点击次数：

论文类型：期刊论文

发表时间：2010-11-01

发表刊物：JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

收录刊物：SCIE、EI、Scopus

卷号：102

期号：2

页面范围：775-783

ISSN号：1388-6150

关键字：Crystallization kinetics; Melting behavior; alpha-Nucleating agent; beta-Nucleating agent; Compound nucleating agents; Isotactic polypropylene

摘要：In this study, alpha-phase nucleating agent (NA) 1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS), beta-phase rare earth NA (WBG), and their compound NAs were introduced into isotactic polypropylene (iPP) matrix, respectively. Crystallization kinetics and subsequent melting behavior of the nucleated iPPs were comparatively studied by differential scanning calorimetry (DSC) under both isothermal and nonisothermal conditions. For the isothermal crystallization process, it is found that the Avrami model successfully described the crystallization kinetics. The active energy of nonisothermal crystallization of iPP was determined by the Kissinger method and showed that the addition of nucleating agents increased the activation energy. Melting behavior and crystalline structure of the nucleated iPPs are dependent on the nature of NAs and crystallization conditions. Higher proportion of beta-phase can be obtained at higher content of beta-nucleating agent and lower crystallization temperature or lower cooling rate.