Silk/Natural Rubber (NR) and 3,4-Dihydroxyphenylalanine (DOPA)-Modified Silk/NR Composites: Synthesis, Secondary Structure, and Mechanical Properties
Silk/Natural Rubber (NR) and 3,4-Dihydroxyphenylalanine (DOPA)-Modified Silk/NR Composites: Synthesis, Secondary Structure, and Mechanical Properties
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DOI：
10.3390/molecules25010235
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发表时间：
2020-01
期刊：
影响因子：
4.6
通讯作者：
H. Sogawa;Treratanakulwongs Korawit;H. Masunaga;K. Numata
中科院分区：
文献类型：
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作者：
H. Sogawa;Treratanakulwongs Korawit;H. Masunaga;K. Numata
将天然橡胶（NR）胶乳与蚕丝脱胶液共混，制备了蚕丝/NR复合材料。一个显着的增强的机械性能被确认为丝绸/NR复合材料相比，NR-只有产品，表明丝绸可以作为一种有效的增强橡胶材料。衰减全反射傅里叶变换红外光谱（ATR-FTIR）和广角X射线衍射（WAXD）分析表明，当蚕丝含量超过20wt%时，NR基体中形成了β-折叠结构。然后，将3，4-二羟基苯丙氨酸（DOPA）改性的蚕丝与NR共混，得到DOPA-蚕丝/NR复合材料，其力学性能比未改性的蚕丝基复合材料有上级的提高。DOPA改性不仅改变了蚕丝的化学结构，而且改变了复合材料中蚕丝的主要二级结构。结果表明，DOPA残基的有效粘附性和二级结构的改变改善了蚕丝与NR的相容性，从而提高了复合材料的力学性能。本文所获得的知识应有助于开发新的丝基弹性材料的制造。
Silk composites with natural rubber (NR) were prepared by mixing degummed silk and NR latex solutions. A significant enhancement of the mechanical properties was confirmed for silk/NR composites compared to a NR-only product, indicating that silk can be applied as an effective reinforcement for rubber materials. Attenuated total reflection Fourier transform infrared (ATR-FTIR) and wide-angle X-ray diffraction (WAXD) analysis revealed that a β-sheet structure was formed in the NR matrix by increasing the silk content above 20 wt%. Then, 3,4-dihydroxyphenylalanine (DOPA)-modified silk was also blended with NR to give a DOPA-silk/NR composite, which showed superior mechanical properties to those of the unmodified silk-based composite. Not only the chemical structure but also the dominant secondary structure of silk in the composite was changed after DOPA modification. It was concluded that both the efficient adhesion property of DOPA residue and the secondary structure change improved the compatibility of silk and NR, resulting in the enhanced mechanical properties of the formed composite. The knowledge obtained herein should contribute to the development of the fabrication of novel silk-based elastic materials.