Characteristics of non-isothermal crystallization of polypropylene with and without talc

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Carmen Albano ◽  
José Papa ◽  
Miren Ichazo ◽  
Jeanette González ◽  
Carmen Ustariz
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Kinetic Equation ◽  
Crystallization Temperature ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Crystallization Activation Energy ◽  
Scanning Calorimetry ◽  
Homogeneous Crystallization ◽  
Temperature Crystallization

Abstract The non-isothermal behaviour of crystallization of polypropylene (PP) and its talc-filled composites was investigated by means of differential scanning calorimetry. Different analytical methods were used to describe the crystallization process. According to the behaviour of crystallization temperature, crystallization activation energy and crystallization parameters and coefficient, talc results in an increase in PP crystallization rate and in a decrease in total energy opposing to homogeneous crystallization. Velisaris-Seferis’ kinetic equation was found to describe reasonably well the non-isothermal behaviour of crystallization of PP and its filled composites.

Crystallization kinetics of amorphous Ga–Sb–Te chalcogenide films: Part I. Nonisothermal studies by differential scanning calorimetry

2004 ◽  
Vol 19 (10) ◽  
pp. 2929-2937 ◽  
Author(s):  
Chain-Ming Lee ◽  
Yeong-Iuan Lin ◽  
Tsung-Shune Chin
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Ternary Phase Diagram ◽  
Film Deposition ◽  
Rate Dependency ◽  
Scanning Calorimetry ◽  
Kinetics Parameters ◽  
Kinetics Of

Nonisothermal crystallization kinetics of amorphous chalcogenide Ga–Sb–Te films with compositions along the pseudo-binary tie-lines connecting Sb7Te3−GaSb and Sb2Te3–GaSb of the ternary phase diagram were investigated by means of differential scanning calorimetry. Powder samples were prepared firstly by film deposition using a co-sputtering method; the films were then stripped from the substrate. The activation energy (Ea) and rate factor (Ko) were evaluated from the heating rate dependency of the crystallization temperature using the Kissinger method. The kinetic exponent (n) was deduced from the exothermic peak integrals using the Ozawa method. The crystallization temperature (Tx = 181 to 327 °C) and activation energy (Ea= 2.8 to 6.5 eV) increased monotonically with increasing GaSb content and reached a maximum value in compositions located at the vicinity of GaSb. The kinetic exponent is temperature dependent and shows higher values in the SbTe-rich compositions. Promising media compositions worthy of further studies were identified through the determined kinetics parameters.

Effect of Hyperbranched Polymer on Crystallization Kinetics of Isotactic Polypropylene

2012 ◽  
Vol 535-537 ◽  
pp. 1142-1145
Author(s):  
Guang Tian Liu ◽  
Jing Lei
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Isotactic Polypropylene ◽  
Isothermal Crystallization ◽  
Hyperbranched Polymer ◽  
Crystallization Rate ◽  
Crystallization Activation Energy ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of

In this paper, the isothermal crystallization kinetics of isotactic polypropylene (iPP) and iPP with 5% hyperbranched polymer (HBP) added had been investigated by differential scanning calorimetry (DSC). The results show that a small addition of HBP affects the crystallization behavior of iPP. During isothermal crystallization, the crystallization rate of the blend is higher than those of iPP remarkably. An increase in the Avrami exponent may be attributed to the fractal structure of hyperbranched polymer. The crystallization activation energy is estimated by the Friedman equation, the results show that the activation energy decreases remarkably by addition of HBP and the crystallization rate of the blend is more sensitive to temperature than that of iPP.

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.

Study on the Crystallization Activation Energy of Poly (L-lactic acid) Nucleated with P-tert-butylcalix[8]arene

2018 ◽  
Vol 26 (2) ◽  
pp. 169-175
Author(s):  
Yaoqi Shi ◽  
Liang Wen ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Crystallization Temperature ◽  
Nucleating Agent ◽  
Crystallization Activation Energy ◽  
Temperature Range ◽  
Chain Mobility

The crystallization activation energy (Δ E) of a polymer comprises the nucleation activation energy Δ F and the transport activation energy Δ E*. In this paper, the Δ E of poly (L-lactic acid) (PLLA) nucleated with nucleating agent p- tert-butylcalix[8]arene (tBC8) was calculated. The results showed that the Δ E of nucleated PLLA was 165.97 kJ/mol, which is higher than that of pure PLLA. The reason why Δ E of PLLA increased when incorporating nucleating agent was studied. The increment of glass transition temperature ( Tg) for nucleated PLLA revealed that the polymer chain mobility was restricted by tBC8, which was considered as the reason for the increase of Δ E*. Further, polyethylene glycol (PEG) was added to improve the chain mobility, thus eliminated the variation of the transport activation energy Δ E* caused by tBC8. Then the effect of the increment of crystallization temperature range on the increase of Δ F was also taken into consideration. It was concluded that both decreasing the mobility of chain segments and increasing the crystallization temperature range caused an increase of Δ E for PLLA/tBC8.

scholarly journals Miscibility, melting and crystallization of poly(ε-caprolactone) and poly (vinyl formal) blend

2007 ◽  
Vol 25 (1) ◽  
pp. 53 ◽  
Author(s):  
David R. Rohindra ◽  
Jagjit R. Khurma
Keyword(s):  
Growth Rate ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Optical Microscopy ◽  
Crystallization Process ◽  
Scanning Calorimetry ◽  
Low Degree ◽  
Solution Cast ◽  
Melting And Crystallization

Solution cast blends of poly(e-caprolactone) [PCL] and poly(vinyl formal) [PVF] from dichloromethane was investigated for miscibility by Differential Scanning Calorimetry [DSC], Fourier Transform Infrared Spectroscopy [FTIR] and optical microscopy. Melting (Tm) and crystallization (Tc) temperatures were for the PCL fraction while the glass transition temperature (Tg) was for PVF fraction in the blends. Blends with 20 wt% and less PCL showed a depression in Tm and Tc. Depression in Tc indicated that during the non-isothermal crystallization process, the presence of PVF decreased the PCL segments migrating to the crystallite-melt interface thus reducing the nucleation rate, growth rate and the thickness of the lamella resulting in a depressed Tm. Crystallinity (Xc) decreased gradually with decreasing content of PCL in the blend and was due to the dilution of PCL by PVF. A depressed Tg was observed for 10 wt% PCL blend and remained the same for all other blend compositions. These observations suggested that this blend system has very low degree of miscibility. The degree of miscibility increased at low polyester concentration. FTIR spectra of the blends with low polyester concentrations showed changes in the C=O, O-H and C-O-C regions in the blended PVF and PCL spectra. Optical microscopy showed phase separation in the melt and in the PCL spherulites.

Study on Curing Kinetics of MEP-15/593/660 System

2014 ◽  
Vol 988 ◽  
pp. 31-35
Author(s):  
Jia Le Song ◽  
Chan Chan Li ◽  
Zhi Mi Zhou ◽  
Chao Qiang Ye ◽  
Wei Guang Li
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Conversion Ratio ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Curing Kinetic ◽  
The Relationship ◽  
Kinetics Of

Curing kinetics of MEP-15/593 system and MEP-15/593/660 system is studied by means of differential scanning calorimetry (DSC). Curing kinetic parameters are evaluated and the relationship between diluent 660 and the curing properties is investigated. The results show that the diluent 660 can not only reduce viscosity and activation energy, but also improve the degree of cure and conversion ratio.

Role of interfacial interaction on the crystallization behavior and melting characteristics of PP/Nano-CaCO3 composites modified with different compatibilizers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuhai Wang ◽  
Hao Shen ◽  
Gu Li ◽  
Kancheng Mai
Keyword(s):  
Synergistic Effect ◽  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Interfacial Interaction ◽  
Scanning Calorimetry ◽  
Polar Groups ◽  
Melting Characteristics

AbstractPP/nano-CaCO3 composites with different interfacial interaction were prepared by addition of compatibilizers with the same polar groups but different backbones. The non-isothermal and isothermal crystallization behavior of PP/nano- CaCO3 composites was investigated using differential scanning calorimetry (DSC). The results indicated that the interfacial interaction between PP and nano-CaCO3 increased the crystallization temperature and crystallization rate of PP due to the heterogeneous nucleation of nano-CaCO3. The interfacial interaction between nano- CaCO3 and compatibilizer further increased the crystallization temperature and crystallization rate of PP and induced the formation of β-crystal of PP due to the synergistic effect of heterogeneous nucleation between nano-CaCO3 and compatibilizer. This synergistic effect of heterogeneous nucleation between nano- CaCO3 and compatibilizer depended on the interfacial interaction between compatibilizer and PP matrix. The increased compatibility between compatibilizer and PP matrix favoured the heterogeneous nucleation between nano-CaCO3 and compatibilizer

DEA and DSC study of cubic silsesquioxane epoxy resin nanocomposites

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Newton Luiz Dias Filho ◽  
Hermes Adolfo de Aquino
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Fracture Toughness ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Tensile Modulus ◽  
Dielectric Analysis ◽  
Epoxy Nanocomposites ◽  
Scanning Calorimetry

AbstractNon-isothermal dielectric analysis (DEA) and differential scanning calorimetry (DSC) techniques were used to study the epoxy nanocomposites prepared by reacting 1,3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.13,9.15,15 .17,13] octasilsesquioxane (ODPG) with methylenedianiline (MDA). Loss factor (ε”) and activation energy were calculated by DEA. The relationships between the loss factor, the activation energy, the structure of the network, and the mechanical properties were investigated. Activation energies determined by DEA and DSC, heat of polymerization, fracture toughness and tensile modulus show the same profile for mechanical properties with respect to ODPG content.

scholarly journals Differential Scanning Calorimetry of Metamict Pu-Substituted Zirconolite

1982 ◽  
Vol 15 ◽  
Author(s):  
Dean E. Peterson ◽  
Frank W. Clinard
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Ambient Temperature ◽  
Total Energy ◽  
Temperature Dependence ◽  
Radiation Damage ◽  
Rate Constant ◽  
Stored Energy ◽  
Scanning Calorimetry ◽  
No Release

ABSTRACTSamples of CaPuTi2O7 were prepared by cold pressing and sintering. Plutonium was substituted for zirconium in order to characterize radiation damage effects. The energy stored in a sample which had reached saturation in swelling after storage at ambient temperature was measured with a differential scanning calorimeter. The total energy of 6.6±0.1 cal/g is released over the range 485–715° C. The activation energy of annealing of the damage is 1.22±0.05 eV. The temperature dependence of the rate constant is described by kT= 5.96E4 exp(−1.22/kBT) s−1 where kB and T are the Boltzmann's constant and temperature(K) respectively. A sample stored at 600°C was similarly evaluated and showed no release of stored energy to the precision of the apparatus (±0.1 cal/g). These results are applied to analysis of waste incorporation in Synroc and are correlated with analogous parameters for other materials.

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