Theβ-PP samples were made by melt-blending three kinds of self-made polypropylene materials with aβnucleating agent. The samples were treated under the same crystallization conditions and the relativeβcrystal contents were measured by utilizing wide angle X-ray diffraction spectrum (WAXD) and differential scanning calorimeter (DSC),respectively. The peak-separating software Peakfit was used to deal with WAXD diffractive peaks and the relativeβcrystal content was calculated according to the intensity of diffractive peaks forαandβcrystals. The software TA Universal Analysis was used to analyze DSC melting curves and theβrelative crystal content was calculated according to the area of melting peak forα andβcrystals. The results show that the relativeβcrystal content of the threeβ-PP samples calculated by WAXD method is 48%,43% and 18%while that calculated by DSC method is 27%,11% and 5%,respectively. The samples are not heated when WAXD method is employed, however,when DSC method is employed,β–α transition happens during the heating process,resulting the calculated relativeβcrystal content value was smaller than the real one due to the decreasedβcrystal content but increasedαcrystal content.%采用β成核剂对3种实验室自制的聚丙烯(PP)分别进行熔融共混制成含β晶的PP (β-PP)试样,并经相同的结晶条件对试样进行处理,分别用广角X射线衍射(WAXD)仪和差示扫描量热(DSC)仪计算试样中的β晶相对含量.利用分峰软件Peakfit对WAXD衍射峰进行处理,根据α晶和β晶的衍射峰强度计算了β晶相对含量;利用TA Universal Analysis软件对DSC熔融曲线进行分析,根据α晶和β晶的熔融峰面积计算了β晶相对含量.计算结果显示,用WAXD法计算的3种β-PP的β晶相对含量分别为48%,43%和18%,而用DSC法计算的分别为27%,11%和5%.用WAXD法测试结晶度时,试样无需受热,而用DSC法时,β晶在加热过程中容易发生β–α转变,导致β晶数量减少、α晶数量增加从而引起计算的β晶相对含量较实际值偏低.
展开▼
