Cui Wei, King Daniel R, Huang Yiwan, Chen Liang, Sun Tao Lin, Guo Yunzhou, Saruwatari Yoshiyuki, Hui Chung-Yuen, Kurokawa Takayuki, Gong Jian Ping
Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan.
Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan.
Adv Mater. 2020 Aug;32(31):e1907180. doi: 10.1002/adma.201907180. Epub 2020 Jun 25.
Soft fiber-reinforced polymers (FRPs), consisting of rubbery matrices and rigid fabrics, are widely utilized in industry because they possess high specific strength in tension while allowing flexural deformation under bending or twisting. Nevertheless, existing soft FRPs are relatively weak against crack propagation due to interfacial delamination, which substantially increases their risk of failure during use. In this work, a class of soft FRPs that possess high specific strength while simultaneously showing extraordinary crack resistance are developed. The strategy is to synthesize tough viscoelastic matrices from acrylate monomers in the presence of woven fabrics, which generates soft composites with a strong interface and interlocking structure. Such composites exhibit fracture energy, Γ, of up to 2500 kJ m , exceeding the toughest existing materials. Experimental elucidation shows that the fracture energy obeys a simple relation, Γ = W · l , where W is the volume-weighted average of work of extension at fracture of the two components and l is the force transfer length that scales with the square root of fiber/matrix modulus ratio. Superior Γ is achieved through a combination of extraordinarily large l (10-100 mm), resulting from the extremely high fiber/matrix modulus ratios (10 -10 ), and the maximized energy dissipation density, W. The elucidated quantitative relationship provides guidance toward the design of extremely tough soft composites.
软质纤维增强聚合物（FRP）由橡胶状基体和刚性织物组成，因其在拉伸时具有高比强度，同时在弯曲或扭曲时能发生挠曲变形，而在工业中得到广泛应用。然而，现有的软质FRP由于界面分层，抗裂纹扩展能力相对较弱，这大大增加了其在使用过程中的失效风险。在这项工作中，开发了一类既具有高比强度又同时表现出非凡抗裂性的软质FRP。策略是在机织织物存在的情况下，由丙烯酸酯单体制备坚韧的粘弹性基体，从而生成具有强界面和互锁结构的软质复合材料。这类复合材料的断裂能Γ高达2500 kJ/m²，超过了现有的最坚韧材料。实验表明，断裂能遵循一个简单的关系，Γ = W·l，其中W是两个组分断裂时拉伸功的体积加权平均值，l是与纤维/基体模量比的平方根成正比的力传递长度。通过极高的纤维/基体模量比（10³ - 10⁴）产生的极大的l（10 - 100 mm）与最大化的能量耗散密度W相结合，实现了优异的Γ。所阐明的定量关系为设计极其坚韧的软质复合材料提供了指导。
