Study On Structure And Mechanical Properties Of Polyolefine Melt Under Low Frequency Vibration Field

Recently, the melt vibration technology has been studied widely by many polymer scholars. In this thesis, a low frequency vibration was put on the Polymer melt by a self-made vibration injection device while injecting. Polymer rheological behavior can be controlled in this way, and the mechanical properties of specimen can be increased accordingly. We mostly research the effect of vibration parameter to polymer mechanical properties at different temperature, observe microstructure by SEM,WAXD,DSC, finally analyze the relationships between them.The research about DPP F401 vibration injection specimen showed that specimen can be self-reinforced and self-toughened when it was under vibration field, the impact strength and tensile strength of sample increased as vibration pressure amplitude rise. The maximum amplitude of impact strength and tensile strength are 94.8% and 12.5% respectively. The test result of SEM,DSC and WAXD showed that the orientation of sample increased, andβ,γcrystalline can be formed more easily when vibration injection is used.The research about HDPE 6098/1158 vibration injection specimen showed that the improvement effect on the HDPE 6098/1158 specimen of the vibration field is much bigger than the effect on the pure HDPE6098 specimen. The test result of SEM,DSC and WAXD showed crystallinity of the vibration injection specimen increased, molecular chain oriented along the injection direction, and shish-kebab structure can be found in the sample.The research about HDPE/LDPE vibration injection specimen showed that the toughness of specimen improved when we add some LDPE in HDPE, and as the weight percentage of HDPE enhanced, tensile strength increased simultaneously. We can also find that the shear effect on the HDPE/LDPE specimen of the vibration field is more distinct than the pure one, and the miscibility of HDPE and LDPE step up when the vibration injection is working.