A disubstituted acetylene polymer, with a molecular-spring main chain and a long alkyl side chain of the octadecyl group (PDMC₁₈SP), was examined as an active material for a thermomechanical actuator and its thermodynamic and (thermo)mechanical properties were compared to those of other two polymer derivatives [i.e., a polymer without a long alkyl side chain (PTMSP) and a polymer with the same long alkyl side chain with a phenyl ring (PDMC₁₈SDPA)]. Unlike PTMSP, PDMC₁₈SP and PDMC₁₈SDPA produced soft films, which could be considerably elongated by an external tensile force at room temperature. When the external force was removed, PDMC₁₈SP recovered to its original form, while PDMC₁₈SDPA did not. Both polymers showed apparent thermodynamic phase transition. PDMC₁₈SP underwent a much greater change under both strain and stress with temperature compared to PDMC₁₈SDPA. PDMC₁₈SP was used as an active layer to prepare a bilayer-type actuator, which showed apparent mechanical actuation with temperature. The direction of mechanical actuation was easily controlled by shearing the active layer.

中文翻译：

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基于带有长烷基侧链的分子弹簧聚合物的热机械执行器

将具有分子弹簧主链和十八烷基长烷基侧链的双取代乙炔聚合物（PDMC ₁₈ SP）作为热机械致动器的活性材料进行了研究，并将其热力学和（热）机械性能进行了比较。其他两种聚合物衍生物的聚合物[即，没有长烷基侧链的聚合物（PTMSP）和具有相同苯环的长烷基侧链的聚合物（PDMC ₁₈ SDPA）]。与PTMSP不同，PDMC ₁₈ SP和PDMC ₁₈ SDPA产生的软膜在室温下可通过外部拉力大大延长。去除外力后，PDMC ₁₈ SP恢复到其原始形式，而PDMC ₁₈SDPA没有。两种聚合物均表现出明显的热力学相变。与PDMC ₁₈ SDPA相比，PDMC ₁₈ SP在应变和应力下均会随温度发生更大的变化。PDMC ₁₈ SP用作活性层以制备双层型致动器，该致动器显示出随温度明显的机械致动。机械致动的方向很容易通过剪切活性层来控制。