Novel Polymer Architectures

新型聚合物架构

• 批准号: 9015729
• 负责人: Harry Gibson
• 金额: $ 30.75万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-15 至 1994-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9015729&HistoricalAwards=false
• 关键词: Novel; Polymer; Architectures

Polyrotaxanes, comprised of macrocyclic rings threaded by linear macromolecules, are a new and still unexploited family of polymers. Due to the potential for the macrocyclic components to move lateraly along the linear backbone as well as circumferentially, these systems are expected to possess properties distinct from those of traditional covalently bonded polymeric materials or blends thereof. The synthesis and characterization of a wide variety of structural types of polyrotaxanes will be carried out. Synthesis by statistical threading of macrocycles by linear monomers will rely on use of the cyclic as the solvent for the polymerization. A directed method is based on an attractive force between the macrocycle and the linear monomer, forming a stable threaded entity (a rotaxane) prior to polymerization. Stability against loss of the macrocycles by diffusion is ensured by incorporation of large end caps or bulky spacers along the backbone. Various combinations of the two components, over a range of polarity, will be considered. Among the macrocycles are both rigid and flexible crown ethers, hydrocarbons, and quaternary ammonium systems. Linear polymeric components, likewise, will vary widely from flexible to rigid-rod structures, formed by both step and chain- growth methods. The overall objective is to explore and exploit the novel topographic and topological features of this novel polymer architecture. Potential areas of utilization include interfacial bonding (adhesion, blend compatibilization), improved processability (enhanced solubility, lower melting points), stabilization (encasement of labile functionality), improved control of molecular ordering (electron and energy transport, molecular level interpenetrating networks for better mechanical performance), and understanding the diffusion of linear macromolecules in the bulk.

聚轮烷是一类新的尚未开发的聚合物，它是由线性大分子连接的大环环组成的。由于大环组分有可能沿线状主干和圆周方向横向移动，这些体系有望具有不同于传统共价键合聚合物材料或其共混物的性质。将进行各种结构类型的多轮烷的合成和表征。通过线性单体对大环进行统计穿线合成将依赖于使用环作为聚合的溶剂。定向方法是基于大环和线性单体之间的吸引力，在聚合之前形成稳定的线状实体(轮烷)。通过沿主干加入大的端盖或笨重的间隔物，确保了防止扩散造成的大环损失的稳定性。将考虑这两种成分在一个极性范围内的各种组合。在大环中既有刚性的和柔性的冠醚、碳氢化合物，也有季铵体系。同样，线性聚合物组分也会有很大的不同，从柔性的到刚性的杆状结构，都是通过阶梯生长和链生长方法形成的。总体目标是探索和利用这种新型聚合物建筑的新颖的地形和拓扑特征。潜在的利用领域包括界面结合(粘合、共混物增容)、改进的加工性(提高溶解性、降低熔点)、稳定化(包裹不稳定的官能团)、改进对分子有序性的控制(电子和能量传输、分子水平互穿网络以获得更好的机械性能)、以及了解线性大分子在整体中的扩散。