Preparation And Properties Of Lldpe/Ldpe Blend And Composite Films

In this paper. LLDPE, two kinds of LDPE and modified nano-ZnO were used to prepare LLDPE/LDPE blend films. LLDPE/nano-ZnO and LLDPE/LDPE/nano-ZnO composite films through melt blowing by Brabender extruder. Their crystallization behavior and crystal morphology were characterized by DSC and POM. Mechanical properties and melt rheological properties were also investigated. In addition, the nano-ZnO modified by silane coupling agent (KH550) was analyzed by FTIR. and dispersion of the nano-ZnO in the composite films was observed by SEM.For LLDPE/LDPE blends, the results showed that the comprehensive mechanical properties of the blend films could be balanced at appropriate amount of LDPE. The crystallinity as well as the spherulite size of the blends decreased with an increase of LDPE. The decrease of melt viscosity of the blend, comparing with pure LLDPE, suggested that LDPE could improve the melt rheological property of LLDPE. The mechanical properties of LLDPE/1#LDPE blend films were better than that of LLDPE/2#LDPE, but their processing rheological properties were in contrast.For LLDPE/nano-ZnO composites, the results showed that the mechanical properties of LLDPE/KH550-modified nano-ZnO composite films were much better than that of LLDPE/unmodified nano-ZnO composite films.For LLDPE/LDPE/nano-ZnO composites, the results indicated that at nano-ZnO content of0.3wt%. modified nano-ZnO particles were well dispersed in LLDPE/LDPE matrix, and the crystallinity of LLDPE and LDPE were increased due to the action of heterogeneous nuclear agent. The comprehensive mechanical properties of the composite films were improved effectively. Besides, the processing rheological properties almost unchanged because of small amount of nano-ZnO. In addition, the improvement of the mechanical properties for LLDPE/2#LDPE/nano-ZnO composite film was more significant than that of LLDPE/1#LDPE/nano-ZnO.