【作者】 周亚斌；

【导师】 史铁钧；

【作者基本信息】 合肥工业大学 ， 材料学， 2003， 硕士

【摘要】 采用乳液聚合法制备了聚苯乙烯／蒙脱土纳米复合材料(PSMN)。采用XRD、FT-IR、DSC和TGA对PSMN进行了表征。XRD表明，苯乙烯乳液聚合插层Na-MMT可以获得一定的插层效果，蒙脱土(001)面片层间距由原土的1.27nm增大到PS／Na-MMT复合材料中的1.59nm。使用不同用量的HTAB处理Na-MMT，然后再进行苯乙烯的乳液聚合。结果发现，HTAB的使用对插层效果影响很大。当HTAB的用量为Na-MMT质量的40％时，制得PSMN中蒙脱土(001)面片层间距达到了4.37nm。而使用同等量HTAB处理Na-MMT制得的O-MMT片层间距仅为2.96nm，这说明在苯乙烯乳液聚合插层O-MMT时，HTAB与苯乙烯发生了协同作用。FT-IR也证明了聚苯乙烯分子确已插层进入蒙脱土片层。DSC和TGA的结果表明，PSMN在热性能方面较纯树脂基体有明显的提高。将制备出的PSMN母料与以聚丙烯(PP)为主体的树脂基体进行熔融共混，制备出聚丙烯／蒙脱土纳米复合材料(PPMN)。分别采用XRD、力学测试、POM和SEM对PPMN进行了表征。XRD表明，蒙脱土(001)面片层间距由PSMN中的4.37nm继续增大到PPMN中的5.07nm，PPMN仍为插层型材料。蒙脱土的加入诱导PP晶型发生转变，生成了聚丙烯β型球晶。力学测试显示，共混组分的共同作用使PPMN具有良好的冲击性能。在其它共混组分含量不变的条件下，随PSMN填充量的增加，复合材料缺口冲击强度逐渐提高，在蒙脱土填充量为2wt％时达到最大值36.24kJ／m~2。继续增加PSMN的填充量，缺口冲击强度开始下降。PSMN的加入对PPMN的拉伸强度无明显影响。POM照片表明，PPMN中PP球晶明显细化，这与聚丙烯β晶型的形成同为PPMN韧性提高的原因。SEM照片显示，对比PP基体的典型脆性断面，PPMN冲击断面起伏较大，形态更加丰富，具有显著的韧性断裂特征。还采用悬浮接枝方法制备出聚丙烯接枝丙烯酰胺(PP-g-AM)，接枝率最高可达1％以上。IR谱图证明了AM已接枝到PP大分子链上。采用DSC方法研究了PP-g-AM的非等温结晶动力学。结果表明，Jeziorny法和Mo法均可较准确的描述PP-g-AM的非等温结晶过程。PP接枝前后Avrami指数n无明显改变，表明两者结晶机理基本相同。接枝产物的校正晶体增长速率常数Z_c略大于纯PP。由Mo法计算得出，PP-g-AM的F(T)值略小于纯PP，表明接枝物的相对结晶速率略大于纯PP。更多还原

【Abstract】 Polystyrene-montmorillonite nanocomposites (PSMN) were prepared by emulsion polymerization method. XRD, FT-IR, DSC and TGA were used to test PSMN. XRD showed that a centain intercalating effect was achieved by styrene intercalating Na-MMT via emulsion polymerization. The 001 layer spacing of montmorillonite had been enhanced from 1.27nm (Na-MMT) to 1.59nm (PS-Na-MMT). HTAB of Various quality was used to organized Na-MMT and then emulsion polymerization of styrene was processed. The results showed that HTAB played an important role in intercalation. When dosage of HTAB was 40% of Na-MMT, the 001 layer spacing of obtained PSMN achieved 4.37nm. While the 001 layer spacing of O-MMT, which was organized with 40% dosage of Na-MMT, was only 2.96nm. It indicated that HTAB and Styrene had corporate effects on styrene intercalating O-MMT. FT-IR also testified that polystyrene had intercalated the layers of montmorillonite. Results of DSC and TGA showed that thermal properties of PSMN were better than PS.PSMN was melt-mixed with resin mixture in which polypropylene was the main component and polypropylene-montmorillonite nanocomposites were prepared. XRD, mechanic test, POM and SEM were used to test PPMN. XRD spectra indicated that the 001 layer spacing of montmorillonite was increased from 4.37nm (PSMN) to 5.07nm (PPMN) and PPMN was still in intercalating type. The crystals of polypropylene were changed which induced by adding montmorillonite and P crystal of polypropylene was found in PPMN. The mechanic test showed that under the corporate effect of all blending components, PPMN processed good impact property. When the contents of other blending components were fixed, with the content increasing of PSMN, izod impact strength of PPMN was enhanced gradually. When the content of montmorillonite was 2wt%, max value of 36.24kJ/m2 was achieved. If more PSMN was added, izod impact strength of PPMN began to decrease. Adding PSMN had no obvious effect on the tensile strength. From the POM photos of polypropylene spherical crystal, we could see that the polypropylene spherical crystal were diminished obviously, which is one of the two reasons that toughness of PPMN was improved. SEM showed that comparing with typical brittlerupture of polypropylene, the impact surface of PPMN had acuter undulation and more abundant configuration which were typical characters of tough rupture.Besides, suspension grafting of acrylamide onto polypropylene was studied in water medium. The maxium degree of grafting had archieved above 1%. The non-isothermal crystallization kinetics of acrylamide graft polypropylene (PP-g-AM) was studied by means of differential scanning calorimetry (DSC). The results showed that both Jeziorny and Mo methods could describe the non-isothermal crystallization course of PP-g-AM accurately. Avrami exponent didn’t change obviously after grafting, which indicated that the crystallization mechanism of PP-g-AM was almost as same as PP. The values of modified Zc of PP-g-AM were a little higher than those of pure PP. The values of F(T) of PP-g-AM were a little lower than those of pure PP, which indicated that PP-g-AM had faster crystallization velocity. This result conformed to the slight degradation of PP chains in grafting process.更多还原