Rothammer Maximilian, Zollfrank Cordt
Chair for Biogenic Polymers, Technical University of Munich, Schulgasse 16, 94315 Straubing, Germany.
Polymers (Basel). 2023 Dec 19;16(1):9. doi: 10.3390/polym16010009.
Replacing petroleum-based polymers with biopolymers such as polysaccharides is essential for protecting our environment by saving fossil resources. A research field that can benefit from the application of more sustainable and renewable materials is photochemistry. Therefore, cellulose-based photoresists that could be photocrosslinked via UV irradiation (λ = 254 nm and λ = 365 nm) were developed. These biogenic polymers enable the manufacturing of sustainable coatings, even with imprinted microstructures, and cellulose-based bulk materials. Thus, herein, cellulose was functionalized with organic compounds containing carbon double bonds to introduce photocrosslinkable side groups directly onto the cellulose backbone. Therefore, unsaturated anhydrides such as methacrylic acid anhydride and unsaturated and polyunsaturated carboxylic acids such as linoleic acid were utilized. Additionally, these cellulose derivatives were modified with acetate or tosylate groups to generate cellulose-based polymers, which are soluble in organic solvents, making them suitable for multiple processing methods, such as casting, printing and coating. The photocurable resist was basically composed of the UV-crosslinkable biopolymer, an appropriate solvent and, if necessary, a photoinitiator. Moreover, these bio-based photoresists were UV-crosslinkable in the liquid and solid states after the removal of the solvent. Further, the manufactured cellulose-based architectures, even the bulk structures, could be entirely regenerated into pure cellulose devices via a sodium methoxide treatment.
用多糖等生物聚合物取代石油基聚合物对于通过节约化石资源来保护环境至关重要。光化学是一个可以从应用更可持续和可再生材料中受益的研究领域。因此，开发了可以通过紫外线照射（λ = 254 nm和λ = 365 nm）进行光交联的纤维素基光刻胶。这些生物聚合物能够制造可持续涂层，甚至是带有压印微结构的涂层，以及纤维素基块状材料。因此，在此，纤维素用含有碳双键的有机化合物进行功能化，以将可光交联的侧基直接引入纤维素主链。因此，使用了甲基丙烯酸酐等不饱和酸酐以及亚油酸等不饱和和多不饱和羧酸。此外，这些纤维素衍生物用乙酸酯或甲苯磺酸酯基团进行改性，以生成可溶于有机溶剂的纤维素基聚合物，使其适用于多种加工方法，如浇铸、印刷和涂层。光固化光刻胶基本上由可紫外线交联的生物聚合物、合适的溶剂以及必要时的光引发剂组成。此外，这些生物基光刻胶在去除溶剂后在液态和固态下均可紫外线交联。此外，制造的纤维素基结构，甚至是块状结构，可以通过甲醇钠处理完全再生为纯纤维素器件。
