The Directional Distribution Of The Core-shell Particles In Two-phase Blends And Their Impact On The Mechanical Properties

Toughening and compatibilizing are essential during the application of many polymers.Core-shell structure modifier is widely applied due to the size controllability, species diversity, composition and structure of adjustable. Meanwhile, the application of core-shell structure modifier makes the performance of polymer to better optimization and control. It is widely used in various polymers modification.Styrene(PS), glycidyl methacrylate(GMA) and maleic anhydride(MAH) were grafted onto butadiene(PB) by emulsion polymerization to prepare PB-g-PS, PB-g-(St-GMA) and PB-g-(St-MAH). The graft copolymer were blended with polyamide 6(PA6) and polystyrene (PS). Rheological and dynamic mechanical properties of blends were investigated. The morphological of blends were observed by scanning electron microscope. The results showed that the torque values of blends increased. And the difference between the glass transition temperature of PA6 phase and PS phase decreased. The size of dispersion phase decreased evidently. Heat resistances of materials were also improved. The compatibility of blend with the functional monomer GMA and MA were better than the blend with PB-g-PS. Introducing the same content of GMA and MA,the compatibility of blends were similar.1 wt% GMA on modifier had best compatibilization. Further increment of functional monomer content in graft copolymer showed no further improvement on compatibility, on the contrary, deteriorated the compatibility. The mechanical performance test results indicated that the modifiers introduced into the blend, its impact strength and tensile strength hadn't been significantly improved, materials were still very crisp. The introduction of functional groups didn't improve the mechanical properties of blends. Compatibilization can not improve the mechanical properties of blends.Core-shell structure modifiers ABS, ABS-g-GMA and ABS-g-MA were synthesized by the same method. The modifiers were blended with PA6,styrene-acrylonitrile (SAN) and PA6/SAN blends. Mechanical performance test results showed that ABS, ABS-g-GMA had little effect on the impact strength of PA6. However the impact strength of materials has been significantly improved with SAN. The impact strength increased 30 times with the ratio of SAN and modifier was 1:1.ABS-g-MA improved the impact strength of PA6 significantly. With 30 wt% ABS-g-MA added, the maximum toughness was over 853 J/m. As compared with pure PA6, toughness increased 40 times.When ABS-g-MA blended with PA6/SAN, the blends showed obvious brittle-ductile transition. Compared to PA6/SAN, the Izod impact strength increased 10 times with 24% rubber in the blends.Different elastomers were applied to toughen PA6 and PA6/SAN blends. The impact strength of the materials was 100J/m or so with EPDM-g-MA, SEBS-g-MA and POE introduced into PA6. But the impact strength of materials has been significantly improved with POE-g-MA introduced. When the content of MA was 1% in the elastomer, the impact strength increased 20 times with the ratio of PA6 to modifier was 76/24. The improvements of the mechanical properties of materials were not significantly when POE-g-MA was blended with PA6/SAN/ABS blends, but the material showed an obvious brittle-ductile transition.