Realizing High Refractive Index Thiol-X Materials: A General and Scalable Synthetic Approach
Realizing High Refractive Index Thiol-X Materials: A General and Scalable Synthetic Approach
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DOI：
10.1021/acsmaterialslett.9b00331
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发表时间：
2019-11-01
影响因子：
11.4
通讯作者：
Bowman, Christopher N.
中科院分区：
文献类型：
--
作者：
Alim, Marvin D.;Mavila, Sudheendran;Bowman, Christopher N.
由硫醇-X“点击”反应家族形成的光聚合物特别形成含硫硫醚键。虽然传统上预期含硫材料会产生高折射率（n(D)/20℃ > 1.6）材料，但由于缺乏具有足够高折射率的单体，硫醇-X光聚合物很少实现这一预期。在这里，提出了一种获得高折射率硫醇-X 单体的有效、模块化合成策略。仅使用市售起始化合物即可产生低粘度（1.64），从而证明了整个方法的有效性。这些合成的单体经过快速硫醇-烯光聚合达到高转化率，在均匀的交联网络中实现高达 1.669 的折射率值 (n(D)/20 摄氏度)，表现出典型的窄且明确的损耗角正切 (tan δ) 峰。低粘度、高光学质量硫醇烯树脂的便利性在两种功能光学元件的制造中得到了证明。首先，使用包覆成型工艺对平凸透镜进行非球面化。其次，使用两级材料和光掩模曝光制造二维光栅。
Photopolymers formed from the family of thiol-X "click" reactions notably form sulfur-containing thioether linkages. While sulfur-containing materials are conventionally expected to result in high refractive index (n(D)/20 degrees C > 1.6) materials, this expectation is rarely realized with thiol-X photopolymers, because of the lack of monomers with sufficiently high refractive indices. Here, an efficient, modular synthetic strategy to obtain high refractive index thiol-X monomers is presented. The efficacy of the overall approach is demonstrated using only commercially available starting compounds to yield low viscosity ( 1.64). These synthesized monomers underwent rapid thiol-ene photopolymerizations to high conversions, achieving refractive index values (n(D)/20 degrees C) up to 1.669 in uniform crosslinked networks exhibiting typical narrow and well-defined loss tangent (tan delta) peaks. The convenience of the low-viscosity, high optical quality thiol-ene resins was demonstrated in the fabrication of two functional optical components. First, a plano-convex lens was aspherized using an overmolding procedure. Second, a two-dimensional grating was fabricated using a two-stage material and a photomask exposure.