Cross⁃linked foaming process and performance of recycled polyethylene

doi:10.19491/j.issn.1001-9278.2022.06.019

Abstract

Abstract:

A cross?linked foamed polyethylene board was prepared through compression molding using three types of recycled linear low?density polyethylene as raw materials and expandable microspheres as a foaming agent. The thermal properties， morphology， impact resistance and tensile properties of cross?linked foamed polyethylene were characterized using differential scanning calorimeter， scanning electron microscope， film impact tester， and electronic universal testing machine. The experimental results indicated that the melting point and molecular weight of recycled polyethylene materials increased after processing owing to the crosslinking effect of dicumyl peroxide. The network structure formed after crosslinking favored the stability of cells. There were independent cells in the recycled polyethylene after crosslinking and foaming. The foamed materials obtained maximum tensile strength of 9.7 N/mm²， impact strength of 21.5 kJ/m²， and oxidation induction time of 7.3 min， and therefore they could meet the requirement for producing various types of plastic products such as floats and buoyancy balls.

Key words: recycled polyethylene, cross?linked foaming, expandable microspheres

CLC Number:

TQ325.1⁺2

LEI Yujie, CHEN Minghuan, WANG Jieyao, CHEN Wangzhi, LI Lei. Cross⁃linked foaming process and performance of recycled polyethylene[J]. China Plastics, 2022, 36(6): 124-129.

Figures/Tables 9

Fig.1. FTIR spectra of recycled polyethylenes

Fig.2. ssNMR spectra of recycled polyethylenes

Fig.3. DSC curves of recycled polyethylenes

Fig.4. DSC curves of cross?linked foamed polyethylenes

Fig.5. SEM of cross?linked foamed polyethylenes

Fig.6. Melt flow rate and cell diameter of crosslinked foamed polyethylenes

Fig.7. Tensile strength and impact strength of cross?linked foamed polyethylenes

Fig. 8. Recycled polyethylene and its crosslinked foaming products

聚乙烯回收料

交联发泡前200 ℃

氧化诱导期/min

交联发泡后200 ℃

氧化诱导期/min

Tab.1. Comparison of oxidation induction time before and after crosslinking foaming

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