Non-Isothermal crystallization of isotactic polypropylene in dotriacontane. II: Effects of dilution, cooling rate, and nucleating agent addition on growth rate

1993 ◽  
Vol 33 (9) ◽  
pp. 537-542 ◽  
Author(s):  
Gordon B. A. Lim ◽  
Kenneth S. McGuire ◽  
Douglas R. Lloyd
Keyword(s):  
Growth Rate ◽  
Cooling Rate ◽  
Isotactic Polypropylene ◽  
Isothermal Crystallization ◽  
Nucleating Agent

scholarly journals Non-Isothermal Crystallization Kinetics of Poly(4-Hydroxybutyrate) Biopolymer

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2840 ◽  
Author(s):  
Ina Keridou ◽  
Luis J. del Valle ◽  
Lutz Funk ◽  
Pau Turon ◽  
Lourdes Franco ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cooling Rate ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Secondary Nucleation ◽  
Scanning Calorimetry ◽  
Limited Region ◽  
First Case ◽  
Biodegradable Poly ◽  
Insertion Mechanism

The non-isothermal crystallization of the biodegradable poly(4-hydroxybutyrate) (P4HB) has been studied by means of differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). In the first case, Avrami, Ozawa, Mo, Cazé, and Friedman methodologies were applied. The isoconversional approach developed by Vyazovkin allowed also the determination of a secondary nucleation parameter of 2.10 × 105 K2 and estimating a temperature close to 10 °C for the maximum crystal growth rate. Similar values (i.e., 2.22 × 105 K2 and 9 °C) were evaluated from non-isothermal Avrami parameters. All experimental data corresponded to a limited region where the polymer crystallized according to a single regime. Negative and ringed spherulites were always obtained from the non-isothermal crystallization of P4HB from the melt. The texture of spherulites was dependent on the crystallization temperature, and specifically, the interring spacing decreased with the decrease of the crystallization temperature (Tc). Synchrotron data indicated that the thickness of the constitutive lamellae varied with the cooling rate, being deduced as a lamellar insertion mechanism that became more relevant when the cooling rate increased. POM non-isothermal measurements were also consistent with a single crystallization regime and provided direct measurements of the crystallization growth rate (G). Analysis of the POM data gave a secondary nucleation constant and a bell-shaped G-Tc dependence that was in relative agreement with DSC analysis. All non-isothermal data were finally compared with information derived from previous isothermal analyses.

Variation of non-isothermal crystallization behavior of isotactic polypropylene with varying β-nucleating agent content

2010 ◽  
Vol 59 (10) ◽  
pp. 1441-1450 ◽  
Author(s):  
Linli Xu ◽  
Xiuju Zhang ◽  
Kai Xu ◽  
Shaoquan Lin ◽  
Mingcai Chen
Keyword(s):  
Isotactic Polypropylene ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Nucleating Agent

Isothermal and non-isothermal crystallization of isotactic polypropylene in the presence of an α nucleating agent and zeolite 13X

2018 ◽  
Vol 667 ◽  
pp. 9-18 ◽  
Author(s):  
Xin Meng ◽  
Weiguang Gong ◽  
Weijie Chen ◽  
Yaoqi Shi ◽  
Yan Sheng ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Zeolite 13X

Non-isothermal crystallization kinetics of isotactic polypropylene nucleated with nucleating agent bicyclic [2,2,1] heptane di-carboxylate

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Yue-fei Zhang ◽  
Xun Li ◽  
Xian-shan Wei
Keyword(s):  
Crystallization Kinetics ◽  
Isotactic Polypropylene ◽  
Growth Pattern ◽  
Isothermal Crystallization ◽  
Three Dimensional ◽  
Nucleating Agent ◽  
Isothermal Crystallization Kinetics ◽  
Spontaneous Nucleation ◽  
Spherulite Growth ◽  
Kinetics Of

AbstractBicyclic [2,2,1] heptane di-carboxylate (commercial product name: HPN- 68) is a novel nucleating agent with high nucleation efficiency for isotactic polypropylene (iPP). In this paper, the non-isothermal crystallization kinetics of virgin iPP and iPP nucleated with HPN-68 were investigated by means of a differential scanning calorimeter (DSC).The Caze method was used to analyze the non-isothermal crystallization kinetics. The results show that addition of HPN-68 can increase the crystallization peak temperature (Tp) of iPP greatly under the same cooling rate. Under non-isothermal conditions, the addition of HPN-68 changes the spherulite growth pattern of iPP. For virgin iPP, the growth pattern is mainly spontaneous nucleation followed by three-dimensional spherulite growth, while for iPP nucleated with HPN-68, the growth pattern is mainly heterogeneous nucleation followed by three-dimensional spherulite growth.

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