Abstract:

Galactomannan (GM), an important plant polysaccharide, was successfully etherified via green hydroxyl-alkyne click reaction by using 1-phenyl-2-propyn-1-one (PPK) as etherification agent. The prepared galactomannan phenyl propylene ketone ether (GMPPK) films exhibited excellent mechanical property, hydrophobic property as well as UV-blocking property. The results showed that the hydroxyl-alkyne click chemistry can achieve efficient etherification of GM surface hydroxyl groups. Compared with the unmodified GM films, the GMPPK films exhibited new UV shielding (shielding 98.86% at 275 nm for GMPPK2), hydrophobicity (water contact angle increased from 74.9° to 96.5°). In addition, the mechanical performance of GMPPK films increased with the increase of molar ratio of —OH∶PPK, with the highest tensile stress of 44.7 MPa, the highest toughness of 1.7 MJ/m³, and Young’s modulus of 25.3 MPa, which were 2.2, 1.9, and 2.4 times of those for unmodified GM films, respectively. The research results lay a theoretical foundation for the development of high performance galactomannan packaging film materials.

Key words: hydroxy-alkyne click chemistry, galactomannan, UV shielding performance, hydrophobicity, mechanical property, biomass, polymers

摘要：

以植物源半乳甘露聚糖(GM)为原料，1-苯基-2-丙炔-1-酮(PPK)为醚化试剂，通过绿色高效的羟基-炔点击化学改性技术，成功地在室温条件下制备得到兼具优异力学性能、疏水性能和紫外屏蔽性能的半乳甘露聚糖苯丙基烯酮醚(GMPPK)薄膜。结果表明：羟基-炔点击化学可以实现GM表面羟基的高效醚化。与未改性的GM薄膜相比，由于PPK分子的引入，GMPPK薄膜表现新的紫外屏蔽性(GMPPK2在275 nm处的屏蔽率高达98.86%)、疏水性(水接触角从74.9°增加至96.5°)和耐水溶胀性。此外，随—OH∶PPK的反应摩尔比增加，GMPPK2薄膜的力学性能进一步增加，其拉伸应力为44.7 MPa，韧性为1.7 MJ/m³，杨氏模量为25.3 MPa，分别是未改性GM薄膜的2.2倍、1.9倍和2.4倍。研究结果可为开发高性能半乳甘露聚糖包装薄膜材料的应用研究奠定理论基础。

关键词: 羟基-炔点击化学, 半乳甘露聚糖, 紫外屏蔽性能, 疏水性, 力学性能, 生物质, 聚合物