Shear and extensional properties of short glass fiber reinforced polypropylene
Shear and extensional properties of short glass fiber reinforced polypropylene
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DOI：
10.1002/pc.20088
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发表时间：
2005-06
影响因子：
5.2
通讯作者：
C. Mobuchon;P. Carreau;M. Heuzey;M. Sepehr;G. Ausias
中科院分区：
文献类型：
--
作者：
C. Mobuchon;P. Carreau;M. Heuzey;M. Sepehr;G. Ausias
使用商用流变仪和新型在线流变仪仔细研究了商用短玻璃纤维增强聚丙烯的剪切和拉伸性能。这种在线狭缝流变仪安装在注塑机上，旨在测量聚合物熔体和复合材料的稳定剪切粘度、第一法向应力差和表观拉伸粘度，剪切速率高达 105 s−1，拉伸速率高达 200 s−1。我们的结果表明，使用在线流变仪进行的稳态粘度测量与使用商业流变仪获得的结果非常一致。研究发现复合材料的稳态和复数粘度与基体相当接近，但复合材料在高速率下的 Cox-Merz 规则尚未得到验证。发现复合材料的弹性与聚丙烯基体的弹性相同。表观拉伸粘度是根据 Cogswell [1] 和 Binding [2] 提出的分析，从狭缝流变仪的平面会聚模具中的压降获得的。发现聚丙烯的拉伸粘度比低应变速率下的剪切粘度大得多，特劳顿比率约为 40，随着应变速率的增加，该比率迅速下降，在 200 s−1 时降至 4。还发现复合材料的拉伸粘度与基体的拉伸粘度接近，30 wt% 和 10 wt% 增强聚丙烯的值分别大 35% 和 5%。将这些结果与戈达德模型 [3] 的预测进行比较，戈达德模型 [3] 被证明高估了我们的实验结果。聚合物。组合。 26:247–264, 2005。© 2005 塑料工程师学会。
Shear and extensional properties of a commercial short glass fiber reinforced polypropylene were carefully investigated using commercial rheometers and a novel on-line rheometer. This on-line slit rheometer, installed on an injection molding press, has been designed to measure the steady shear viscosity, the first normal stress difference, and the apparent extensional viscosity of polymer melts and composites for high strain rates up to 105 s−1 in shear and 200 s−1 in extension. Our results show that the steady-state viscosity measurements using the on-line rheometer are in excellent agreement with those obtained using commercial rheometers. The steady-state and the complex viscosities of the composites were found to be fairly close to that of the matrix, but the Cox-Merz rule was not verified for the composites at high rates. The elasticity of the composites was found to be equal to that of the polypropylene matrix. The apparent extensional viscosity was obtained from the pressure drop in the planar converging die of the slit rheometer using the analyses proposed by Cogswell [1] and Binding [2]. The extensional viscosity of the polypropylene was found to be much larger than the shear viscosity at low strain rates with a Trouton ratio of about 40 that decreased rapidly with increasing strain rate down to the value of 4 at 200 s−1. The extensional viscosity of the composites was also found to be close to that of the matrix, with values 35 and 5% larger for the 30 and 10 wt% reinforced polypropylenes, respectively. These results are compared with the predictions of the Goddard model [3], which are shown to overpredict our experimental results. POLYM. COMPOS. 26:247–264, 2005. © 2005 Society of Plastics Engineers.