基于NOL环的高性能纤维与环氧树脂的匹配性研究

纤维与树脂的界面对复合材料的整体力学性能有着显著的影响。基于NOL环的宏观力学测试一般被用来反映复合材料的界面粘结性能,因此适用于评价纤维与树脂之间的宏观力学性能匹配性。为了探究高性能碳纤维T700SC、T800HB及高强玻璃纤维与环氧树脂的宏观力学性能匹配性,本研究首先根据GB/T 1458—2008国家标准制备NOL环试样,再借助NOL环的拉伸和层间剪切强度测试分析了高性能纤维与环氧树脂不同匹配组合宏观力学性能差异的原因,并寻找出最佳匹配组合。结果表明:玻璃纤维与环氧树脂的界面存在最佳的粘结强度,而且不同粘结强度导致拉伸强度和破坏机理不同,而碳纤维复合材料界面性能较差,容易分层破坏;T800HB与环氧树脂的宏观力学匹配性优于T700SC,环氧树脂力学性能、碳纤维的表面微观结构与性质以及环氧树脂与碳纤维之间的相互作用关系是影响界面粘结性能的根本原因。该研究在高性能纤维单向复合材料的材料选择与设计方面具有现实意义。

STUDY ON INTERFACE COMPATIBILITY OF HIGH-PERFORMANCE FIBER AND EPOXY RESIN BASED ON TEST OF NOL RINGS

The interface of fiber and resin exerts an outstanding influence on the entire mechanical properties of composite.Macromechanics test based on NOL rings is commonly used to reflect interfacial adhesion property of composite,so it applies to evaluate macromechanical compatibility of fiber and resin.The experiment is conducted to probe into macromechanical compatibility of high-performance fibers,such as T700SC,T800HB and highstrength glass fiber,and epoxy resins.The specimens of NOL rings were firstly prepared referrings to national standards GB/T 1458-2008.Then,we analyzed the causes of differences on macromechanical properties of matching combinations of high-performance fibers and epoxy resins by combinations of tensile and interlaminar shear test of NOL rings with observation of its fracture surface by SEM.And the optimal matching combinations were found out.The results suggest that interfacial properties of glass fiber and epoxy resin is superior to that of epoxy with carbon fiber,and the former posseses optimal interfacial adhesion strength,and different adhesion strength leads to different mechanical properties and modes of damages.But poor interface of carbon composite easily arises delamination,which restricts the use of carbon fiber.Macromechanical compatibility of T800HB and epoxy resin is superior to that of T700SC and epoxy,and mechanical proprerties of composites and that of resin matrix are directly related.The properties of resin,surfacial structure and character of fiber and interaction between carbon fiber and resin are the ultimate cause of affecting interfacial properties.The paper plays practical significance in selection and design of materials of composite reinforced by high-performance fibers.