The Structure, Properties And Their Blending Spinning Of New Thermoplastic Polyolefin Elastomers

ExxonMobile and DOW chemical company developed propylene-ethylene copolymers,Vistamaxx and Versify,by confined geometry configuration catalyst technology respectively.The copolymers have excellent elasticity,mechanical properties and processability due to their controlled structures.They have potential application in film and packing materials,the modification of polymer.In this article,¹³C-NMR was used to investigate the chemical structure of Vistamaxx(VM) and Versify.The obvious difference of the structure between VM1000,VM2210,VM3000 and Versify3401 was found.VM1000 and Versify3401 have the most content of crystalline ethylene chain,and VM3000 has the least.The stereoregularity of VM and Versify3401 was studied by the means of FTIR.The short sequences were proven to be the major part of the macromolecules with spiral conformation in the crystalline zone.The fact that the spiral conformation exists in the melt when the temperature rises above the melting temperature of VM2210 was detected,but the spiral conformation of Versify3401 was mainly destroyed at the melting temperature.The crystallization of VM and Versify3401 was studied by the means of DSC, WAXD and polarized microscope.It was showed that both VM and Versify3401 have very low crystallinity with imperfect crystal and slow crystallization speed,the crystallinity is spherulite.And the crystallinity of VM2210 was a little higher than Versify3401.VM and Versify were arranged in terms of crystalline temperature from high to low:VM2210, VM1100,Versify3401 and VM3000.Moreover,the study on nonisothermal crystallization behaviors showed that crystallizable rate and crystallizable enthalpy increased,but Avarami index did not have obvious change when iPP was added.Polyolefin elastomer/iPP blending fibers were spun by melting blending extrusion spinning machine which was designed by special method.Their crystallinity,orientation of segments and mechanical properties were investigated by the means of WAXD,birefringence and mechanical property tests.With increasing the content of iPP,the crystallinity and the degree of orientation of Polyolefin elastomer/iPP blending fibers increased.Drawing can improve the orientation of segments.Tensile strength of polyolefin blending fibers is enough for clothing applications.When iPP was added in polyolefin fiber,the strength could be enhanced.On the other hand,toughness can be enhanced when polyolefin elastomers were added in polypropylene fiber.