Brittle–ductile transition of polypropylene/ethylene–propylene–diene monomer blends induced by size, temperature, and time
Brittle–ductile transition of polypropylene/ethylene–propylene–diene monomer blends induced by size, temperature, and time
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DOI：
10.1002/polb.20023
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发表时间：
2004-04
期刊：
影响因子：
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通讯作者：
Wei Jiang;Donghong Yu;L. An;B. Jiang
中科院分区：
文献类型：
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作者：
Wei Jiang;Donghong Yu;L. An;B. Jiang
为了研究聚丙烯(PP)/三元乙丙橡胶(EPDM)共混物的脆韧转变(BDT)随尺寸、温度和时间的变化，研究了PP/EPDM共混物在较宽的EPDM含量、温度和应变速率范围内的韧性。共混物的韧性是由侧边缺口样品的拉伸断裂能确定的。引入粒子间距(ID)的概念，探讨了尺寸效应对PP/EPDM共混物BDT的影响，而时间的影响与应变速率的影响是一致的。在断裂能与ID、温度和应变率的关系中，观察到了由尺寸、温度和时间引起的BDT。从这些转变中得到了不同含量的三元乙丙橡胶在不同初始应变速率下的临界BDT温度。临界颗粒间距(IDC)随温度的升高呈非线性增加，且初始应变速率越低，IDC越大。此外，对于不同的三元乙丙橡胶含量，初始应变速率倒数随温度倒数的变化遵循不同的直线。这些直线具有相同的斜率。
To study the brittle-ductile transition (BDT) of polypropylene (PP)/ethylene-propylene-diene monomer (EPDM) blends induced by size, temperature, and time, the toughness of the PP/EPDM blends was investigated over wide ranges of EPDM content, temperature, and strain rate. The toughness of the blends was determined from the tensile fracture energy of the side-edge notched samples. The concept of interparticle distance (ID) was introduced into this study to probe the size effect on the BDT of PP/EPDM blends, whereas the effect of time corresponded to that of strain rate. The BDT induced by size, temperature, and time was observed in the fracture energy versus ID, temperature, and strain rate. The critical BDT temperatures for various EPDM contents at different initial strain rates were obtained from these transitions. The critical interparticle distance (IDc) increased nonlinearly with increasing temperature, and when the initial strain rate was lower, the IDc was larger. Moreover, the variation of the reciprocal of the initial strain rate with the reciprocal of temperature followed different straight lines for various EPDM contents. These straight lines were with the same slope.