Polymorphism in polyamide 6 and polyamide 6/clay nanocomposites molded via water-assisted injection molding
Polymorphism in polyamide 6 and polyamide 6/clay nanocomposites molded via water-assisted injection molding
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水辅助注射成型聚酰胺 6 和聚酰胺 6/粘土纳米复合材料的多晶型
DOI：
10.1016/j.compositesb.2011.10.002
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发表时间：
2012-04
影响因子：
13.1
通讯作者：
Zhou, Wei-Wen
中科院分区：
文献类型：
--
作者：
Huang, Han-Xiong;Wang, Bin;Zhou, Wei-Wen
与传统注射成型不同，水辅助注射成型（WAIM）的特点是冷却速率从外层到芯层单调递减，而WAIM的特点是冷却速率在整个零件壁面上的独特分布，这将导致WAIM零件形成独特的分层结构。因此，研究了两种不同分子量的聚酰胺6（PA 6 s）和PA 6（具有较高分子量）/粘土纳米复合材料的WAIM部分的晶体结构。结果表明，在较低的冷却速率下，α相占主导地位，而在较高的冷却速率下，或在粘土存在下，结合适当的冷却速率，γ相占主导地位，这可能受到上、下临界值的限制。随着降温速率的降低，PA 6分子量对γ晶型的形成影响更大。此外，剪切被发现阻碍了具有较高MW的PA 6的γ-型的形成。这一工作有助于进一步了解PA 6及其纳米复合材料在加工过程中的晶体形成机制。
Differing from the conventional injection molding, being featured by a monotonous decrease of cooling rate from the outer layer to the core layer, the water-assisted injection molding (WAIM) is characterized by a unique distribution of cooling rate across the part wall, which would be expected to result in the formation of unique hierarchical structures in WAIM parts. So the crystal structures of the WAIM parts of two grades of polyamide 6 (PA6s) with different molecular weights (MWs) and PA6 (with higher MW)/clay nanocomposite were investigated. It is found that the α-form is predominant at low cooling rates, whereas the γ-form is predominant when the cooling rate is high or in the presence of the clay combining with an appropriate cooling rate, which may be confined by both upper and lower critical values. The MW of the PA6 exhibits more effect on the formation of the γ-form as the cooling rate decreases. Moreover, the shear is found to hinder the formation of the γ-form for the PA6 with higher MW. This work help further understand the crystal formation mechanism in the PA6 and its nanocomposites upon processing.
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影响因子：
4.6
作者：
D. M. Lincoln;R. Vaia;Zhi-Gang Wang;B. Hsiao;R. Krishnamoorti
通讯作者：
D. M. Lincoln;R. Vaia;Zhi-Gang Wang;B. Hsiao;R. Krishnamoorti
影响因子：
3
作者：
Hanxiong Huang;Zhi-Wu Deng
通讯作者：
Hanxiong Huang;Zhi-Wu Deng
DOI：
10.1016/j.compositesa.2003.10.006
发表时间：
2004-02
影响因子：
8.7
作者：
Shih-Jung Liu;Yen-Shou Chen
通讯作者：
Shih-Jung Liu;Yen-Shou Chen
影响因子：
4.6
作者：
M. Yuan;L. Turng
通讯作者：
M. Yuan;L. Turng
影响因子：
4.6
作者：
Campoy, I;Gomez, MA;Marco, C
通讯作者：
Marco, C