Helical Polymers: Optical Activity

本研究涉及螺旋聚合物的设计、合成、表征及其性质的研究。主要的推力仍然是制备等规螺旋聚合物，这些聚合物的结构仅由一个螺旋感的等规大分子螺旋组成，并显示基于大分子不对称的光学活性。目标是：a.)通过确定目前在结晶状态下得到的所有氯醛聚合线性低聚物的绝对构型，明确了初始传播机制。b。)用大体积的手性引发剂引发制备单螺旋意义的聚过卤乙醛。c。)以纯手性氟氯溴乙醛为单体进行过卤乙醛聚合，确定单体手性中心对螺旋聚合物手性的影响。d。)建立这种新发现的测量固体旋光度方法的极限。e)。完善手性引发过程中螺旋形成的构型和构象势能计算，并进行计算机模拟，以显示基于等规聚合物链体积的螺旋“锁定”。f。)研究在偏振光作用下单螺旋感螺旋聚合物的合成，以及固态或直接单体铸造技术制备螺旋聚合物以制备高强度纤维。

This research deals with an investigation to design, synthesize, and characterize helical polymers and to study their properties. The primary thrust will still be the preparation of isotactic helical polymers, those polymers whose structure consists of only isotactic macromolecular helices of one screw sense and which display optical activity based on macromolecular asymmetry. The goals are: a.)To identify clearly the initial propagation mechanism by determining the absolute configuration of all the linear oligomer of the chloral polymerization now obtained in the crystalline state. b.)To prepare polyperhaloacetaldehydes of one screw sense by initiation with bulky chiral initiators. c.)To use pure chiral fluorochlorobromoacetaldehyde as monomer for the perhaloacetaldehyde polymerization to ascertain the influence of the chiral center of the monomer on the handedness of the helical polymer. d.)To establish the limits of this newly discovered method of measuring the optical rotation of solids. e.)To perfect the potential energy calculations of configuration and conformation for the developing of the helix during chiral initiation and follow it up with computer simulation to show the "locking" of the helix based on the bulkiness of the isotactic polymer chain. f.)To investigate the synthesis of helical polymers of one screw sense in the presence of polarized light and the fabrication of helical polymers in the solid state or by direct monomer casting techniques to forum oriented high tenacity fibers.