Recycled Polyethylene Radiation Crosslinking Modification

Plastic is one of the most widely used materials in modern society.It also confront by the problem of how to cope with the plastic scrap when widely used. In common situation,the mechanics properties of regenerated plastic drop a lot, which limits its regeneration utilization.In plastics,PE is the product with the biggest production and the most widespread purpose,so it has important significance in both society and environment to research the recycling of PE.In plastic process technique,utilize the radiation technique to exploit some product with high-performance is the forward position in plastic modification research. The radiation cross-linking modification can improve the properties of regenerated PE effectively,which is one of the development aspect and trend in the recycling of PE scrap.The key research aspect of this thesis is use the radiation technique to improve the situation of low performance of recycling PE,and expand the application domain.This paper use the ⁶⁰Co—γray radiation technique to research the cross-linking properties of recycling PE,especially the effect to the gel content with radiation dosage or different cross-linking agent,the content of cross-linking agent.And the change of mechanical properties, thermal properties,the crystallization of recycling PE after cross-linking.On the basis of this,the mechanism of enhancing radiation cross-linking of polyfunctional material was proposed and discussed.We study the simple radiation cross-linking firstly,the effect of radiation dosage on cross-linking result is researched.After the radiation processing,the gel content rises with the increase of content of radiation dosage,but the raise region is lager at lower dosage than higher dosage.On the basis of the simple radiation cross-linking,take the cross-linking agent into regenerated PE can improve the efficiency of radiation cross-linking. Different cross-linking agent makes different cross-linking behavior,there are three cross-linking agents are used in this paper.TMPTMA can produce certain cross-linking reaction under low dosage,TAC and TAlC need higher dosage to fulfill cross-linking,however.And they have better cross-linking reaction properties at a higher dosage.With the consideration of economic and efficiency, this paper takes TAIC as the cross-linking agent to research the regulation of enhanced radiation cross-linking of regenerated PE.Compared the efficiency and properties with different experiment prescription,2%is the best choice.After simple radiation cross-linking,the mechanics property of regenerated PE improves in different extent,especially after being joined with the cross-linking agent.The mechanics properties of LDPE come to the extreme value with 200kGy dosage,probably two times as before radiation.But after joined with the cross-linking agent,the tensile strength and the flexural strength come to 23.6MPa and 25.2MPa with 150kGy dosage only,more than two times as the 10.1MPa and 11.2MPa before radiation.The DSC diagrams show that,the crystallization of regenerated PE decreases with the increase of radiation dosage. The occurrence of extreme value demonstrated that the regenerated PE products can have better performance only in an appropriate amount of radiation cross-linking.