Effect of Anodic Alumina Oxide Pore Diameter on the Crystallization of Poly(butylene adipate).
Effect of Anodic Alumina Oxide Pore Diameter on the Crystallization of Poly(butylene adipate).
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DOI：
10.1021/acs.langmuir.6b00251
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发表时间：
2016-03
期刊：
影响因子：
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通讯作者：
Xiaoli Sun;Qunqun Fang;Huihui Li;Z. Ren;Shouke Yan
中科院分区：
文献类型：
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作者：
Xiaoli Sun;Qunqun Fang;Huihui Li;Z. Ren;Shouke Yan
将聚己二酸丁二醇酯(PBA)渗透到孔径分别为30、70和100 nm左右的氧化铝模板中，制得不同直径的PBA纳米管。用X射线衍射仪和差示扫描量热仪研究了包裹在纳米孔中的PBA纳米管的结晶和相变行为。在非等温结晶过程中，只有α-PBA晶体在块体中形成。相反，主要的β-PBA晶体在AAO模板中形成。在孔径小于70 nm的纳米孔中形成的β-PBA晶体倾向于b轴平行于孔的长轴的取向。在熔体再结晶过程中，发现块体β形成纯PBA晶体的临界温度(T)为20℃。随着AAO模板剂中PBA的孔径增大，PBA的孔径值显著下降。此外，与块体晶体相比，多孔模板中的β-晶体具有更大的晶格参数。通过监测β晶体在加热过程中的变化，发现孔径为30 nm(D30)的AAO模板中的β-晶体直接熔化，而孔径为100 nm(D100)的模板中的β-晶体转变为α-晶体。β晶体的(020)Bragg峰强度在D30和D100中以相似的速率减小，但在D30中在较低的温度下消失。另一方面，在D100模板中形成的β-PBA晶体的β(110)峰强度在α晶体出现之前先以较慢的速度下降，然后在β向α相变时以较快的速度下降。
Poly(butylene adipate) (PBA) was infiltrated into the anodic alumina oxide (AAO) templates with the pore diameter of around 30, 70, and 100 nm and PBA nanotubes with different diameters were prepared. The crystallization and phase transition behavior of the obtained PBA nanotubes capped in the nanopores have been explored by using X-ray diffraction and differential scanning calorimetry. Only α-PBA crystals form in the bulk sample during nonisothermal crystallization. By contrast, predominant β-PBA crystals form in the AAO templates. The β-PBA crystals formed in the nanopores with pore diameter less than 70 nm prefer to adopt an orientation with their b-axis parallel to the long axis of the pore. During the melt recrystallization, it was found that the critical temperature (Tβ), below which pure β-crystals form, is 20 °C for bulk PBA. It drops down significantly with the pore diameter for the PBA in the AAO template. Moreover, the β-crystals in the porous template exhibit larger lattice parameters compared with the bulk crystals. By monitoring the change of β-crystals in the heating process, it was found that β-crystals in the AAO template with the pore diameter of 30 nm (D30) melt directly while the β-crystals transform to α-crystals in the template with the pore diameter of 100 nm (D100). The intensity of (020) Bragg peak of β-crystals decreases at a similar rate in both D30 and D100 but disappears at a relatively lower temperature in D30. On the other hand, the β(110) peak intensity of β-PBA crystals formed in the D100 template decreases first at slower rate before α crystals appear, and then at a faster rate once the β to α phase transition takes place.