核壳结构科技论文写作.docxVIP

Effect of Different Core-Shell Weight Ratios of Impact Modifier to Toughed PolycarbonateAbstract Polycarbonate (PC) has excellent mechanical properties at room temperature, dimensional stability, heat resistance and electrical insulation, but its low temperature toughness limits its application. The toughening of polycarbonate has attracted dramatically attention. However, very little research has been carried out to investigate the effect of core-shell impact modifier structure on toughened PC. In this study, core-shell structured polyacrylic (named ACR) impact modifiers consisting of a rubbery poly(n-butyl acrylate) (BA) core and a rigid poly(methyl methacrylate) shell with different core-shell weight ratios (85:15; 80:20; 75:25; 70:30) were prepared to modify the toughness of PC. The mechanical properties of the ACR/PC blends were measured, and scanning electron microscope (SEM) was used to observe the fractured morphology. As a result, the notch impact strength of ACR/PC blends with a core-shell weight ratio of 80:20 was 6.7 times greater than that of pure PC, and the mechanical properties agreed well with the SEM observation.KeywordsCore-shell structured polyacrylic Polycarbonate Toughness Structure-property relationsIntroductionPolycarbonate exhibits a series of excellent properties including remarkable heat resistance, toughness, optical transparency, and electrical properties[1]. These characteristics make it attractive for use in many applications ranging from video disk to helmet for astronauts. Nevertheless, PC will undergo brittle fracture during impact tests in the presence of notches that concentrate stress due to its low-crack propagation energy, especially at low temperature[2]. Most studies on the brittle fracture behavior of toughened polycarbonate are studied in literature. For example, Yee et al.[3] investigated the fracture mechanism of toughened PC blends and concluded that cavitation of rubber particles occurs first, followed by the enhanc