The development of tunable and degradable crosslinked-polyanhydride networks from renewably derived itaconic anhydrides and multifunctional thiols is presented. Itaconic acid was initially converted to ethyl itaconic anhydride and isoamyl itaconic anhydride via a two-step synthetic procedure on hundred-gram scale with minimal purification. Dinorbornene-functionalized derivatives were prepared via cycloaddition chemistry, and photoinitiated thiol–ene polymerization reactions were explored using commercially available tetra- and hexa-functional thiols, all using solvent-free syntheses. The thiol–ene reaction kinetics of different monomer compositions were characterized by real-time Fourier transform infrared (RT-FTIR) spectroscopy, with the norbornene functionalized derivatives exhibiting the highest reactivity towards thiol–ene photopolymerizations. The thermal and mechanical characteristics of the thermosets were analyzed and the viscoelastic behavior was investigated by dynamic mechanical analysis to understand the influence of the ester functionality and choice of crosslinker on the material properties. The anhydride backbone was found to be susceptible to controlled degradation under physiologically-(phosphate-buffered saline) and environmentally-relevant (artificial seawater) testing conditions over a period of 60 days at 50 °C. This work demonstrates that itaconic acid may be a useful feedstock in the generation of degradable polyanhydride networks via thiol–ene photopolymerization.

中文翻译：

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衣康酸衍生的可降解聚酐网络

介绍了可再生和可降解的交联聚酸酐网络从可再生衍生的衣康酸酐和多功能硫醇的发展。衣康酸最初通过百步规模的两步合成程序以最小的纯化转化为乙基衣康酸酐和异戊基衣康酸酐。二降冰片烯官能化的衍生物是通过使用可商购的四官能和六官能硫醇探索了环加成化学和光引发的硫醇-烯聚合反应，全部使用无溶剂合成方法。实时傅立叶变换红外光谱（RT-FTIR）表征了不同单体组成的硫醇-烯反应动力学，降冰片烯官能化衍生物对硫醇-烯光聚合反应具有最高的反应活性。分析了热固性塑料的热和机械特性，并通过动态力学分析研究了粘弹性行为，以了解酯官能度和交联剂选择对材料性能的影响。发现酸酐骨架在50°C下60天的生理（磷酸盐缓冲盐水）和与环境相关的（人造海水）测试条件下易于受控降解。这项工作表明衣康酸可能是可降解聚酸酐网络生成中的有用原料通过硫醇烯光聚合。