A study concerning the effect of vibration on the crystal structure and morphology for isotactic polypropylene(iPP) was conducted. The crystallite size, crystal structure and crystallinity of iPP under or without vibr...A study concerning the effect of vibration on the crystal structure and morphology for isotactic polypropylene(iPP) was conducted. The crystallite size, crystal structure and crystallinity of iPP under or without vibration treatment were investigated by means of differential scanning calorimetry(DSC) and wide-angle X-ray diffraction(WAXD). The results reveal that the crystallinity of the vibrated samples decreases at a high cooling rate, but it remains constant at a low cooling rate because of the chain relaxation of iPP. It has been found that vibration obviously increases the content of β-form of crystal phase and the amount of β-crystal mainly depends on the vibration amplitude.展开更多
基金Supported by the National Science Funds for Distinguished Young Scholars(No.5 0 12 5 312 ) Special Funds for MajorState Basic Research Project of China(No.G19990 6 4 80 0 ) and Key Program of the National Natural Science Foundation ofChina(No.5 0 1
文摘A study concerning the effect of vibration on the crystal structure and morphology for isotactic polypropylene(iPP) was conducted. The crystallite size, crystal structure and crystallinity of iPP under or without vibration treatment were investigated by means of differential scanning calorimetry(DSC) and wide-angle X-ray diffraction(WAXD). The results reveal that the crystallinity of the vibrated samples decreases at a high cooling rate, but it remains constant at a low cooling rate because of the chain relaxation of iPP. It has been found that vibration obviously increases the content of β-form of crystal phase and the amount of β-crystal mainly depends on the vibration amplitude.
