Isothermal Crystallization of Polyethylene/Montmorillonite Nanocomposites Prepared by In Situ Polymerization

2012 ◽  
Vol 271-272 ◽  
pp. 42-45
Author(s):  
Min Li ◽  
Li Guang Xiao ◽  
Hong Kai Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
In Situ Polymerization ◽  
Crystallization Rate ◽  
Avrami Exponent ◽  
Scanning Calorimetry ◽  
Montmorillonite Nanocomposites

Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The isothermal crystallization of PE/MMT nanocomposites at different MMT concentration (from 0.1 wt % to 1.2 wt %) was investigated by differential scanning calorimetry (DSC). The crystallization kinetics shows that the Avrami exponent of PE/MMT nanocomposites is decreased compared with pure PE, which indicates a decrease in the crystal growth dimension. This is attributed to the stems of PE crystals confined in the MMT layers. The crystallization rates of PE/MMT nanocomposites are faster than those of pure PE. However, when the content of MMT increases from 0.1 wt % to 1.2 wt %, the crystallization rate of PE/MMT nanocomposites is decreased.

Crystallization Behavior of Polyethylene/Montmorillonite Nanocomposites Prepared by In Situ Polymerization

2012 ◽  
Vol 184-185 ◽  
pp. 932-935
Author(s):  
Min Li ◽  
Li Guang Xiao ◽  
Hong Kai Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
Crystallization Process ◽  
In Situ Polymerization ◽  
Nucleating Agent ◽  
Lower Content ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Montmorillonite Nanocomposites

Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The crystallization behavior of PE/MMT nanocomposites at different MMT concentrations (from 0.1 to 1.2 wt %) were investigated by differential scanning calorimetry (DSC). The equilibrium melting points increase by the addition of MMT. The crystallization rates of PE/MMT nanocomposites are faster than those of pure PE. The addition of MMT facilitated the crystallization of PE, with the MMT functioning as a heterogeneous nucleating agent at lower content; at higher concentrations, however, the physical hindrance of the MMT layers to the motion of PE chains retarded the crystallization process.

Research in Non-Isothermal Crystallization Kinetics of LDPE Composite Films

2013 ◽  
Vol 848 ◽  
pp. 46-49
Author(s):  
Zi Nian Zhao ◽  
Xiao Li Lei
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystallization Kinetics ◽  
Heterogeneous Nucleation ◽  
Isothermal Crystallization ◽  
Composite System ◽  
Crystallization Rate ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Inorganic Particles ◽  
Kinetics Of

By means of melt blending process in a co-rotating twin screw extruder and blow molding , the low density polyethylene (LDPE)/thermoplastic elastomer(TPE) mixed membranes and LDPE/inorganic particles composite membrane were prepared. by differential scanning calorimetry(DSC) to study the non-isothermal crystallization kinetics of the LDPE composite system by differential scanning calorimetry (DSC).Use modified Jeziorny method to process the data ,the results shows that ZMS, SiO2, EVA and EMAA all play a role of heterogeneous nucleation and the crystallization rate of LDPE has been increased,especially the ZMS/LDPE composite system which heterogeneous nucleation is more obvious and crystallization rate is faster.

Orthogonal Smectic Layers Favour Nucleation through Diffusioncontrolled Transformations: A Systematic Crystallization Kinetics Study

2002 ◽  
Vol 57 (5) ◽  
pp. 226-232 ◽  
Author(s):  
P. A. Kumar ◽  
Pisupati Swathi ◽  
V. G. K. M. Pisipati
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Crystallization Process ◽  
Avrami Exponent ◽  
Kinetics Study ◽  
Nucleation Process ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Kinetics Of

Systematic investigations of the crystallization kinetics of two representative compounds of p-phenylbenzylidene-p´ -alkylanilines are performed, using differential scanning calorimetry, to study the influence of the kinetophase (occurs prior to the crystal phase) on the nucleation process. The dimensionality of the crystal growth and the related crystallization process are discussed in terms of the Avrami parameters n and b. The trend in the magnitude of the Avrami exponent n supports the occurrence of temperature-dependent transformations in the orthorhombic molecular array.

The non-isothermal crystallization behavior of polyamide 6 and polyamide 6/HDPE/MAH/L-101 composites

2019 ◽  
Vol 39 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Bingxiao Liu ◽  
Guosheng Hu ◽  
Jingting Zhang ◽  
Zhongqiang Wang
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Isothermal Condition ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis And Design ◽  
Processing Techniques

AbstractStudy of the crystallization kinetics is particularly necessary for the analysis and design of processing operations, especially the non-isothermal crystallization behavior, which is due to the fact that most practical processing techniques are carried out under non-isothermal conditions. The non-isothermal crystallization behaviors of polyamide 6 (PA6) and PA6/high-density polyethylene/maleic anhydride/2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (PA6/HDPE/MAH/L-101) composites were investigated by differential scanning calorimetry (DSC). The crystallization kinetics under non-isothermal condition was analyzed by the Jeziorny and Mo equations, and the activation energy was determined by the Kissinger and Takhor methods. The crystal structure and morphology were analyzed by wide-angle X-ray diffraction (WXRD) and polarized optical microscopy (POM). The results indicate that PA6/HDPE/MAH/L-101 has higher crystallization temperature and crystallization rate, which is explained as due to its heterogeneous nuclei.

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