Abstract:

IPP injection samples are prepared by self-made vibration injection mold in different tempera- turepressure and vibrate frequency.WAXD methods were used to study the development and transi tions of different crvstalforms insurface laver. When melt temperature was 230C crvstal formed whose contentincreased with increasingvibration frequency and vibration pressure. Tensile strength in- creases with the vibration pressure.The elongation at break may be decreased by vibration of low fre- quency,however increased by high frequencyones.The orientation of a-crystal was characterized with polefigures. At low vibration frequency,low temperature and high vibration pressure, the normal of (040) plane of IPP orientated in Mdirection, while in the opposite condition in N-direction.

Key words: isotactic polypropylene;orientation；vibration injection; , pole figure；wide angle X ray diffraction