β-nucleators and β-crystalline form of isotactic polypropylene
β-nucleators and β-crystalline form of isotactic polypropylene
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DOI：
10.1002/app.1995.070561014
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发表时间：
1995-06
影响因子：
3
通讯作者：
Mei-Rong Huang;Xin-Gui Li;Bowen Fang
中科院分区：
文献类型：
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作者：
Mei-Rong Huang;Xin-Gui Li;Bowen Fang
通过一系列添加剂的共混，使等规聚丙烯（iPP）产生不同程度的β晶型结晶。X射线衍射分析表明，kx值从0到0.95不等。发现靛蓝素棕IRRD、靛蓝素红紫IRH、Cibantine橙子HR、靛蓝素粉红IR、Cibantine蓝2B、靛蓝素金黄IGK和靛蓝素灰IBL是有效的β-成核剂。含有0.05重量%的上述七种b-成核剂的iPP样品的相应Kx值为0.54、0.68、0.82、0.82、0.86、0.92和0.95。所有的β-成核剂在分子结构中都含有稠合苯环或杂环。X射线衍射研究表明，它们的最强或次强衍射峰几乎都位于d间距为2.83埃处。其大小约为β晶型结晶度d间距（5.64 A）的一半。β-晶型水平还取决于我们控制的许多因素，如β-成核剂浓度、冷却速率、结晶温度和熔体温度。偏光显微镜观察表明，β球晶具有明亮的颜色，它们的马耳他十字形显示出一些具有相当尖锐的锯齿状特征的同心条带。扫描电子显微镜观察到它们的层状结构呈相关的树枝状
Different levels of β-form crystallinity in isotactic polypropylene (iPP) were produced by blending a series of additives. X-ray diffraction analyses showed that the kx values varied from 0 to 0.95. Indigosol Brown IRRD, Indigosol Red Violet IRH, Cibantine Orange HR, Indigosol Pink IR, Cibantine Blue 2B, Indigosol Golden Yellow IGK, and Indigosol Grey IBL were found to be effective β-nucleators. The respective Kx values of the iPP samples containing the above seven b-nucleators of 0.05 wt % are 0.54, 0.68, 0.82, 0.82, 0.86, 0.92, and 0.95. All the β-nucleators possess fused benzene rings or heterocycles in their molecular structures. X-ray diffraction studies on them revealed a mutual character in that the strongest or the second-strongest reflections almost locate at the d-spacing of 2.83 A. The magnitude is about half of that of the β-form crystallinity d-spacing (5.64 A). The β-form level also depends on a number of factors under our control, such as the β-nucleator concentration, cooling rate, crystallization temperature, and melt temperature. Polarizing microscope observations suggested that β-spherulites possess a bright color and that their Maltese Crosses display some concentric banding of a rather spiky, jagged character. Their lamellae exhibit a correlated and dendritic structure seen by a scanning electron microscope