高折射率,低双折射光聚合物是通过自由基介导的,1,2-二硫杂环戊烷官能化单体的开环均聚,随后作为全息记录介质进行评价。这项研究系统地表征了反应动力学,热力学,和1,2-二硫戊烷均聚的体积收缩以及光学透明度,折射率,双折射,多官能1,2-二硫杂环戊烷官能化单体及其所得聚合物的全息性能。单官能1,2-二硫杂环戊烷单体的实时动力学和热力学分析,硫辛酸甲酯(LipOMe),表明单体快速转化,在60秒内超过90%,总反应焓为18±1kJ/mol。开环聚合导致低收缩率(10.6±0.3cm3/mol二硫杂环戊烷)和显著的体积折射率增加(0.030±0.003)。所得的光聚合物表现出高的光学透明度,最小的雾霾,和可忽略的双折射,表明1,2-均聚物作为光学材料的潜力。为了进一步探索用作高性能全息记录应用的特定功能,用选择用于实验的乙二硫醇硫辛酸单体(EDT-Lip2)合成了几种多官能单体。使用该单体书写的全息衍射光栅实现了0.008的峰-均折射率调制,雾度和双折射最小。
High refractive index, low birefringence photopolymers were created via the radical-mediated, ring opening homopolymerization of 1,2-dithiolane functionalized monomers and were subsequently evaluated as holographic recording media. This investigation systematically characterized the reaction kinetics, thermodynamics, and volume shrinkage of the 1,2-dithiolane homopolymerization as well as the optical transparency, refractive index, birefringence, and holographic performance of multifunctional 1,2-dithiolane functionalized monomers and their resultant polymers. Real-time kinetic and thermodynamic analyses of a monofunctional 1,2-dithiolane monomer, lipoic acid methyl ester (LipOMe), indicated rapid monomer conversion, exceeding 90% in 60 s, with an overall enthalpy of reaction of 18 ± 1 kJ/mol. The ring-opening polymerization resulted in low shrinkage (10.6 ± 0.3 cm3/mol dithiolane) and a significant bulk refractive index increase (0.030 ± 0.003). The resulting photopolymers exhibited high optical transparency, minimal haze, and negligible birefringence, suggesting the potential of 1,2-homopolymers as optical materials. To further explore the specific capabilities for use as high-performance holographic recording applications, several multifunctional monomers were synthesized with the ethanedithiol lipoic acid monomer (EDT-Lip2) selected for experimentation. Holographic diffraction gratings written using this monomer achieved a peak-to-mean refractive index modulation of 0.008 with minimal haze and birefringence.