电电磁屏蔽复合材料的性能研究

以镀银铝粉为高导电填料,硅橡胶为基材,对胶料性能和硫化体系、偶联剂用量进行了研究。结果表明,当镀银铝粉用量为260份,硫化体系选用DBPMH,偶联剂选用A151,硫化条件为160℃×15min时,所制备的镀银铝粉∕硅橡胶复合材料的综合性能较好。     

硅橡胶/聚氨酯热塑性弹性体的制备

采用过氧化物硫化体系制备了硅橡胶(VSR)与聚氨酯(TPU)质量比为50/50的VSR/TPU热塑性弹性体。考察了VSR的硫化条件,研究了抑制剂4-羟基2,2,6,6-四甲基哌啶氧(TEMPO)用量对VSR/TPU体系动态硫化过程及性能的影响。结果表明,当Hakke流变仪转速为110 r/min、硫化温度为180℃、硫化剂2,5-二甲基-2,5双(过氧化叔丁基)己烷用量为1.0份(质量,下同)、抑制剂TEMPO用量为0.3份时,制备的VSR/TPU热塑性弹性体具有较精细的相态,分散相VSR在TPU连续相中分散较均匀,热塑性弹性体的拉伸强度及扯断伸长率分别达到4.4 MPa及291%,流变性能较好,压缩永久变形最小。     

镀银镍粉填充型导电硅橡胶的性能研究

试验研究镀银镍粉填充的甲基乙烯基硅橡胶（MVQ）的物理性能和导电性能。结果表明，随着镀银镍粉用量的增大，MVQ硫化胶的硬度和压缩永久变形增大，拉伸强度和拉断伸长率减小，体积电阻率呈减小趋势；镀银镍粉用量为450份时，MVQ硫化胶的物理性能和导电性能均较优，体积电阻率随热空气老化温度的升高而呈增大趋势，随压缩率的增大而先减小后增大，压缩率以10％～30％为宜。     

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。