振动注射对PP／LLDPE性能及凝聚态结构影响

Study on Morphology Structure and Properties of PP/LLDPE Blend in Vibration Injection Molding

主要对比了普通注塑试样和振动注塑PP/LLDPE(聚丙烯/线型低密度聚乙烯)共混试样晶型及力学性能的差别,研究了施加振动对PP/LLDPE(质量比为70/30)样条力学性能和晶体形态的影响。结果表明,试样在加入振动后,特别是在低频高压条件下,样条的拉伸强度比未加振动试样有所提高,而断裂伸长率有所降低。通过广角X射线衍射(WAXD)测试发现,施加振动后,试样的β晶含量提高,同时在高振动压力下试样中出现了γ晶。

The difference between mechanical properties and crystal morphology of conventional injection molding and vibration injection molding were compared. The effects of vibration frequency and pressure on the mechanical properties and crystal morphology of PP/ LLDPE（mass ratio 70/30） were studied. The tensile strength of samples produced by vibration injection molding is higher than that of the samples produced by normal injection mold- ing, especially in the low frequency, high-pressured conditions. The change of crystal structure was observed by WAXD. More β forms are found after vibration, γ forms are also ob- served when vibration pressure is high.