College of Paper and Plant Resources Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, China; Department of Chemical & Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA.
College of Paper and Plant Resources Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, China.
J Biotechnol. 2018 Mar 10;269:8-15. doi: 10.1016/j.jbiotec.2018.01.015. Epub 2018 Feb 4.
An effective method to functionalize chitosan with 4-hexyloxyphenol (HP) under homogeneous reaction conditions was developed using laccase as the catalyst. The resulting copolymer was characterized for chemical structure, grafted-HP content, surface morphology, thermal stability, antioxidant capacity, hydrophobic properties and tensile strength. Solid-state C NMR spectrum confirmed the incorporation of HP onto chitosan. X-ray diffraction (XRD) showed a decrease in the degree of crystallinity for laccase/HP treated chitosan compared to pure chitosan. The grafted-HP content in laccase/HP-treated chitosan first increased and then declined with increase of the initial HP/chitosan ratio. A heterogeneous surface with spherical particles on the laccase/HP treated chitosan was observed by environmental scanning electron microscopy (ESEM) and scanning probe microscopy (SPM). The laccase/HP treatment of chitosan improved the thermal stability of copolymer. More significantly, the HP functionalized chitosan showed greatly improved ABTS and DPPH radicals scavenging capacity, compared with pure chitosan. The hydrophobicity property of the HP functionalized chitosan also significantly increased although its tensile strength decreased. This new type of composite with double functionalities (i.e., antioxidant and hydrophobic) could potentially be used as food packaging materials or coating agents.
采用漆酶作为催化剂，在均相反应条件下开发了一种将 4-己氧基苯酚（HP）有效官能化壳聚糖的方法。对所得共聚物进行了化学结构、接枝-HP 含量、表面形态、热稳定性、抗氧化能力、疏水性和拉伸强度的表征。固态 C NMR 谱证实了 HP 已接枝到壳聚糖上。X 射线衍射（XRD）表明，与纯壳聚糖相比，漆酶/HP 处理的壳聚糖的结晶度降低。与纯壳聚糖相比，接枝-HP 含量在漆酶/HP 处理的壳聚糖中先增加后减少，初始 HP/壳聚糖比增加。环境扫描电子显微镜（ESEM）和扫描探针显微镜（SPM）观察到漆酶/HP 处理的壳聚糖具有异质表面，表面有球形颗粒。壳聚糖的漆酶/HP 处理提高了共聚物的热稳定性。更重要的是，与纯壳聚糖相比，HP 官能化壳聚糖的 ABTS 和 DPPH 自由基清除能力大大提高。尽管 HP 官能化壳聚糖的拉伸强度降低，但疏水性也显著增加。这种具有双重功能（抗氧化和疏水性）的新型复合材料可能用作食品包装材料或涂层剂。
