Evaluation and characterization of polyethylene composites with β-cyclodextrin andβ-cyclodextrin-based derivatives as foaming nucleating agent

Abstract

In this study, we prepared nanosponges (NS) by crosslinking the hydroxyl group of β-cyclodextrin (CD) molecular. Furthermore, we modified the CD molecular by 1, 2-cyclohexanediamine (TRK) through simple chemical method. CD, NS and CD-TRK were used as nucleating agent in the injection foaming process of polyethylene (PE) with 4, 4'-oxydibenzenesulfonyl hydrazide as blowing agent. With addition of CD-TRK, the crystallinity increased from 39.17% for pure PE to 46.02% for PE/CD-TRK-1.0 composites. Results showed that PE/CD-TRK-1.0 composites presented the best foam morphology. The cell density increased by about 10 times, while the cell diameter reduced by about 56% compared with that of pure PE. Scanning electron microscopy analysis showed that CD-TRK exhibited more compact and dense network structure with uniform cavity distribution, which may reduce the cell nucleation barrier and provide proper nucleation site for cells. The dynamic mechanical analysis showed that PE/CD-TRK-1.0 composites displayed proper modulus and viscoelasticity, which were favor for cell nucleation, growth and stabilization, resulting in the best cell morphology of PE/CD-TRK composites. Tensile and impact strength of foaming PE composites were systematically analyzed. The maximum impact strength reached 27.4 KJ·m−2, and the maximum tensile strength reached 27.5 MPa.