Non-isothermal crystallization kinetics of poly(3-hydroxybutyrate)/EVA 80 blends enhanced by NH4Cl as a nucleating agent

2019 ◽  
Vol 137 (5) ◽  
pp. 1657-1672 ◽  
Author(s):  
Safaa H. El-Taweel ◽  
Arwa Al-Ahmadi
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of

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.

Isothermal Crystallization Kinetics of Polypropylene and Hyperbranched Polyester Blends

2011 ◽  
Vol 396-398 ◽  
pp. 1688-1691
Author(s):  
Qing Chun Fan ◽  
Fei Hong Duan ◽  
Huai Bing Guo ◽  
Tian Wu
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Interfacial Free Energy ◽  
Crystallization Time ◽  
Hyperbranched Polyester ◽  
Isothermal Crystallization Kinetics ◽  
Half Crystallization Time ◽  
Kinetics Of

The isothermal crystallization kinetics of PP with different contents of AB2 hyperbranched polyester(HBP) added has been investigated. The results show that HBP acts as a nucleating agent for PP, and the hyperbranched polyester can decrease the half crystallization time (t1/2) and increase the crystallization rate of PP greatly. The Avrami exponents of PP and nucleated PP are all close to 2.5. Hoffman theory was adopted to calculate the interfacial free energy per unit area perpendicular to PP chains σe of PP and PP/HBP blends.

Non-Isothermal Crystallization Kinetics of Polyvinyl Alcohol-Graphene Oxide Composites

2013 ◽  
Vol 446-447 ◽  
pp. 206-209
Author(s):  
Cheng Peng Li ◽  
Mary She ◽  
Ling Xue Kong
Keyword(s):  
Graphene Oxide ◽  
Side Effects ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Crystallization Time ◽  
Isothermal Crystallization Kinetics ◽  
Blending Method ◽  
Kinetics Of

Polyvinlyl alcohol (PVA)/graphene oxide (GO) composites are prepared by solution blending method. And the non-isothermal crystallization kinetics of as-prepared composites is evaluated by differential scanning calorimetry (DSC). The results indicate the graphene oxide can significantly modify the non-isothermal crystallization behavior of the PVA, for instance improved crystallization temperature and prolonged crystallization time. Enhanced crystallization temperature illustrates that GO can act as effective nucleating agent. However, prolonged crystallization time means that GO can retard the whole crystallization. Further kinetics analysis indicates that both the crystallization kinetics of neat PVA and PVA/GO match the Mo model very well. According to the Mo model, during the whole crystallization process, graphene oxide perform as a retardant. In conclusion, graphene oxide can act as effective nucleating agent due to strong interaction bewteen graphene oxide and PVA matrix. On the other hand, graphene oxide loaded may lead to other side effects. This side effects may lead to the retarded crystallization speed finally.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

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