Le Fevere de Ten Hove Cédric, Penelle Jacques, Ivanov Dimitri A, Jonas Alain M
Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003-4530, USA.
Nat Mater. 2004 Jan;3(1):33-7. doi: 10.1038/nmat1028. Epub 2003 Nov 30.
The development of robust methodologies to control the solid-state structure of polymeric materials by appropriate design of the macromolecular architecture has a crucial impact on the mechanical properties of these materials. Here, we demonstrate the feasibility of controlling chain folding of polymers by steric interactions only, in contrast to previous attempts aimed at engineering polymer crystallization through hydrogen bonding. In a linear synthetic macromolecule similar to polyethylene, we encoded structural instructions that are translated during a crystallization process to generate a unique, semi-crystalline morphology with structure-controlled crystal thickness of approximately 5 nm that remains constant over a wide temperature range. The molecular code consists of a linear backbone alternating crystallizable, long alkyl sequences of monodisperse sizes separated by short spacers containing side-chains and acting as stops and fold-controlling units. This simple strategy could be used to produce advanced polymeric materials with fine control of the crystalline and amorphous regions.
通过对大分子结构进行适当设计来开发稳健的方法以控制聚合物材料的固态结构，对这些材料的机械性能有着至关重要的影响。在此，我们证明了仅通过空间相互作用来控制聚合物链折叠的可行性，这与之前旨在通过氢键作用来设计聚合物结晶的尝试形成对比。在一种类似于聚乙烯的线性合成大分子中，我们编码了结构指令，这些指令在结晶过程中被转化，以生成一种独特的半结晶形态，其结构可控的晶体厚度约为5纳米，并且在很宽的温度范围内保持恒定。分子编码由线性主链组成，主链交替排列着单分散尺寸的可结晶长烷基序列，这些序列被含有侧链的短间隔基团隔开，这些间隔基团起到终止和控制折叠单元的作用。这种简单的策略可用于生产对结晶区和非晶区有精细控制的先进聚合物材料。
