N-对甲苯基马来酰亚胺乳液共聚物性能表征

通过乳液聚合制得N-对甲苯基马来酰亚胺(NPTMI)、甲基丙烯酸甲酯、苯乙烯的三元共聚物．采用热重分析、维卡软化点测试、差示扫描量热分析等方法研究了不同单体配比共聚物的热性能及力学性能．用凝胶渗透色谱(GPC)测定了共聚物的分子量及其分布。结果表明：加入NPTMI可以有效地提高共聚物的热稳定性,NPTMI质量分数为20％的共聚物与不含NPTMI的共聚物相比．玻璃化转变温度、维卡软化点、热分解起始温度、分解50％时的温度分别提高了22．6,19．5,42．8,46．2℃．但力学性能有所下降。GPC测定结果表明,分子量在合适的单体配比下出现最大值。     

N-环己基马来酰亚胺／甲基丙烯酸甲酯／苯乙烯乳液共聚物与PVC共混的研究

通过乳液共聚合得到N-环己基马来酰亚胺(ChMI)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)的三元共聚物(ECMS)，用共聚物作耐热改性剂与PVC共混，用TBA和TGA研究了共聚物含量对共混物热性能、力学性能、流变性能及维卡软化点的影响。结果表明随三元共聚物含量的增加，共混物的玻璃化温度及维卡软化点逐渐上升；PVC第一阶段降解完毕。后平台区残留量逐渐上升；拉伸强度提高，冲击强度下降；熔体表观粘度增加，呈假塑性流体。     

聚丙烯／层状硅酸盐纳米复合材料的制备和性能研究

以PP-g-MAH作为相容剂，有机蒙脱土为填料．与聚丙烯经熔融共混得到复合材料．研究了蒙脱土含量对复合材料的力学性能、热性能和流动性能的影响。结果表明．复合材料的拉伸强度、维卡软化点和熔体流动速率较纯聚丙烯都有显著提高，同时冲击强度略有下降；在蒙脱土含量为6％时，复合材料的拉伸强度和熔体流动速率达到最佳值．在蒙脱土含量为8％时，维卡软化点的上升趋于平缓。     

PP/ABS-g-MAH/SCF复合材料的制备及性能表征

采用熔融共混法制备了聚丙烯(PP)/马来酸酐接枝丙烯腈-丁二烯-苯乙烯共聚物(ABS-g-MAH)/短碳纤维(SCF)复合材料,并利用万能电子试验机、冲击试验机、维卡软化和负荷热变形温度测试仪、热重分析仪以及熔体流动速率仪分别研究了其力学性能、热学性能及流动性能。力学性能测试表明:以PP-g-MAH作为增容剂,适量的加入SCF(5%~10%),复合材料的力学性能提升明显。维卡软化温度实验结果显示:SCF的加入提高了复合材料的维卡软化温度。热重分析表明:随着体系内SCF含量的逐渐增加,复合材料失重5%时的温度(T_(5%))有逐渐上升的趋势,说明SCF的加入在一定程度上提高了复合体系的热稳定性。熔体流动速率分析表明:随着SCF含量的不断增加,复合材料的熔体流动速率下降明显,流动性能受到抑制。     

甲基丙烯酸甲酯-N-环己基马来酰亚胺-丙烯腈共聚物的合成及其与PVC共混的研究

通过悬浮聚合得到了甲基丙烯酸甲酯-N-环己基马来酰亚胺-丙烯腈三元共聚物，将其作为耐热改性剂与PVC共混。研究了单体配比对共聚物的玻璃化转变温度和溶度参数的影响及共聚物含量对共混物热性能和力学性能的影响。结果表明，共聚物的玻璃化转变温度随N-环己基马来酰亚胺（CHMI）用量的增加明显提高，随丙烯腈（AN）用量的增加而降低；溶度参数随CHMI用量的增加上升，随AN用量的增加而下降。将此共聚物与PVC共混，当其用量为PVC的40％（质量分数，下同）时，PVC的维卡软化点提高了20℃。     

ChMI/ MMA/AN悬浮共聚物与PVC共混的研究

通过悬浮共聚得到了N－环己基马来酰亚胺（ChMI）、甲基丙烯酸甲酯（MMA）、丙烯腈（AN）三元共聚物（PCMA），用作耐热改性剂与PVC共混。考察了共聚物用量对共混物热性能、力学性能、流变性能的影响，用扫描电镜（SEM）观察其断面。结果表明：随共聚物用量的增加，共混物的玻璃化温度和维卡软化点明显提高；PVC第一阶段降解速率减小，降解守毕后平台区残留量逐渐上升；拉伸强度明显提高，冲击强度在一定比例范围内几乎不变；熔体表观粘度增加，呈假塑性流体。     

纳米ZnO／ABS复合材料的制备及性能研究

制备了改性纳米ZnO／丙烯腈-丁二烯-苯乙烯共聚物复合材料，研究改性纳米ZnO用量对复合材料维卡软化温度及紫外线老化前后力学性能的影响。结果表明：适量添加改性纳米ZnO既可有效提高ABS复合材料的维卡软化温度及各种力学性能，又可赋予复合材料优良的耐老化性能。改性纳米ZnO用量为3％时，ABS复合材料的维卡软化温度达102℃，比纯ABS树N（98．7℃）提高3．2℃；紫外线老化前后复合材料的拉伸强度较纯ABS树脂分别提高37．4％和44．6％、断裂伸长率提高0．9％和357％、硬度提高45．4％和29％、缺口冲击强度提高13.8％和44．7％、无缺口冲击强度提高12．4％和44.4％。     

采用分子模拟技术研究开发高耐热ABS

利用分子模拟技术建立了丁二烯胶乳、苯乙烯－丙烯腈共聚物、丙烯腈－丁二烯－苯乙烯三元共聚物（ABS）粉料和ABS树脂模型，利用这些模型在计算机上进行了高耐热ABS树脂的研究，并利用实验进行验证。结果表明：开发的高耐热ABS（以HH7．3为例）的拉伸强度为58MPa，弯曲强度为100MPa，弯曲模量为2834MPa，悬臂梁冲击强度为206J／m，热变形温度为100℃，熔体流动指数为14．9g/10min，洛氏硬度为115，维卡软化点为112℃，其性能超过国外同类产品。     

苯乙烯氯化原位接枝改性氯化聚氯乙烯的研究

采用氯化原位接枝技术在聚氯乙烯（PVC）进行氯化反应的同时接枝上各种不同单体．从而制备改性的氯化聚氯乙烯（CPVC）。研究了PVC固相法氯化原位接枝St的规律，讨论了单体苯乙烯（St）加入量、氯含量对产物物理力学性能及流变性能的影响。结果表明：St的加入量为10份时，改性CPVC的屈服强度明显高于空白CPVC的屈服强度，但维卡软化点降低；改性CPVC的屈服强度和维卡软化点均随氟含量增加而增大；St的加入量适当，可以同时提高改性CPVC的屈服强度和冲击性能，降低熔体粘度。     

PDA型PUR弹性体的制备与性能

以聚己二酸二乙二醇酯二醇(PDA)为软段,4,4′–二苯基甲烷二异氰酸酯(MDI)和1,4–丁二醇(BDO)为硬段,采用预聚体法制备一系列PDA型PUR弹性体。采用力学性能测试、广角X射线衍射(WAXD)、傅立叶变换红外光谱(FTIR)、差示扫描量热(DSC)、热重(TG)分析和维卡软化点温度测定等研究手段,研究硬段含量对其力学性能、微观形态和热性能的影响。结果表明,随着硬段含量的增加,PDA型PUR弹性体的硬度、拉伸强度、300%定伸应力、拉伸永久变形和撕裂强度都增大,当硬段含量为40.1%时,弹性体的综合力学性能最佳,硬度(邵A)为88,拉伸强度为33.9 MPa,300%定伸应力为12.5 MPa,拉伸永久变形为31%,撕裂强度为90.3 k N/m;WAXD分析表明,弹性体为无定型结构;FTIR分析表明,硬段含量的增加使弹性体总的氢键化程度增加,微相分离程度改善;DSC测试表明,硬段含量的增加使弹性体的微相分离程度提高;TG和维卡软化点温度测试表明,弹性体的热性能随着硬段含量的增加而提高,当硬段含量为40.1%时,弹性体的初始分解温度(失重5%的温度)和维卡软化点温度分别达到324.5℃和144.1℃,具有较好的热性能。     

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.     

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.     

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.     

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。     

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。     

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。     

聚丙烯基抗菌塑料的制备与性能研究

利用熔融挤出共混技术制备了聚丙烯(PP)基抗菌塑料。研究了抗菌母料Antim-PP对PP的抗菌性能和力学性能的影响。结果表明,当抗菌母料与PP的质量比为4:100时,抗菌PP塑料对大肠杆菌的抗菌率大于99%,抗菌母料的加入使共混物的冲击性能有明显改善,其他力学性能基本不受影响。     

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。     

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.