Novel Structure to Improve Mechanical Properties of Polymer Blends: Multilayered Ribbons

Ribbon-like dispersed phase in polymer blends can provide excellent mechanical properties for the matrix, compared with the fibrillar or spherical dispersed phase. However, it is difficult to control the uniformity of size in the current preparation methods. In this work, polyethylene (PE)/PA11 alternating multilayered pellets were first obtained via multilayered coex- trusion technology, and further novel multilayered ribbons with PA11 layers intercalated by PE layers were successfully constructed via secondary processing of the pellets. The morphology analysis showed that the formation of the novel multilayered ribbons was highly dependent on the thickness of the PA11 layer in the pellets, the adhesive strength of the layer interface, and the secondary processing temperature. When the PA11 layer thickness decreased to submicron, and the adhesive strength of the layer interface reached a certain level while the secondary processing temperature dropped to a certain degree, the multilayered ribbons with a uniform size could be obtained. The crystallinity of the PA11 layer in the multilayered ribbons could be increased by decreasing the secondary processing temperature. The yield strength and notch impact strength of the (PE/PEgMAH-50%)/PA11 blends with PA11/(PE/PEgMAH-50%) multilayered ribbons were 40 and 134% higher than those of the traditional pellet blends and were 64 and 26% higher than those of the corresponding matrix, respectively. This work provides a novel structure of a ribbon-like dispersed phase to improve the mechanical properties of polymer blends.