Pattern Formation in Polymer Solidification

聚合物凝固中的图案形成

• 批准号: 9115308
• 负责人: Jerold Schultz
• 金额: $ 24.5万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 1995-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9115308&HistoricalAwards=false
• 关键词: Pattern; Formation; Polymer; Solidification

The kinetics of crystallization are, in general, controlled by two competitive phenomena, the thermodynamic driving force, which forces the crystal/noncrystal interface forward, and the rate at which the heat of fusion and any unincorporable components can flow away from that interface. Over a wide range of conditions, this competition causes the interface to assume intricate patterns. The aim of the proposed work is to develop an experimental base and a theoretical framework by which such pattern formation in polymer systems can be understood. This work will be directed at spherulitic crystallization in polymer blends and at the development of microstructure in melt-spun fibers. An experimental program for quiescent crystallization will be carried out. In this, both constrained (by forced movement through a temperature gradient) and unconstrained spherulite-like growth will be studied. In both cases, microstructural parameters will be measured and compared to model predictions. Likewise, a study will be made of the temperature and crystallite radius of oriented polymer fibers crystallized by running them through a temperature gradient. These will be compared to those of a model developed by the principal investigator. It is expected that the work will also extend existing theory for pattern development in polymers.

结晶的动力学通常由两个因素控制， 竞争现象，热力学驱动力， 迫使晶体/非晶体界面向前， 熔化热和任何不可分解的成分可以流动 远离这个接口。 在广泛的条件下， 竞争导致界面呈现复杂的模式。 的 建议工作的目的是建立一个实验基地， 这种模式在聚合物中形成的理论框架 系统可以理解。 这项工作将针对 球晶结晶在聚合物共混物和在 熔纺纤维微观结构的发展。 静态结晶的实验程序将是 贯彻 在这种情况下，两者都受到约束（通过强制运动 温度梯度）和无约束的球晶状生长 将被研究。 在这两种情况下，微观结构参数将是 测量并与模型预测进行比较。 同样，一项研究将 由取向的温度和微晶半径组成 聚合物纤维结晶， 梯度离心 这些将与由以下开发的模型进行比较： 首席调查员 预计这项工作还将 扩展了聚合物图案发展的现有理论。