Nucleation Meclianism of Polymers - role of entanglement and chain sliding diffusion

聚合物成核机制 - 缠结和链滑动扩散的作用

• 批准号: 12305062
• 负责人: HIKOSAKA Masamichi
• 金额: $ 17.47万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 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/grant/KAKENHI-PROJECT-12305062/
• 关键词: nucleation; polymer; induction period; crystallization; nucleating agent; rubber; crystalgrowth; morpholoogy

Topological mechanism of the nucleation of polymers have been studied. The direct evidence was shown for the first time that nuclei have been formed during the "inducstion 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, accummulation 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 determine the equilibrium melting temperature was also establised.

研究了聚合物成核的拓扑机制。通过小角X射线散射(SAXS)首次证明了在成核的“诱导期=初始阶段”期间成核已形成的直接证据。通过添加成核剂，成核剂的散射强度显着增加，提出了剪切流下成核的新机制：通过固定“钉”或“钉”的钉扎效应，可以轻松地拉长无规卷曲聚合物链。 熔体中的粉尘，导致形成束型核和所谓的“希什”形态。还研究了单个薄片的球状形态的发生机制。由于长链的拓扑性质，可以看到单个片层表面上的应变累积，这导致螺旋位错和片层开始分支。确定薄片层可靠熔化温度的新方法 聚合物成立。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

K.Yamada: "Equilibrium melting temperature of isotactic polypropylene(1) -Differential thermal analysis"Macromolecules. (In press).

K.Yamada：“等规聚丙烯的平衡熔融温度（1）-差热分析”大分子。

M. Hikosaka, S. Yamazaki, I. Wataoka, N. C. Das, K. Okada and A. Toda, K. Inoue: "Direct Evidence of Nucleation During the Induction Period of Polyethylene by SAXS"J. Macromol. Set., Phys.. (in press).

M. Hikosaka、S. Yamazaki、I. Wataoka、N. C. Das、K. Okada 和 A. Toda、K. Inoue：“SAXS 在聚乙烯诱导期间成核的直接证据”J。

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

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

P.Maiti: "Lamellar thickening in isotactic polypropylene with high tacticity crystallized at high temperature"Macromolecules. 33. 9069-9075 (2000)

P.Maiti：“高温结晶的高立构聚丙烯的层状增稠”大分子。

K.Nozaki: "Mechanism of primary nucleation and origin of hysteresis in the rotator phase of an Odd n-alkane"J.Mat.Sci.,. 35. 1239-1252 (2000)

K.Nozaki：“奇数正烷烃旋转相中的初级成核机制和滞后起源”J.Mat.Sci.，。