Abstract：The surface direct fluorination was utilized in this paper to improve the bending fatigue behavior of Poly (methyl methacrylate) (PMMA). The effect of the surface direct fluorination on the fracture toughness and bending strength of PMMA were firstly tested. Then the bending fatigue behaviors, including the fatigue life as well as the fatigue crack propagation process of PMMA with different types of pre-notch before and after surface direct fluorination were comprehensively studied. The experimental result of the bending fatigue life showed that the fatigue performance of PMMA was improved significantly after surface direct fluorination, which was accounted for the structural constraining effect of the fluorinated surface layer. In addition, the evolution of the regular striation morphology on the fatigue fracture surface was found to be correlated to the occurrence of the craze at the crack tip. As another evidence of the improvement of the fatigue life of PMMA, the propagation rate of fatigue striation decreased obviously after the surface direct fluorination. This work showed that the surface direct fluorination is a feasible approach to improve the fatigue property of PMMA, which provided useful guidance for substantial industrial application.
2020, Vol. 41 
