Micro-Structure and Fracture Behavior of High-Melt-Strength PPs Prepared by Reactive Extrusion
Micro-Structure and Fracture Behavior of High-Melt-Strength PPs Prepared by Reactive Extrusion
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DOI：
10.1080/00222348.2011.574061
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
Yucheng Hou;Bang-hu Xie;Wei Yang;Ming‐bo Yang
中科院分区：
文献类型：
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作者：
Yucheng Hou;Bang-hu Xie;Wei Yang;Ming‐bo Yang
在过氧化二异丙苯和抗氧剂的存在下，以聚丙烯（PP）和不同量的二乙烯基苯为原料，通过反应挤出制备了高熔体强度聚丙烯（PP），并对所得材料的动态流变行为、结晶形态和断裂行为进行了研究。结果表明，在较低的频率下，随着交联度和支化度的增加，改性PP熔体的复数粘度显著增加，然后趋于平稳。熔体的模量，特别是储能模量增加。具有较高含量的交联和支化结构的熔体的储能模量在整个测试频率范围内均高于损耗模量，表明完全弹性行为。改性PP的结晶度降低，球晶尺寸减小，球晶数目增加。与纯PP相比，改性PP的断裂比基本功和断裂比非基本功均有所降低，但断裂比基本功随交联结构和支化结构的增加而呈增加趋势。
In this study, high-melt-strength polypropylenes (PPs) were prepared by reactive extrusion of PP and varied amount of divinylbenzene in the presence of dicumyl peroxide and an antioxidant, and the dynamic rheological behavior, crystalline morphology, and fracture behavior of the resultant materials were investigated. It was found that at relatively low frequency, with the cross-linking and branching structures increasing, the complex viscosity of the melt of the modified PP increased significantly and then leveled off. The modulus of the melt, particularly the storage modulus, increased. The storage moduli of the melts with higher content of cross-linking and branching structures were higher than the loss modulus in the whole range of testing frequency, indicative of a completely elastic behavior. The crystallinity and the size of spherulites of the modified PP decreased, while the number of spherulites increased. The specific essential work of fracture and the specific non-essential work of fracture of the modified PP were found to be reduced compared with pure PP, but the specific essential work of fracture showed an increasing trend with the cross-linking and branching structures increasing.