pps proceeding - Abstract Preview
pps proceeding
Symposium: S02 - Extrusion and extrusion processes
Oral Presentation
 
 

Simultaneous reinforcing and toughening of polypropylene via tailoring the crystalline structure and phase morphology

Wu Hong (1)*, Zhang Tianci (1), Wang Jianfeng (1), Guo Shaoyun (1)

(1) Polymer Research Institute of Sichuan University - Sichuan - China

The toughening modification of polymers always accompanied by a decrease in strength and searching for a universal and feasible strategy to simultaneous reinforcing and toughening polymers is highly desirable. From the structure-dominated performance point of view, the ultimate mechanical properties of polymers can be optimized by tailoring their structure. In current work, two novel processing techniques were adopted to tailor crystalline structure and phase morphology of polypropylene/poly(ethylene-co-octene) (PP/POE) and polypropylene/ultrahigh-molecular-weight polyethylene-olefin block copolymer (PP/UHMWPE-OBC) blends to realize ‘structuring processing’ to prepare high-performance PP materials. Based on PP/POE blends, an advanced multilayered micro-co-extrusion technique was used to fabricate PP and PP/POE alternating multilayered materials to control regional enrichment distribution of POE to enhance the toughening efficiency and the existence of rigid PP layer can contribute rigidity to maintain a good balance between toughness and strength. Moreover, a kind of multi-stretched extrusion (MSEDC) technique was adopted to tailor the crystalline structure and phase morphology of PP/POE and PP/UHMWPE-OBC blends. The results showed that that flow-induced highly oriented densely stacked shish-kebabs and fiber-like UHMWPE micro-nanostructures accounting for efficient PP self-reinforcement, while the planner POE phase with micro-/nano-sheets can induce the deflection of crack, the UHMWPE with long molecular chains and well-defined interlocking UHMWPE-OBC crystalline can induce the formation of stress conduction network, providing the blends with greatly increased toughness. Keywords: PP, Simultaneous reinforcing and toughening, structuring processing, multilayered micro-co-extrusion, multi-stretched extrusion