As a part of a serial work about the annealing inducing improvement of fracture toughness of polypropylene （PP） articles, in this work, a highly efficient mobilizer was introduced into PP and the injection-molded sa...As a part of a serial work about the annealing inducing improvement of fracture toughness of polypropylene （PP） articles, in this work, a highly efficient mobilizer was introduced into PP and the injection-molded samples were annealed at different temperatures. The mobility of chain segments of PP was investigated by measuring the glass transition temperature. Differential scanning calorimetry （DSC） and wide angle X-ray diffraction （WAXD） were used to characterize the variation of crystalline structure of PP during the annealing process. The fracture behaviors including notched Izod impact fracture and universal tensile fracture were investigated to detect the mechanical properties in response to the variations of both chain segments mobility and crystalline structures. It was found that the mobilizer greatly improved the chain segments mobility. Further results showed that the mobilizer also induced apparent changes of the glass transition temperature and the degree of crystallinity of PP during the annealing process. Consequently, the annealed PP samples containing a few amount of mobilizer exhibited largely increased fracture toughness.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51173151, 50973090)Program for New Century Excellent Talents in Universities (NCET-08-0823)+1 种基金Distinguished Young Scholars Foundation of Sichuan (2012JQ0057)the Fundamental Research Funds for the Central Universities (SWJTU11CX142,SWJTU11ZT10)
文摘As a part of a serial work about the annealing inducing improvement of fracture toughness of polypropylene （PP） articles, in this work, a highly efficient mobilizer was introduced into PP and the injection-molded samples were annealed at different temperatures. The mobility of chain segments of PP was investigated by measuring the glass transition temperature. Differential scanning calorimetry （DSC） and wide angle X-ray diffraction （WAXD） were used to characterize the variation of crystalline structure of PP during the annealing process. The fracture behaviors including notched Izod impact fracture and universal tensile fracture were investigated to detect the mechanical properties in response to the variations of both chain segments mobility and crystalline structures. It was found that the mobilizer greatly improved the chain segments mobility. Further results showed that the mobilizer also induced apparent changes of the glass transition temperature and the degree of crystallinity of PP during the annealing process. Consequently, the annealed PP samples containing a few amount of mobilizer exhibited largely increased fracture toughness.
