【摘要】 研究了主要含β晶型的聚丙烯在不同温度下的应力-应变性质,并与同一商品牌号得到的α晶型聚丙烯作了对比。发现,β晶型试样的屈服强度低于α晶型,而抗冲击强度则比α晶型试样高1—2倍。结合X射线衍射法对β晶型试样在拉伸过程中发生的晶型转变的研究及形变的分子机制解释了二种晶型试样在力学性质上的差异。更多还原

【Abstract】 The stress-strain behavior of mainly β-form of isotactic polypropylene was measured at various temperatures and compared with those of α-form of the same grade sample. The results show that β-form sample has a lower yield strength and a higher impact strength than that of the α-form. The change of crystalline structure during stretching was studied by X-ray differaction technique. The difference in mechanical behavior of α- and β-forms was explained qualitatively with molecular model of deformation and structure transformation during strecting.更多还原