Research On The Aging Resistance Of Recycled HDPE Bottle Caps

The main topic of this paper is about the innovative two-step reactive extrusion method. It can avoid the confrontation between the additives, when the waste polymer materials (mostly recycled HDPE bottle cap materials) are reused. In this thesis, the thermal stabilities of HDPE during processing and oven-aging were evaluated by using Oxidation Inducing Time (OIT), Environmental Stress Cracking Resistance (ESCR), Melt Flow Index (MFI), mechanical property tests such as tensile strength and the elongation at break.Through the study of the effect of two-step reactive extrusion method on the HDPE antioxidant stability with different DCP contents, different types and contents of antioxidants, it was found that, two-step reactive extrusion method can greatly improve the OIT and ESCR value of HDPE; through multi-extrusion experiment found that two-step reactive extrusion method can improve the HDPE processing stability; hot water immersion tests also proved that antioxidant's migration rate of samples with two-step reactive extrusion method is lower, effectively improve the long-term stability of the material. Both for Irganox1035 and Irganox300, OIT with two-step extrusion method is much higher than that with one-step.