SAXS Investigation Of The Structures And Irradiation Effects In HDPE, HDPE/C

Small angle X-ray scattering (SAXS) is a non-destructive technology used todetect nanoscale structures between one to hundreds nanometers. High densitypolyethylene(HDPE) and polyethylene/carbon composites(HDPE/C) have becomeimportant materials in many areas. Study of the structure and properties of HDPE andHDPE/C helps to develop these materials. The crystalline morphology of polymer andthe information of nanoparticles effects in polymer composites can be studied by SAXS.The irradiation effects of polymers induced by swift heavy ions are includeamorphization, chain scission and cross-linking processes, carbonizaiotn and ion trackformation. SAXS is an effective technology for studying the irradiation effects.Firstly, microstructure variation of high density polyethylene (HDPE) withtemperature is investigated by using Small Angle X-ray Scattering (SAXS) technique.The structure changes of HDPE lamella obtained by Lorentz corrections, onedimensional correlation function and integral invariant of scattering intensity. Thestudy reveales that at temperatures below100C the long period of HDPE shows nochange with temperature while the thickness of crystalline and amorphous layers showslight decreasing and increasing with increase of temperature, respectively. Thecorresponding linear crystallinity decreases gradually. Above110C the long period,the thickness of crystalline layer as well as the thickness of amorphous layer increasestrongly with increase of temperature. Above120C the lamella is melted rapidly.The polymer composites HDPE/CNT and HDPE/CB are investigated by SAXSand differential scanning calorimetry(DSC). The investigation shown that the longperiod of HDPE is changed with the dopping of carbon particles. CNT and CB exitstthe effects of nucleating agent in composite materials. It is found that the carbon particles can reinforce the crystalline structure of HDPE as revealed by its temperaturevariation behaviors.Semi-crystalline high density polyethylene (HDPE) samples were irradiated with1.157GeV56Fe ion beams to fluences ranging from1×1011to6×1012ions/cm2. Theradiation induced changes in nano/microstructure were investigated with small angleX-ray scattering (SAXS) technique. The scattering contributions from HDPE matrixand ion tracks are successfully separated and analyzed through tilted SAXSmeasurements with respect to the X-ray beam direction. Lorentz correction, one-dimensional correlation function calculation, fractal nature analysis of the isotropicscattering pattern reveal that HDPE long period polymeric structures are damaged andclusters of carbon-rich materials are formed inside the ion tracks. The radius of iontrack and the change of electron density inside track are obtained by least square curvefitting of the scattering contribution from the ion track based on the core-shell structuremodel of ion track.Finally1.157GeV Fe ion irradiated polymer composite HDPE/CB is investigatedby SAXS and X-ray diffraction(XRD). The structure shows different behaviors withincreasing of irradiated fluence for smaples filling with different concentrations of CBparticles. The results reveales that filling with CB has the effect of protecting the longperiod of HDPE.