Crystallization with Nodular Aggregation near the Glass Transition Temperature for Syndiotactic Polypropylene
Crystallization with Nodular Aggregation near the Glass Transition Temperature for Syndiotactic Polypropylene
复制标题
间规聚丙烯在玻璃化转变温度附近的结节状聚集结晶
DOI：
10.1021/acsmacrolett.2c00666
复制
发表时间：
2023
影响因子：
7.015
通讯作者：
and Yoshihisa Miyamoto
中科院分区：
文献类型：
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作者：
Takashi Konishi;Ken Taguchi;Koji Fukao;Noriaki Takagi;and Yoshihisa Miyamoto
用广角X射线衍射仪(WAXD)、小角X射线散射仪(SAXS)和光学显微镜研究了间规聚丙烯(SPP)的熔融结晶过程。WAXD和SAXS结果表明，在玻璃化转变温度附近，结晶和介晶结节覆盖了整个样品，形成了聚集区，说明了晶化机制。对于SAXS分析，提出了三组分体系的散射函数。此外，为了分析SPP聚集区的生长动力学，提出了含时结构因子和均匀和非均匀成核生长动力学相结合的方法。分析表明，SPP聚集区的生长动力学为均相成核生长过程。聚集区的生长速度是球晶生长速度向高过冷区的自然外推。这些结果可能表明，在聚合物的玻璃化转变温度附近，结节聚集的结晶过程是基本的结晶过程。
The isothermal crystallization from the melt state of syndiotactic polypropylene (sPP) has been studied by wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), and optical microscopy. The WAXD and SAXS results show the crystallization mechanism near the glass transition temperature in which the crystalline and mesomorphic nodules cover the entire sample with the formation of aggregation regions. For the SAXS analysis, the scattering function for the three-component system has been suggested. Furthermore, to analyze the growth kinetics of the aggregation region for sPP, the time-dependent structure factor combined with the homogeneous and inhomogeneous nucleation-and-growth kinetics has been suggested. The analysis shows that the growth kinetics of the aggregation region for sPP is the homogeneous nucleation-and-growth. The growth velocity of the aggregation region is a natural extrapolation of that of spherulite to the high supercooling region. These results might indicate that the crystallization with the nodular aggregation is a fundamental crystallization process near the glass transition temperature for polymers.