Topological Mechanism of Nucleation of Polymers

聚合物成核的拓扑机制

• 批准号: 12127205
• 负责人: HIKOSAKA Masamichi
• 金额: $ 11.33万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12127205/
• 关键词: nucleation; polymer; induction period; crystallization; nucleating agent; rubber; crystal growth; morpholoogy; 絡みみ合い; 分子量; バンド球晶; 形態; 天然ゴム; 脂肪酸

Topological mechanisms of the nucleation of polymers have been studied. The direct evidence was shown for the first time that nuclei have been formed during the "induction period = initial stage) of the nucleation by means of Small angle X-ray scattering (SAXS). The scattering intensity of the nuclei was significantly increased by adding the nucleating agents. A new mechanism of nucleation under shear flow was presented : random coiled polymer chain can be easily elongated by pinning effect by fixed "pins" or dusts in the melt, which results in formation of bundle type nuclei and so called "shish" morphology. The onset mechanism of spherultic morphology from a single lamella was also studied. Due to topological nature of long chains, accumulation of strain on the surface of a single lamella can be seen, which results in screw dislocation and branching of lamellae will start. New method to determine the reliable melting temperature of thin lamellae of polymers was established. Using this method new method of determining the equilibrium melting temperature was also established.

研究了聚合物成核的拓扑机制。用x射线小角散射（SAXS）方法首次直接证明了在成核的“诱导期=初始阶段”形成了核。成核剂的加入使核的散射强度显著提高。提出了一种剪切流动下聚合物成核的新机制：聚合物链在熔体中的固定“钉”或粉尘的钉钉作用下容易被拉长，从而形成束状核，称为“shish”形态。研究了单晶片形成球状形态的机理。由于长链的拓扑性质，可以看到应变在单个片层表面积累，导致螺旋位错，片层开始分支。建立了确定聚合物薄层熔融温度的新方法。利用该方法还建立了确定平衡熔化温度的新方法。

项目成果

A.Toda, T.Arita, M.Hikosaka: "Three-dimensional morphology of PVDF single crystals forming banded spherulites"Polymer. 42. 2225-2235 (2001)

A.Toda、T.Arita、M.Hikosaka：“PVDF 单晶形成带状球晶的三维形态”聚合物。

G.Z.Li, T.Yamamoto, K.Nozaki, M.Hikosaka: "Effect of cyrstallization conditions on single crystals of ladderlike polyphenylsesquioxnae (PPSQ)"Polymer. 41. 2827-2830 (2000)

G.Z.Li、T.Yamamoto、K.Nozaki、M.Hikosaka：“结晶条件对梯状聚苯倍半氧 (PPSQ) 单晶的影响”聚合物。

F.Gu, M.Hikosaka, A.Toda, S.K.Ghosh, S.Yamazaki, M.Arakaki 他: "Second-order phase transition of high isotactic polypropylene at high temperature"Polymer. 43. 1473-1481 (2002)

F.Gu、M.Hikosaka、A.Toda、S.K.Ghosh、S.Yamazaki、M.Arakaki 等人：“高温下高等规聚丙烯的二级相变”聚合物 43. 1473-1481 (2002)

A.Toda, Y.Takahashi, T.Arita, M.Hikosaka, T.Furukawa: "Application of periodically modulated driving force to the transition kinetics in VDF/TrFE copolymers"J.Chem.Phys.. 114. 6896-6905 (2001)

A.Toda、Y.Takahashi、T.Arita、M.Hikosaka、T.Furukawa：“周期性调制驱动力在 VDF/TrFE 共聚物转变动力学中的应用”J.Chem.Phys.. 114. 6896-6905 (

S.K.Ghosh: "Power law of molecular weight of the nucleation of folded chain crystals of polyethylene"Macromolecules. 18. 6985-6991 (2002)

S.K.Ghosh：“聚乙烯折叠链晶体成核分子量的幂律”大分子。