Reactive Compatibilization Of In-Situ Microfibrillar LLDPE/PET Blends

In this paper, compatibilized LLDPE/PET blend was prepared through melt reactive extrusion, followed by continuous drawing and isotropization. The formation of grafted polymer LLDPE-g-GMA was determined by FTIR spectrum. The effect of mass ratio on LLDPE/PET blend properties was investigated. The effort of compatibilizer content and in-situ microfibrillar method on the compatibilized blend properties was studied. The main results have been presented as follows:The characterizations such as SEM, mechanical properties testing, DSC, DMA, and rheometer were employed. The results showed that the mass ratio had a greater influence on the properties of blends. The tensile properties and flexural properties of microfibrillar reinforced composites (MFC) can be improved greatly by increasing of PET content. However, the effect of PET content on the properties of MFC was more obvious than NB.The LLDPE/PET (80/20wt%) blends compatibilized with reactive compatibilizer LLDPE-g-GMA were prepared by melt extrusion. The effect of LLDPE-g-GMA on the morphology, mechanical properties, crystallization behavior and rheological properties were studied. The results showed that the addition of compatibilizer affected the continuity of the dispersed PET fibrils, but it improved the tensile properties and charpy impact strength of LLDPE/PET alloy significantly. Meanwhile, the adding of LLDPE-g-GMA promoted the crystallization rate of LLDPE. The rheologial property proved a higher apparent viscosity of blends after compatibilizer was added. All these illustrated that addition of LLDPE-g-GMA can enhance the interaction force between LLDPE and PET.The LLDPE/PET (80/20wt%) blends compatibilized with reactive compatibilizer LLDPE-g-MAH were prepared by using the same method. The results showed that addition of compatibilizer affected the continuity of the dispersed PET microfibrils, making them shorter and fewer in MFC and reduced the size of the dispersed PET phase, making them dispersed uniformly in NB. The compatibilizer had a positive effect on the tensile properties and Charpy impact strength of the MFC and NB, especially when there were PET microfibrils in the blends. The compatibilizer promoted the crystallinity of LLDPE. The intensity and magnitude of the E’, E"and tanδ were all improved after being compatibilized. In the compatibilization system, the presence of microfibrils showed a positive effect on the E’and E", but it made the tanδ peak very lower and broader. In addition, a displacement of the Tg peak to higher temperatures was observed when compatibilizer was added. Blend melt showed typical pseudoplastic fluid in the HT and LT and the viscosity of the blends were increased by the compatibilizer.