The Study Of The Compatibility And Spinnability Of SEBS/PP Composites And The Preparation Of SEBS/PP Melt Blown Nonwoven

Elastic nonwovens has been widely applied to various fields, such as tissue engineering, filtermaterial and shape memory materials. Polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene(SEBS) is a thermoplastic block copolymer with good elasticity. Due to high melt viscosity, it isdifficult to produce SEBS meltblown nonwovens. Polypropylene (PP) is the polymer commonlyused in meltblown process with low molecular weight and narrow molecular weight distribution.Thus, we try to preparation the SEBS/PP meltblown nonwovens by melt blending PP and SEBS.In this thesis, we study three aspects based on present research: the structure and properties ofSEBS/PP composites with different blend ratio, the spinnability of the preparation of SEBS/PPmeltblown nonwovens, exploring the meltblown technological parameter of manufacturing theSEBS/PP nonwovens.First, we acquired the SEBS/PP composites with different blend ratio by melt blending. Thestructure and properties of SEBS/PP composites were investigated by fourier transform infra-redspectra (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), dynamicmechanical analysis (DMA), scanning electron microscope (SEM). It revealed that SEBS/PPcomposites are immiscible. The morphology of SEBS/PP composites blending at200℃were“sea-island” structure. The crystallization temperature, crystalline, crystallization speed andstorage modulus of SEBS/PP composites decrease with the increase of the proportion of SEBS inblends. The crystalline form has no change after blending. There is no obvious chemical interactionbetween two components.Second, the spinnability of SEBS/PP composites was investigated by thermo-gravimetricanalysis (TG), capillary rheometer and cone-and-plate-rheometer. It indicated that the thermalstability of composites were enhanced in different degree compared to pure SEBS. Raising theSEBS contents have more obvious influence on increasing elasticity than viscosity.Besides, raisingthe temperature and decreasing the SEBS contents both can reduce the melt viscosity of SEBS/PPcomposites. Nevertheless, the viscous flow activation energy of SEBS/PP blends was changedwith variation of SEBS contents, which means that the rate of decline of melt viscosity of SEBS/PP blends with elevating processing temperature. With the increasing shear rate, the viscous flowactivation energy of all SEBS/PP blends decrease.Finally, combining the rheological analysis and meltblown trials, we found the propertechnical parameter including the blending proportion of SEBS/PP composites, the spinningtemperature and hot air temperature, and successfully prepared the SEBS/PP meltblownnonwovens, and then analyzed the influence of some process parameters on the morphology andproperties of SEBS/PP meltblown nonwovens such as the diameter of fibers, breaking force,breaking elongation and elastic recovery.