PET抗静电复合材料的性能研究

以PET为基体树脂,研究了3种不同类型的抗静电剂与PET熔融共混制备的抗静电复合材料的力学性能、抗静电性能及微观形态。结果表明,含磺酸盐及聚醚的复合抗静电母料和聚醚型复合抗静电母料均可显著提高PET的抗静电性能,当两种母料的质量分数均为3%时,可使PET复合材料的表面电阻率均降低6~7个数量级,而对复合材料的力学性能影响不大;非离子型表面活性剂的改性效果较差。     

纳米蒙脱土母料对PA6力学性能的影响

简述了纳米蒙脱土(MMT)母料制备工艺及过程,分别阐述了不同载体树脂、不同分散程度及用不同方法处理的纳米MMT母料对聚酰胺6力学性能的影响。     

纳米碳酸钙母料研制及对聚丙烯力学性能的影响

分别将未经过表面处理和经过PMMA包覆的纳米CaCO3粒子制备成母料并与PP复合,制备PP／Ca CO3纳米复合材料。通过TEM观察了表面处理后纳米粒子的粒径与分散情况,对纳米复合材料的力学性能进行了测试并观察了缺口冲击断面形貌。     

PMA表面接枝包覆纳米TiO2及其在PP中抗紫外老化的研究

以硅烷偶联剂对纳米TiO2进行表面预处理，在此基础上以聚甲基丙烯酸（PMA）对其表面接枝包覆，后以马来酸酐接枝聚丙烯（PP-g-MAH）为载体，通过母料复合工艺制备了PP纳米复合材料。分析了处理后纳米TiO2的结构并对其在PP中的分散情况及抗紫外老化性能进行了比较。结果表明：PMA在纳米TiO2表面接枝率约为50％；与未处理TiO2及硅烷处理样品相比，PMA接枝包覆使纳米TiO2在PP中的分散均匀性及抗紫外老化性能均获得了改进。     

反应单体改性纳米CaCO3/PP母料的制备和性质研究

用溶液法制备了反应性单体改性PP包覆纳米CaC03母料，用IR、DSC和TGA等方法研究了母料中的化学作用、结晶与熔融行为、热稳定性和表面性质等。研究结果表明：反应性单体改性PP形成接枝物包覆纳米CaCO3，纳米CaCO3的质量分数高达80％。不同单体对PP结晶温度有不同的影响，结晶温度高低顺序为甲基丙烯酸甲酯〉丙烯酸甲酯〉丙烯酸丁酯。丙烯酸与苯乙烯混合物〉无单体。马来酸酐。丙烯酸〉苯乙烯。单体改性使母料接触角进一步提高。     

二氧化钛/聚合物复合微球的制备及聚合物表面性质的影响研究

以多孔聚(苯乙烯.二乙烯基苯)接枝马来酸酐聚合微球[P(St-DVB)/MAH]为底物,成功制备了表面均匀包覆纳米二氧化钛(TiO2)的复合微球.主要考察了聚合物微球的表面性质(多孔性和表面功能基团)对TiO2粒子在其表面包覆分散性和数量的影响.复合粒子微球的形态通过扫描电镜和X射线衍射分析等进行了表征.结果表明,聚合物微球的多孔性和表面功能基团都提高了TiO2粒子在微球表面的分散性.平均孔径为136.8 nm的多孔微球与无孔和平均孔径为42 nm的多孔微球相比,能够进一步提高表面TiO2粒子的均匀性和连续性,产生表面均匀覆盖粒径为60 nm TiO2的复合微球.     

环氧灌封材料的研究进展

介绍了电子产品环氧灌封材料的两种灌封工艺；常态灌封和真空灌封；针对环氧树脂本身脆性大的缺点，详述了环氧灌封材料的增韧方法，主要包括端羧基聚丁二烯-丙烯腈(CTBN)增韧、复合弹性体微粒增韧、液晶环氧增韧、氰酸酯树脂增韧和纳米粒子增韧，同时对其增韧效果进行了评价；最后列举了三种典型环氧灌封材料的应用配方和它们的性能指标。     

反应单体改性纳米CaC0_3/PP母料的制备和性质研究

用溶液法制备了反应性单体改性PP包覆纳米CaCO_3母料,用IR、DSC和TGA等方法研究了母料中的化学作用、结晶与熔融行为、热稳定性和表面性质等。研究结果表明:反应性单体改性PP形成接枝物包覆纳米CaCO_3,纳米CaCO_3的质量分数高达80%。不同单体对PP结晶温度有不同的影响,结晶温度高低顺序为甲基丙烯酸甲酯>丙烯酸甲酯>丙烯酸丁酯≈丙烯酸与苯乙烯混合物>无单体≈马来酸酐≈丙烯酸>苯乙烯。单体改性使母料接触角进一步提高。     

反应单体改性纳米CaCO3／PP母料的制备和性质研究

用溶液法制备了反应性单体改性PP包覆纳米CaCO3母料，用IR、DSC和TGA等方法研究了母料中的化学作用、结晶与熔融行为、热稳定性和表面性质等。研究结果表明反应性单体改性PP形成接枝物包覆纳米CaCO3，纳米CaCO3的质量分数高达80％。不同单体对PP结晶温度有不同的影响结晶温度高低顺序为甲基丙烯酸甲酯〉丙烯酸甲酯〉丙烯酸丁酯-丙烯酸与苯乙烯混合物〉无单体-马来酸酐-丙烯酸〉苯乙烯。单体改性使母料接触角进一步提高。     

分散聚合法制备环氧基磁性复合微球

采用化学共沉淀法制备了油酸包覆的Fe3O4磁性纳米粒子,以此为核·采用分散聚合法制备了表面带有环氧基团的Fe3O4／聚甲基丙烯酸缩水甘油酯（PGMA）磁性复合微球,探讨了聚合工艺、聚合条件对甲基丙烯酸缩水甘油酯（GMA）利用效率的影响规律,并用傅立叶变换红外光谱仪（FTIR）、热重分析仪（TGA）、振动样品磁强计（VSM）和扫描电镜（SEM）等对磁性复合微球的结构、磁性能和包覆量进行了表征．采用盐酸一丙酮法测定了磁性复合微球表面环氧基的含量。结果表明,在优化的条件下。GMA利用效率高达61．26％。磁性复合微球具有良好的单分散性·粒径为1～2μm．具有超顺磁性．比饱和磁强度为17．12emu·g^-1。环氧基含量达3．5mmol·g^-1。     

CaCO_3纳米粉填充环氧树脂分散技术研究

对CaCO3 纳米粉填充环氧树脂的均匀分散技术进行了探讨。采用超声波振动和对CaCO3纳米粉进行硅烷偶联处理两种方法改进CaCO3 在环氧树脂中的分散效果。扫描电镜观察表明 ,以上两种方法比普通搅拌混合效果显著 ,实现了CaCO3 纳米粉在环氧树脂中的均匀分散。     

CaCO_3对EPDM/PP热塑性弹性体性能的影响

在双螺杆挤出机上采用动态硫化的方法制备CaCO3改性三元乙丙橡胶/聚丙烯(EPDM/PP)共混型热塑性弹性体(TPV),研究了CaCO3添加量对热塑性弹性体拉伸性能、流动性能和邵氏A硬度的影响,并对材料进行热失重分析、差示扫描量热分析以及X射线衍射分析。结果表明:CaCO3对TPV有增强的作用,随着CaCO3含量的增加,热塑性弹性体的拉伸强度和断裂伸长率有很大提高,当CaCO3质量分数为9%时,拉伸强度、断裂伸长率、100%定伸应力与邵氏A硬度达到最大值,随后逐渐降低;CaCO3的加入增加了TPV的流动性,使其热稳定性提高,结晶温度降低,使PP的β(300)晶面消失。     

Effect of elastomer modification on the adhesive characteristics of maleimide‐functional phenolic resins

The effect of addition of elastomeric modifiers on the adhesive properties like lap shear strength and T‐peel strength of an addition curable, maleimide functional novolac phenolic resin (PMF), self‐cured and cocured with a novolac epoxy resin, was studied using aluminium adherends. The modifiers used were (1) two grades of carboxyl terminated butadiene acrylonitrile copolymer (CTBN) of different molecular weights, (2) a low molecular weight, epoxidized hydroxyl‐terminated polybutadiene, and (3) a high molecular weight acrylate terpolymer containing pendant epoxy functionality. The adhesive properties, when examined as a function of the varying concentrations of the additives, ranging from 10 to 30 parts per hundred parts (phr) of the resin, were found to depend on the nature of the matrix being modified as well as on the nature and concentration of the elastomer. The adhesive properties at ambient temperature of the self‐cured, highly brittle PMF resin were dramatically improved by the inclusion of all the elastomers, the increase being substantial in the case of high molecular weight CTBN. For the more rigid, less ductile, epoxy‐cured PMF system, the adhesive properties were marginally improved by the high molecular weight CTBN, whereas the other elastomers were practically ineffective. For both self‐cured and epoxy‐cured PMF systems, the inclusion of these elastomers generally decreased the high‐temperature adhesive properties, implying impairment of thermal characteristics, evidenced also from their dynamic mechanical spectra. The presence of phase‐separated elastomer particles in the modified systems has been evidenced from scanning electron micrographs. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2321–2332, 1999     

Modification of Epoxy by a Liquid Elastomer and Solid Rubber Particles

Summary This work covers studies on epoxy resin systems modified with two different rubber phases. The first modification was the use of recycled car tire rubber particles; while in the second one a silicon based liquid elastomer (Tegomer) was mixed with the epoxy resin matrix. In the third method epoxy resin was modified with both solid rubber particles and liquid elastomer together.Mechanical tests showed that these modifications resulted in no significant improvements in the mechanical performance of the epoxy resin system. Fractographic studies indicated that poor interfacial adhesion was occurred between the epoxy matrix and the solid rubber particles, while liquid elastomer resulted in formation of round rubbery domains and some plastic deformation lines in the epoxy matrix. For better improvements interfacial phenomenon will be explored.     

纳米CaCO3填充环氧树脂分散技术研究

对纳米CaCO3填充环氧树脂的均匀分散技术进行了探讨。采用超声波振动和对纳米CaCO3进行硅烷偶联处理两种方法改进CaCO3在环氧树脂中的分散效果。扫描电镜观察表明，以上两种方法比普通搅拌混合效果更好，实现了纳米CaCO3在环氧树脂中的均匀分散。     

环氧树脂/CaCO_3纳米复合材料的力学及光学性能研究

采用CaCO3 纳米颗粒均匀溶混于环氧树脂中 ,制得环氧树脂 /CaCO3 纳米复合材料 ,并对该复合材料进行了宏观力学性能测试 ,微观断口分析及光弹实验测试。结果表明 ,掺杂纳米粉后 ,实现了材料的增强增韧 ,同时对材料的光透性没有明显影响     

相变材料在路面裂缝修补技术中的应用

以石蜡为相变材料、聚氨酯/环氧树脂互穿网络聚合物为载体,采用一步法制备含有相变调温功能的路面裂缝修补材料。通过差示扫描量热(DSC),结果表明,材料A的熔化潜热值为45.7 kJ/kg,相变温度为-0.3℃;红外光谱(FT-IR)和热重(TG)结果表明,石蜡很好地分散在互穿网络聚合物载体中,与载体间没有发生化学反应,热稳定性保持在300℃以上。     

PVC/PU共混改性的研究

采用机械共混的方法,将聚氯乙烯树脂及其助剂进行高速混合,然后与热塑性聚氨酯弹性的体熔融共混。测试其拉伸性能及流变性能,确定共混的工艺条件,和加工条件。综合试验的结果,找出增韧性较好的最佳合金配比。另外,在聚合物中加入少量的ＣａＣＯ３,即降低了成本,同时又提高了聚合物的力学性能。     

Effects of Loading Rate and Temperature on the Mechanical Properties of Structural Adhesives Containing a Carrier

The viscoelastic related properties of four structural adhesives were studied in their bulk form. All four adhesives were based on rubber-toughened epoxy resin with a thermoplastic carrier. Two of the adhesives were commercial film adhesives (120°C curing systems) and the other two were formulated by us from commercially available constituents. The first formulation is a high-temperature-curing system based on cyclo-aliphatic resin and anhydride hardener, toughened with carboxy-terminated butadiene elastomer. The second self-prepared formulation is a special room-temperature-curing adhesive for elevated temperature service, based on a blend of trifunctional and tetrafunctional expoxies cured with triethylene tetramine toughened with amine-terminated butadiene elastomer. The latter formulation was also prepared, in addition to the carrier-containing composition, without the thermoplastic carrier.

As expected for viscoelastic materials, it was found that the yield stress and modulus decreased with temperature. The rate of loading had a pronounced effect on the yield stress which increased with increasing loading rates, and a negligible influence on the modulus. The rate-temperature effects on the yield stress were shown to obey the superposition as described by Eyring's theorem of viscosity. Consequently, the activation energy and activation volume were determined. The high-temperature-curing adhesives comprising a carrier exhibited higher activation energies compared with the room-temperature-curing formulation and other epoxy adhesives cured with aliphatic amines or polyamides reported in the literature.     

Processing of highly elastomeric toughened cyanate esters through a modified resin transfer molding technique

Model cyanate ester resins containing different quantities of epoxy functional butadiene-acrylonitrile rubber (ETBN) to improve the fracture performance were developed as matrices for composites. With the elastomeric modification, the resin systems exhibited rheological characteristics inappropriate for laminate fabrication by conventional resin transfer molding (RTM). To fabricate the carbon fiber based laminates in one liquid molding operation successfully, a process named bleed resin transfer molding (BRTM) was established. The BRTM process combines features of RTM and resin film infusion processes (RFI) and was therefore appropriate for processing high viscosity matrix resins. A novel catalyst was selected for the cyanate ester resin that provided enough latency for the impregnation steps in the BRTM process. Through the use of thermal analytical tools, a high degree of phase separation and conversion was obtained. The conversion and the glass transition temperature were found not to decrease with increasing elastomer content, which is in contradiction to most toughening modifications. Mode I and Mode II interlaminar fracture toughness were found to increase significantly with increasing elastomer content. In Mode I, an increase of up to 140% was observed. Collectively, this work showed that through the use of the BRTM technique, matrices with toughness improvements usually only achieved by prepreg systems can be processed in an RTM-like manner.