玻璃纤维对聚甲醛基导电复合材料性能的影响

采用在转矩流变仪中熔融混合的方法制备了聚甲醛(POM)/多壁碳纳米管(MWCNTs)/玻璃纤维(GF)和POM/炭黑(CB)/GF复合材料,研究了GF的加入对复合材料的导电性能、结晶行为和动态力学性能的影响.采用场发射扫描电镜(FESEM)观察了复合材料中导电填料的分散状态,发现GF的加入对MWCNTs和CB的分散状态没有明显影响.虽然GF为导电惰性填料,但因其加入起到了占位作用,明显提高了导电填料的有效浓度,从而使复合材料的体积电阻率明显降低.采用示差扫描量热仪(DSC)研究了复合材料中POM的结晶行为,发现GF的加入对POM的结晶温度、熔点和结晶度均无明显影响.采用动态机械分析仪(DMA)对复合材料的动态力学性能进行了研究,表明GF的加入能够明显地提高复合材料的储能模量.

EFFECT OF GLASS FIBER ON THE PROPERTIES OF ELECTRICALLY CONDUCTIVE POLYOXYMETHYLENE COMPOSITES

Polyoxymehtylene(POM)/multiwalled carbon nanotubes(MWCNTs)/glass fiber(GF) and POM/carbon black(CB)/GF composites were prepared by melt mixing in a rotational rheometer.The effects of GF on the electrical conductivity,crystallization behavior and dynamic mechanical properties of the composite materials were investigated.The morphology of the composites was observed by field emission scanning electron microscopy(FESEM),showing that GF does not significantly affect the dispersion state of MWCNTs and CB.Although GF is electrically inert,its presence can increase the effective concentration of the conductive filler by holding up some space,therefore the conductivity of the material increases.The electrical resistivity/effective concentration data points are all around the electrical resistivity/conductive filler concentration curve of POM/MWCNTs and POM/CB composites,proving that the concept of effective volume concentration can be used to explain the decrease in the electrical resistivity with the incorporation of GF.The crystalline behavior of POM in the composites was investigated by differential scanning calorimetry(DSC).The crystallization temperature,melting temperature and degree of crystallinity have no significant change by incorporation of GF,revealing that GF does not have obvious influence on the crystalline behavior of POM.The storage modulus,as measured by dynamic mechanical analysis(DMA),increases significantly by the presence of GF,showing a strong reinforcing effect.Therefore,GF-filled POM/MWCNTs and GF-filled POM/CB are promising materials having both good electrical conductivity and good mechanical properties.